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ZyXEL ZYWALL10 User's Manual

1. esse ee ie ees terris so ese de Sua o SER o GN CRY ee Ee Gee ee NG UP Pa SER SEV S RES EE esu RD dee dbe 17 1 xiv Table of Contents ZyWALL 10 Internet Security Gateway ILI Introd ction euis ER E EE EE EE EI aE IIS 17 1 17 2 Creating Editing A Custom POEL eiecti i ces ce tete HUE 17 3 Chapter ERE c 18 1 18 RE s uere eR REI See bum meme EE ee 18 1 Chapter 19 Example Firewall Rules se eee eese eese eese Bee Be etta seta staat Se Ee Ee stesse toss Ge EG seas eg 19 1 UC DND Eu 19 1 19 1 1 Example 1 Firewall Rule To Allow Web Service From The Internet 19 1 19 1 2 Example 2 Small Office With Mail FTP and Web Server 19 6 19 1 3 Example 3 DHCP Negotiation and Syslog Connection from the Internet 19 12 Chapter 20 Content Filtering 4 esse ee ee Ge Ge EG EG Ge EG etna Ee Bee Be ee Ee Ee sete Ge Ge EE ease tassa 20 1 DN e ER AE EE ir to Re UE EE EE 20 1 20 1 1 Restrict Web Features cic sc Ge ee Ee EERDER Asch e ie petet ee E ke 20 1 MERE Filter E ER EE EE OO EE ait d ee eter 20 1 20 1 3 DE Mei MA ER RE e AE EE EE EI EE 20 1 20 2 Update EE 20 3 20 3 Exempiing Computers see breede Ge BERE SEGE DER GE Ee Rek EE Ke Gee ER Ge SEGE Ke Ke ee 20 4 EE amp ei Fa EE vembesei cess ceesem ayn Shigseeeerens 20 5 20 3 ORE ME EE EO EE EE 20 6 20 6 Eog RE EE EER EE I Dt etie tec tete tutes 20 7 Troubleshooting Appe
2. 10BaseT ARP Authenticity Back Door Backbone BackOrifice Bandwidth Bit Brute Force Glossary of Terms The 10 Mbps baseband Ethernet specification that uses two pairs of twisted pair cabling Category 3 or 5 one pair for transmitting data and the other for receiving data Address Resolution Protocol is a protocol for mapping an Internet Protocol address IP address to a physical machine address that is recognized in the local network Proof that the information came from the person or location that reportedly sent it One example of authenticating software is through digital signatures A deliberately planned security breach in a program Back doors allow special access to a computer or program Sometimes back doors can be exploited and allow a cracker unauthorized access to data A high speed line or series of connections that forms a major pathway within a network BackOrifice is a remote administration tool which allows a user to control a computer across a TCP IP connection using a simple console or GUI application BackOrifice is a potentially disastrous Trojan horse since it can provide the user unlimited access to a system This is the capacity on a link usually measured in bits per second bps Binary Digit A single digit number in base 2 in other words either a 1 or a zero The smallest unit of computerized data A technique used to find passwords or encryption keys Force Hacking involves tryin
3. FIELD DESCRIPTION EXAMPLE Set Name This is the name of the set you selected in menu SUA 15 1 or enter the name of a new set you want to create Idx This is the index or rule number 1 Local Start IP Local Start IP is the starting local IP address ILA 0 0 0 0 Local End IP see Figure 6 1 Local End IP is the ending local 255 255 255 255 IP address ILA If the rule is for all local IPs then the Start IP is 0 0 0 0 and the End IP is 255 255 255 255 Global Start IP This is the starting global IP address IGA If you 0 0 0 0 have a dynamic IP enter 0 0 0 0 as the Global Start IP Global End IP This is the ending global IP address IGA N A Type These are the mapping types discussed above Server see Table 6 2 Type Server allows us to specify multiple servers of different types behind NAT to this machine See section 6 4 3 below for some examples Press ENTER to confirm or ESC to cancel For all Local and Global I Ps the End IP address must begin after the I P Start address Now let s look at Option 1 in menu 15 1 Enter 1 to bring up this menu We ll just look at the differences from the previous menu Note that this screen is not read only so we have extra Action and Select Rule fields Note also that the in the Set Name field means that this is a required field and you must enter a name for the set If the Set Name field is left blank the entire set will be deleted N
4. Idle Timeout 100 IP Address Assignment Dynamic IP Address N A IP Subnet Mask N A Gateway IP Address N A Network Address Translation Full Feature Press ENTER to Confirm or ESC to Cancel Figure 3 8 Internet Access Setup PPPoE Table 3 6 New Fields in Menu 4 PPPoE screen FIELD DESCRIPTION EXAMPLE Encapsulation Press the SPACE BAR and then press ENTER to choose PPPoE PPPoE The encapsulation method influences your choices for IP Address Idle Timeout This value specifies the time in seconds that elapses before the 100 ZyWALL automatically disconnects from the PPPOE server default If you need a PPPoE service name to identify and reach the PPPoE server please go to menu 11 and enter the PPPOE service name provided to you in the Service Name field 3 12 Internet Access ZyWALL 10 Internet Security Gateway 3 4 Basic Setup Complete Well done You have successfully connected installed and set up your ZyWALL to operate on your network as well as access the Internet Please note that when the firewall is activated the default policy allows all communications to the I nternet that originate from the LAN and blocks all traffic to the LAN that originates from the I nternet You may deactivate the firewall in menu 21 2 or via the ZyW ALL Web Configurator You may also define additional firewall rules or modify existing ones but please exercise extreme caution in doing so See Part 4 for more i
5. Remote Node Filter Ethernet Encapsulation Menu 11 5 Remote Node Filter Input Filter Sets protocol filters 3 Device filters Output Filter Sets protocol filters 1 device filters Call Filter Sets protocol filters 1 Device filters Enter here to CONFIRM or ESC to CANCEL Figure 4 7 Menu 11 5 Remote Node Filter PPPoE or PPTP Encapsulation 4 10 Remote Node Setup ZyWALL 10 Internet Security Gateway Chapter 5 IP Static Route Setup This chapter shows you how to configure static routes with your ZyWALL Static routes tell the ZyW ALL routing information that it cannot learn automatically through other means This can arise in cases where RIP is disabled on the LAN Each remote node specifies only the network to which the gateway is directly connected and the ZyWALL has no knowledge of the networks beyond For instance the ZyW ALL knows about network N2 in the following diagram through remote node Router 1 However the ZyW ALL is unable to route a packet to network N3 because it doesn t know that there is a route through the same remote node Router 1 via gateway Router 2 The static routes are for you to tell the ZyWALL about the networks beyond the remote nodes N1 N2 N3 Router 2 Router 1 Figure 5 1 Example of Static Routing Topology IP Static Route Setup 5 1 ZyWALL 10 Internet Security Gateway 5 1 IP Static Route Setup You configure IP static routes in menu 12 1 by selec
6. 7 2 3 TCP IP Filter Rule This section shows you how to configure a TCP IP filter rule TCP IP rules allow you to base the rule on the fields in the IP and the upper layer protocol e g UDP and TCP headers To configure TCP IP rules select TCP IP Filter Rule from the Filter Type field and press ENTER to open Menu 21 1 1 TCP IP Filter Rule as shown next Menu 21 1 1 1 TCP IP Filter Rule Filter 1 1 Filter Type TCP IP Filter Rule Active Yes IP Protocol 6 IP Source Route No Destination IP Addr 0 0 0 0 IP Mask 0 0 0 0 Port 137 Port Comp Equal Source IP Addr 0 0 0 0 IP Mask 0 0 0 0 Port Port Comp None TCP Estab No More No Log None Action Matched Drop Action Not Matched Check Next Rule Press ENTER to Confirm or ESC to Cancel Press Space Bar to Toggle Figure 7 9 Menu 21 1 1 1 TCP IP Filter Rule Filters 7 7 ZyWALL 10 Internet Security Gateway The following table describes how to configure your TCP IP filter rule Table 7 3 TCP IP Filter Rule Menu Fields FIELD DESCRIPTION OPTIONS Active Yes activates the filter rule and No deactivates it Yes No IP Protocol Protocol refers to the upper layer protocol e g TCP is 6 0 255 UDP is 17 and ICMP is 1 This value must be between 0 and 255 A value of 0 matches ANY protocol IP Source Route If Yes the rule applies to packet with IP source route Yes No option
7. After the ZyWALL finishes displaying you will have the option to clear the error log System Information amp Diagnosis 9 5 ZyWALL 10 Internet Security Gateway Menu 24 3 System Maintenance Log and Trace 1 View Error Log 2 UNIX Syslog 4 Call Triggering Packet Please enter selection Figure 9 6 Menu 24 3 System Maintenance Log and Trace Examples of typical error and information messages are presented in the figure below 59 Thu Jan 1 00 00 03 2000 Session 60 Thu Jan 1 00 05 11 2000 PINI INFO SMT Session End 61 Thu Jan 1 00 17 59 200D PINI INFO SMT Session Begin 1 PINI INFO SMT Session End INFO SMT Session Beg Figure 9 7 Examples of Error and Information Messages 9 3 2 UNIX Syslog The ZyW ALL uses the UNIX syslog facility to log the CDR Call Detail Record and system messages to a syslog server Syslog and accounting can be configured in Menu 24 3 2 System Maintenance Syslog and Accounting as shown next Menu 24 3 2 System Maintenance UNIX Syslog and Accounting UNIX Syslog Active No Syslog IP Address Log Facility Local 1 Types CDR No Packet Triggered No Filter log No PPP log No Firewall log No Press ENTER to Confirm or ESC to Cancel Figure 9 8 Menu 24 3 2 System Maintenance UNIX Syslog 9 6 System Information amp Diagnosis ZyWALL 10 Internet Security Gateway You need to configure the UNIX syslog param
8. From 192 168 1 2 To 10 100 6 66 not match UDP src port 01054 dest port 00053 lt 1 02 gt dest port From 192 168 1 2 To 10 100 6 45 attack ICMP type 00008 code 00000 land Clear Firewall Log y n Figure 14 4 View Firewall Log Each log consists of two lines showing the information described in the following table 14 4 Introducing the ZyWALL Firewall ZyWALL 10 Internet Security Gateway Table 14 4 View Firewall Log DESCRIPTION EXAMPLES This is the index number of the firewall log 128 entries 23 are available numbered from 0 to 127 Once they are all used the log will wrap around and the old logs will be lost This is the time the log was recorded in this format mm dd yy e g Jan 1 00 You must configure menu 24 10 for real time gou otherwise the clock will start at 2000 01 01 00 00 00 hh mm ss eg 00 00 00 the last time the ZyWALL 10 was reset Packet This field lists packet information such as protocol and From and To IP addresses Information src dest port numbers TCP UDP or protocol type Brotocol e d SE EE b ITE Y and code ICMP rotocol and port numbers Reason This field states the reason for the log i e was the not match rule matched not matched or was there an attack The set and rule coordinates X Y where X 1 2 1 01 dest IP Y 00 10 follow with a simple explanation There are This means this packet does two policy sets set 1 X 1 is for LAN to WAN rules not m
9. Press Space Bar to Toggle Figure 6 9 Menu 15 1 1 1 Editing an Individual Rule in a Set NAT 6 11 ZyWALL 10 Internet Security Gateway The following table describes the fields in this screen Table 6 6 Menu 15 1 1 1 Configuring an Individual Rule FIELD DESCRIPTION EXAMPLE Type Press the SPACE BAR to toggle through a One to One total of five types These are the mapping types discussed above see Table 6 2 Type Server allows you to specify multiple servers of different types behind NAT to this machine See section 6 4 3 below shown next for some examples Local IP Only local IP fields are N A for server Global IP fields MUST be set for Server Start This is the starting local IP address ILA 0 0 0 0 End This is the ending local IP address ILA If 255 255 255 255 the rule is for all local IPs then put the Start IP as 0 0 0 0 and the End IP as 255 255 255 255 This field is N A for One to One and Server types Global IP Start This is the starting global IP address IGA 0 0 0 0 If you have a dynamic IP enter 0 0 0 0 as the Global IP Start Note that Global IP Start can be set to 0 0 0 0 only if the types are Many to One or Server End This is the ending global IP address IGA 172 16 23 55 This field is N A for One to One Many to One and Server types Once you have finished configuring a rule in this menu press ENTER at the message Press ENTER to Confirm to save
10. y password show the seed of password generator change system time to hour min sec or show current time change system date to year month day or show current date dump RAS stack dump Boot Module Common Area dump memory contents from address write address x with write address x with 16 bit write address x with 32 bit display the display the display the run program boot router 8 bit value 16 bit value 32 bit value at addr x or 8 bit x for length y value y value y value y address x of address x of address x boot router of run Hardware Test Program Enable Hardware Test Program at boot up block0 write enable RAM test level w write MAC addr 1 enable from address x to y Country code other disable z iterations EngDbgFlag FeatureBit to flash ROM write Country code to flash ROM copy from FLASH ROM to working buffer clear working buffer save working buffer to FLASH ROM dump manufacturer related data in working buffer dump manufacturer related data in ROM set set set set set set set set check amp dump memMapTab download from address x for length y to PC via XMODEM download router configuration to PC via XMODEM upload to RAM address x for length y from PC via XMODEM upload router firmware to flash ROM upload router configuration file to flash ROM xmodem upload from flash block x to y erase flash rom from block x to y copy data from addr x to flash addr y xmodem select
11. 2 9 LEAN SetiD nie ee EER it EG ESE OE Re ee Ip oC ed 2 13 2 9 1 LAN Port Filter Setup ocn Romae ertet p UR Ae 2 14 Chapter 3 Internet Uer DRR 3 1 3 1 TCP IP and DHCP fotr LAN EE SEE Se GE Gee AE DE EE PE RR EE REUS 3 1 3 1 1 Factory LAN Defaults iret EHE RP ERES 3 1 3 1 2 DHCP Siel die EE 3 1 3 1 3 IP Address and Subnet Mask AAA 3 2 3 1 4 Private IP e EE 3 2 3 1 5 RIP Set p ite ep Uere tte REG RH D OE He OL E 3 3 3 1 6 IDEE EE AE EE AE ES EE EE ER EER 3 3 3 1 7 PIERRE EER ERROR AE OE ee EE EE E 3 4 32 TCEP IP and DHCP Ethernet Setup nter inre ORO DH RR ees EER Ee 3 4 3 2 1 IP GEEN ER N te t de d RERO et E 3 7 3 3 Internet Access Setup seno bene ect e pr PO Re PE e DER e N 3 8 3 3 1 Ethernet Encapsulation noie eie eno NU iR 3 8 3 3 2 PPTP Enca psul ti fi einer De RU mend 3 10 3 3 3 Configuring the PPTP CIENT ete peer e ee SE oe Eege dees ee ep ed Eder 3 10 3 3 4 PPPOE Encapsulation 3 n neret tente proe e Qe S RE ER eg Ree pepe ket eiat 3 11 34 Basic Setup Complete eee pete b tente e epe erts 3 13 Advanced ADPIICAHOTS io HERD H CE II Chapter 4 Remote Node Setup sees Bee eee eee eese eese eee seen etta tts tona Ge Ge EG BEG ease ta sense ease tns sete sna a 4 1 41 Remote Node Profile eoe err ere erret e RE ere Re 4 1 4 1 1 Ethernet Encapsulation etr Rt XR FRU Th IRL EES Eed 4 1 4 1 2 PPPOE Encapsu lation mtt tte RR
12. Internet Access Setup Ethernet essere enne 3 9 Figure 3 7 Internet Access Setup PPETD eie ip er t or e e e i oe 3 11 Figure 3 8 Internet Access Setup PPPOE AAA 3 12 Figure 4 1 Menu 11 1 Remote Node Profile for Ethernet Encapsulation esee 4 1 Figure 4 2 Menu 11 1 Remote Node Profile for PPPoE Encapsulation esse sesse see see se ee se ee se ee se ee ee 4 3 Figure 4 3 Menu 11 1 Remote Node Profile for PPTP Encapsulapon see see se ee Gee ee 4 5 List of Figures xvii ZyWALL 10 Internet Security Gateway Figure 4 4 Menu 11 3 Remote Node Network Layer Oppons essere 4 6 Figure 4 5 Menu 11 3 Remote Node Network Layer Options esee 4 8 Figure 4 6 Menu 11 5 Remote Node Filter Ethernet Encapsulation seen 4 10 Figure 4 7 Menu 11 5 Remote Node Filter PPPoE or PPTP Encapsulation eese 4 10 Figure 5 1 Example of Static Routing Topology esse ee ee Ge Se Re Gee Ge ee enne ener 5 1 Figure 5 2 Menu 12 IP Static Route Setup 5 2 Figure 5 3 Menu 12 1 Edit IP Static Route 5 2 Figure 6 1 How NAT Works tee t oett e Pee iere EO be ete N eed 6 2 Figure 62 NAT WE CO eie Rete Pede edited eret ette rete eet edente eet boten Us 6 5 Figure 6 3 Menu 4 Applying NAT for Internet Access esse se se se see ee Ge ee ee ee ee Ge Se eene eene 6 6 Figure 6 4 Menu 11 3 Applying NAT to the Remote Node 6 6 Figure 6 5 Menu
13. Menu 3 2 TCP IP and DHCP Ethernet Setup DHCP Server Configuration Client IP Pool Starting Add Size of Client IP Pool 32 Primary DNS Server 0 0 0 0 E Secondary DNS Server 0 0 0 0 DHCP Server Address N A ss 192 168 1 33 TCP IP Setup IP Address 192 168 1 1 IP Subnet Mask 255 255 255 0 RIP Direction Both Version RIP 1 Multicast IGMP v2 Edit IP Alias No Press ENTER to Confirm or ESC to Cancel Figure 3 4 Menu 3 2 TCP IP and DHCP Ethernet Setup Follow the instructions in the next table on how to configure the DHCP fields First address in the IP Pool Size of the IP Pool IP addresses of the DNS servers Internet Access 3 5 ZyWALL 10 Internet Security Gateway Table 3 1 DHCP Ethernet Setup Menu Fields FIELD DESCRIPTION EXAMPLE DHCP This field enables disables the DHCP server If set to Server your ZyWALL will act as a DHCP server If set to None the DHCP server will be disabled If set to Relay the ZyWALL acts as a surrogate DHCP server and relays requests and responses between the remote server and the clients When set to Server the following four items need to be set Server Configuration Client IP Pool Starting Address Size of Client IP Pool Primary DNS Server Secondary DNS Server DHCP Server Address This field specifies the first of the contiguous addresses in the IP address poo
14. Upload Router Firmware sees 10 6 Figure 10 11 Example Xmodem Upload 10 6 Figure 10 12 Menu 24 7 2 System Maintenance Upload Router Configuration File 10 7 Figure 10 13 Telnet into Menu 24 7 1 see se ee ee ee Ge Ge GR GR re enne Ge ee tenete ettet trennen eren E ene 10 10 Figure 10 14 Telnet into Menu 24 7 2 System Maintenance esee eene 10 10 Figure 10 15 FTP Session Example esse sees sees sees se esse ee ee Ge Gee Ge tene tene tren trennen nennen ene 10 11 Figure 11 1 Command Mode in Menu 24 se see ee ee ee nennen eren Re GRA Re Ge ee ee ee ee 11 1 Figure 11 2 Valid Command S eu p unenoneteemo tee Drei e e Be GEE Ee eg De RD Reed GER EE He RSG SERS ER RE Ge ERGE ER 11 1 Figure 11 3 Call Contiol EE EE N EE N e 11 2 Figure 11 4 Budget Management sees se esse ees es se SE eo ee GE ee Ge GE He Re SE eo RA enne et RA GE Ge ee GE Ge ee SE reet EG EE 11 2 Figure 11 5 Call History ee SE Ge Ee EES ek De ene ROW nU Ege 11 4 Figure 11 6 Menu 24 System Maintenance iese sees se ee ee ee Ge Se GR GR Re RA GRA Re Gee Ge ee ee Ge ee ee ee 11 5 Figure 11 7 Menu 24 10 System Maintenance Time and Date Seng 11 5 Figure 11 8 Menu 24 11 Remote Management Control esee 11 7 Figure 11 9 Option to Enter Debug Mode AAA 11 8 Figure 11 10 Boot Module Commandes 11 9 XX List of Figures ZyWALL 10 Internet Security Gateway Figure 12 1 Telnet C
15. 10 T 12 1026 rved Press ENTER to Confirm or ESC to Cancel Figure 6 11 Menu 15 2 NAT Server Setup Table 6 7 Services amp Port numbers SERVICES PORT NUMBER FTP File Transfer Protocol 21 Telnet 23 SMTP Simple Mail Transfer Protocol 25 DNS Domain Name System 53 HTTP Hyper Text Transfer protocol or WWW Web 80 PPTP Point to Point Tunneling Protocol 1723 6 14 NAT ZyWALL 10 Internet Security Gateway 6 4 Examples 6 4 1 Internet Access Only In the following Internet access example you only need one rule where all your ILAs Inside Local addresses map to one dynamic IGA Inside Global Address assigned by your ISP Inside Local One Dynamic PC 3 Im O Addresses ILA Inside Global Addresses IGA Assigned by ISP Figure 6 12 NAT Example 1 Menu 4 Internet Access Setup ISP s Name ChangeMe Encapsulation Ethernet Service Type Standard My Login N A My Password N A Login Server IP N A IP Address Assignment Dynamic IP Address N A IP Subnet Mask N A Gateway IP Address N A Network Adgee ranslation SUA Only Press ENTER to Confirm or ESC to Cancel Figure 6 13 Menu 4 internet Access amp NAT Example From menu 4 shown above simply choose the SUA Only option from the Network Address Translation field This is the Many to One mapping discussed in section 6 1 4 The SUA Only read only option from NAT 6 15 ZyWALL 10
16. 15 6 Three Way Handshake AAA 13 5 STUT GE IR eere e 13 6 14 3 Threshold Values ees ee ee ee ee Ee ee ee 15 7 SNMP me 8 1 Time and Date Setting 1 3 11 4 11 5 11 6 de et 8 1 TIME ZOE seien rete geg 11 6 Configuring ee m edes m pee 8 1 Timeout 3 11 3 12 4 4 16 14 16 15 Community ees see sesse ee se se ee ke Ge ee ee 8 1 dice ER EER ED EL EE 9 5 Trap GE RE EE RE EE GE ei 8 2 Traceroute EE aii 14 4 Tr sted HOSt eor eer tete tme 8 2 Troubleshhoting the Firewall 21 3 SNMP Simple Network Management Protocol Troubleshooting M 1 2 Internet Access Source amp Destination Addresses 16 12 LAN Interface Source Address 16 2 16 11 WAN Interface RE RR tenete 19 9 Stateful Inspection 1 1 13 1 13 2 13 6 13 7 U PIGEESS POSEE EE NEE 13 7 ZY WALL SG isole mna voii 13 8 UDP ICMP Security uie ee ee ee ee ee ee ee 13 9 Structure of this Manual 1111 xxii Diet 3 3 SUA Single User Account See NAT UNIX CSVSlDg nons cotes Ded 9 6 9 7 Subnet Mask 3 2 3 6 3 10 4 6 4 8 5 3 16 13 Upload Firmware eee 10 5 Support BI EMI Imm xxviii Upper Layer Protocols eene 13 8 13 9 SYN Flood een 13 4 13 5 14 4 Ad DEE 13 5 14 4 ARE eee lend es 19 12 V Syslog IP Address 9 7 n System Infor
17. 6 The firewall can block specific URL traffic that might occur in the future The URL can be saved in an Access Control List ACL database Introducing the ZyWALL Firewall 14 7 ZyWALL 10 Internet Security Gateway Chapter 15 Introducing the ZyWALL Web Configurator This chapter shows you how to configure your firewall with the Web Configurator 15 1 Web Configurator Login and Welcome Screens Launch your web browser and enter 192 168 1 1 as the URL This is the factory default IP address of the ZyWALL when shipped You will see the following Login screen ZyXEL Figure 15 1 Login screen as seen in Netscape BOW OE 5 The default Username and Password is admin and 1234 respectively The Password is configurable but the Username is not The Password is case sensitive The Web Configurator times out after five minutes of inactivity The time out is not configurable Please make sure that your web browser is Java and J avaScript enabled You can ONLY configure the firewall via ZyWALL Web Configurator or CLI command You will not be able to access the ZyW ALL Web Configurator from the WAN if 1 The firewall is activated as the firewall by default blocks all WAN to LAN traffic To access the ZyW ALL Web Configurator from the WAN when the firewall is activated you will need to create a firewall rule see the Example Firewall Rules chapter ahead to allow web traffic initiated from the WAN 2 You ha
18. 9 resets the counters and ESC takes you back to the previous screen System Information amp Diagnosis 9 1 ZyWALL 10 Internet Security Gateway System up Time 22 11 43 Name xxx baboo mickey com Routing IP ZyNOS F W Version V324WA0b06 3 14 2001 Press Command COMMANDS 1 Drop WAN 9 Reset Counters ESC Exit Menu 24 1 System Maintenance Status 23 10 28 Sat Jan 01 2000 Port Status TxPkts RxPkts Cols Tx B s Rx B s Up Time WAN 10M Half 67 289 0 74 64 2 20 56 LAN 10M Half 299 220 0 74 64 2 20 54 Port Ethernet Address IP Address IP Mask DHCP WAN 00 a0 c5 21 8c a3 xy 2155297 255 255 25550 Client LAN 00 a0 c5 21 8c a2 192 168 1 1 255 255 25540 Server Figure 9 2 Menu 24 1 System Maintenance Status The following table describes the fields present in Menu 24 1 System Maintenance Status These fields are READ ONLY and are meant to be used for diagnostic purposes The upper right corner of the screen shows the time and date according to the format you set in menu 24 10 Table 9 1 System Maintenance Status Menu Fields FIELD DESCRIPTION Port The WAN or LAN port Status Shows the port speed and duplex setting if you re using Ethernet Encapsulation and Down line is down idle line ppp idle dial starting to trigger a call and drop dropping a call if you re using PPPoE Encapsulation TxPkts The number of transmitted packets on this port RxP
19. Bl s Empty s E s Empty zl s s Empty s i s Apply Edit Delete d H 4 Status Ready Figure 16 3 Firewall Rules Summary First Screen The following table describes the fields in this screen Creating Custom Rules 16 5 ZyWALL 10 Internet Security Gateway Table 16 1 Firewall Rules Summary First Screen FIELD DESCRIPTION OPTIONS General Name This is the name of the firewall rule set Type a name to Name distinguish the LAN to WAN filter set from the WAN to LAN filter set The default action for Should packets that do not match the following rules be Block packets not matching blocked or forwarded Make your choice from the drop Forward following rules down list box Note that block means the firewall silently discards the packet Default Permit Log Check this box to log all matched rules in the ACL default set Firewall Rule Summary The following fields summarize the rules you have created Note that these fields are read only Click the tab at the top of the box to order the rules according to that tab No This is your firewall rule number The ordering of your rules is important as rules are applied in turn The Move field below allows you to reorder your rules Source IP This is the source address of the packet Destination IP This is the destination address of the packet Service This is the service to which the rule applies See Table 16 2 for more
20. CRC mode default x 0 Int Trap Log Cmd MAC address in working buffer country code in working buffer EngDebugFlag in working buffer ROMRAS address in working buffer System type in working buffer vendor name in working buffer product name in working buffer feature bits in working buffer length z x 1 checksum mode Figure 11 10 Boot Module Commands System Maintenance amp Information 11 9 ZyWALL 10 Internet Security Gateway Chapter 12 Telnet Configuration and Capabilities This chapter covers the Telnet Configuration and Capabilities of the ZyWALL 12 1 About Telnet Configuration Before the ZyW ALL is properly setup for TCP IP the only option for configuring it is through the console port Once your ZyWALL is configured you can use telnet to configure it remotely as shown below ZyWALL Modem User telnets into the LAN via the ZyWALL Figure 12 1 Telnet Configuration on a TCP IP Network 12 2 Telnet Under NAT When Network Address Translation NAT is enabled and an inside server is specified telnet connections from the outside will be forwarded to the inside server So to configure the ZyWALL via telnet from the outside you must first telnet to the inside server and then telnet from the server to the ZyW ALL using its inside LAN IP address If no inside server is specified telnetting to the NAT s IP address will connect to the ZyW ALL directly 12 3 Telnet Capabilities 12 3 1 Single Admi
21. Figure 15 6 check the Generate an alert when attack detected checkbox or when a rule is matched in the creating editing a firewall rule screen see Figure 16 4 When an event generates a report an alert a message is immediately sent to an e Introducing the ZyWALL Web Configurator 15 3 ZyWALL 10 Internet Security Gateway mail account Enter the complete e mail address to which alert messages will be sent in the E mail Alerts To field and schedule times for sending alerts in the Alert Timer fields in the E mail screen following screen 15 3 2 What are Logs A log is a detailed record that you create for packets that either match a rule don t match a rule or both when you are creating editing a firewall rule see Figure 16 4 You can also choose not to create a log for a rule in this screen An attack automatically generates a log Click Firewall then Configuration then the E mail tab to bring up the following screen CONFIGURATION LOCAL NETWORK INTERNET CUSTOM PORTS 192 168 10 2 AS EER Ee Ed LOGOUT user2 zyxel com tw DG Weekly E Tuesday Figure 15 4 E mail Screen The following table describes the fields in this screen 15 4 Introducing the ZyWALL Web Configurator ZyWALL 10 Internet Security Gateway Table 15 1 E mail FIELD DESCRIPTION OPTIONS Address Information Mail Server Mail Subject E mail Alerts To Return address Enter the IP address of your mail server in
22. IGMP v2 At start up the ZyWALL queries all directly connected networks to gather group membership After that the ZyWALL periodically updates this information IP Multicasting can be enabled disabled on the ZyW ALL LAN and or Internet Access 3 3 ZyWALL 10 Internet Security Gateway WAN interfaces using menus 3 2 LAN and 11 3 WAN Select None to disable IP Multicasting on these interfaces 3 1 7 IP Alias IP Alias allows you to partition a physical network into different logical networks over the same Ethernet interface The ZyW ALL supports three logical LAN interfaces via its single physical Ethernet interface with the ZyWALL itself as the gateway for each LAN network ZyWALL LAN 1 IP address menu 3 2 LAN 2 IP alias 1 menu 3 2 1 LAN 3 P alias 2 menu 3 2 1 Ethernet Interface Figure 3 1 Physical Network Figure 3 2 Partitioned Logical Networks Use menu 3 2 1 to configure IP Alias on your ZyWALL 3 2 TCP IP and DHCP Ethernet Setup From the main menu enter 3 to open Menu 3 LAN Setup to configure TCP IP RFC 1155 and DHCP Ethernet setup 3 4 Internet Access ZyWALL 10 Internet Security Gateway Menu 3 LAN Setup Li LAN Po e 25 CP IP and DHCP Setup Enter Menu Selection Number Figure 3 3 Menu 3 LAN Setup From menu 3 select the submenu option TCP IP and DHCP Setup and press ENTER The screen now displays Menu 3 2 TCP IP and DHCP Ethernet Setup as shown
23. Initial Setup ZyWALL 10 Internet Security Gateway console port of the ZyW ALL and the other end choice of 9 pin or 25 pin depending on your computer end to a serial port COMI COM2 or other COM port of your workstation You can use an extension RS 232 cable if the enclosed one is too short After the initial setup you can modify the configuration remotely through telnet connections Step 2 Connecting the ZyWALL to the Broadband Modem Step 2a Connecting the ZyWALL to the Cable Modem Connect the WAN port silver on the ZyWALL to the Ethernet port on the cable modem using the cable that came with your cable modem The Ethernet port on the cable modem is sometimes labeled PC or Workstation OR Step 2b Connecting the ZyWALL to the xDSL Modem Connect the WAN port silver on the ZyWALL to the Ethernet port on the xDSL modem using the cable that came with your xDSL modem Step 3 Connecting the ZyWALL to the LAN For a single computer connect the 10 100M LAN port on the ZyW ALL to the Network Adapter on the computer using the white straight through cable and push in the Uplink button on If the Uplink button is not on you must use a crossover cable for this connection If you have more than one computer then you must use an external hub Connect the 10 100M LAN port gold on the ZyW ALL to a port on the hub using a straight through Ethernet cable and make sure the Uplink button is off Connecting the Power Adapte
24. TCP IP and DHCP Setup Enter Menu Selection Number Figure 2 11 Menu 3 LAN Setup 2 9 1 LAN Port Filter Setup This menu allows you to specify the filter sets that you wish to apply to the LAN traffic You seldom need to filter the LAN traffic however the filter sets may be useful to block certain packets reduce traffic and prevent security breaches Menu 3 1 LAN Port Filter Setup Input Filter Sets protocol filters 2 device filters Output Filter Sets protocol filters device filters Press ENTER to Confirm or ESC to Cancel Figure 2 12 Menu 3 1 LAN Port Filter Setup Menu 3 2 is discussed in the next chapter Please read on 2 14 Hardware Installation amp Initial Setup ZyWALL 10 Internet Security Gateway Chapter 3 Internet Access This chapter shows you how to configure the LAN as well as the WAN of your ZyWALL for Internet access 3 1 TCP IP and DHCP for LAN The ZyW ALL has built in DHCP server capability that assigns IP addresses and DNS servers to systems that support DHCP client capability 3 1 1 Factory LAN Defaults The LAN parameters of the ZyW ALL are preset in the factory with the following values 1 IP address of 192 168 1 1 with subnet mask of 255 255 255 0 24 bits 2 DHCP server enabled with 32 client IP addresses starting from 192 168 1 33 These parameters should work for the majority of installations If your ISP gives you an explicit DNS server address
25. Valid for PPPoE encapsulation only This field is valid for RoadRunner service type only The ZyWALL will find the RoadRunner Server IP automatically if this field is left blank If it does not then you must enter the authentication server IP address here jim kkkkk Route This field refers to the protocol that will be routed by your ZyWALL IP is the only option for the ZyWALL 10 Edit IP This field leads to a hidden menu Press SPACE BAR to select Yes and press ENTER to go to Menu 11 3 Remote Node Network Layer Options Yes Session Options Edit Filter sets This field leads to another hidden menu Use the SPACE BAR to select Yes and press ENTER to open menu 11 5 to edit the filter sets See the Remote Node Filter section for more details Yes 4 2 Remote Node Setup ZyWALL 10 Internet Security Gateway Once you have configured the Remote Node Profile Menu press ENTER to return to menu 11 Press ENTER at the message Press ENTER to Confirm to save your configuration or press ESC at any time to cancel 4 1 2 PPPoE Encapsulation The ZyWALL supports PPPoE Point to Point Protocol over Ethernet You can only use PPPoE encapsulation when you re using the ZyW ALL with an xDSL modem as the WAN device If you change the Encapsulation to PPPoE then you will see the next screen Please see the Appendices for more information on PPPoE Menu 11 1 Re
26. ZyWALL 10 Internet Security Gateway 1 CDR CDR Message Format SdcmdSyslogSend SYSLOG CDR SYSLOG INFO String String board xx line xx channel xx call xx str board the hardware board ID line the WAN ID in a board Channel channel ID within the WAN call the call reference number which starts from 1 and increments by 1 for each new call str C01 Outgoing Call dev xx ch xx dev device No ch channel No L02 Tunnel Connected L2TP C02 OutCall Connected xxxx means connected speed xxxxx means Remote Call Number L02 Call Terminated C02 Call Terminated Jul 19 11 19 27 192 168 102 2 ZyXEL board 0 line 0 channel 0 call 1 C01 Outgoing Call dev 2 ch 0 40002 Jul 19 11 19 32 192 168 102 2 ZyXEL board 0 line 0 channel 0 call 1 C02 OutCall Connected 64000 40002 Jul 19 11 20 06 192 168 102 2 ZyXEL board 0 line 0 channel 0 call 1 C02 Call Terminated 2 Packet triggered Packet triggered Message Format sdcmdSyslogSend SYSLOG PKTTRI SYSLOG NOTICE String String Packet trigger Protocol xx Data X 900XXXXX X Protocol 1 IP 2 IPX 3 IPXHC 4 BPDU 5 ATALK 6 IPNG Data We will send forty eight Hex characters to the server Jul 19 11 28 39 192 168 102 2 ZyXEL Packet Trigger Protocol 1 Data 4500003c100100001 010004c0a86614ca849a7508004a5c020001006162636465666768696a6b6c6d6e6 7071727374 Jul 19 11 28 56 192 168 102 2 ZyXEL Packet Trigger Protocol 1 Data 4500002c1b0140001f06b50ec0a86614ca849a7
27. ZyWALL as a PPPOE Client When using the ZyW ALL as a PPPOE client the PCs on the LAN see only Ethernet and are not aware of PPPOE This alleviates the administrator from having to manage the PPPOE clients on the individual PCs ADSL Modem Ethernet Concentrator Diagram 2 ZyWALL as a PPPoE Client B PPPoE ZyWALL 10 Internet Security Gateway Appendix B PPTP What is PPTP PPTP Point to Point Tunneling Protocol is a Microsoft proprietary protocol RFC 2637 for PPTP is informational only to tunnel PPP frames How can we transport PPP frames from a PC to a broadband modem over Ethernet A solution is to build PPTP into the ANT ADSL Network Termination where PPTP is used only over the short haul between the PC and the modem over Ethernet For the rest of the connection the PPP frames are transported with PPP over AAL5 RFC 2364 The PPP connection however is still between the PC and the ISP The various connections in this setup are depicted in the following diagram The drawback of this solution is that it requires one separate ATM VC per destination ATM over ADSL PC ANT ISP PP TP RF C 2354 PPP Diagram 3 Transport PPP frames over Ethernet PPTP and the ZyWALL When the ZyW ALL is deployed in such a setup it appears as a PC to the ANT ADSL Network Termination In Windows VPN or PPTP Pass Through feature the PPTP tunneling is created from Windows 95 98 and NT clients to an NT server in
28. applicable to all protocols that understands data in the packet is intended for other layers from the network layer IP headers up to the application layer Q The firewall performs stateful inspection It takes into account the state of connections it handles so that for example a legitimate incoming packet can be matched with the outbound request for that packet and allowed in Conversely an incoming packet masquerading as a response to a nonexistent outbound request can be blocked O The firewall uses session filtering i e smart rules that enhance the filtering process and control the network session rather than control individual packets in a session Q The firewall provides e mail service to notify you of routine reports and when alerts occur When To Use The Firewall 1 To prevent DoS attacks and prevent hackers cracking your network 2 Arange of source and destination IP addresses as well as port numbers can be specified within one firewall rule making the firewall a better choice when complex rules are required 3 To selectively block allow inbound or outbound traffic between inside host networks and outside host networks Remember that filters can not distinguish traffic originating from an inside host or an outside host by IP address 4 The firewall performs better than filtering if you need to check many rules 5 Use the firewall if you need routine e mail reports about your system or need to be alerted when attacks occur
29. forward Ifoteard D I forward Example Firewall Rules 18 1 ZyWALL 10 Internet Security Gateway Table 18 1 Log Screen FIELD DESCRIPTION EXAMPLES No This is the index number of the firewall log 128 entries are available numbered from 0 to 127 Once they are all used the log will wrap around and the old logs will be lost Time This is the time the log was recorded in this dd mm yy eg Jan 1 0 format You must configure menu 24 10 for real EET time otherwise the time shown in these examples Ph mm ss e g 00 00 00 is displayed Packet This field lists packet information such as From and To IP addresses Information lt 99 ooo Tom eee ee IU eae al protocol and port numbers Reason This field states the reason for the log i e was not match the rule matched not matched or was there an attack The set and rule coordinates X Y gt 1 01 dest IP where X 1 2 Y 00 10 follow with a simple This means this packet explanation There are two policy sets set 1 X does not match the 1 is for LAN to WAN rules and set 2 X 2 for destination IP address in WAN to LAN rules Y represents the rule in the set 1 rule 1 Other reasons set You can configure up to 10 rules in any set Y instead of dest IP are src 01 to 10 Rule number 00 is the default rule IP dest port src port and protocol This is a log is for a DoS attack attack land ip spoofing icmp echo icmp vulnerability Ne
30. the resulting ICMP traffic will not only clog up the intermediary network but will also congest the network of the spoofed source IP address known as the victim network This flood of broadcast traffic consumes all available bandwidth making communications impossible Ping Responses Attacker broadcasts ping Every host on the Intermediary network responds by sending responses to every host on the victim network Figure 13 4 Smurf Attack 4 Often many DoS attacks also employ a technique known as IP Spoofing as part of their attack IP Spoofing may be used to break into systems to hide the hacker s identity or to magnify the effect of the DoS attack IP Spoofing is a technique used to gain unauthorized access to computers by tricking a router or firewall into thinking that the communications are coming from within the trusted network To engage in IP spoofing a hacker must modify the packet headers so that it appears that the packets originate from a trusted host and should be allowed through the router or firewall The ZyWALL blocks all IP Spoofing attempts packets with a spoofed source address to every host on the intermediary network 13 4 Stateful Inspection With stateful inspection fields of the packets are compared to packets that are already known to be trusted For example if you access some outside service the proxy server remembers things about your original request like the port number and source and dest
31. 13 4 2 Stateful Inspection amp the Zy WALL sees se ee se ee ee AA nennen nnne nennen entente 13 8 E We ei N de ei EE EE EDE EE EE 13 8 13 44 4 GP VS dei NR EE EE 13 9 13 45 Upper Layer ve o eee RR EE ER EE EN 13 9 13 5 Guidelines For Enhancing Security With Your Firewall sse 13 9 133 1 Securty In General e ex dees 13 10 Chapter 14 Introducing the ZyWALL Firewall ecce sees ee ee eere seen EE Ge EE EE sts toss ease toss ense tn 14 1 Table of Contents xiii ZyWALL 10 Internet Security Gateway 14 1 SMT ii EE EE ER EE N EE shea PEE RE E 14 1 LL View Firewall EOg i iere GE TR Ee OH eO Dn DRE 14 2 T431 2 Attack SEY POS E 14 2 14 2 The Big Picture Filtering Firewall and NAT seen 14 5 143 P cket Filtering Vs Firewall eee tote toten e anions tec interitus 14 6 Fa Packet Filtering tUe EE AE RR EE OR N EE 14 6 14 3 2 tee eege Ee thee eR ERU doe Ded estu que aav re tabe qe 14 7 Chapter 15 Introducing the ZyWALL Web Configurator eee ee esee ee ette Gee Ge EE Ge Ge Ge ee 15 1 15 1 Web Configurator Login and Welcome Sereeng esse ese ee ee Ge Se Se GR GR GRA ee ee se ee ee 15 1 15 2 Enabling the Firewall EERS ER Re Ke enesc hector tratte tla 15 3 E e UE 15 3 15 3 What are Alerts ssec et ED o desee Eege RC E reet ur dEr 15 3 15 32 What are L0882 scie o htec i ese etr tiere ie uem petis iet EE DE Gee De gede dp
32. 155 93 TCP spo 01170 dpo 00021 S04 gt RO0O1mF 4 PPPlog PPP Log Message Format sdcmdSyslogSend SYSLOG PPPLOG SYSLOG NOTICE String String ppp Proto Starting ppp Proto Opening ppp Proto Closing ppp Proto Shutdown Proto LCP ATCP BACP BCP CBCP CCP CHAP PAP IPCP IPXCP Jul 19 11 42 44 192 168 102 2 ZyXEL ppp LCP Closing Jul 19 11 42 49 192 168 102 2 ZyXEL ppp IPCP Closing Jul 19 11 42 54 192 168 102 2 ZyXEL ppp CCP Closing 5 Firewall log Firewall Log Message Format sdcmdSyslogSend SYSLOG_FIREWALL SYSLOG_NOTICE buf buf IP Src xx xx xx xx SPO Xxxx Dst XX XX XX XX dpo2xxxx prot rule action Src Source Address spo Source port empty means no source port information Dst Destination Address dpo Destination port empty means no destination port information prot Protocol TCP UDP ICMP IGMP GRE ESP rule a b where a means set number b means rule number action nothing N block B forward F 08 01 2000 11 48 41 Locall Notice 192 168 10 10 RAS FW 172 21 1 80 v137 2172 21 1 80 137 UDP default permit lt 2 0 gt B 08 01 2000 11 48 41 Locall Notice 192 168 10 10 RAS FW 192 168 77 88 7520 gt 192 168 77 88 2520 UDP default permit lt 2 0 gt B 08 01 2000 11 48 39 Locall Notice 192 168 10 10 RAS FW 172 21 1 50 2172 21 1 50 IGMP lt 2 gt default permit lt 2 0 gt B 08 01 2000 11 48 39 Local
33. 2 Main Menu Commands OPERATION KEYSTROKES DESCRIPTION Move down to ENTER To move forward to a submenu type in the number of the desired another menu submenu and press ENTER Move up to a ESC Press the ESC key to move back to the previous menu previous menu Move to a hidden menu Press the SPACE BAR to change No to Yes then press ENTER Fields beginning with Edit lead to hidden menus and have a default setting of No Press the SPACE BAR to change No to Yes then press ENTER to go to a hidden menu Move the cursor ENTER or UP DOWN arrow keys Within a menu press ENTER to move to the next field You can also use the UP DOWN arrow keys to move to the previous and the next field respectively Enter information Fill in or press the SPACE BAR to select from choices You need to fill in two types of fields The first requires you to type in the appropriate information The second allows you to cycle through the available choices by pressing the SPACE BAR Required fields 29 All fields with the symbol lt gt must be filled in order be able to save the new configuration N A fields N A Some of the fields in the SMT will show a N A This symbol refers to an option that is Not Applicable Save your ENTER Save your configuration by pressing ENTER at the message configuration Press ENTER to confirm or ESC to cancel Saving the data on th
34. Access Setup ISP s Name ChangeMe Encapsulation Ethernet Service Type Standard My Login N A My Password N A Login Server IP N A IP Address Assignment Dynamic IP Address N A IP Subnet Mask N A Gateway IP Address N A Network Address Translation Full Feature Press ENTER to Confirm or ESC to Cancel Figure 3 6 Menu 4 Internet Access Setup Ethernet The following table describes this screen Table 3 4 Internet Access Setup Menu Fields FIELD DESCRIPTION ISP s Name Enter the name of your Internet Service Provider e g mylSP This information is for identification purposes only Encapsulation Press SPACE BAR and then press ENTER to choose Ethernet The encapsulation method influences your choices for IP Address Service Type Press the SPACE BAR to select Standard RR Toshiba RoadRunner Toshiba authentication method or RR Manager RoadRunner Manager authentication method Choose a RoadRunner flavor if your ISP is Time Warner s RoadRunner otherwise choose Standard Note xDSL users must choose the Standard option only The Server IP My Login IP and My Password fields are not applicable in this case My Login Name Enter the login name given to you by your ISP My Password Enter the password associated with the login name above Login Server IP does not then you must enter the authentication server IP address The ZyWALL will find the RoadRunne
35. Cable xDSL and wireless modem via Ethernet port as Internet access media Q Multiple office department connections via access devices O E commerce EDI applications Your ZyW ALL 10 is easy to install and configure The ZyW ALL Web Configurator Web Configurator is a web based utility that allows you to access the ZyW ALL s management settings and configure the firewall Most functions of the ZyWALL 10 are also software configurable via the SMT System Management Terminal interface The SMT is a menu driven interface that you can access from a terminal emulator through the console port or over a telnet connection You can configure most features of the ZyWALL 10 via SMT but we recommend you configure the firewall using the ZyWALL Web Configurator About This User s Manual This manual is designed to guide you through the SMT configuration of your ZyW ALL 10 for its various applications Structure of this Manual This manual is structured as follows Part I Getting Started Chapters 1 3 is structured as a step by step guide to help you connect install and setup your ZyW ALL to operate on your network and access the Internet Part II Advanced Applications Chapters 4 6 describes the advanced applications of your ZyW ALL such as Remote Node Setup IP Static routes and NAT Part III Advanced Management Chapters 7 12 provides information on ZyW ALL Filtering System Information and Diagnosis Transferring Files
36. Check Dest IP Addr Matched Y vi phas n z L IP Protocol Not Matched e Matched L lt lt cece Rte Not Matched ih gt Dest Port_ Matched Y Not Matched N gt lt 8 More 3 Yes No Action Not Matched Action Matched 3 Check Next Rule Check Next Rule Drop Forward i Ax EN EN ER pa Drop Forward PPP l A Y Y VY P d L a oa Drop Packet Check Next Rule Accept Packet NL 27 27 NC Figure 7 10 Executing an IP Filter 7 10 Filters ZyWALL 10 Internet Security Gateway 7 2 4 Generic Filter Rule This section shows you how to configure a generic filter rule The purpose of generic rules is to allow you to filter non IP packets For IP it is generally easier to use the IP rules directly For generic rules the ZyW ALL treats a packet as a byte stream as opposed to an IP or IPX packet You specify the portion of the packet to check with the Offset from 0 and the Length fields both in bytes The ZyWALL applies the Mask bit wise ANDing to the data portion before comparing the result against the Value to determine a match The Mask and Value are specified in hexadecimal numbers Note that it takes two hexadecimal digits to represent a byte so if the length is 4 the value in either field will take 8 digits e g FFFFFFFF To configure a generic rule select Gener
37. Destination Addresses esse 16 13 Table 16 5 Timeout Menu aite ER Ret etes pete qoo et Ua e uo rU teed pe re dE 16 15 xxiv List of Tables ZyWALL 10 Internet Security Gateway Table 17 1 Custom Ports nro OR Pri EE RE EE EN 17 2 Table 17 2 Creating Editing A Custom Port 17 4 Table 18 1 Log Screen EE 18 2 Table 21 1 Troubleshooting the Start Up of your Zy WALL esse esse esse esse ese see ee ee Gee Gee Ge ee ee ee ee se ke ee 21 1 Table 21 2 Troubleshooting the LAN Interface A 21 2 Table 21 3 Troubleshooting the WAN interface ee ee see se ee ee Ge Ge Ge GR Re GR RA Re ee Ge ee ee ee ee ee ee 21 2 Table 21 4 Troubleshooting Internet Access ese see se ee ee ee Ge Ge Se GR Re GR RA Re Gee Ge ee ee ee ee ee ee 21 3 Table 21 5 Troubleshooting the Firewall ee ed Ge Gee ee ee ee ee Se SR Re Ge Re GR RA Re Gee ee ee ee ee 21 3 List of Tables XXV ZyWALL 10 Internet Security Gateway Preface About Your Router Congratulations on your purchase of the ZyW ALL 10 Internet Security Gateway Don t forget to register your ZyWALL fast easy online registration at www zyxel com for free future product updates and information The ZyWALL 10 is a dual Ethernet Internet Security Gateway integrated with robust firewall solutions and network management features that allows access to the Internet via Cable ADSL modem or Internet router It is designed for Q Home offices and small businesses with
38. GE Mie he esie te eai 6 12 6 3 1 Multiple Servers behind NAT se ee Ge Se Re a Se GR RA RA Gee nre 6 13 6 3 2 Configuring a Server behind NAT ee see see se ee ee ee Se ee RR GRA Gee Gee ee Re Se ee ke ee 6 13 E E iuncto OE EE Dp Dan RE 6 15 6 4 1 Internet Access Only 5 5 oer EE EE EE te he REIR N 6 15 6 4 2 Example 2 Internet Access with an Inside Server 6 16 6 4 3 Example 3 General Case eege abet edat GEE Pt Oo RA EES 6 17 6 4 4 Example 4 NAT Unfriendly Application Programs see 6 20 Advanced Managemert 5 ec PR EEN EES Ke se ESE KERE ED ERO ED Perg te Pe ERE ERES III Chapter 7 Filter Configuration 4 eese eese eese tenete EG EG tense Bee Ee seta seta sete EG Ee Ee Ge GE Ge ee enses sta 7 1 T About leg emerat er etae iy eee Eus Spoeg ee eu Ee 7 1 7 1 1 The Filter Structure of the ZyWALL ee se ee se ee Re ee ee ee nennen nennen nennen nenne 7 2 12 Configuring a Filter Set eee tree He eR GELEE DRR Se RR SE Re ee RM Rees 7 4 7 2 1 Filter Rules Summary Men 7 6 7 2 2 Configuring a Filter di eter ene erede eerte etti 7 7 7 2 3 TCP IP Filt r R le 5 EE EE OE N etate deis 7 7 7 2 4 Generic Filter Rule ig foie ion ais DPI e a eis 7 11 1 3 Exaniple Filter ene ne a ted ee aed ee 7 13 74 olie SE GAM RE rte RR EE Nt eL ORE E ee REESE ES 7 15 Teds PE Wallies EE EE N ER M 7 16 7 6 Applying a Filter and Factory Defaults ese se see ee ee SA Re Gee ee ee ee ee ee ee ee 7 16 7 6 1 T
39. Line 1kV AC DC Line to Earth 2kV Immunity to conducted disturbances Induced by radio frequency fields EN 61000 4 6 1996 0 15 80MHz with 1kHz AM 80 Modulation 3V m Power frequency magnetic field immunity test according to EN 61000 4 8 1993 3A m at frequency 50Hz Voltage dips short interruptions and voltage variations immunity test according to EN 61000 4 11 1994 30 Reduction 10ms 500ms 60 Reduction 100ms gt 95 Reduction 10ms 5000ms The following importer manufacturer is responsible for this declaration Company Name Communications ZyXEL Services GmbH Company Address Thaliastrasse 125a 2 2 4 A 1160 Wien AUSTRIA Telephone Tel 01 494 86 77 0 Facsimile Fax 01 494 Person is responsible for marking this declaration I icmtred DEcLA ZyXEL Techn Support Name Full Name al Pogition Uclebu 23 Ate lot Zeal Date i Ldgal Signdure ommunications ZyX Services GmbH Thaliastrasse 125a 2 2 4 A 1160 Wien AUSTRIA Tel 01 494 86 77 0 Fax 01 494 86 78 vi CE ZyWALL 10 Internet Security Gateway ZyXEL Limited Warranty ZyXEL warrants to the original end user purchaser that this product is free from any defects in materials or workmanship for a period of up to two years from the date of purchase During the warranty period and upon proof of purchase should the product have indications of failure due to faulty workmanship and or materials ZyXEL will at its
40. Login Host Protocol used for Terminal Access Controller Access Control System Telnet is the login and terminal emulation protocol common on the Internet and in UNIX environments It operates over TCP IP networks Its primary function is to allow users to log into remote host systems Trivial File Transfer Protocol is an Internet file transfer protocol similar to FTP but uses the UDP User Datagram Protocol rather than TCP Transmission Control Protocol Another videoconferencing solution Creating Custom Rules 16 9 ZyWALL 10 Internet Security Gateway 16 5 1 Creating Editing Firewall Rules To create a new rule click a number No then click Edit in the last screen shown to display the following Screen RULE CONFIG Local Network to Internet EBB Source IP Address SEER Jeng Destination IP S CONFIGURATION Any LOCAL NETWORK DestE dit LOGOUT Syslog UDP 514 l POP TCP 110 Any TCP SMTP TCP 25 Any UDP BGP TCP 173 BOOTP CLIENT UDP 68 Figure 16 4 Creating Editing A Firewall Rule 16 10 Creating Custom Rules ZyWALL 10 Internet Security Gateway Table 16 3 Creating Editing A Firewall Rule this rule generates an alert when the rule is matched FIELD DESCRIPTION OPTIONS Source Address Press SrcAdd to add a new address SrcAdd SrcEdit to edit an existing one or SrcDelete SrcEdit to delete one Please see the next section ok
41. Name Enter the domain name if you know it here If you leave this field zyxel com tw blank the ISP may assign a domain name via DHCP You can go to menu 24 8 and type sys domain name to see the current domain name used by your router If you want to clear this field just press the SPACE BAR The domain name entered by you is given priority over the ISP assigned domain name Edit Dynamic DNS Press the SPACE BAR to select Yes or No default Select Yes to configure Menu 1 1 Configure Dynamic DNS discussed next When you have completed this menu press ENTER at the prompt Press ENTER to Confirm to save your configuration or press ESC at any time to cancel 2 7 3 Configuring Dynamic DNS To configure Dynamic DNS go to Menu 1 General Setup and use the SPACE BAR to select Yes in the Edit Dynamic DNS field Press ENTER to display Menu 1 1 Configure Dynamic DNS shown next Menu 1 1 Configure Dynamic DNS Service Provider WWW DynDNS ORG Active Yes Host me ddns org EMAIL mail mailserver User username Password Enable Wildcard No Press ENTER to confirm or ESC to cancel Figure 2 9 Configure Dynamic DNS Follow the instructions in the next table to configure Dynamic DNS parameters Hardware Installation amp Initial Setup 2 11 ZyWALL 10 Internet Security Gateway Table 2 5 Configure Dynamic DNS Menu Fields FIELD
42. Options Menu Fields FIELD DESCRIPTION EXAMPLE IP Address If your ISP did not assign you an explicit IP address select Dynamic Assignment Dynamic otherwise select Static and enter the IP address amp subnet mask in the following fields IP Address If you have a Static IP Assignment enter the IP address assigned to you by your ISP IP Subnet If you have a Static IP Assignment enter the subnet mask assigned Mask to you Gateway IP If you have a Static IP Assignment enter the gateway IP address Addr assigned to you Network Use the SPACE BAR to select either Full Feature None or SUA SUA Only Address Only See the NAT chapter for a full discussion on this feature Translation Metric This field is valid only for PPTP PPPoE encapsulation The metric 3 represents the cost of transmission for routing purposes IP routing uses hop count as the measurement of cost with a minimum of 1 for directly connected networks Enter a number that approximates the cost for this link The number need not be precise but it must be between 1 and 15 In practice 2 or 3 is usually a good number 4 6 Remote Node Setup ZyWALL 10 Internet Security Gateway FIELD DESCRIPTION EXAMPLE Private This field is valid only for PPTP PPPOE encapsulation This Yes parameter determines if the ZyWALL will include the route to this remote node in its RIP broadcasts If set to Yes this route is kept private and not incl
43. Step 3 From this menu you have two choices as shown in the next figure Menu 24 2 System Information and Console Port Speed 1 System Information 2 Console Port Speed Please enter selection Figure 9 3 Menu 24 2 System Information and Console Port Speed System Information amp Diagnosis 9 3 ZyWALL 10 Internet Security Gateway 9 2 1 System Information System Information gives you information about your system as shown below More specifically it gives you information on your routing protocol Ethernet address IP address etc Menu 24 2 1 System Maintenance Information Name xxx baboo mickey com Routing IP ZyNOS F W Version V324WA0b05 3 5 2001 LAN Ethernet Address 00 a0 c5 21 8c a2 IP Address 192 168 1 1 IP Mask 255 255 255 0 DHCP Server Press ESC or RETURN to Exit Figure 9 4 Menu 24 2 1 System Maintenance Information Table 9 2 Fields in System Maintenance Information FIELD DESCRIPTION Name This is the ZyWALL s system name domain name assigned in Menu 1 E G System Name xxx Domain Name baboo mickey com Names xxx baboo mickey com Routing Refers to the routing protocol used ZyNOS F W Version Refers to the version of ZyXEL s Network Operating System software Ethernet Address Refers to the Ethernet MAC Media Access Control address of your ZyWALL IP Address This is the IP address of the ZyWALL in dotted decimal notation IP Ma
44. System Maintenance and Telnet Part IV Firewall Chapters 13 20 defines the term firewall introduces the ZyWall firewall and ZyWall web configurator describes how to create custom rules and configure customized ports explains logs and provides example firewall rules Chapter 20 explains content filtering and how to use the ZyWALL to restrict web features such as ActiveX controls Java applets and cookies disable web proxies and block specific URLs Part V Troubleshooting Chapter 21 provides information about solving common problems as well as some Appendices a Glossary and an Index Preface xxvii ZyWALL 10 Internet Security Gateway Regardless of your particular application it is important that you follow the steps outlined in Chapters 1 and 2 to connect your ZyWALL to your LAN You can then refer to the appropriate chapters of the manual depending on your applications Related Documentation Support Disk More detailed information about the ZyW ALL and examples of its use can be found in our included disk as well as on the zyxel com web site This disk contains information on configuring your ZyW ALL for Internet Access a General FAQ an Advanced FAQ Applications Notes Troubleshooting Reference CI Commands as well as bundled software Read Me First Our Read Me First is designed to help you get your ZyW ALL up and running right away It contains a detailed easy to follow connection diagram ZyW ALL defau
45. This restricts all IRC access from the LAN to the Internet Or This allows a remote Lotus Notes server to synchronize over the Internet to an inside Notes server 2 Isthe intent of the rule to forward or block traffic 3 Whatis the direction connection from the LAN to the Internet or from the Internet to the LAN 4 WhatIP services will be affected Creating Custom Rules 16 1 ZyWALL 10 Internet Security Gateway 5 What computers on the LAN are to be affected if any 6 What computers on the Internet will be affected The more specific the better For example if traffic is being allowed from the Internet to the LAN it is better to allow only certain machines on the Internet to access the LAN 16 2 2 Security Ramifications Once the logic of the rule has been defined it is critical to consider the security ramifications created by the rule 1 Does this rule stop LAN users from accessing critical resources on the Internet For example if IRC is blocked are there users that require this service 2 Is it possible to modify the rule to be more specific For example if IRC is blocked for all users will a rule that blocks just certain users be more effective 3 Does arule that allows Internet users access to resources on the LAN create a security vulnerability For example if FTP ports TCP 20 21 are allowed from the Internet to the LAN Internet users may be able to connect to computers with running FTP server
46. Transfer Protocol over LAN Although TFTP should work over WAN as well it is not recommended To use TFTP your workstation must have both telnet and TFTP clients To transfer the firmware and the configuration file follow the procedure shown next Firmware and Configuration File Maintenance 10 7 ZyWALL 10 Internet Security Gateway Step 1 Use telnet from your workstation to connect to the ZyWALL and log in Because TFTP does not have any security checks the ZyW ALL records the IP address of the telnet client and accepts TFTP requests only from this address Step 2 Put the SMT in command interpreter CI mode by entering 8 in Menu 24 System Maintenance Step 3 Enter command sys stdio 0 to disable the SMT timeout so the TFTP transfer will not be interrupted Enter command sys stdio 5 to restore the five minute SMT timeout default when the file transfer is complete Step 4 Launch the TFTP client on your workstation and connect to the ZyW ALL Set the transfer mode to binary before starting data transfer Step 5 Use the TFTP client see the example below to transfer files between the ZyWALL and the workstation The file name for the firmware is ras and the configuration file is rom 0 rom Zero not capital o If you upload the firmware to the ZyWALL it will reboot automatically when the file transfer is completed the SYS LED will flash Note that the telnet connection must be active and the SMT in CI mode before a
47. ZyWALL 10 Internet Security Gateway 2 Think about access control before you connect a console port to the network in any way including attaching a modem to the port Be aware that a break on the console port might give unauthorized individuals total control of the firewall even with access control configured 3 Limit who can telnet into your router Don t enable any local service such as SNMP or NTP that you don t use Any enabled service could present a potential security risk A determined hacker might be able to find creative ways to misuse the enabled services to access the firewall or the network 5 For local services that are enabled protect against misuse Protect by configuring the services to communicate only with specific peers and protect by configuring rules to block packets for the services at specific interfaces 6 Protect against IP spoofing by making sure the firewall is active 7 Keep the firewall in a secured locked room 13 5 1 Security In General You can never be too careful Factors outside your firewall filtering or NAT can cause security breaches Below are some generalizations about what you can do to minimize them 1 Encourage your company or organization to develop a comprehensive security plan Good network administration takes into account what hackers can do and prepares against attacks The best defense against hackers and crackers is information Educate all employees about the importance of
48. ZyWALL 10 Internet Security Gateway Events FAQ FCC Firewall Flash memory FTP Gateway Hacker HDLC Host HTTP IANA ICMP These are network activities Some activities are direct attacks on your system while others might be depending on the circumstances Therefore any activity regardless of severity is called an event An event may or may not be a direct attack on your system Frequently Asked Questions FAQs are documents that list and answer the most common questions on a particular subject The FCC Federal Communications Commission is in charge of allocating the electromagnetic spectrum and thus the bandwidth of various communication systems A hardware or software wall that restricts access in and out of a network Firewalls are most often used to separate an internal LAN or WAN from the Internet The nonvolatile storage that can be electrically erased and reprogrammed so that data can be stored booted and rewritten as necessary File Transfer Protocol is an Internet file transfer service that operates on the Internet and over TCP IP networks FTP is basically a client server protocol in which a system running the FTP server accepts commands from a system running an FTP client The service allows users to send commands to the server for uploading and downloading files FTP is popular on the Internet because it allows for speedy transfer of large files between two systems A gateway is a co
49. ZyWALL using Internet appropriate cable Check with the manufacturer of your Cable xDSL device about your cable requirement because for some devices may require crossover cable and others a regular patch cable Verify your settings in menu 3 2 and menu 4 21 5 Problems with the Firewall Table 21 5 Troubleshooting the Firewall Problem Corrective Action Cannot configure the You can ONLY configure the firewall via ZyWALL Web Configurator firewall or Cl command You will not be able to access the ZyWALL Web Configurator from the WAN if The firewall is activated as the firewall by default blocks all WAN to LAN traffic To access the ZyWALL Web Configurator from the WAN when the firewall is activated you will need to create a firewall rule see the Example Firewall Rules chapter to allow web traffic initiated from the WAN You have applied a filter in menu 3 1 LAN or in menu 11 5 WAN to block web service You have an SMT console session running Troubleshooting 21 3 ZyWALL 10 Internet Security Gateway Appendix A PPPoE PPPoE in Action An ADSL modem bridges a PPP session over Ethernet PPP over Ethernet RFC 2516 from your PC to an ATM PVC Permanent Virtual Circuit which connects to a xDSL Access Concentrator where the PPP session terminates see the next figure One PVC can support any number of PPP sessions from your LAN PPPoE provides access control and billin
50. a remote location The pass through feature allows users on the network to access a different remote server using the ZyW ALL s Internet connection In NAT mode the ZyWALL is able to pass the PPTP packets to the internal PPTP server i e NT server behind the NAT Users need to forward PPTP packets to port 1723 by configuring the server in Menu 15 2 Server Set Setup In the case above as the PPTP connection is initialized by the remote PPTP Client the user must configure the PPTP clients The ZyWALL initializes the PPTP connection hence there is no need to configure the remote PPTP clients PPTP Protocol Overview PPTP is very similar to L2TP since L2TP is based on both PPTP and L2F Cisco s Layer 2 Forwarding Conceptually there are three parties in PPTP namely the PNS PPTP Network Server the PAC PPTP PPTP C ZyWALL 10 Internet Security Gateway Access Concentrator and the PPTP user The PNS is the box that hosts both the PPP and the PPTP stacks and forms one end of the PPTP tunnel The PAC is the box that dials answers the phone calls and relays the PPP frames to the PNS The PPTP user is not necessarily a PPP client can be a PPP server too Both the PNS and the PAC must have IP connectivity however the PAC must in addition have dial up capability The phone call is between the user and the PAC and the PAC tunnels the PPP frames to the PNS The PPTP user is unaware of the tunnel between the PAC and the PNS PPTP User
51. and Capabilities ese ee ee Ee Ge Ge Ge Ge Ge Ge EG EG eg 12 1 12 1 About Telnet Configuration eser et Ee ERGE ESE ED ede ERGER EER pH Gegee Oe EE 12 1 PEER G DLE VEE RE OE N EE IR E 12 1 12 3 Telnet Capabilitie t N Veg GEROER Se ERG ER he DEGREE oe Eg re pee eis en 12 1 12 3 1 Single Administrator eee bte eite ec hocks eb cei e Se oceans 12 1 12 32 E TIMEOUT E 12 2 12 4 Telnet Behind the Firewall esses GR RA Ge eene ennemi nter eene 12 2 Firewall and Content Filters rtt REG PERIERE ERR WERE E WEE EAR 13 1 Chapter 13 What is a Firewall see se ee ee sees seen ette Ge EG etna Bee tasto setae tasto seta sete stesse testo aetas eg 13 1 13 1 TTypes of oie ELE haee ee Ier eme oi EE RE 13 1 13 1 1 Packet Filtering Firewalls tette tto ee ttr p REIR te bees 13 1 13 1 2 Application level Firewalls eese esee eene Ge ee ennt enne enne 13 1 13 1 3 Stateful Inspection Firewalls 20 0 0 esse ee ee se Se GR RA Ge ee eene nnne nennen nennen enne 13 2 13 2 Introduction to ZyXEL s Firewall esee neret enne ee ge ee ee nennen 13 2 13 3 Demal ege TE 13 3 KGR p ED H 13 3 13 32 Typesof DoS attacks edo rrt Red E Hee thee 13 4 13 4 Stateful Inspection etre one RR REL LO REED DEGREE GEED Ee eb IR EER SERS 13 6 13 441 Stateful Inspection Process eerte eter tti rir rei ire rip eren 13 7
52. are subdivided into Local Network and Internet By default the ZyWALL s stateful packet inspection allows all communications to the Internet that originate from the local network and blocks all traffic to the LAN that originates from the Internet You may define additional rules and sets or modify existing ones but please exercise extreme caution in doing so If you try to configure rules but do not have a good understanding of how rules work you might inadvertently introduce security risks to the firewall and to the protected network You should be sure you test your rules after you configure them For example you may create rules to Block certain types of traffic such as IRC Internet Relay Chat from the LAN to the Internet Allow certain types of traffic such as Lotus Notes database synchronization from specific hosts on the Internet to specific hosts on the LAN Allow everyone except your competitors to access a Web server Restrict use of certain protocols such as Telnet to authorized users on the LAN These custom rules work by comparing network traffic s Source IP address Destination IP address IP protocol type to rules set by the administrator Your customized rules take precedence and may override the ZyW ALL s default rules 16 2 Rule Logic Overview Study these points carefully before beginning to configure rules 16 2 1 Rule Checklist 1 State the intent of the rule For example
53. can block web features such as ActiveX controls Java applets cookies as well as disable web proxies 20 1 2 Filter List The administrator can block categories such as pornography or racial intolerance or monitor visitation from a pre defined list Upon registration of the ZyW ALL the use of the list is free for a trial period After this period you must subscribe to the list periodically 20 1 3 Days and Times The ZyWALL also allows the administrator to define time periods and days during which content filtering is enabled Content Filtering 20 1 ZyWALL 10 Internet Security Gateway Content Filter REGISTRY Figure 20 1 Categories Screen 20 2 Content Filtering ZyWALL 10 Internet Security Gateway 20 2 Update List Content on the Internet is constantly changing so the content filter list should be updated on a weekly basis Content Filter REGISTRY Free iCard CATEGORIES EXEMPT ZONE CUSTOMIZE Download Now URL KEYWORD Bj LOGS Wednesday ILOGOUT Status Ready Figure 20 2 List Update Screen Content Filtering 20 3 ZyWALL 10 Internet Security Gateway 20 3 Exempting Computers This screen allows the administrator to include or exclude a range of users on the LAN from content filtering Ed MAIN MENU Content Filter REGISTRY Free LIST UPDATE EXEMPT ZONE CUSTOMIZE URL KEYWORD 192 168 1 5 192 168 1 12 LOGOUT Figure 20 3 Exempt Zone Screen 20 4 Conte
54. connection can be very expensive for obvious reasons Remote Node Setup 4 3 ZyWALL 10 Internet Security Gateway Do not specify a nailed up connection unless your telephone company offers flat rate service or you need a constant connection and the cost is of no concern The following table describes the fields not already described in Table 4 1 Table 4 2 Fields in Menu 11 1 PPPoE Encapsulation Specific FIELD DESCRIPTION EXAMPLE Authen This field sets the authentication protocol used for CHAP PAP outgoing calls Options for this field are CHAP PAP Your ZyWALL will accept either CHAP or PAP when requested by this remote node CHAP accept CHAP only PAP accept PAP only Telco Option Allocated Budget The field sets a ceiling for outgoing call time for this 10 remote node The default for this field is 0 meaning no budget control Period hr This field is the time period that the budget should be 1 reset For example if we are allowed to call this remote node for a maximum of 10 minutes every hour then the Allocated Budget is 10 minutes and the Period hr is 1 hour Schedules You can apply up to four schedule sets here For more details please refer to the Call Schedule Setup chapter Nailed Up This field specifies if you want to make the connection to Connection this remote node a nailed up connection More details are given earlier in this section Session Options This value spe
55. different IP address known within another network 6 1 1 NAT Definitions Inside outside denotes where a host is located relative to the ZyWALL e g the workstations of your subscribers are the inside hosts while the web servers on the Internet are the outside hosts Global local denotes the IP address of a host in a packet as the packet traverses a router e g the local address refers to the IP address of a host when the packet is in the local network while the global address refers to the IP address of the host when the same packet is travelling in the WAN side Note that inside outside refers to the location of a host while global local refers to the IP address of a host used in a packet Thus an inside local address ILA is the IP address of an inside host in a packet when the packet is still in the local network while an inside global address IGA is the IP address of the same inside host when the packet is on the WAN side The following table summarizes this information Table 6 1 NAT Definitions TERM DEFINITION Inside This refers to the host on the LAN Outside This refers to the host on the WAN Local This refers to the packet address source or destination as the packet travels on the LAN Global This refers to the packet address source or destination as the packet travels on the WAN The IP address either local or global of an outside host is never changed 6 1 2 What NAT Does In th
56. dotted decimal format Your Internet Service Provider ISP should be able to provide this information If this field is left blank log and alert messages will not be sent via e mail Enter a subject that you want to appear in the subject field of your e mail here see Figure 15 5 If you leave this field blank then the default Firewall Alert From ZyWALL displays as your e mail subject Enter the e mail address username mydomain com of whoever is responsible for maintaining the firewall e g your system administrator If this field is left blank alert messages will not be sent via E mail Enter an e mail address to identify the ZyWALL as the sender of the e mail messages i e a return to sender address for backup purposes Log Timer Alert Schedule Day for Sending Alerts Time for Sending Alerts This pop up menu is used to configure the frequency of log messages being sent as e mail daily weekly hourly only when the log is full or none If the Weekly or the Daily option is selected specify a time of day when the e mail should be sent If the Weekly option is selected then also specify which day of the week the e mail should be sent If the When Log is Full option is selected an alert is sent when the log fills up If you select None no log messages are e mailed Click which day of the week you want to send the alert from the drop down list box Click the up or down arrows to the right of the lis
57. else the packet must not have source route option The majority of IP packets do not have source route Destination IP Address Enter the destination IP Address of the packet you wish to 0 0 0 0 filter This field is ignored if it is 0 0 0 0 IP Mask Enter the IP mask to apply to the Destination IP Addr 0 0 0 0 Port Enter the destination port of the packets that you wish to 0 65535 filter The range of this field is 0 to 65535 This field is ignored if it is O Port Comp Select the comparison to apply to the destination port in None Less Greater the packet against the value given in Destination Port 8 Equal Not Equal Source IP Address Enter the source IP Address of the packet you wish to 0 0 0 0 filter This field is ignored if it is 0 0 0 0 IP Mask Enter the IP mask to apply to the Source IP Addr 0 0 0 0 Port Enter the source port of the packets that you wish to filter 0 65535 The range of this field is 0 to 65535 This field is ignored if it is 0 Port Comp Select the comparison to apply to the source port in the None Less Greater packet against the value given in Source Port 8 Equal Not Equal TCP Estab This field is applicable only when the IP Protocol field is 6 Yes No TCP If Yes the rule matches packets that want to establish a TCP connection SYN 1 and ACK 0 if No it is ignored More If Yes a matching packet is passed to the next filter rule Yes No before an action is taken if No the packet is dispose
58. here so that port 23 only the packet will be dropped if its destination is the telnet port Select Forward here so that the packet will be forwarded if its destination is not the telnet port Figure 7 13 Example Filter Menu 21 1 1 1 When you press ENTER to confirm you will see the following screen Note that there is only one filter rule in this set 7 14 Filters ZyWALL 10 Internet Security Gateway Menu 21 1 3 Filter Rules Summary Filter Rules ZA 0 0 0 0 DA 0 0 0 0 Enter Filter Buke Number 1 6 to Configure 1 This shows you that you have M N means an action can be taken configured and activated A immediately The action is to drop the Y a TCP IP filter rule Type packet m D if the action is matched and IP Pr 6 for destination to forward the packet immediately n 2 F if telnet ports DP 23 the action is not matched no matter whether there are more rules to be checked there aren t in this example Figure 7 14 Example Filter Rules Summary Menu 21 1 3 After you ve created the filter set you must apply it Step 1 Enter 11 from the main menu to go to menu 11 Step 2 Go to the Edit Filter Sets field press the SPACE BAR to select Yes and press ENTER Step 3 This brings you to menu 11 5 Apply a filter set our example filter set 3 as shown in Figure 7 17 Step 4 Press ENTER to confirm after you enter the set numbers and to leave menu 11 5 7 4 Filte
59. indicates the IP port number that defines the service Note that there may be more than one IP protocol type For example look at the default configuration labeled DNS UDP TCP 53 means UDP port 53 and TCP port 53 Up to 128 entries are supported Custom services may also be configured using the Custom Ports function discussed later Creating Custom Rules 16 7 ZyWALL 10 Internet Security Gateway Table 16 2 Predefined Services SERVICE DESCRIPTION BGP TCP 179 BOOTP CLIENT UDP 68 BOOTP SERVER UDP 67 CU SEEME TCP UDP 7648 24032 DNS UDP TCP 53 FINGER TCP 79 FTP TCP 20 21 HTTP TCP 80 HTTPS ICMP ICQ UDP 4000 IRC TCP UDP 6667 NEWS TCP 144 NFS UDP 2049 NNTP TCP 119 RCMD TCP 512 REAL AUDIO TCP 7070 REXEC TCP 514 RLOGIN TCP 513 RTELNET TCP 107 RTSP TCP UDP 554 Border Gateway Protocol DHCP Client DHCP Server A popular videoconferencing solution from White Pines Software Domain Name Server a service that matches web names e g www zyxel com to IP numbers Finger is a UNIX or Internet related command that can be used to find out if a user is logged on File Transfer Program a program to enable fast transfer of files including large files that may not be possible by e mail Hyper Text Transfer Protocol a client server protocol for the world wide web HTTPS is a secured http session often used in e commerce ICMP service allows norma
60. may crash hang or reboot 1 b Teardrop attack exploits weaknesses in the reassembly of IP packet fragments As data is transmitted through a network IP packets are often broken up into smaller chunks Each fragment looks like the original IP packet except that it contains an offset field that says for instance This fragment is carrying bytes 200 through 400 of the original non fragmented IP packet The Teardrop program creates a series of IP fragments with overlapping offset fields When these fragments are reassembled at the destination some systems will crash hang or reboot Weaknesses in the TCP IP specification leave it open to SYN Flood and LAND attacks These attacks are executed during the handshake that initiates a communication session between two applications 13 4 What Is a Firewall ZyWALL 10 Internet Security Gateway Client Server SYN PET N Ack Figure 13 2 Three Way Handshake Under normal circumstances the application that initiates a session sends a SYN synchronize packet to the receiving server The receiver sends back an ACK acknowledgment packet and its own SYN and then the initiator responds with an ACK acknowledgment After this handshake connection is established 2 a SYN Attack floods a targeted system with a series of SYN packets Each packet causes the targeted system to issue a SYN ACK response While the targeted system waits for the ACK that follow
61. on how to transfer the configuration file to your ZyWALL 2 7 General Setup Menu 1 General Setup contains administrative and system related information System Name is for identification purposes ZyXEL recommends you enter your computer s Computer name Click Start gt Settings Control Panel gt Network click the Identification tab and note the entry for the Computer name field Hardware Installation amp Initial Setup 2 9 ZyWALL 10 Internet Security Gateway The Domain Name entry is what is propagated to the DHCP clients on the LAN If you leave this field blank the domain name obtained by DHCP from the ISP is used While you must enter the host name System Name on each individual machine the domain name can be assigned from the ZyWALL via DHCP 2 7 1 Dynamic DNS Dynamic DNS allows you to update your current dynamic IP address with one or many dynamic DNS services so that anyone can contact you in NetMeeting CU SeeMe etc You can also access your FTP server or Web site on your own computer using a DNS like address e g myhost dhs org where myhost is a name of your choice which will never change instead of using an IP address that changes each time you reconnect Your friends or relatives will always be able to call you even if they don t know your IP address First of all you need to have registered a dynamic DNS account with www dyndns org This is for people with a dynamic IP from their ISP or DHCP
62. part of a URL appearing after a colon right after the domain name Every service on an Internet server listens on a particular port number on that server Most services have standard port numbers e g Web servers normally listen on port 80 Plain Old Telephone Service is the analog telephone service that runs over copper twisted pair wires and is based on the original Bell telephone system Twisted pair wires connect homes and businesses to a neighborhood central office This is called the local loop The central office is connected to other central offices and long distance facilities Point to Point Protocol PPP encapsulates and transmits IP Internet Protocol datagrams over serial point to point links PPP works with other protocols such as IPX Internetwork Packet Exchange The protocol is defined in IETF Internet Engineering Task Force RFC 1661 through 1663 PPP provides router to router host to router and host to host connections Point to Point Tunneling Protocol Actively capturing packet information from a network Most computers only collect packets specifically addressed to them Promiscuous packet capture acquires all network traffic it can regardless of where the packets are addressed Protocol A language for communicating on a network Protocols are sets of standards or rules used to define format and transmit data across a network There are many different protocols used on networks For example most web pages
63. press ENTER to return to menu 11 Press ENTER at the message Press ENTER to Confirm to save your configuration or press ESC at any time to cancel 4 2 2 Editing TCP IP Options with PPPoE Encapsulation Make sure Encapsulation is set to PPPoE in menu 11 1 Move the cursor to the Edit IP field in Menu 11 1 and press the SSPACE BAR to select Yes Press ENTER to open Menu 11 3 Network Layer Options The menu and fields are the same as described for PPTP encapsulation above 4 3 Remote Node Filter Move the cursor to the field Edit Filter Sets in menu 11 1 then press the SPACE BAR to set the value to YES Press ENTER to open Menu 11 5 Remote Node Filter Use menu 11 5 to specify the filter set s to apply to the incoming and outgoing traffic between this remote node and the ZyW ALL to prevent certain packets from triggering calls You can specify up to 4 filter sets separated by commas e g 1 5 9 12 in each filter field Note that spaces are accepted in this field For more information on defining the filters please refer to the Filters chapter For PPPoE or PPTP encapsulation you can also specify remote node call filter sets Remote Node Setup 4 9 ZyWALL 10 Internet Security Gateway Menu 11 5 Remote Node Filter Input Filter Sets protocol filters 3 device filters Output Filter Sets protocol filters 1 device filters Enter here to CONFIRM or ESC to CANCEL Figure 4 6 Menu 11 5
64. rrt REESE PER EFE D ERE E 4 3 4 1 3 PPTP Encapsulation EE 4 4 4 2 Editing TCP IP Options with Ethernet Encapsulation eee 4 6 4 2 1 Editing TCP IP Options with PPTP Encapsulation seen 4 7 4 2 2 Editing TCP IP Options with PPPoE Encapsulation eee 4 0 ka Remote Node FIlter aeos ete RE OE ep cover EE EE 4 9 Chapter 5 IP Static Route Setup sees see see Se eene Bee testen setenta tosta setas etas ease ease ease tne Bee Ee EE Ge Ge a 5 1 X Table of Contents ZyWALL 10 Internet Security Gateway 5 1 IP Static Route Setup iter et eri ERREUR DH EE ee herbe reta es 5 2 Chapter 6 Network Address Translation NAT sees sees sesse sees sees se sees seen eren eren eene netos tons tone EG EG Bee ee 6 1 6 1 Introd ction OR EE oo e Ed c eie ede tere EN 6 1 6 1 1 NAT Definitions ihe ee SOR be Eee ri ee detect 6 1 6 1 2 What NAT Does eoe e ORI eg anne attt ess 6 1 6 1 3 HOW NAT WOrkS EER RE RA OR ER EE 6 2 6 1 4 NAT Mapping Types ete eet ede per breue ER AE 6 3 6 1 5 SUA Single User Account Versus NAT nennen ener enne 6 4 6 1 6 NAT Application e EE edel 6 4 6 2 SMT Menus tee EER Sais OE e RP OO RUE O ER 6 5 6 2 1 Applying NAT in the SMT Menu 6 5 6 2 2 Configuring NAT EER EE babe chek una dub EE 6 7 6 2 3 Address Mapping Sets and NAT Server SetS use se se se es ee ee Ge ee ee ee ee Ge Ge ee 6 7 Dh NAT Server Setsve ied Su DE SR
65. s to save your settings back to the ZyWALL ZyXEL O Rule 1 Allow DHCP negotiation between the ISP and the amo ZyWALL 10 Firewall Rule 2 Allow a syslog connection from the WAN CONFIGURATION ACL Default Set LOCAL NETWORK INTERNET CUSTOM PORTS Mi 1 Configured Any Any E BOOTP CLIENT UDP 68 Forward None LOGOUT c Configured 10 0 0 10 10 0 0 15 v Any Y Syslog UDP 514 zl Forward None CB Easy s EI s C Empty sl 2 EI cE Emy z EI LR CENE El IR IR CA Emy 7 E E C B ren x IR IR C MEmpy zl E E CME sl E KE Apply Edit Delete Click Apply to save your e 4 settings back to the ZyWALL Status Ready Figure 19 13 Example 3 Rule Summary 19 14 Example Firewall Rules ZyWALL 10 Internet Security Gateway Chapter 20 Content Filtering This chapter provides a brief overview of content filtering using the Web Configurator For more detailed information consult the HTML help section of the included disk Internet content filtering allows schools and businesses to create and enforce Internet access policies tailored to their needs Content filtering gives the ability to block certain web features or specific URLs and should not be confused with packet filtering via SMT menu 21 1 To access these functions Click on Main Menu then Content Filter to expand the content filter menus 20 1 Categories 20 1 1 Restrict Web Features The ZyW ALL
66. s unique hardware number On an Ethernet LAN it s the Glossary of Terms ZyWALL 10 Internet Security Gateway Name Resolution NAT NDIS NetBIOS Network NIC Node PAC Packet Filter PAP Password Cracker Password encryption Password Shadowing Penetration Phreaking Ping Attack Pirate same as your Ethernet address The MAC layer frames data for transmission over the network then passes the frame to the physical layer interface where it is transmitted as a stream of bits The allocation of an IP address to a host name See DNS Network Address Translation is the translation of an Internet Protocol address used within one network to a different IP address known within another network see also SUA Network Driver Interface Specification is a Windows specification for how communication protocol programs such as TCP IP and network device drivers should communicate with each other Network Basic Input Output System NetBIOS is an extension of the DOS BIOS that enables a PC to connect to and communicate with a LAN Any time you connect 2 or more computers together so that they can share resources you have a computer network Connect 2 or more networks together and you have an internet Network Interface Card A board that provides network communication capabilities to and from a computer system Also called an adapter Any single computer connected to a network The box that calls answers the ph
67. security and how to minimize risk Produce lists like this one 2 DSLorcable modem connections are always on connections and are particularly vulnerable because they provide more opportunities for hackers to crack your system Turn your computer off when not in use 3 Never give out a password or any sensitive information to an unsolicited telephone call or e mail 4 Never e mail sensitive information such as passwords credit card information etc without encrypting the information first 5 Never submit sensitive information via a web page unless the web site uses secure connections You can identify a secure connection by looking for a small key icon on the bottom of your browser Internet Explorer 3 02 or better or Netscape 3 0 or better If a web site uses a secure connection it is safe to submit information Secure web transactions are quite difficult to crack 6 Never reveal your IP address or other system networking information to people outside your company 7 Be careful of files e mailed to you from strangers One common way of getting BackOrifice on a system is to include it as a Trojan horse with other files 13 10 What Is a Firewall ZyWALL 10 Internet Security Gateway 8 Change your passwords regularly Also use passwords that are not easy to figure out The most difficult passwords to crack are those with upper and lower case letters numbers and a symbol such as or 9 Upgrade your software regul
68. this is the case enter the IP address assigned to the WAN port of your ZyWALL Note that this is the address assigned to your local ZyWALL not the remote router Network Use the SPACE BAR to select either Full Feature None or SUA SUA Only Address Only See the NAT chapter for a full discussion on this feature Translation Metric The metric represents the cost of transmission for routing purposes 1to 15 4 8 Remote Node Setup ZyWALL 10 Internet Security Gateway FIELD DESCRIPTION EXAMPLE number Private This parameter determines if the ZyWALL will include the route to this Yes remote node in its RIP broadcasts If set to Yes this route is kept private and not included in RIP broadcast If No the route to this remote node will be propagated to other hosts through RIP broadcasts RIP Press the SPACE BAR to select the RIP direction from Both None None In Only Out Only and None default Version Press the SPACE BAR to select the RIP version from RIP 1 RIP RIP 1 2B RIP 2M Multicast IGMP Internet Group Multicast Protocol is a session layer protocol None used to establish membership in a Multicast group The ZyWALL supports both IGMP version 1 IGMP v1 and version 2 IGMP v2 Press the SPACE BAR to enable IP Multicasting or select None to disable it See the previous Part for more information on this feature Once you have completed filling in the Network Layer Options Menu
69. this menu 11 Remote Node Setup Use this menu to configure detailed remote node settings your ISP is also a remote node as well as apply WAN filters 12 Static Routing Setup Configure static routes for bridging and IP in this menu 15 NAT Setup Use this menu to configure Network Address Translation 21 Filter and Firewall Setup Configure filters activate deactivate the firewall and view the firewall log 22 SNMP Configuration Use this menu to configure SNMP related parameters 23 System Password Change your password in this menu recommended 24 System Maintenance From displaying system status to uploading firmware this menu provides comprehensive system maintenance 26 Schedule Setup Use this menu to schedule outgoing calls 99 Exit Use this menu to exit necessary for remote configuration Hardware Installation amp Initial Setup 2 7 ZyWALL 10 Internet Security Gateway 2 5 3 SMT Menus at a Glance M Menu henu 1 Menu 2 Menu 3 Menu 4 General Selup WAN Setup Ether net Setup Internet Access Set up Menu3 1 Menu 32 LAN Port Filter Setup FC P P and DHCP Set up henu 14 1 Rerrm Node Setup Menu tt 4 Femote Node Profle Menu 12 Menu 15 IP Static Route Setup NAT Setup Menu 15 1 Ad dess Wapping Sets Menu 15 14 Address Wapping Rules Menu 15 1 1 3 Address Mapping Rule Menu 12 1 Editi P Static Route Menu 113 Femote Node Network Menu i amp Layer Opt
70. to 192 168 1 254 zero and 255 are reserved In other words the first 3 numbers specify the network number while the last number identifies an individual workstation on that network Once you have decided on the network number pick an IP address that is easy to remember e g 192 168 1 1 for your ZyW ALL but make sure that no other device on your network is using that IP The subnet mask specifies the network number portion of an IP address Your ZyW ALL will compute the subnet mask automatically based on the IP address that you entered You don t need to change the subnet mask computed by the ZyW ALL unless you are instructed to do otherwise 3 1 4 Private IP Addresses Every machine on the Internet must have a unique IP address If your networks are isolated from the Internet e g only between your two branch offices you can assign any IP addresses to the hosts without problems However the Internet Assigned Numbers Authority IANA has reserved the following three blocks of IP addresses specifically for private networks 10 0 0 0 10 255 255 255 172 16 0 0 172 31 255 255 192 168 0 0 192 168 255 255 You can obtain your IP address from the IANA from an ISP or have it assigned by a private network If you belong to a small organization and your Internet access is through an ISP the ISP can provide you with the 3 2 Internet Access ZyWALL 10 Internet Security Gateway Internet addresses for your local networks On
71. to 8 Default Mask Enter the mask in Hexadecimal notation to apply to the data portion before comparison Value Enter the value in Hexadecimal notation to compare with the data portion More If Yes a matching packet is passed to the next filter rule before an action Yes No is taken else the packet is disposed of according to the action fields If More is Yes then Action Matched and Action Not Matched will be No Log Select the logging option from the following None No packets will be logged None Action Matched Only packets that match the rule parameters will be Action logged Matched Action Not Matched Only packets that do not match the rule Action Not parameters will be logged Matched Both All packets will be logged Both Action Select the action for a packet matching the rule Check Next Matched Rule Forward Drop Action Not Select the action for a packet not matching the rule Check Next Matched Rule Forward Drop Once you have completed filling in Menu 21 4 1 1 Generic Filter Rule press ENTER at the message Press ENTER to Confirm to save your configuration or press ESC to cancel This data will now be displayed on Menu 21 1 1 Filter Rules Summary 7 12 Filters ZyWALL 10 Internet Security Gateway 7 3 Example Filter Let s look at an example to block outside users from telnetting into the ZyW ALL Please see our included disk for more example filters User trying to te
72. to act as a secure gateway for all data passing between the Internet and the LAN The ZyWALL has one Ethernet WAN port and one Ethernet LAN port which are used to physically separate the network into two areas Q The WAN Wide Area Network port attaches to the broadband modem cable or ADSL connecting to the Internet Q The LAN Local Area Network port attaches to a network of computers which need security from the outside world These computers will have access to Internet services such as e mail FTP and the World Wide Web However inbound access will not be allowed unless the remote host is authorized to use a specific service 13 2 What Is a Firewall ZyWALL 10 Internet Security Gateway 5 Deniay l WAN EtHernet ZyWALL LAN WAN Figure 13 1 ZyWALL Firewall Application 13 3 Denial of Service Denials of Service DoS attacks are aimed at devices and networks with a connection to the Internet Their goal is not to steal information but to disable a device or network so users no longer have access to network resources The ZyWALL is pre configured to automatically detect and thwart all known DoS attacks 13 3 1 Basics Computers share information over the Internet using a common language called TCP IP TCP IP in turn is a set of application protocols that perform specific functions These protocols such as HTTP Web FTP File Transfer Protocol POP3 E mail etc are identified by a
73. your configuration or press ESC to cancel For all Local and Global IPs the End I P address must begin after the IP Start address i e you cannot have an End IP address beginning before the Start I P address 6 3 NAT Server Sets A NAT server set is a list of inside servers behind NAT on the LAN that you can make visible to the outside world Menu 15 2 NAT Server Sets is used to configure these servers Entry 12 set to port 1026 is displayed in Figure 6 11 and is non editable 6 12 NAT ZyWALL 10 Internet Security Gateway 6 3 1 Multiple Servers behind NAT If you wish you can make inside servers for different services e g web or FTP visible to the outside users even though NAT makes your whole inside network appear as a single machine to the outside world A service is identified by the port number e g web service is on port 80 and FTP on port 21 As an example see the following figure if you have a web server at 192 168 1 36 and an FTP server at 192 168 1 33 then you need to specify for port 80 web the server at IP address 192 168 1 36 and for port 21 FTP another at IP address 192 168 1 33 Please note that a server can support more than one service e g a server can provide both FTP and DNS service while another provides only web service In addition to the servers for specified services SUA supports a default server A service request that does not have a server explicitly designated fo
74. 15 NAT Setup ses see ss ese ee ES ee ee Bee Be ee See Se bee see Bee Be ee nnt tren Be ee Bee Se ener 6 7 Figure 6 6 Menu 15 1 Address Mapping Sets eie see se ese se GR RA GR Ge Ge ee ee ee ee Se Ge Re GR Re RA ee ee 6 8 Figure 6 7 Menu 15 1 2535 SUA Address Mapping Rules se se se ee ee Ge ee ee Ge Ge Ge ee Ge ee 6 8 Figure 6 8 Menu 15 1 1 First Sef ER EE ER EE EE EE EE OE 6 10 Figure 6 9 Menu 15 1 1 1 Editing an Individual Rule in a Set 6 11 Figure 6 10 Multiple Servers Behind NAT esse ese se ee se ee ee Ge Se ene Ge ee Ge ee ee ee ee ee ee 6 13 Figure 6 11 Menu 15 2 NAT Server Setup 6 14 Figure 6 12 NAT o EURO AE OR 6 15 Figure 6 13 Menu 4 Internet Access amp NAT Example esse esse ese se see se ee ee Gee Gee nennen 6 15 Figure 6 14 NAT EE EE OE dukes cute EE EE OE N EE EE EG Ie 6 16 Figure 6 15 Menu 15 2 Specifying an Inside Servet sess nen 6 16 Figiire 6 16 MEE EURO EE EE EE OE EEr 6 17 Fisure 6 17 Exanple 3 Menu H 3 teste SE Den ORO leise dde ote S eg end 6 18 Figure 6 18 Example 3 Menu 151ll eene Re ee Eoaea trennen 6 18 Figure 6 19 Example 3 Final Menu 15 1 1 sees see se ee ee ee Ge Ge GR GR GRA GRA Ge Gee Ge ee nennen 6 19 Figure 6 20 Example 3 Menu 15 2 ey EE De in ee ese Er edere em estere 6 19 xviii List of Figures ZyWALL 10 Internet Security Gateway Fig re 6 2 NAT Example4 oen KO reete e pO TRO AE e I rr RU 6 20 Figure 6 22 Example 4 Menu 15 1 1 1 Addr
75. 15 10 Customized Gervices sees ee ee ee 17 2 Attack Types 14 3 IRCAS OM EE 14 5 D Autbentteaton ee nnen ee eenen 4 3 4 4 DDNS B Configuration sooren Re ees 2 11 Default Permit Log ees se ee Ee 16 6 GE EE EE ER eee N Denial of Service 13 2 18 8 14 1 15 8 GE iicet tete red 10 2 Denial of Services Big Picture Thresholds sr EE EE Ge OG Ge EER Ge sg es 15 10 Filtering Firewall and NAT 14 5 DestAdd iL erecto create de Ged 19 10 Blocking Time 15 8 15 11 Destination Address 16 2 16 11 Boot Commande 11 8 DHCP Dynamic Host Configuration Protocol Broadband Access Security Gateway weedy XXvil Il oem HMM Hee eee eee 1 2 3 1 Brute Force Hacking N DHCP Ethernet Setup 3 4 Budget Management 11 2 11 3 DHCP Negotaton ee ee ee ee 19 12 RE Lee 9 10 C DING mz EE OR N 3 1 Domain Name 3 1 6 14 9 3 9 4 P Cable Modem s 2 2 2 3 13 2 DoS Call Control 11 2 EE 13 3 Call History PM nc ee en N PLA 1 1 3 11 4 Types Geet I eS ad aa M MS 13 4 Call Trigerring Packet 9 10 DoS Denial of Service 1 1 CDR sue uan ule e D 9 7 Dynamic DND 2 10 2 11 CBAB re cur EE UP e ies 4 4 DYNDNS Videon 2 10 CLI Commande G Command Interpreter Mode 11 1 E Configuring A POP Custom Port 19 8 e EE 2 2 9 3 9 5 E EG 2 Internet Rule Summary 19 12 Content Filtering esses 20 1 EG 2 Loca
76. 2 Small Office With Mail FTP and Web Servers A small office has i A mail server with an IP of 192 168 10 2 ii Two FTP servers You want FTP server One IP of 192 168 10 3 to be accessible from the Internet but FTP server Two 192 168 10 4 may only be accessed by internal users i e from the local network iii HTTP proxy server at 192 168 10 5 You want i To send alerts when there is an attack ii To only allow access to the Internet from the HTTP proxy server and your mail server iii To only allow FTP server One to be accessible from the Internet 19 6 Example Firewall Rules ZyWALL 10 Internet Security Gateway Step 1 First you want to send alerts when there is an attack Go to the Attack Alert screen click Configuration then the Attack Alert tab shown next E Mail CONFIGURATION LOCAL NETWORK INTERNET Check this box to send alerts CUSTOM PORTS D LOGS when there is an attack LOGOUT Figure 19 6 Send Alerts When Attacked Step 2 Configure the E mail screen as shown in example 1 your mail server s IP is 192 168 10 2 Step 3 Now you want to restrict access to the Internet except for the HTTP proxy server and your mail server First you need to create a custom port for POP3 POP Post Office Protocol is an Internet mail server protocol that provides an incoming message storage system It works in conjunction with the SMTP Simple Mail Transfer Protocol which provides the message transport se
77. 4 4 allows you to choose among various types of diagnostic tests to evaluate your system as shown next 9 10 System Information amp Diagnosis ZyWALL 10 Internet Security Gateway Menu 24 4 System Maintenance Diagnostic TCP IP 1 Ping Host 2 WAN DHCP Release 3 WAN DHCP Renewal 4 Internet Setup Test System 11 Reboot System Enter Menu Selection Number Host IP Address N A Figure 9 10 Menu 24 4 System Maintenance Diagnostic Follow the procedure below to get to Menu 24 4 System Maintenance Diagnostic Step 1 From the main menu select option 24 to open Menu 24 System Maintenance Step 2 From this menu select option 4 Diagnostic This will open Menu 24 4 System Maintenance Diagnostic 9 4 1 WAN DHCP DHCP functionality can be enabled on the LAN or WAN as shown in Figure 9 11 LAN DHCP has already been discussed The ZyWALL can act either as a WAN DHCP client IP Address Assignment field in menu 4 or menu 11 3 is Dynamic and the Encapsulation field in menu 4 or menu 11 is Ethernet or None i e you have a static IP The WAN Release and Renewal fields in menu 24 4 conveniently allow you to release and or renew the assigned WAN IP address subnet mask and default gateway in a fashion similar to winipcfg System Information amp Diagnosis 9 11 ZyWALL 10 Internet Security Gateway DHCP Figure 9 11 WAN amp LAN DHCP The following table describes the diagnostic te
78. 4 or 11 3 as displayed next The next figure shows you how to apply NAT for Internet access in menu 4 Enter 4 from the main menu to go to Menu 4 Internet Access Setup NAT 6 5 ZyWALL 10 Internet Security Gateway Menu 4 Internet Access Setup ISP s Name ChangeMe Encapsulation Ethernet Service Type Standard My Login N A My Password N A Login Server IP N A IP Address Assignment Dynamic IP Address N A IP Subnet Mask N A Gateway IP Address N A N twork Address Translation SUA Only Press ENTER to Confirm or ESC to Cancel Figure 6 3 Menu 4 Applying NAT for Internet Access The following figure shows how you apply NAT to the remote node in menu 11 1 Step 1 Enter 11 from the main menu Step 2 Move the cursor to the Edit IP field press the SPACE BAR to select Yes and then press ENTER to bring up Menu 11 3 Remote Node Network Layer Options Menu 11 3 Remote Node Network Layer Options IP Address Assignment Dynamic IP Address N A IP Subnet Mask N A Gateway IP Addr N A Network Address Translation Full Feature fetrcic N A Private N A RIP Direction None Version N A Multicast None Figure 6 4 Menu 11 3 Applying NAT to the Remote Node The following table describes the options for Network Address Translation NAT ZyWALL 10 Internet Security Gateway Table 6 3 Applying NAT in Menus 4 amp 11 3 FIELD OPTIONS DESCRIPTION Network Full Feature When you
79. A is the destination address on the LAN and the IGA is the destination address on the WAN NAT maps private local IP addresses to globally unique ones required for communication with hosts on other networks It replaces the original IP source address and TCP or UDP source port numbers for Many to One and Many to Many Overload NAT mapping in each packet and then forwards it to the Internet The Zy WALL keeps track of the original addresses and port numbers so incoming reply packets can have their original values restored The following figure illustrates this NAT Table Inside Local Inside Global IP Address IP Address LAN 192 168 1 10 IGA 1 WAN 192 168 1 11 IGA 2 192 168 1 13 192 168 1 12 IGA 3 192 168 1 13 IGA 4 Inside Global Addresses IGA Inside Local Addresses ILA 192 168 1 11 192 168 1 10 Figure 6 1 How NAT Works 6 2 NAT ZyWALL 10 Internet Security Gateway 6 1 4 NAT Mapping Types NAT supports five types of IP port mapping They are 1 One to One In One to One mode the ZyWALL maps one local IP address to one global IP address 2 Manyto One In Many to One mode the ZyW ALL maps multiple local IP addresses to one global IP address This is equivalent to SUA i e PAT port address translation ZyXEL s Single User Account feature that previous ZyXEL routers supported the SUA Only option in today s routers 3 Many to Many Overload In Many to Many Overload mode the ZyW ALL maps the mul
80. AMPLE FTP service active Press SPACE BAR to select No and press ENTER to disable all FTP activity both LAN and WAN No Telnet service active Press SPACE BAR to select No and press ENTER to disable all Telnet activity both LAN and WAN No Secured Client IP The default value for Secured Client IP is 0 0 0 0 which means you don t care which host is trying to telnet If you enter an IP in this field the ZyWALL will check if the client IP matches the value here when a Telnet session is up If it does not match the ZyWALL will disconnect the session immediately If the Telnet service active field is disabled No then this field is not applicable N A 0 0 0 0 System Maintenance amp Information ZyWALL 10 Internet Security Gateway 11 5 Boot Commands The BootModule AT commands execute from within the router s bootup software when debug mode is selected before the main router firmware ZyNOS is started When you start up your ZyW ALL you are given a choice to go into debug mode by pressing a key at the prompt shown in the following screen In debug mode you have access to a series of boot module commands for example ATUR for uploading firmware and AT LC for uploading the configuration file These are already discussed in the Transferring Files chapter Bootbase Version V2 02 10 11 2000 13 58 03 RAM Size 8192 Kbytes DRAM Post Testing 8192K OK FLASH Intel 16M
81. AMPLE IP Alias Choose Yes to configure the LAN network for the ZyWALL Yes IP Address Enter the IP address of your ZyWALL in dotted decimal notation 192 168 2 1 IP Subnet Mask Your ZyWALL will automatically calculate the subnet mask based on 255 255 255 0 the IP address that you assign Unless you are implementing subnetting use the subnet mask computed by the ZyWALL RIP Direction Press the SPACE BAR to select the RIP direction from Both In None Only Out Only or None Version Press the SPACE BAR to select the RIP version from RIP 1 RIP RIP 1 2B or RIP 2M Incoming Enter the filter set s you wish to apply to the incoming traffic 1 Protocol Filters between this node and the ZyWALL Outgoing Enter the filter set s you wish to apply to the outgoing traffic between 2 Protocol Filters this node and the ZyWALL When you have completed this menu press ENTER at the prompt Press ENTER to Confirm to save your configuration or press ESC at any time to cancel 3 3 Internet Access Setup You will see three different menu 4 screens depending on whether you chose Ethernet PPTP or PPPoE Encapsulation 3 3 1 Ethernet Encapsulation You must choose the Ethernet option when the WAN port is used as a regular Ethernet The PPPoE choice is for a dial up connection using PPPOE If you choose Ethernet in menu 4 you will see the next screen 3 8 Internet Access ZyWALL 10 Internet Security Gateway Menu 4 Internet
82. AT 6 9 ZyWALL 10 Internet Security Gateway Menu 15 1 1 Address Mapping Rules Set Name NAT SET Idx Local Start IP Local End IP Global Start IP Global End IP 2 3 4 S 6 K 8 95 0 m Action Edit Select Rule Press ENTER to Confirm or ESC to Cancel Figure 6 8 Menu 15 1 1 First Set The Type Local and Global Start End IPs are configured in menu 15 1 1 1 described later and the values are displayed here Ordering Your Rules Ordering your rules is important because the ZyWALL applies the rules in the order that you specify When a rule matches the current packet the ZyW ALL takes the corresponding action and the remaining rules are ignored If there are any empty rules before your new configured rule your configured rule will be pushed up by that number of empty rules For example if you have already configured rules 1 to 6 in your current set and now you configure rule number 9 In the set summary screen the new rule will be rule 7 not 9 Now if you delete rule 4 rules 5 to 7 will be pushed up by 1 rule so as old rule 5 becomes rule 4 old rule 6 becomes rule 5 and old rule 7 becomes rule 6 The description of the other fields is as described above The Type Local and Global Start End IPs are configured in menu 15 1 1 1 described later and the values are displayed here 6 10 NAT ZyWALL 10 Internet Security Gateway Table 6 5 Fields in Menu 15 1 1 FIELD DESCRIPTION EXAMPLE Se
83. Add from the screen above To edit an existing source or destination address select it from the box and click SrcEdit or DestEdit from the screen above Either action displays the following screen RULE IP CONFIG Local Network to Internet CONFIGURATION Single Address LOCAL NETWORK 192 168 10 2 LOGOUT Status Ready Figure 16 5 Adding Editing Source and Destination Addresses 16 12 Creating Custom Rules ZyWALL 10 Internet Security Gateway Table 16 4 Adding Editing Source and Destination Addresses FIELD DESCRIPTION OPTIONS Address Type Do you want your rule to apply to packets with a particular Single Address single IP address a range of IP addresses e g 192 168 1 10 R Add to 192 169 1 50 a subnet or any IP address Select an option ange ress from the drop down list box Subnet Address Any Address Start IP Address Enter the single IP address or the starting IP address in a range here End IP Address Enter the ending IP address in a range here Subnet Mask Enter the Subnet Mask here if applicable When you have finished click Apply to save your customized settings and exit this screen Cancel to exit this screen without saving or Help for online HTML help on fields in this screen Creating Custom Rules 16 13 ZyWALL 10 Internet Security Gateway 16 6 Timeout The fields in the Timeout screens are the same for Local and Internet networks so the discussio
84. CP IP software and are not directly apparent to the application user Glossary of Terms ZyWALL 10 Internet Security Gateway Integrity internet Internet Internet Worm Intranet Intruder IP IPCP PPP IPX IRC ISP LAN Linux Logic Bomb MAC Proof that the data is the same as originally intended Unauthorized software or people have not altered the original information Lower case i Any time you connect 2 or more networks together you have an internet Upper case The vast collection of inter connected networks that all use the TCP IP protocols and that evolved from the ARPANET of the late 60 s and early 70 s The Internet now July 1995 connects roughly 60 000 independent networks into a vast global internet See Worm A private network inside a company or organization that uses the same kinds of software that you would find on the public Internet but that is only for internal use Person or software interested in breaking computer security to access modify or damage data Also see Cracker Internet Protocol he IP currently IP version 4 or IPv4 is the underlying protocol for routing packets on the Internet and other TCP IP based networks IP Control Protocol allows changes to IP parameters such as the IP address Internetwork Packet eXchange The native NetWare internetworking protocol is IPX Internetwork Packet Exchange Like IP Internet Protocol IPX is an internetworking pro
85. DESCRIPTION EXAMPLE Service Enter the name of your Dynamic DNS client www dyndns org Provider Active Press SPACE BAR to cycle between Yes or No Yes Host Enter the domain name assigned to your ZyWALL by your me dyndns org Dynamic DNS provider EMAIL Enter your e mail address mail mailserver User Enter your user name Password Enter the password assigned to you Enable Your ZyWALL supports DYNDNS Wildcard Press SPACE Yes Wildcard BAR to cycle between Yes or No This field is N A when you choose DDNS client as your service provider When you have completed this menu press ENTER at the prompt Press ENTER to Confirm to save your configuration or press ESC at any time to cancel The IP address will be updated when you reconfigure Menu 1 or perform DHCP client renewal If you have a private WAN IP address then you cannot use Dynamic DNS 2 8 WAN Setup This section describes how to configure the WAN using Menu 2 WAN Setup From the main menu enter 2 to open menu 2 ZyXEL recommends you configure this menu even if your ISP does not require MAC address authentication 2 12 Hardware Installation amp Initial Setup ZyWALL 10 Internet Security Gateway Menu 2 WAN Setup MAC Address Assigned By IP address attached on LAN IP Address 192 168 1 12 Press ENTER to Confirm or ESC to Cancel Press Space Bar to Toggle Figure 2 10 Menu 2 WAN Setup The MAC addres
86. Destination Addresses see 16 12 Figure 16 6 Timeout Screen ec ene eere ee e eere th be re e ripe OR beret 16 14 Figure 17 1 Custom Ports oe eot pine pou en Dip en p RU UP ptm 17 1 Figure 17 2 Creating Editing A Custom Port 17 3 Figure 18 1 Lop Screen EE 18 1 Figure 19 1 Activate The Firewall essent nee enne be ee ee ee Se Se tren trennen enne 19 2 List of Figures xxi ZyWALL 10 Internet Security Gateway Figure 19 2 Example 1 E mail Screen S eeeost ne eite tite ree eter eR p atero rat 19 3 Figure 19 3 Example 1 Configuring a Rule 19 4 Figure 19 4 Example 1 Destination Address for Traffic Originating from the Internet 19 5 Figure 19 5 Example 1 Rule Summary Screen 19 6 Figure 19 6 Send Alerts When Attacked sess nente nennen 19 7 Figure 19 7 Configuring A POP Custom Pont 19 8 Figure 19 8 Example 2 Local Network Rule 1 Confteuraton enn 19 9 Figure 19 9 Example 2 Local Network Rule Summare eese nennen 19 10 Figure 19 10 Example Internet to Local Network Rule Summary eee 19 11 Figure 19 11 Custom Port for Syslog monente tpe mee Dee tire te tpe teer agen reto 19 12 Figure 19 12 Syslog Rule Configuration esee nennen tren teen Re RA ene 19 13 Figure 19 13 Example 3 Rule Summary esse ee ee Se Ge GR RA GRA Gee nennen rene ene 19 14 Figure 20 1 Categories Sereen eee nnne nennen nenne enne G
87. ESCRIPTION Use Time Server Enter the time service protocol that your time server sends when you turn on the when Bootup ZyWALL Not all time servers support all protocols so you may have to check with your ISP network administrator or use trial and error to find a protocol that works The main differences between them are the format Daytime RFC 867 format is day month year time zone of the server Time RFC 868 format displays a 4 byte integer giving the total number of seconds since 1970 1 1 at 0 0 0 NTP RFC 1305 is similar to Time RFC 868 None is the default value Enter the time manually Each time you turn on the ZyWALL the time and date will be reset to 2000 1 1 0 0 0 Time Server IP Enter the IP address of your time server Check with your ISP network Address administrator if you are unsure of this information Current Time This field displays an updated time only when you reenter this menu New Time Enter the new time in hour minute and second format Current Date This field displays an updated date only when you reenter this menu New Date Enter the new date in year month and day format Time Zone Press SPACE BAR to set the time difference between your time zone and Greenwich Mean Time GMT Daylight Saving If you use daylight savings time then choose Yes Start Date If using daylight savings time enter the month and day that it starts on End Date If using daylight savings ti
88. Filter Setup 2 Firewall Setup Lew i eus OQ Figure 14 2 Menu 21 Filter and Firewall Setup Enter option 2 in this menu to bring up the following screen Press the SPACE BAR to select Yes in the Active field to activate the firewall The firewall must be active to protect against Denial of Service DoS attacks Additional rules may be configured using the ZyWALL Web Configurator Introducing the ZyWALL Firewall 14 1 ZyWALL 10 Internet Security Gateway Menu 21 2 Firewall Setup The firewall protects against Denial of Service DOS attacks when it is active The default Policy sets 1 allow all sessions originating from the LAN to the WAN and 2 deny all sessions originating from the WAN to the LAN You may define additional Policy rules or modify existing ones but please exercise extreme caution in doing so Su N i Name ACL Default Set WAN to LAN Set Name ACL Default Set Please configure the Firewall function through ZyWALL Web Configurator Press ENTER to Confirm or ESC to Cancel Figure 14 3 Menu 21 2 Firewall Setup Configure the firewall rules using the ZyWALL Web Configurator or CLI commands 14 1 1 View Firewall Log Enter option 3 from menu 21 to view the firewall log Firewall logs may also be viewed from the ZyWALL Web Configurator or may be sent to a syslog server using SMT Menu 24 3 2 System Maintenance UNIX Syslog and setting the Firewall log field to Yes Attack types t
89. Internet Security Gateway the Network Address Translation field in menus 4 and 11 3 is specifically pre configured to handle this case 6 4 2 Example 2 Internet Access with an Inside Server Inside Local One Dynamic PC3 ET Ll Addresses ILA Inside Global Addresses IGA Assigned by ISP Inside Server IP 192 168 1 10 Figure 6 14 NAT Example 2 In this case you do exactly as above use the convenient pre configured SUA Only set and also go to menu 15 2 to specify the Inside Server behind the NAT as shown in the next figure Menu 15 2 NAT Server Setup Port IP Address U 0 0 0 0 0 0 0 0 0 1 026 Press ENTER to Confirm or ESC to Cancel Figure 6 15 Menu 15 2 Specifying an Inside Server 6 16 NAT ZyWALL 10 Internet Security Gateway 6 4 3 Example 3 General Case In this example there are 3 IGAs from our ISP There are many departments but two have their own FTP server All departments share the same router The example will reserve one IGA for each department with an FTP server and the other IGA is used by all Now you map the FTP servers to the first two IGAs and the other LAN traffic to the remaining IGA Map the third IGA to an inside web server and mail server Four rules need to be configured two bi directional and two one directional as follows Rule 1 Map the first IGA to the first inside FTP server for FTP traffic in both directions 1 1 mapping giving both local and glob
90. L In case of a power overload the supply circuits and supply wiring should not become hazardous The input rating of the ZyWALL is printed on the nameplate The AC adapter must plug in to the right supply voltage i e 120VAC adapter for North America and 230V AC adapter for Europe Make sure that the supplied AC voltage is correct and stable If the input AC voltage is over 1096 lower than the standard may cause the ZyW ALL to malfunction Installation in restricted access areas must comply with Articles 110 16 110 17 and 110 18 of the National Electrical Code ANSI NFPA 70 Do not allow anything to rest on the power cord of the AC adapter and do not locate the product where anyone can walk on the power cord Do not service the product by yourself Opening or removing covers can expose you to dangerous high voltage points or other risks Refer all servicing to qualified service personnel Generally when installed after the final configuration the product must comply with the applicable safety standards and regulatory requirements of the country in which it is installed If necessary consult the appropriate regulatory agencies and inspection authorities to ensure compliance A rare condition can create a voltage potential between the earth grounds of two or more buildings If products installed in separate building are interconnected the voltage potential can cause a hazardous condition Consult a qualified electrical consultant to d
91. LAN is not connected on On The ZyWALL is connected to a 100Mbps LAN Flashing The 100M LAN is sending receiving packets Hardware Installation amp Initial Setup 2 1 ZyWALL 10 Internet Security Gateway LEDS FUNCTION INDICATOR ACTIVE DESCRIPTION STATUS WAN WAN Green Off The WAN Link is not ready or has failed On The WAN Link is OK Flashing The 10M WAN link is sending receiving packets 2 2 ZyWALL 10 Rear Panel and Connections The following figure shows the rear panel of your ZyW ALL 10 and the related connections POWER UPLINK 10 1 00M 12VDC LAN CONSOLE Broadband modem Internet Router Internet Service Provider Computer cq Figure 2 2 ZyWALL 10 Rear Panel and Connections This section outlines how to connect your ZyW ALL 10 to the LAN and the WAN In the case of connecting a cable modem you must connect the coaxial cable from your cable service to the threaded coaxial cable connector on the back of the cable modem Connect an xDSL Modem to the xDSL Wall Jack Please also see Appendix C for important safety instructions on making connections to the ZyWALL Step 1 Connecting the Console Port For the initial configuration of your ZyW ALL you need to use terminal emulator software on a workstation and connect it to the ZyWALL through the console port Connect the 9 pin end of the console cable to the 2 2 Hardware Installation amp
92. Ls by using the keyword feature Packet Filtering The Packet Filtering mechanism blocks unwanted traffic from entering leaving your network PPPOE PPPOE facilitates the interaction of a host with an Internet modem to achieve access to high speed data networks via a familiar dial up networking user interface Getting to Know Your ZyWALL 1 1 ZyWALL 10 Internet Security Gateway PPTP Encapsulation Point to Point Tunneling Protocol PPTP is a network protocol that enables secure transfer of data from a remote client to a private server creating a Virtual Private Network VPN using a TCP IP based network PPTP supports on demand multi protocol and virtual private networking over public networks such as the Internet The ZyW ALL supports one PPTP server connection at any given time Dynamic DNS Support With Dynamic DNS support you can have a static hostname alias for a dynamic IP address allowing the host to be more easily accessible from various locations on the Internet You must register for this service with a Dynamic DNS client to use this service IP Multicast Traditionally IP packets are transmitted in two ways unicast or broadcast Multicast is a third way to deliver IP packets to a group of hosts IGMP Internet Group Management Protocol is the protocol used to support multicast groups The latest version is version 2 see RFC 2236 The ZyW ALL supports both versions 1 and 2 IP Alias IP Alias allows you to partiti
93. NMP ZyWALL 10 Internet Security Gateway Chapter 9 oystem Information amp Diagnosis This chapter covers SMT menus 24 1 to 24 4 This chapter covers the diagnostic tools that help you to maintain your ZyW ALL These tools include updates on system status port status log and trace capabilities and upgrades for the system software Select menu 24 in the main menu to open Menu 24 System Maintenance as shown below Menu 24 System Maintenance System Status System Information and Console Port Speed Log and Trace Diagnostic Backup Configuration Restore Configuration Upload Firmware Command Interpreter Mode Call Control Time and Date Setting Remote Management Setup oo vw Oo AO U d GA NP HO Enter Menu Selection Number Figure 9 1 Menu 24 System Maintenance 9 1 System Status The first selection System Status gives you information on the version of your system firmware and the status and statistics of the ports as shown in the next figure System Status is a tool that can be used to monitor your ZyWALL Specifically it gives you information on your system firmware version number of packets sent and number of packets received To get to the System Status Step 1 Enter number 24 to go to Menu 24 System Maintenance Step 2 In this menu enter 1 to open System Maintenance Status Step 3 There are three commands in Menu 24 1 System Maintenance Status Entering 1 drops the WAN connection
94. P Multicasting or select None default to disable it Edit IP Alias The ZyWALL supports three logical LAN interfaces via its single Yes physical Ethernet interface with the ZyWALL itself as the gateway for each LAN network Press the SPACE BAR to toggle No to Yes then press ENTER to bring you to menu 3 2 1 When you have completed this menu press ENTER at the prompt Press ENTER to Confirm to save your configuration or press ESC at any time to cancel 3 2 1 IP Alias Setup You must use menu 3 2 to configure the first network and move the cursor to the Edit IP Alias field and press SPACE BAR to choose Yes and press ENTER to configure the second and third network Pressing ENTER opens Menu 3 2 1 IP Alias Setup as shown next Menu 3 2 1 IP Alias Setup IP Alias 1 No IP Address N A IP Subnet Mask N A RIP Direction N A Version N A Incoming protocol filters N A Outgoing protocol filters N A IP Alias 2 No IP Address N A IP Subnet Mask N A RIP Direction N A Version N A Incoming protocol filters N A Outgoing protocol filters N A Enter here to CONFIRM or ESC to CANCEL Press Space Bar to Toggle Figure 3 5 Menu 3 2 1 IP Alias Setup Internet Access 3 7 ZyWALL 10 Internet Security Gateway Use the instructions in the following table to configure IP Alias parameters Table 3 3 IP Alias Setup Menu Fields FIELD DESCRIPTION EX
95. PU power of servers in your LAN network 4 Network bandwidth Introducing the ZyWALL Web Configurator 15 7 ZyWALL 10 Internet Security Gateway 5 Type of traffic for certain servers If your network is slower than average for any of these factors especially if you have servers that are slow or handle many tasks and are often busy then the default values should be reduced You should make any changes to the threshold values before you continue configuring firewall rules 15 4 2 Half Open Sessions An unusually high number of half open sessions either an absolute number or measured as the arrival rate could indicate that a Denial of Service attack is occurring For TCP half open means that the session has not reached the established state the TCP three way handshake has not yet been completed see Figure 13 2 For UDP half open means that the firewall has detected no return traffic The ZyW ALL measures both the total number of existing half open sessions and the rate of session establishment attempts Both TCP and UDP half open sessions are counted in the total number and rate measurements Measurements are made once a minute When the number of existing half open sessions rises above a threshold max incomplete high the ZyW ALL starts deleting half open sessions as required to accommodate new connection requests The ZyW ALL continues to delete half open requests as necessary until the number of existing half open sessio
96. Phone call PAC PPP frames PNS Diagram 4 PPTP Protocol Overview Microsoft includes PPTP as a part of the Windows OS In Microsoft s implementation the PC and hence the ZyWALL is the PNS that requests the PAC the ANT to place an outgoing call over AALS5 to an RFC 2364 server Control amp PPP connections Each PPTP session has distinct control connection and PPP data connection Call Connection The control connection runs over TCP Similar to L2TP a tunnel control connection is first established before call control messages can be exchanged Please note that a tunnel control connection supports multiple call sessions The following diagram depicts the message exchange of a successful call setup between a PC and an ANT Start Control Connection Request Start Control Connection Reply Outgoing Call Reply PPP Frames Outgoing Call Request PPP Frames Diagram 5 Example Message Exchange between PC and an ANT PPP Data Connection The PPP frames are tunneled between the PNS and PAC over GRE General Routing Encapsulation RFC 1701 1702 The individual calls within a tunnel are distinguished using the Call ID field in the GRE header ei PPTP ZyWALL 10 Internet Security Gateway Appendix C Hardware Specifications Power Specification VP AC 120V 60Hz O P DC 12V 1200 mA MTBF 100000 hrs Operation Temperature 0 C 40 C Ethernet Specification for 10Mbit Half Dupl
97. Pr 17 SA 0 0 0 0 DA 0 0 0 0 DP 138 NDN 6 Y IP Pr 17 SA 0 0 0 0 DA 0 0 0 0 DP 139 NDF Enter Filter Rule Number 1 6 to Configure Press ENTER to Confirm or ESC to Cancel Figure 7 6 NetBIOS WAN Filter Rules Summary Menu 21 1 2 Filter Rules Summary Filter Rules Pr 17 SA 0 0 0 0 DA 0 0 0 0 DP 53 Enter Filter Rule Number 1 6 to Configure Menu 21 3 Filter Rules Summary Filter Rules Enter Filter Rule Number 1 6 to Configure Figure 7 8 TEL_FTP_WEB_WAN Filter Rules Summary Filters 7 5 ZyWALL 10 Internet Security Gateway 7 2 1 Filter Rules Summary Menu This screen shows the summary of the existing rules in the filter set The following tables contain a brief description of the abbreviations used in the previous menus Table 7 1 Abbreviations Used in the Filter Rules Summary Menu FIELD DESCRIPTION The filter rule number 1 to 6 A Active Y means the rule is active N means the rule is inactive Type The type of filter rule GEN for Generic IP for TCP IP Filter Rules These parameters are displayed here M More Y means there are more rules to check which form a rule chain with the present rule An action cannot be taken until the rule chain is complete N means there are no more rules to check You can specify an action to be taken i e forward the packet drop the packet or check the next rule For the latter the next rule is independent of the ru
98. SAN Eie io RE OE OE EE RE RE antes 7 16 Table of Contents Xi ZyWALL 10 Internet Security Gateway 7 6 2 Remote Node Filtets o eire eter EE EE EE 7 17 Chapter 8 SNMP Configuration ceres eere eee eese eese nennen setas etas etas etas tte sete sone esee aetas EG ease ease See 8 1 8 About SNMP 25 0 GE SG coe RO OUR p Ole etn EUR E baee 8 1 82 Configuning SNMB ote Uam uarie deua dana 8 1 Chapter 9 System Information amp Diagnosis eee see eee Bee Bee Se Ee eene Se Ee setate Ge Ge toss taa etna seas 9 1 AAS EE RO AE EE EE EE RAO E EH RR EE 9 1 9 2 System Information and Console Port Speed see see ee ee Ge eee ee 9 3 9 2 1 System Information orco esc he eie eo RR eR reo t 9 4 9 2 2 Console Port Speed nne tae boue pe m He beth end 9 5 9 3 Log and Trace EE 9 5 9 3 1 Viewing Error Log SE OR OR OE EE EN ees 9 5 9 3 2 UNIEK Zeg e Re EE rtt Sieh oe etel tet qui EO sR int 9 6 9 3 3 Call Triggering Packet eene ertet rb o EET Feet Fete entis 9 10 QA DIAGNOSTIC EE 9 10 9 4 1 WAN DHCP neinu ae A E ed ee EEE 9 11 Chapter 10 Firmware and Configuration File Maintenance usse ese see ese ees se ese Se ee See Be EE Gee Ee Se Ee 10 1 10 1 Filename conventions SERS Re KS mente DRUSI ERE ERR t eS R GED RE ee Ee 10 1 10 1 1 ie AB iS EE metere EE EE EN 10 2 10 2 Backup ConfiguratiOn oe torte erae dii pri i i toe eter 10 2 10 2 1 Example Backup Configuration Using HyperTermina
99. To configure a PPTP client you must configure the My Login and Password fields for a PPP connection and the PPTP parameters for a PPTP connection After configuring My Login and Password for PPP connection press SPACE BAR in the Encapsulation field in Menu 4 Internet Access Setup to choose PPTP as your encapsulation option This brings up the following screen 3 10 Internet Access ZyWALL 10 Internet Security Gateway Menu 4 Internet Access Setup ISP s Name ChangeMe Encapsulation PPTP Service Type N A My Login username My Password Idle Timeout 100 IP Address Assignment Dynamic IP Address N A IP Subnet Mask N A Gateway IP Address N A Network Address Translation SUA Only Press ENTER to Confirm or ESC to Cancel Figure 3 7 Internet Access Setup PPTP The following table contains instructions about the new fields when you choose PPTP in the Encapsulation field in Menu 4 Table 3 5 New Fields in Menu 4 PPTP screen FIELD DESCRIPTION EXAMPLE Encapsulation Press the SPACE BAR and then press ENTER to choose PPTP PPTP The encapsulation method influences your choices for IP Address Idle Timeout This value specifies the time in seconds that elapses before 100 the ZyWALL automatically disconnects from the PPTP arva default 3 3 4 PPPoE Encapsulation The ZyWALL supports PPPoE Point to Point Protocol over Ethernet PPPoE is an IETF Draft standard RFC 2516 sp
100. Voltage dips short interruptions and voltage variations immunity 1994 tests Declaration of Conformity V ZyWALL 10 Internet Security Gateway Declaration of Conformity The following products is herewith confirmed to comply with the requirements set out in the Council Directive on the Approximation of the laws of the Member States relating to Electromagnetic Compatibility Directive 89 336 EEC The listed standard as below were applied The following Equipment Product LAN Gateway Router Model Number PRESTIGE 310 310 S ZyWALL 10 RFI Emission Generic emission standard according to EN 50081 1 1992 Limit class B according to EN 55022 1998 Limits class A for harmonic current emission according to EN 61000 3 2 1995 Limitation of voltage fluctuation and flicker in low voltage supply system according to EN 61000 3 3 1995 Immunity Generic immunity standard according to EN 50082 1 1997 EN 55024 1998 Electrostatic Discharge according to EN 61000 4 2 1995 Contact Discharge 4 kV Air Discharge 8 kV Radio frequency clectromagnetic field according to EN 61000 4 3 1996 80 L000MHz with kHz AM 80 Modulation 3V m Electromagnctie field from digital telephones according to ENV 50204 1995 900 5MHz with 200Hz rep Frequency Duty Cycle 50 Electrical fast transient burst according to EN 61000 4 4 1995 AC DC power supply 1kV Data Signal lines 0 5kV Surge immunity test according to EN 61000 4 5 1995 AC DC Line to
101. ZyNOS Version V324Nwa0b05 3 5 2001 18 00 34 Press any key to enter debug mode within 3 seconds Figure 11 9 Option to Enter Debug Mode Enter ATHE to view all available ZyWALL boot module commands as shown in the next screen ATBAx allows you to change the console port speed The x denotes the number preceding the colon to give the console port speed following the colon in the list of numbers that follows e g ATBA3 will give a console port speed of 9 6 Kbps ATSE displays the seed that is used to generate a password to turn on the debug flag in the firmware The ATSH command shows product related information such as boot module version vendor name product model RAS code revision etc ATGO allows you to continue booting the system Most other commands aid in advanced troubleshooting and should only be used by qualified engineers 11 8 System Maintenance amp Information ZyWALL 10 Internet Security Gateway AT ATHE ATBAx ATENx y ATSE ATTI h m s ATDA y m d ATDS ATDT ATDUx y ATWBx y ATWWx y ATWLx y ATRBx ATRWx ATRLx ATGO x ATGR ATGT ATSTx ATBTx ATRTw x y z ATWEa b c d ATCUX ATCB ATCL ATSB ATBU ATSH ATWMx ATCOx ATFLx ATSTx ATSYx ATVDx ATPNx ATFEx y ATMP ATDOx y ATTD ATUPx y ATUR ATLC ATUXx y ATERx y ATWEX Y Z ATXSx ATLOa b c d just answer print help change baudrate set BootExtension Debug Flag OK 1 38 4k 2 19 2k 3 9 6k 4 57 6k 5 115 2k
102. ZyWALL 10 Internet Security Gateway User s Guide Version 3 24 April 2001 ZyXEL TOTAL INTERNET ACCESS SOLUTION ZyWALL 10 Internet Security Gateway Copyright Copyright 2001 by ZyXEL Communications Corporation The contents of this publication may not be reproduced in any part or as a whole transcribed stored in a retrieval system translated into any language or transmitted in any form or by any means electronic mechanical magnetic optical chemical photocopying manual or otherwise without the prior written permission of ZyXEL Communications Corporation Published by ZyXEL Communications Corporation All rights reserved Disclaimer ZyXEL does not assume any liability arising out of the application or use of any products or software described herein Neither does it convey any license under its patent rights nor the patent rights of others ZyXEL further reserves the right to make changes in any products described herein without notice This publication is subject to change without notice Trademarks Trademarks mentioned in this publication are used for identification purposes only and may be properties of their respective owners ii Copyright ZyWALL 10 Internet Security Gateway Federal Communications Commission FCC Interference Statement This device complies with Part 15 of FCC rules Operation is subject to the following two conditions This device may not cause harmful interference T
103. ZyWALL 10 Internet Security Gateway sesenta 1 1 1 2 Featuresof The Zweeter nies ek eee pe EE Pen 1 1 1 3 Applications for ZyWALL 10 ies sesse ses ERG ure ete tee Ee Re etri ertet rft 1 3 1 3 1 Broadband Internet Access via Cable or xDSL Modem eee 1 3 Chapter 2 Hardware Installation amp Initial Setup eee See eee eese eee Be Ee ense ee Gee Se suse Se suus 2 1 2 1 Front Panel LEDs and Back Panel Porte 2 1 2 1 1 Front Panel EBDS niter eter ese eek eee Gee sevens TEE tune ee ege EU 2 1 2 2 ZyWALL 10 Rear Panel and Connections esent 2 2 2 3 Additional Installation Requirements see se ee ee Ge ee ee ee ee nennen enne ens 2 3 2 4 Tum On Your ZyWALL ORE RE EE ER ER OE EEN 2 4 2 5 Navigating the SMI Interface oio een rre Ue ri Oder Ec ERU E inte 2 4 2 5 1 Man Men eerten RE RE RR N 2 6 2 5 2 System Management Terminal Interface Summary sse 2 7 2 5 3 SMT Menus at Glance eoa ER OT ER ie eee depen 2 8 2 6 Changing the System Password 2 9 2 6 1 Resetting th ZYWALL EE 2 9 Table of Contents ix ZyWALL 10 Internet Security Gateway E SN EE EE 2 9 2 7 1 BENADE RE EE RE NEE p Dui 2 10 2 7 2 Procedure For Configuring Menu 1 esee retener 2 10 2 7 3 Configuring Dynamic DNS tte Zeg dead SR Ge SERE a De ER ER EE Se AO REEE ee sk Se ee 2 11 2 8 WAN SELDE io DE EE SE Er SR Ges ead enn ise tire tees rion made EE eem 2 12
104. about using the log screen to view the results of the rules you 18 1 Log Screen have configured When you configure a new rule you also have the option to log events that match don t match or both this rule see Figure 16 4 Click on the Logs to bring up the next screen Firewall logs may also be viewed in SMT Menu 21 3 see section 14 1 1 or via syslog SMT Menu 24 3 2 System Maintenance UNIX Syslog Syslog is an industry standard protocol used for capturing log information for devices on a network 128 entries are available numbered from 0 to 127 Once they are all used the log wraps around and the old logs are lost ZyXEL MAIN MEN Firewall Time i120 Jeh 1 00 12 a21 Jan 1 d 21 o 00 13 04 9 Fton 19 i22 Jan 1 00115 123 Jan 1 00 16 124 Jan 1 00 16 125 9en 1 it Packet Inforretion From 192 Tee rees 192 tomp fom TCP from iter 168 1 33 Toi182 ero port 01055 dest 148 1 223 sre 0 From 192 1 O Fcom 152 268 1 33 0011615 i2 Jan 1 00 17 UDP 0 Frow 16N P 70 224 168 1 1 port 00080 0 3 22 port 00000 24 0 1 22 t port 00000 168 1 1 port 00000 2 165 21 1 port conso 2 165 1 288 t porr 00138 0 1 23 port 00000 Figure 18 1 Log Screen Peason default permit volt permit Mit permit permit slt permit c permit mit permit Aet ton Ifotvard j forward fotvard forward
105. al IP addresses Rule 2 Map the second IGA to our second inside FTP server for FTP traffic in both directions 1 1 mapping giving both local and global IP addresses Rule3 Map the other outgoing LAN traffic to IGA3 Many 1 mapping Rule4 You also map your third IGA to the web server and mail server on the LAN Type Server allows you to specify multiple servers of different types to other machines behind NAT on the LAN The example situation looks somewhat like this Other computers on the LAN Mapping Rules 1 FTP 1 lt gt IGA 1 Type 1 1 Mail 2 FTP 2 lt gt IGA 2 Type 1 1 Server 3 Other LAN traffic gt IGA 3 4 5 Type MM Ov Outgoing Traffic 192 168 1 20 4 IGA 3 gt Internal web server and mail server Incoming Traffic Web Server 192 168 1 21 FTP Server 1 192 168 1 10 Pe INNIS 10 132 50 1 IGA 1 10 132 50 2 2 IGA 2 10 132 50 3 IGA 3 10 132 50 4 IGA 4 10 132 50 5 IGA 5 FTP Server 2 192 168 1 11 Figure 6 16 NAT Example 3 Step 1 In this case you need to configure Address Mapping Set 1 from Menu 15 1 Address Mapping Sets Therefore you must choose the Full Feature option from the Network Address Translation field in menu 4 or menu 11 3 in Figure 6 17 Step 2 Then enter 15 from the main menu NAT 6 17 ZyWALL 10 Internet Security Gateway Step 3 Enter 1 to configure the Address Mapping Sets Step 4 Enter 1 to begin configuring this new set Enter a Set Name
106. ansfer then Send File to display the following screen Send File ki xi Type the rom configuration file s Folder C ProjectsJohn Zy WALL1 0SFirmwaresbS location or use Browse Filename to search for it CAZyARELSConfig rom Browse Protocol Choose the Xmodem modem v protocol Send Ele Cancel Then click Send Figure 10 6 Example Restore Configuration 10 4 Firmware and Configuration File Maintenance ZyWALL 10 Internet Security Gateway Menu 24 6 Restore Configuration To transfer the firmware and the configuration file follow the procedure below 1 Launch the FTP client on your workstation 2 Type open and the IP address of your router Then type root and SMT password as requested 3 Type put backupfilename rom 0 where backupfilename is the name of your backup configuration file on your workstation and rom spt is the remote file name on the router This restores the configuration to your router 4 The system reboots automatically after a successful file transfer For details on FTP command client program For detail remain in the menu to back S please consult the documentation of your FTP S on restoring using TFTP note that you must up using TFTP please see your router manual Figure 10 8 Telnet into Menu 24 6 Restore Configuration 10 4 Upload Firmware Menu 24 7 System Maintenance Upload Firmware allows you to upgrade the firmware and the configuration file v
107. are transmitted using the HTTP protocol T Glossary of Terms ZyWALL 10 Internet Security Gateway Proxy Server PSTN Public Key Encryption PVC Reconnaissance RFC RIP Router SAP SATAN A server that performs network operations in lieu of other systems on the network Proxy Servers are most often used as part of a firewall to mask the identity of users inside a corporate network yet still provide access to the Internet When a user connects to a proxy server via a web browser or other networked application he submits commands to the proxy server The server then submits those same commands to the Internet yet without revealing any information about the system that originally requested the information Proxy servers are an ideal way to also have all users on a corporate network channel through one point for all external communications Proxy servers can be configured to block certain kinds of connections and stop some hacks Public Switched Telephone Network was put into place many years ago as a voice telephone call switching system The system transmits voice calls as analog signals across copper twisted cables from homes and businesses to neighborhood COs central offices this is often called the local loop The PSTN is a circuit switched system meaning that an end to end private circuit is established between caller and callee System of encrypting electronic files using a key pair The key pair contains a public
108. arly Many older versions of software especially web browsers have well known security deficiencies When you upgrade to the latest versions you get the latest patches and fixes 10 If you use chat rooms or IRC sessions be careful with any information you reveal to strangers 11 If your system starts exhibiting odd behavior contact your ISP Some hackers will set off hacks that cause your system to slowly become unstable or unusable 12 Always shred confidential information particularly about your computer before throwing it away Some hackers dig through the trash of companies or individuals for information that might help them in an attack What Is a Firewall 13 11 ZyWALL 10 Internet Security Gateway 14 1 SMT Chapter 14 Introducing the ZyWALL Firewall This chapter shows you how to get started with the ZyWALL Firewall Please see Chapter 13 for some background information on firewalls Menus From the main menu see below enter 21 to go to Menu 21 Filter Set and Firewall Configuration This is menu 21 Copyright c 1994 2000 ZyXEL Communications Corp ZyWALL 10 Main Menu Getting Started 1 General Setup 2 WAN Setup 3 LAN Setup 4 Internet Access Setup System Maintenance Advanced Applications Schedule Setup 11 Remote Node Setup 12 Static Routing Setup 15 NAT Setup 99 Exit Enter Menu Selection Number Figure 14 1 SMT Main Menu Menu 21 Filter and Firewall Setup 1
109. at Note for Austrian users with at domain only www zyxel de ftp europe zyxel com Regular Mail ZyXEL Communications Corp 6 Innovation Road Il Science Based Industrial Park HsinChu Taiwan ZyXEL Communications Inc 1650 Miraloma Avenue Placentia CA 92870 U S A ZyXEL Communications A S Columbusvej 5 2860 Soeborg Denmark ZyXEL Communications Services GmbH Thaliastrasse 125a 2 2 4 A 1160 Vienna Austria ZyXEL Deutschland GmbH Adenauerstr 20 A4 D 52146 Wuerselen Germany viii Customer Support ZyWALL 10 Internet Security Gateway Table of Contents is ER EEN ii Federal Communications Commission FCC Interference Statement se ee eere eese ee ee iii Information for Canadian Users eere eee e eee SEE eese estne Be tne Be sens tastes tuse Se sse Be sens tastes eene Se suse Se ao iv ZYXEL Limited Warranty ERE vii Customer Support esse sessies M viii Table of Contents usse sesse ese se ees se Se ee Se EE Se EE EE Se EE EE SE EE SR EE SE SR EE SR EE Ee SE EE Ee SR EER EE Se SR EE Ee SR EE Ee See ge ix INO iss is ss od DE xvii EET dt OE E T E E T xxiii reageieren ee ee EE EE xxvii Getting Started 3 RE RE delito Aes tine ae eg ase I Chapter 1 Getting to Know Your ZyWALL cesses se eee ense tnter seen EE Be EG thats enses sosta sensn senatu senatus 1 1 1 1 The
110. at your timeserver will send when you turn on the ZyW ALL then you can enter the time manually but each time the system is booted the time and date will be reset to 2000 01 01 00 00 00 11 4 System Maintenance amp Information ZyWALL 10 Internet Security Gateway Select menu 24 in the main menu to open Menu 24 System Maintenance as shown next Menu 24 System Maintenance d System Status 2 System Information and Console Port Speed 3 Log and Trace 4 Diagnostic 5 Backup Configuration 6 Restore Configuration ds Upload Firmware 8 Command Interpreter Mode 9 je 9 ro 0 Time and Date Setting 11 Remote Management Setup Enter Menu Selection Number Figure 11 6 Menu 24 System Maintenance Then enter 10 to go to Menu 24 10 System Maintenance Time and Date Setting to update the time and date settings of your ZyW ALL as shown in the following screen Menu 24 10 System Maintenance Time and Date Setting Use Time Server when Bootup None Time Server IP Address N A Current Time New Time hh mm ss Current Date New Date yyyy mm dd Time Zone GMT 0800 Daylight Saving No Start Date mm dd 01 00 End Date mm dd 01 00 Press ENTER to Confirm or ESC to Cancel Figure 11 7 Menu 24 10 System Maintenance Time and Date Setting System Maintenance amp Information 11 5 ZyWALL 10 Internet Security Gateway Table 11 3 Time and Date Setting Fields FIELD D
111. atch the destination IP and set 2 X 2 for WAN to LAN rules Y represents address in set 1 rule 1 Other the rule in the set You can configure up to 10 rules in reasons instead of dest IP any set Y 01 to 10 Rule number 00 is the default are src IP dest port src port rule and protocol This is a log for a DoS attack attack land ip spoofing icmp echo icmp vulnerability NetBIOS smtp illegal command traceroute teardrop or syn flood Action This field displays whether the packet was blocked block forward forwarded or neither None means that no action is dictated by this rule or none After viewing the firewall log ENTER y to clear the log or n to retain it With either option you will be returned to Menu 21 Filter and Firewall Setup 14 2 The Big Picture Filtering Firewall and NAT The following figure illustrates the path a packet takes as it passes through the filtering firewall and NAT processes An earlier chapter covers NAT what follows is a brief comparison of the firewall and filtering Introducing the ZyWALL Firewall 14 5 ZyWALL 10 Internet Security Gateway LAN WAN LAN to WAN Outbound Traffic LAN Device LAN Protocol Check Routing Remote Node LAN to WAN NAT Remote Node Filter Filter Table Protocol Filte Firewall DeviceFilter LAN to WAN Firewall To Router IP application e g Telnet SNMP WAN to LAN Firewall LAN Device VANCtOCEAN LAN Protoco
112. ateway The gateway is an immediate neighbor of your ZyWALL that will forward the packet to the destination On the LAN the gateway must be a router on the same segment as your ZyWALL over the WAN the gateway must be the IP address of one of the Remote Nodes Metric Metric represents the cost of transmission for routing purposes IP routing uses hop count as the measurement of cost with a minimum of 1 for directly connected networks Enter a number that approximates the cost for this link The number need not be precise but it must be between 1 and 15 In practice 2 or 3 is usually a good number Private This parameter determines if the ZyWALL will include the route to this remote node in its RIP broadcasts If set to Yes this route is kept private and not included in RIP broadcast If No the route to this remote node will be propagated to other hosts through RIP broadcasts Once you have completed filling in this menu press ENTER at the message Press ENTER to Confirm to save your configuration or press ESC to cancel IP Static Route Setup 5 3 ZyWALL 10 Internet Security Gateway Chapter 6 Network Address Translation NAT This chapter discusses how to configure NAT on the ZyWALL 6 1 Introduction NAT Network Address Translation NAT RFC 1631 is the translation of the IP address of a host in a packet e g the source address of an outgoing packet used within one network to a
113. ation ZyWALL 10 Internet Security Gateway The total budget is the time limit on the accumulated time for outgoing calls to a remote node When this limit is reached the call will be dropped and further outgoing calls to that remote node will be blocked After each period the total budget is reset The default for the total budget is 0 minutes and the period is 0 hours meaning no budget control You can reset the accumulated connection time in this menu by entering the index of a remote node Enter 0 to update the screen The budget and the reset period can be configured in menu 11 1 for the remote node Table 11 1 Budget Management FIELD DESCRIPTION EXAMPLE Remote Node Enter the index number of the remote node you want to reset just one in this case 1 Connection Time Total This is the total connection time that has gone by 5 10 means that 5 elapsed time is the time used up within this period Budget within the allocated budget that you set in menu minutes out of a 11 1 total allocation of 10 minutes have lapsed Elapsed Time Total The period is the time cycle in hours that the 0 5 1 means that Period allocation budget is reset see menu 11 1 The 30 minutes out of the 1 hour time period has lapsed Enter 0 to update the screen or press ESC to return to the previous screen 11 2 2 Call History This is the second option in Menu 24 9 System Maintenance Call Contr
114. ation address as the IP of your server on the LAN RULE IP CONFIG Internet to Local Network See 10 100 1 2 is the IP of our INTERNET CUSTOM PORTS LOGS bone server on the LAN supporting E FTP HTTP Telnet and mail 000 services to which we wish to forward traffic originating from ooo LOGOUT Re the Internet Status Ready Figure 19 4 Example 1 Destination Address for Traffic Originating from the Internet Example Firewall Rules 19 5 ZyWALL 10 Internet Security Gateway Step 5 When you have finished configuring your rules the Rule Summary screen should look like this Click Apply in this screen to save your configuration back to the ZyWALL RE E Block packets that don t match the rules specified below MAIN MENU Interneti to Local Network Firewall CONFIGURATION ACL Default Set LOCAL NETWORK Bock 2 INTERNET CUSTOMPORTS LOGS d BOOTP CLIENT UDP 68 z orwartHen LOGOUT q 1 Forward Match Log of packets should match this rule in the ACL Default Set Gil Glass Gil Apply Edit Delete The first rule is a default rule to allow DHCP negotiation between the ISP and the ZyW ALL 10 The second rule is what we configured in the last 2 screens See Table 16 1 Click Apply in this screen when you have finished configuring to save your configuration back to the ZyWALL Figure 19 5 Example 1 Rule Summary Screen 19 1 2 Example
115. b0427001700195b3e00000000600220008cd4000002040 5b4 Jul 19 11 29 06 192 168 102 2 ZyXEL Packet Trigger Protocol 1 Data 45000028240140001 f06ac12c0a86614ca849a7b0427001700195b451d1430135004000077600000 3 Filter log Filter log Message Format SdcmdSyslogSend SYSLOG FILLOG SYSLOG_NOTICE String String IP Src xx xx xx xx Dst XX XX XX XX prot spo2xxxx dpo2xxxx SO4 RO1MD IP is the packet header and S04 R01mD means filter set 4 S and rule 1 R match m drop D Src Source Address Dst Destination Address prot Protocol TCP UDP ICMP spo Source port dpo Destination port 9 8 System Information amp Diagnosis ZyWALL 10 Internet Security Gateway Mar 03 10 39 43 202 132 155 97 ZyXEL GEN fffffffffffnordff0080 SO05 gt RO1mF Mar 03 10 41 29 202 132 155 97 ZyXEL GEN 00a0c5 502fnord010080 S05 gt RO1mF Mar 03 10 41 34 202 132 155 97 ZyXEL IP Src 192 168 2 33 Dst 202 132 155 93 ICMP S04 gt RO1mF Mar 03 11 59 20 202 132 155 97 ZyXEL GEN 00a0c5 502fnord010080 S05 gt RO1mF Mar 03 12 00 31 202 132 155 97 ZyXEL GEN fffffffffffnordff0080 SO05 gt RO1mF Mar 03 12 00 52 202 132 155 97 ZyXEL GEN ffffffffffff0080 S505 ROlmF Mar 03 12 00 57 202 132 155 97 ZyXEL GEN 00a0c5 502010080 S05 gt RO1mF Mar 03 12 01 01 202 132 155 97 ZyXEL IP Src 192 168 2 33 Dst 202 132 155 93 TCP spo 01170 dpo 00021 SO4 RO1mF Mar 03 12 01 06 202 132 155 97 ZyXEL IP Src 192 168 2 33 Dst 202 132
116. ces the main features and applications of the ZyWALL 1 1 The ZyWALL 10 Internet Security Gateway The ZyW ALL 10 is a dual Ethernet Internet Security Gateway integrated with a robust firewall and network management features designed for home offices and small businesses to access the Internet via Cable ADSL modem or Internet router By integrating NAT and firewall capability ZyXEL s ZyW ALL 10 provides not only ease of installation and Internet access but also a complete security solution to protect your Intranet and efficiently manage data traffic on your network The ZyW ALL Web Configurator is a breeze to operate and totally independent of the operating system platform you use 1 2 Features of The ZyWALL 10 The following are the main features of the ZyWALL 10 Firewall The ZyW ALL is a stateful inspection firewall with DoS Denial of Service protection By default when the firewall is activated all incoming traffic from the WAN to the LAN is blocked unless it is initiated from the LAN The ZyWALL firewall supports TCP UDP inspection DoS detection and prevention real time alerts reports and logs You can configure most features of the ZyWALL 10 via SMT but we recommend you configure the firewall and Content Filters using the ZyWALL Web Configurator Content Filtering The ZyW ALL can block web features such as ActiveX controls Java applets and cookies as well as disable web proxies The ZyW ALL can also block specific UR
117. choose the Edit Action and then enter 1 for the Select Rule field Press ENTER to confirm Step 5 Select Type as One to One direct mapping for packets going both ways and enter the local Start IP as 192 168 1 10 the IP address of FTP Server 1 the global Start IP as 10 132 50 1 our first IGA See Figure 6 16 Step 6 Repeat the previous step for rules 2 to 4 as outlined above Step 7 When finished menu 15 1 1 should look like as shown in Figure 6 19 Menu 11 3 Remote Node Network Layer Options IP Address Assignment Dynamic IP Address N A IP Subnet Mask N A Gateway IP Addr N A Network Address Translation Full Fea e Metric N A Private N A RIP Direction None Version N A Figure 6 17 Example 3 Menu 11 3 The following figure shows how to configure the first rule Menu 15 1 1 1 Address Mapping Rule Typ One to One Local IP Start 192 168 1 10 End MQ Global IP Start End A Press ENTER to Confirm or ESC to Cancel Press Space Bar to Toggle Figure 6 18 Example 3 Menu 15 1 1 1 6 18 NAT ZyWALL 10 Internet Security Gateway When you have configured all four rules Menu 15 1 1 should look as follows Menu 15 1 1 Address Mapping Rules Set Name Idx e 192 168 1 10 192 168 1 11 0 0 0 0 255 255 42585 255 Action Edit Select Rule Press ENTER to Confirm or ESC to Cancel Figure 6 19 Example 3 Final Menu 15 1 1 Now configure the IGA3 to map to our web
118. cifies the idle time i e the length of time 100 seconds there is no traffic from the ZyWALL to the remote node default in seconds that can elapse before the ZyWALL automatically disconnects the PPPoE connection This option only applies when the ZyWALL initiates the call Idle Timeout 4 1 3 PPTP Encapsulation If you change the Encapsulation to PPTP in menu 11 1 then you will see the next screen Please see the appendices for information on PPTP 4 4 Remote Node Setup ZyWALL 10 Internet Security Gateway Menu 11 1 Remote Node Profile Rem Node Name ChangeMe Route IP Active Yes Encapsulation PPTP Edit IP No Service Type Standard Telco Option Service Name N A Allocated Budget min 0 Outgoing Period hr 0 My Login Schedules My Password Nailed up Connections Authen CHAP PAP PPRTP My Session Options Edit Filter Sets No IP Addr Idle Timeout sec 100 Server IP Addr Connection ID Name Press ENTER to Confirm or ESC to Cancel Press Space Bar to Toggle Figure 4 3 Menu 11 1 Remote Node Profile for PPTP Encapsulation The next table shows how to configure fields in menu 11 1 not previously discussed above Table 4 3 Fields in Menu 11 1 PPTP Encapsulation FIELD DESCRIPTION EXAMPLE Encapsulation Toggle the space bar to choose PPTP You must also go to PPTP menu 11 3 to check the IP Address setting once you have sele
119. cted the encapsulation method My IP Addr Enter the IP address of the WAN Ethernet port 10 0 0 140 My Server IP Enter the IP address of the ANT modem 10 0 0 138 Addr Connection Enter the connection ID or connection name in the ANT It N My ISP ID Name must follow the c id and n name format This field is optional and depends on the requirements of your xDSL Modem Schedules You can apply up to four schedule sets here For more details please refer to the Call Schedule Setup chapter Nailed Up Use the SPACE BAR to select Yes if you want to make the No Connections connection to this remote node a nailed up connection Remote Node Setup 4 5 ZyWALL 10 Internet Security Gateway 4 2 Editing TCP IP Options with Ethernet Encapsulation Move the cursor to the Edit IP field in menu 11 1 then press the SPACE BAR to toggle and set the value to Yes Press ENTER to open Menu 11 3 Network Layer Options Menu 11 3 Remote Node Network Layer Options IP Address Assignment Dynamic IP Address N A IP Subnet Mask N A Gateway IP Addr N A Network Address Translation SUA Only Metric N A Private N A RIP Direction None Version N A Multicast None Enter here to CONFIRM or ESC to CANCEL Press Space Bar to Toggle Figure 4 4 Menu 11 3 Remote Node Network Layer Options The next table gives you instructions about configuring remote node network layer options Table 4 4 Remote Node Network Layer
120. cts and edits a destination address range of traffic which comply to this rule Selects and edits the destination port of the traffic which comply with this rule For non consecutive port numbers the user may repeat this command line to enter in the multiple port numbers Selects and edits a destination port range of traffic which comply to this rule Selects and edits the destination port of the traffic which comply with this rule For non consecutive port numbers the user may repeat this command line to enter in the multiple port numbers Selects and edits a destination port range of traffic which comply to this rule Types in the desired custom port name CLI Commands ZyWALL 10 Internet Security Gateway Function CLI Syntax Delete config delete firewall config delete firewall config delete firewall gt config delete firewall gt rule lt rule gt e mail attack set lt set set lt set Description Removes all the settings for e mail alert Resets all the settings for attack to default setting Removes the specified set from the firewall configuration Removes the specified rule in a set from the firewall configuration CLI Commands ZyWALL 10 Internet Security Gateway Appendix F Power Adapter Specifications AC Power Adapter Specifications North America AC Power Adapter model MW48 1201200 Input power AC120Volts 60Hz Output power DC12Volts 1 2A Powe
121. d of 7 8 Filters ZyWALL 10 Internet Security Gateway FIELD DESCRIPTION OPTIONS according to the action fields If More is Yes then Action Matched and Action Not Matched will be N A Log Select the logging option from the following None No packets will be logged None Action Matched Only packets that match the rule parameters will be logged Action Not Matched Only packets that do not match the rule parameters will be logged Both All packets will be logged Action Matched Action Not Matched Both Action Matched Select the action for a matching packet Check Next Rule Forward Drop Action Not Matched Select the action for a packet not matching the rule Check Next Rule Forward Drop Press SPACE BAR to select properties for fields that do not need to be typed in When you have Menu 21 1 1 1 TCP IP Filter Rule configured press ENTER at the message Press ENTER to Confirm to save your configuration or press ESC to cancel This data will now be displayed on Menu 21 1 1 Filter Rules Summary Filters 7 9 ZyWALL 10 Internet Security Gateway The following figure illustrates the logic flow of an IP filter Packet into IP Filter Filter Active No Yes Y Apply SrcAddrMask to Src Addr Y Check Sr IPAddr Not Matched Matched Y Apply DestAddrMask to Dest Addr BW
122. discretion repair or replace the defective products or components without charge for either parts or labor and to whatever extent it shall deem necessary to restore the product or components to proper operating condition Any replacement will consist of a new or re manufactured functionally equivalent product of equal value and will be solely at the discretion of ZyXEL This warranty shall not apply if the product is modified misused tampered with damaged by an act of God or subjected to abnormal working conditions NOTE Repair or replacement as provided under this warranty is the exclusive remedy of the purchaser This warranty is in lieu of all other warranties express or implied including any implied warranty of merchantability or fitness for a particular use or purpose ZyXEL shall in no event be held liable for indirect or consequential damages of any kind of character to the purchaser To obtain the services of this warranty contact ZyXEL s Service Center for your Return Material Authorization number RMA Products must be returned Postage Prepaid It is recommended that the unit be insured when shipped Any returned products without proof of purchase or those with an out dated warranty will be repaired or replaced at the discretion of ZyXEL and the customer will be billed for parts and labor All repaired or replaced products will be shipped by ZyXEL to the corresponding return address Postage Paid This warranty gives you specific l
123. distinguish it as such packets that match Click Apply these rules when finished Figure 19 8 Example 2 Local Network Rule 1 Configuration Step 6 Similarly configure another local network to Internet rule allowing traffic from our web HTTP proxy server Example Firewall Rules 19 9 ZyWALL 10 Internet Security Gateway Step 7 The Rule Summary screen should look like Figure 19 9 Don t forget to click Apply when you have finished configuring your rule s to save your settings back to the ZyW ALL ZyXE L LION LOCAL NETWORK Check this box to log all MAIN MENU Local Network ia Inis mat matched rules in the ACL Timo Out Default Set Firewall CONFIGURATION ACLDefeMtSe 7 EE e Configured 192 168 10 2 POP TCP 110 Forward None LOGOUT Configured 192 168 10 5 E HTTP TCP 80 7 Forward None z El Rule 1 forwards SMTP and POP traffic from the mail server and Rule 2 forwards HTTP traffic from the proxy web server This rule will not generate a log 4 Li Don t forget to click Apply to save your settings back to the ZyWALL Status Ready Figure 19 9 Example 2 Local Network Rule Summary Step 8 Now you want an FTP server IP of 192 168 10 3 to be accessible from the Internet Remember the default Internet to Local Network ACL Set blocks all traffic from the Internet so you want to create a hole for this server Click the Internet link to see its Rule Summary scree
124. dress Assignment Dynamic Rem IP Address N A Rem Subnet Mask N A My WAN Addr 0 0 0 0 Network Address Translation Full Feature Metric 1 Private No RIP Direction None Version N A Multicast None Enter here to CONFIRM or ESC to CANCEL Press Space Bar to Toggle Figure 4 5 Menu 11 3 Remote Node Network Layer Options The next table gives you instructions about configuring remote node network layer options Table 4 5 Remote Node Network Layer Options Menu Fields the remote node FIELD DESCRIPTION EXAMPLE IP Address If your ISP did not assign you an explicit IP address select Dynamic Dynamic Assignment otherwise select Static and enter the IP address amp subnet mask in the following fields Rem IP Address If you have a Static IP Assignment enter the IP address assigned to 192 168 1 1 Rem IP Subnet Mask If you have a Static IP Assignment enter the subnet mask assigned to the remote node 255 255 255 0 IP routing uses hop count as the measurement of cost with a minimum of 1 for directly connected networks Enter a number that approximates the cost for this link The number need not be precise but it must be between 1 and 15 In practice 2 or 3 is usually a good My WAN Addr Some implementations especially the UNIX derivatives reguire the WAN link to have a separate IP network number from the LAN and each end must have a unique address within the WAN network number If
125. e Sys exit device ether poe config ip ppp hdap ras Figure 11 2 Valid Commands System Maintenance amp Information 11 1 ZyWALL 10 Internet Security Gateway 11 2 Call Control Support The ZyW ALL provides two call control functions budget management and call history Please note that this menu is only applicable when Encapsulation is set to PPPoE or PPTP in menu 4 or menu 11 1 The budget management function allows you to set a limit on the total outgoing call time of the ZyWALL within certain times When the total outgoing call time exceeds the limit the current call will be dropped and any future outgoing calls will be blocked Call history chronicles preceding incoming and outgoing calls To access the call control menu select option 9 in menu 24 to go to Menu 24 9 System Maintenance Call Control as shown in the next table Menu 24 9 System Maintenance Call Control 1 Budget Management 2 Call History Enter Menu Selection Number Figure 11 3 Call Control 11 2 1 Budget Management Menu 24 9 1 shows the budget management statistics for outgoing calls Enter 1 from Menu 24 9 System Maintenance Call Control to bring up the following menu Menu 24 9 1 Budget Management Remote Node Connection Time Total Budget Elapsed Time Total Period 1 ChangeMe No Budget No Budget Reset Node 0 to update screen Figure 11 4 Budget Management 11 2 System Maintenance amp Inform
126. e second is to leave this field blank i e 0 0 0 0 in this case the ZyWALL acts as a DNS proxy Internet Access 3 1 ZyWALL 10 Internet Security Gateway Example of network properties for LAN servers with fixed IP addresses Choose an IP address 192 168 1 2 192 168 1 32 192 168 1 65 192 168 1 254 Subnet mask 255 255 255 0 Gateway or default route 192 168 1 1 ZyWALL LAN IP 3 1 3 IP Address and Subnet Mask Similar to the way houses on a street share a common street name the machines on a LAN share one common network number also Where you obtain your network number depends on your particular situation If the ISP or your network administrator assigns you a block of registered IP addresses follow their instructions in selecting the IP addresses and the subnet mask If the ISP did not explicitly give you an IP network number then most likely you have a single user account and the ISP will assign you a dynamic IP address when the connection is established If this is the case it is recommended that you select a network number from 192 168 0 0 to 192 168 255 0 and you must enable the Network Address Translation NAT feature of the ZyWALL The Internet Assigned Number Authority IANA reserved this block of addresses specifically for private use please do not use any other number unless you are told otherwise Let s say you select 192 168 1 0 as the network number which covers 254 individual addresses from 192 168 1 1
127. e for the firmware is ras and for the configuration file is rom 0 Binary Transfer the file in binary mode Abort Stop transfer of the file TFTP over WAN will not work if 1 2 3 A You have disabled Telnet service in menu 24 11 You have applied a filter in menu 3 1 LAN or in menu 11 5 WAN to block Telnet service The IP you entered in the Secured Client IP field in menu 24 11 does not match the client IP If it does not match the ZyW ALL will disconnect the Telnet session immediately You have an SMT console session running The firewall is active The default firewall policies block all traffic from the WAN so to enable TFTP over the WAN you must turn the firewall off menu 21 2 or create a firewall rule to allow TFTP from the WAN 10 6 FTP File Transfer In addition to uploading the firmware and configuration via the console port and TFTP client you can also upload the ZyWALL firmware and configuration files using FTP To use this feature your workstation must have an FTP client When you telnet into the ZyWALL you will see the following screens for uploading firmware and the configuration file using FTP Firmware and Configuration File Maintenance 10 9 ZyWALL 10 Internet Security Gateway Menu 24 7 1 System Maintenance Upload Router Firmware To upload the router firmware follow the procedure below 1 Launch the FTP client on your workstation 2 Type open a
128. e half opened incomplete low 0 255 sessions config edit firewall attack tcp The threshold to start executing the block field max incomplete 0 255 Sets config edit firewall set set 4 Edits the name for a specified set name desired name H CLI Commands ZyWALL 10 Internet Security Gateway Function Config edit default pe Config edit icmp timeo Config edit udp idle t Config edi connection Config edi fin wait t Config edi tcp idle t Config edit log yes Rules Config edi rule rule gt p Config edi rule rule a Config edit rule t firewall set lt set no gt t firewall set lt se ermit lt forward b t firewall set lt se ctive lt yes no gt t firewall set lt se CLI Syntax firewall rmit forward firewall ut seconds firewall imeout seconds firewall se se se se t se timeout seconds firewall imeout seconds firewall imeout seconds se se rule gt protocol integer protocol value t set t set t set t set t set BE gt ck gt gt gt gt gt gt gt gt ock gt gt gt Config edit firewall set lt set gt rule lt rule gt log lt none match both gt ma Cotte not Config edit firewall set set gt rule rule 4 alert yes n Oz c
129. e screen will take you in most cases to the previous menu Exit the SMT Type 99 then press Type 99 at the main menu prompt and press ENTER to exit the ENTER SMT interface Hardware Installation amp Initial Setup 2 5 ZyWALL 10 Internet Security Gateway 2 5 1 Main Menu After you enter the password the SMT displays the Zy WALL 10 Main Menu as shown next Copyright c 1994 2001 ZyXEL Communications Corp ZyWALL Main Menu Getting Started Advanced Management General Setup WAN Setup LAN Setup Internet Access Setup Filter and Firewall Setup SNMP Configuration System Password System Maintenance Advanced Applications 11 Remote Node Setup 12 Static Routing Setup 15 NAT Setup Schedule Setup Enter Menu Selection Number Figure 2 5 ZyWALL 10 Main Menu 2 6 Hardware Installation amp Initial Setup ZyWALL 10 Internet Security Gateway 2 5 2 System Management Terminal Interface Summary Table 2 3 Main Menu Summary NO MENU TITLE FUNCTION General Setup Use this menu to set up routing bridging and general information 2 WAN Setup Use this menu to clone a MAC address from a computer on your LAN 3 Ethernet Setup Use this menu to configure LAN DHCP and TCP IP settings as well as apply LAN filters 4 Internet Access Setup Configure your Internet Access setup Internet address gateway login etc with
130. e section 6 1 5 The Server Set is a list of LAN side servers mapped to external ports To use this set one set for the ZyW ALL 10 a server rule must be set up inside the NAT Address Mapping set Please see section 6 5 for further information on these menus NAT 6 7 ZyWALL 10 Internet Security Gateway Enter 1 to bring up Menu 15 1 Address Mapping Sets Menu 15 1 Address Mapping Sets 1 NAT SET 255 SUA read only Enter Menu Selection Number Figure 6 6 Menu 15 1 Address Mapping Sets 1 NAT SET is a set name that was created as an example Information about creating your own address mapping sets is provided later in the chapter Let s look first at Option 255 Option 255 is equivalent to SUA in previous ZyXEL routers see section 6 1 5 The fields in this menu cannot be changed Entering 255 brings up this screen Menu 15 1 255 Address Mapping Rules Set Name SUA Start IP Local End IP Global Start IP Global End IP Server Press ENTER to Confirm or ESC to Cancel Figure 6 7 Menu 15 1 255 SUA Address Mapping Rules The following table explains the fields in this screen The fields in this menu are read only The Type Local and Global Start End IPs are normally not for this read only menu configured in menu 15 1 1 1 described later and the values are displayed here 6 8 NAT ZyWALL 10 Internet Security Gateway Table 6 4 SUA Address Mapping Rules
131. e simplest form NAT changes the source IP address in a packet received from a subscriber the inside local address to another the inside global address before forwarding the packet to the WAN side When the response comes back NAT translates the destination address the inside global address back the inside local address before forwarding it to the original inside host Note that the IP address either local or global of an outside host is never changed NAT 6 1 ZyWALL 10 Internet Security Gateway The global IP addresses for the inside hosts can be either static or dynamically assigned by the ISP In addition you can designate servers e g a web server and a telnet server on your local network and make them accessible to the outside world If you do not define any servers for Many to One and Many to Many Overload mapping see below NAT offers the additional benefit of firewall protection If no server is defined in these cases all incoming inquiries will be filtered out by your ZyW ALL thus preventing intruders from probing your network For more information on IP address translation refer to RFC 1631 The IP Network Address Translator NAT 6 1 3 How NAT works Each packet has two addresses a source address and a destination address For outgoing packets the ILA Inside Local Address is the source address on the LAN and the IGA Inside Global Address is the source address on the WAN For incoming packets the IL
132. ecifying how a personal computer PC interacts with a broadband modem i e xDSL cable wireless etc connection For the service provider PPPoE offers an access and authentication method that works with existing access control systems e g Radius For the user PPPoE provides a login amp authentication method that the existing Microsoft Dial Up Networking software can activate and therefore requires no new learning or procedures for Windows users One of the benefits of PPPoE is the ability to let end users access one of multiple network services a function Internet Access 3 11 ZyWALL 10 Internet Security Gateway known as dynamic service selection This enables the service provider to easily create and offer new IP services for specific users Operationally PPPOE saves significant effort for both the end user and ISP carrier as it requires no specific configuration of the broadband modem at the customer site By implementing PPPoE directly on the ZyWALL 10 rather than individual computer s the computers on the LAN do not need PPPOE software installed since the ZyW ALL does that part of the task Furthermore with NAT all of the LAN s computers will have access If you enable PPPoE in menu 4 you will see the next screen For more information on PPPoE please see the Appendices Menu 4 Internet Access Setup ISP s Name ChangeMe Encapsulation PPPOE Service Type My Login My Password
133. ee ennt eene tentes trennen eene 20 2 Figure 20 2 Bist Update Screen eat ier d Ee Dee ee oe seek oe ERRORES 20 3 Figure 20 3 Exempt Zone SCreen 6 5 opone or ene Hte Er REEF Rr Pe tei HEP EE ESQ S 20 4 Figure 20 4 Customize Screen E 20 5 Figure 20 5 Keyword Screens EE En Ute te erc N RE EE EN 20 6 Figure 20 6 Eogs Sereen onini eee dE Rha in eet is Be eee 20 7 xxii List of Figures ZyWALL 10 Internet Security Gateway List of Tables Table 2 1 EED f nctions eoo etae eH e E ee ute ae m bees 2 1 Table 2 2 Main Menu Commands rie eet e pei se He sage E PERO SR De ree rer EE BEG BEDR Tes S 2 5 Table 2 3 Mam Menu Stunde eege peii ro dete ordei dete ir sce E ey 2 7 Table 2 4 General Setup Menu Field 2 11 Table 2 5 Configure Dynamic DNS Menu Fields 2 12 Table 2 6 WAN Setup Menu Fields se see se se ee ee eee nennen ren rennen treten trennen tren 2 13 Table 3 1 DHCP Ethernet Setup Menu Fields 3 6 Tabl 3 2 LAN TCP IP Setup Menu Fields eer tr eee ho e tel leet de Ee ee os 3 6 Table 3 3 IP Alias Setup Menu Fields iese see see se ee ee Ge Se Se GR RA RA nren trennen trennen trenes 3 8 Table 3 4 Internet Access Setup Menu Fields se Ge RA Ge ee Ge ee ee ee ee GR Se Re GR Re 3 9 Table 3 5 New Fields in Menu 4 PPTP screen 3 11 Table 3 6 New Fields in Menu 4 PPPOE screen iese sesse ee se se ee ee se ee ER Re ee Ge ee ee GR Re ee ee ee Re ee Ge ee nennen nene 3 12 Table 4 1 Fieldsin Men
134. egal rights and you may also have other rights that vary from country to country ZA Online Registration Don t forget to register your ZyXEL product fast easy online registration at www zyxel com for free future product updates and information ZyXEL Limited Warranty vii ZyWALL 10 Internet Security Gateway Customer Support When you contact your customer support representative please have the following information ready ZyWALL Model and serial number Information in Menu 24 2 1 System Information Warranty Information Date you received your ZyWALL Brief description of the problem and the steps you took to solve it 999 Method Region Worldwide North America Scandinavia EMAIL Support EMAIL Sales SUpport zyxel com tw support europe zyxel com sales zyxel com tw Telephone Fax 886 3 578 3942 886 3 578 2439 Web Site FTP Site www zyxel com www europe zyxel com ftp europe zyxel com support zyxel com sales zyxel com support zyxel dk sales zyxel dk 1 714 632 0882 800 255 4101 1 714 632 0858 45 3955 0700 45 3955 0707 support zyxel at sales zyxel at support zyxel de sales zyxel de 43 1 4948677 0 0810 1 ZyXEL 0810 1 99935 43 1 4948678 49 2405 6909 0 0180 5213247 Tech Support hotline 0180 5099935 49 2405 6909 99 www zyxel com ftp zyxel com www zyxel dk ftp zyxel dk www zyxel at ftp zyxel
135. en sessions per minute The above numbers cause the ZyWALL to start deleting half open sessions when more than 100 session establishment attempts have been detected in the last minute and to stop deleting half open sessions when fewer than 80 session establishment attempts have been detected in the last minute Maximum Incomplete Low This is the number of existing half open sessions that causes the firewall to stop deleting half open sessions The ZyWALL continues to delete half open requests as necessary until the number of existing half open sessions drops below this number 80 existing half open sessions Maximum Incomplete High This is the number of existing half open sessions that causes the firewall to start deleting half open sessions When the number of existing half open sessions 100 half open sessions per minute The above values causes the ZyWALL to start deleting 15 10 Introducing the ZyWALL Web Configurator ZyWALL 10 Internet Security Gateway FIELD DESCRIPTION DEFAULT VALUES rises above this number the ZyWALL half open sessions when deletes half open sessions as required to the number of existing accommodate new connection requests half open sessions rises Do not set Maximum Incomplete High to above 100 and to stop lower than the current Maximum deleting half open Incomplete Low number sessions with the number of existing half open s
136. en to the RIP multicast address and so will not receive the RIP packets However if one router uses multicasting then all routers on your network must use multicasting also By default RIP Direction is set to Both and the Version set to RIP 1 3 1 6 IP Multicast Traditionally IP packets are transmitted in one of either two ways Unicast 1 sender 1 recipient or Broadcast 1 sender everybody on the network Multicast delivers IP packets to a group of hosts on the network not everybody and not just 1 IGMP Internet Group Multicast Protocol is a session layer protocol used to establish membership in a Multicast group it is not used to carry user data IGMP version 2 RFC 2236 is an improvement over version 1 RFC 1112 but IGMP version 1 is still in wide use If you would like to read more detailed information about interoperability between IGMP version 2 and version 1 please see sections 4 and 5 of RFC 2236 The class D IP address is used to identify host groups and can be in the range 224 0 0 0 to 239 255 255 255 The address 224 0 0 0 is not assigned to any group and is used by IP multicast computers The address 224 0 0 1 is used for query messages and is assigned to the permanent group of all IP hosts including gateways All hosts must join the 224 0 0 1 group in order to participate in IGMP The address 224 0 0 2 is assigned to the multicast routers group The ZyWALL supports both IGMP version 1 IGMP v1 and IGMP version 2
137. end the alerts Tuesday We want to send an alert at this time Figure 19 2 Example 1 E mail Screen Example Firewall Rules 19 3 ZyWALL 10 Internet Security Gateway Step 3 Configure your firewall rule as shown in the following screen The default firewall blocks all Internet traffic entering our local network but you want to create a hole for web service from the Internet Click Internet and go to the Rule Summary Configure this screen as shown win LON Click DestAdd to Fa droe ES This is an Internet to Local Network rule iN configure the destination MAIN MENU Internet to Local Network address as the IP of the server on the LAN See AHHA Source IP Address fth DestinftionIPAd the next screen CONFIGURATION Any LOCAL NETWORK INTERNET CUSTOM PORTS LOGS SrcAdd _SrcEdit SrcDelete Firewall Select this POP TCP 110 HTTP TCP 80 joe web Syslog UDP 514 service from the SE Available BGP TCP 173 Services list box and click gt gt LOGOUT Forward the packet when it matches this rule remember the default is to block all packets from the Internet log packets that match this rule and to send alerts when this happens Click this button when you have finished editing screens Figure 19 3 Example 1 Configuring a Rule 19 4 Example Firewall Rules ZyWALL 10 Internet Security Gateway Step 4 Click DestAdd to configure the destin
138. enu 21 to prevent NetBIOS traffic from triggering calls and block incoming telnet FTP and HTTP connections If you do not activate the firewall it is advisable to apply these default filters as shown next 7 6 1 LAN traffic LAN traffic filter sets may be useful to block certain packets reduce traffic and prevent security breaches Go to menu 3 1 shown next and enter the number s of the filter set s that you want to apply as appropriate You can choose up to four filter sets from twelve by entering their numbers separated by commas e g 3 4 6 11 Input filter sets filter incoming traffic to the ZyWALL and output filter sets filter outgoing traffic from the ZyWALL The factory default set NetBIOS LAN can be inserted in the protocol filters field under Input Filter Sets in menu 3 1 to block NetBIOS traffic to the ZyWALL from the LAN 7 16 Filters ZyWALL 10 Internet Security Gateway Menu 3 1 LAN Port Filter Setup Input Filter Sets Apply B protocol filters 2 default filter device filters 2 here Output Filter Sets protocol filters device filters Press ENTER to Confirm or ESC to Cancel Figure 7 16 Filtering LAN Traffic 7 6 2 Remote Node Filters Go to menu 11 5 shown below note that call filter sets are only present for PPPoE encapsulation and enter the number s of the filter set s as appropriate You can cascade up to four filter sets by entering their numbers se
139. ep 1 Enter y at the prompt to go into debug mode Step 2 Enter atlc after the Enter Debug Mode message Step 3 Wait forthe Starting XMODEM upload message before activating Xmodem upload on your terminal Xmodem upload will be similar to the previous example for uploading firmware Step 4 After successful firmware upload enter at go to restart the ZyWALL Menu 24 7 2 System Maintenance Upload Router Configuration File To upload router configuration file 1 Enter y at the prompt below to go into debug mode 2 Enter atlc after Enter Debug Mode message 3 Wait for Starting XMODEM upload message before activating Xmodem upload on your terminal 4 After successful configuration file upload enter atgo to restart the router Warning 1 Proceeding with the upload will erase the current configuration file 2 The router s console port speed Menu 24 2 2 may change when it is restarted please adjust your terminal s speed accordingly The password may change menu 23 also 3 When uploading the DEFAULT configuration file the console port speed will be reset to 9600 bps and the password to 1234 Do You Which To Proceed Y N Figure 10 12 Menu 24 7 2 System Maintenance Upload Router Configuration File 10 5 TFTP File Transfer In addition to the direct console port connection the ZyW ALL supports the up downloading of the firmware and the configuration file using TFTP Trivial File
140. er Firmware 10 4 2 Example Xmodem Upload Using HyperTerminal Click Transfer then Send File to display the following screen Send File KHE Type the bin firmware Folder C Projects John ZyWALL10 Fimware b M Browse to look for it Filename CAZYKELMFimware bin Browse Protocol Choose the Xmodem de protocol Send 55E Cance Then click Send Figure 10 11 Example Xmodem Upload 10 4 3 Uploading Router Configuration File The configuration data system related data the error log and the trace log are all stored in the configuration file Please be aware that uploading the configuration file replaces everything contained within 10 6 Firmware and Configuration File Maintenance ZyWALL 10 Internet Security Gateway Menu 24 6 replaces the current configuration with your customized configuration you backed up previously Menu 24 7 2 shows you the instructions for uploading the Router Configuration file that replaces the current configuration file with the default configuration file i e zywall rom You will lose all configurations that you had before and the speed of the console port will be reset to the default of 9600 bps with 8 data bit no parity and 1 stop bit 8n1 You will need to change your serial communications software to the default before you can connect to the ZyWALL again The password will be reset to the default of 1234 also Follow the procedure below to upload the configuration file St
141. es skip ahead to section 3 2 to see how to enter the DNS server address es 3 1 2 DHCP Configuration DHCP Dynamic Host Configuration Protocol RFC 2131 and RFC 2132 allows the individual clients to obtain the TCP IP configuration at start up from a server You can configure the ZyWALL as a DHCP server or disable it When configured as a server the ZyW ALL provides the TCP IP configuration for the clients If set to None DHCP service will be disabled and you must have another DHCP sever on your LAN or else the workstation must be manually configured IP Pool Setup The ZyWALL is pre configured with a pool of 32 IP addresses starting from 192 168 1 33 to 192 168 1 64 This configuration leaves 31 IP addresses excluding the ZyW ALL itself in the lower range for other server machines e g server for mail FTP telnet web etc that you may have DNS Server Address DNS Domain Name System is to map a domain name to its corresponding IP address and vice versa e g the IP address of www zyxel com is 204 217 0 2 The DNS server is extremely important because without it you must know the IP address of a machine before you can access it There are two ways that an ISP disseminates the DNS server addresses The first is for an ISP to tell a customer the DNS server addresses usually in the form of an information sheet when you sign up If your ISP does give you the DNS server addresses enter them in the DNS Server fields in DHCP Setup Th
142. ess Mapping Rule see 6 21 Figure 6 23 Example 4 Menu 15 1 1 Address Mapping Rules esee 6 21 Figure 7 1 Outgoing Packet Filtering Process AA 7 1 Figure 7 2 Filter Rule Process SR EE DR Ee Ee ne e pee t eere 7 3 Figure 7 4 Menu 21 Filter and Firewall Setup 7 4 Figure 7 5 Menu 21 1 Filter Set Configuration essent nennen eene ener 7 4 Figure 7 6 NetBIOS WAN Filter Rules Summary sees nennen nene en nennen eene 7 5 Figure 7 7 NetBIOS LAN Filter Rules Summary see see se ee ee Ge Se ee ee eene 7 5 Figure 7 8 TEL FTP WEB WAN Filter Rules Summary 7 5 Figure 7 9 Menu 21 1 1 1 TCP IP Filter Rule 7 7 Figure 7 10 Executing an IP Per 7 10 Figure 7 11 Menu 21 4 1 1 Generic Filter Rule 7 11 Figure 7 12 Telnet Filter Example eher tere EEE ertet eri es 7 13 Figure 7 13 Example Filter Menu 21 7 14 Figure 7 14 Example Filter Rules Summary Menu 21 1 3 uie se se se se Ge RA GR Gee Ge ee ee ee ee ee ee ee 7 15 Figure 7 15 Protocol and Device Filter Sets iese se se ee ed Ge ee Ge ee ee ee ee Ge Se Re Se Re RA Ge ed Ge 7 16 Figure 7 16 Filtering LAN Traffic 7 17 Figure 7 17 Filtering Remote Node Traffic 7 17 Figure 8 1 Menu 22 SNMP Confteuraton nennen nennen rennen ener 8 1 Figure 9 1 Menu 24 System Maintenance nenne trennen trennen rennen enne 9 1 Figure 9 2 Menu 24 1 System Maintenance Stats 9 2 Figure 9 3 Menu 24 2 System Information and Console Port S
143. essions drops below 80 TCP Maximum This is the number of existing half open 10 existing half open TCP Incomplete TCP sessions with the same destination sessions host IP address that causes the firewall to start dropping half open sessions to that same destination host IP address Enter a number between 1 and 250 As a general rule you should choose a smaller number for a smaller network a slower system or limited bandwidth Blocking Time When TCP Maximum Incomplete is Check this checkbox to reached you can choose if the next specify a number in session should be allowed or blocked If minutes min text box you check Blocking Time any new sessions will be blocked for the length of time you specify in the next field min and all old incomplete sessions will be cleared during this period If you want strong security it is better to block the traffic for a short time as it will give the server some time to digest the loading min Enter the length of Blocking Time in 10 minutes When you have finished click Apply to save your customized settings and exit this screen Cancel to exit this screen without saving or Help for online HTML help on fields in this screen Introducing the ZyWALL Web Configurator 15 11 ZyWALL 10 Internet Security Gateway Chapter 16 Creating Custom Rules This chapter contains instructions for defining both Local Network and Internet rules 16 1 Rules Overview Firewall rules
144. et gt rule rule s address subnet ma rcaddr subnet ip Sk config edit firewall set set gt rule rule s rcaddr range start ip address end ip address config edit firewall set rule rule gt destaddr single address config edit firewall set rule rule gt destaddr subnet address subnet ma config edit firewall set rule rule 4 destaddr range start ip set gt ip set gt ip Sk set gt address end ip address config edit firewall set set gt rule rule 4 TCP destport single port gt config edi rule rule start por config edi rule rule gt U port gt config edi rule rule start por config edi rule rule t firewall set set 4 gt TCP destport range t gt lt end port gt t firewall set lt set gt DP destport single t firewall set set 4 gt UDP destport range t gt lt end port gt t firewall set lt set gt gt destport custom lt desired custom port name gt Description Selects and edits a source address and subnet mask of traffic which comply to this rule Selects and edits a source address range of traffic which comply to this rule Selects and edits a destination address of the traffic which comply to this rule Selects and edits a destination address and subnet mask of traffic which comply to this rule Sele
145. etermine whether or not this phenomenon exists and if necessary implement corrective action before interconnecting the products If the equipment is to be used with telecommunications circuit take the following precautions e Never install telephone wiring during a lightning storm e Never install telephone jacks in wet location unless the jack is specially designed for wet location e Never touch uninsulated telephone wires or terminals unless the telephone line has been disconnected at the network interface e Use caution when installing or modifying telephone lines other than a cordless telephone during an electrical storm There is a remote risk of electric shock from lightning Safety Instructions ZyWALL 10 Internet Security Gateway Appendix E Firewall CLI Commands The following table describes the syntax used to configure your firewall using Command Line Interface CLI commands Select Menu 24 8 Command Interpreter Mode from the main menu to go into CLI mode For details on other CLI commands to configure your ZyW ALL please consult the included disk Function Firewall Set Up CLI Syntax config no edit firewall active yes config retrieve firewall config save firewall Display config display firewall config gt display firewall set lt set config display firewall set lt set gt rule lt rule gt config display firewall attack config display firewall e mail confi
146. eters described in the following table to activate syslog then choose what you want to log Table 9 3 System Maintenance Menu Syslog Parameters PARAMETER DESCRIPTION UNIX Syslog Active Syslog IP Address Log Facility Press SPACE BAR to turn syslog on or off Enter the IP Address of the server that will log the CDR Call Detail Record and system messages i e the syslog server Press SPACE BAR to select a Local option The log facility allows you to log the message to different files in the server Please refer to your UNIX manual for more details Types CDR Call Detail Record CDR logs all data phone line activity if set to Yes Packet triggered The first 48 bytes or octets and protocol type of the triggering packet is sent to the UNIX syslog server when this field is set to Yes Filter log No filters are logged when this field is set to No Filters with the individual filter Log Filter field set to Yes Menu 21 x x are logged when this field is set to Yes PPP log PPP events are logged when this field is set to Yes Firewall log When set to Yes the ZyWALL sends the firewall log to a syslog server When finished configuring this screen press ENTER to confirm or ESC to cancel Your ZyWALL sends five types of syslog messages Some examples not all ZyWALL specific of these syslog messages with their message formats are shown next System Information amp Diagnosis 9 7
147. ex WAN Ethernet Specification for 10 100 Mbit Half Full Auto negotiation LAN Console Port RS 232 Pin 1 NON Pin 2 DTE RXD Pin 3 DTE TXD Pin 4 DTE DTR Pin 5 GND Pin 6 DTE DSR Pin 7 DTE RTS Pin 8 DTE CTS PIN 9 NON See Figure below Pinl O O O O O OO O Q Pin 9 Pin 6 WAN LAN Cable Pin Layout Straight Through Crossover Switch Adapter Switch Switch 1 IRD 1 OTD 1 IRD 1 IRD 2 IRD 2 OTD 2 IRD 2 IRD 3 OTD 3 IRD 3 OTD 3 OTD 6 OTD 6 IRD 6 OTD 6 OTD Hardware Specifications E ZyWALL 10 Internet Security Gateway Appendix D Important Safety Instructions The following safety instructions apply to the ZyWALL 1 2 NR La 10 11 Be sure to read and follow all warning notices and instructions The maximum recommended ambient temperature for the ZyWALL is 40 Celsius 104 Fahrenheit Care must be taken to allow sufficient air circulation or space between units when the ZyWALL is installed inside a closed rack assembly The operating ambient temperature of the rack environment might be greater than room temperature Installation in a rack without sufficient airflow can be unsafe Racks should safely support the combined weight of all equipment The connections and equipment that supply power to the ZyW ALL should be capable of operating safely with the maximum power requirements of the ZyW AL
148. f the LAN LEDs come on immediately after the SYS LED comes on if connections have been made to the LAN and WAN ports Initial Screen When you turn on your ZyW ALL it performs several internal tests as well as line initialization After the tests the ZyWALL asks you to press ENTER to continue as shown next Copyright c 1994 2001 ZyXEL Communications Corp initialize ch 0 ethernet address 00 a0 c5 41 51 61 initialize ch 1 ethernet address 00 a0 c5 41 51 62 Press ENTER to continue Figure 2 3 Initial Screen Entering Password The login screen appears after you press ENTER prompting you to enter the password as shown below For your first login enter the default password 1234 As you type the password the screen displays an X for each character you type Please note that if there is no activity for longer than five minutes after you log in your ZyWALL will automatically log you out and will display a blank screen If you see a blank screen press ENTER to bring up the login screen again Enter Password XXXX Figure 2 4 Password Screen 2 5 Navigating the SMT Interface The SMT System Management Terminal is the interface that you use to configure your ZyWALL 2 4 Hardware Installation amp Initial Setup ZyWALL 10 Internet Security Gateway Several operations that you should be familiar with before you attempt to modify the configuration are listed in the table below Table 2
149. for more information on adding and editing SrcDelete Source addresses Destination Address Press DestAdd to add a new address DestAdd DestEdit to edit an existing one or DestEdit DestDelete to delete one Please see the Bst next information on adding and editing DestDelete destination addresses Services Please see Table 16 2for more information gt gt Available Selected on services available Highlight a service valepleieelsele from the Available Services box on the left SES then press to add it to the Selected Services box on the right To remove a service highlight it in the Selected Services box on the right then press Action for Matched Packets Should packets that match this rule be Block blocked or forwarded Make your choice Forward from the drop down list box Note that Block ONE means the firewall silently discards the packet Log This field determines if a log is created for Match packets that match the rule don t match the Not Match rule both or no log is created BEIEN Both None Alert Check the Alert check box to determine that When you have finished click Apply to save your customized settings and exit this screen Cancel to exit this screen without saving or Help for online HTML help on fields in this screen Creating Custom Rules 16 11 ZyWALL 10 Internet Security Gateway 16 5 2 Source and Destination Addresses To add a new source or destination address click SrcAdd or Dest
150. g Hacking every possible combination of letters numbers etc until the code is broken Byte A set of bits that represent a single character There are 8 bits in a Byte Camping Out Staying in a safe place once a hacker has broken into a system The term can be used with a physical location electronic reference or an entry point for future attacks CDR Call Detail Record This is a name used by telephone companies for call related information CHAP Challenge Handshake Authentication Protocol is an alternative protocol that avoids sending passwords over the wire by using a challenge response technique Cipher Text Text that has been scrambled or encrypted so that it cannot be read without deciphering it See Encryption Client A software program that is used to contact and obtain data from a Server software program on another computer Each Client program is designed to work with one or more specific kinds of Server programs and each Server requires a specific kind of Client A Web Browser is a specific kind of Client N Glossary of Terms ZyWALL 10 Internet Security Gateway Cookie Countermeasures Cracker Cracker Tools Cracking Crossover Ethernet cable Cryptoanalysis CSU DSU DCE Decryption Denial of Service DHCP A string of characters saved by a web browser on the user s hard disk Many web pages send cookies to track specific user information Cookies can be used to retain information as the user br
151. g display firewall Edit E mail config edit firewall e mail mail server ip address of mail server config edit firewall e mail return addr e mail address Description Activates or deactivates the saved firewall settings Retrieves currently saved firewall settings Saves the current firewall settings Displays the all the firewall settings including e mail attack and sets rules Displays current entries of a set configuration including timeout values name default permit and number of rules under it If you don t put after set it will display all the sets rules information Displays current entries of a rule in a set configuration Displays all the settings for attack alert Displays all the setting for e mail part Displays all the available sub commands Edits the mail server which alerting e mail messages are sent through Edits the source address for sending mail usage CLI Commands ZyWALL 10 Internet Security Gateway Function CLI Syntax Description config edit firewall e mail Edits the mail address which you want to send the alert to email to e mail address config edit firewall e mail Edits whether the current firewall traffic log contents are sent policy through e mail when the log is full hourly daily or weekly full hourly daily weekly config edit firewall e mail day Edits the day the current fi
152. g functionality in a manner similar to dial up services using PPP Benefits of PPPoE PPPoE offers the following benefits l It provides you with a familiar dial up networking DUN user interface 2 It lessens the burden on the carriers of provisioning virtual circuits all the way to the ISP on multiple switches for thousands of users For GSTN PSTN amp ISDN the switching fabric is already in place 3 It allows the ISP to use the existing dial up model to authenticate and optionally to provide differentiated services Traditional Dial up Scenario The following diagram depicts a typical hardware configuration where the PCs use traditional dial up networking ISP 1 O 423 fo il 412 Cc q YU Cc ISP 2 o QO Diagram 1 Single PC per Modem Hardware Configuration PPPoE A ZyWALL 10 Internet Security Gateway How PPPoE Works The PPPOE driver makes the Ethernet appear as a serial link to the PC and the PC runs PPP over it while the modem bridges the Ethernet frames to the Access Concentrator AC Between the AC and an ISP the AC is acting as a L2TP Layer 2 Tunneling Protocol LAC L2TP Access Concentrator and tunnels the PPP frames to the ISP The L2TP tunnel is capable of carrying multiple PPP sessions With PPPOE the VC Virtual Circuit is equivalent to the dial up connection and is between the modem and the AC as opposed to all the way to the ISP However the PPP negotiation is between the PC and the ISP
153. gure below The community for Get Set and Trap fields is simply SNMP s terminology for password Menu 22 SNMP Configuration SNMP Get Community public Set Community public Trusted Host 0 0 0 0 Trap Community public Destination 0 0 0 0 Press ENTER to Confirm or ESC to Cancel Figure 8 1 Menu 22 SNMP Configuration SNMP 8 1 ZyWALL 10 Internet Security Gateway The following table describes the SNMP configuration parameters Table 8 1 SNMP Configuration Menu Fields FIELD DESCRIPTION DEFAULT Get Enter the get community which is the password for the public Community incoming Get and GetNext requests from the management station Set Enter the set community which is the password for incoming public Community Set requests from the management station Trusted Host If you enter a trusted host your ZyWALL will only respond to blank SNMP messages from this address If you leave the field blank default your ZyWALL will respond to all SNMP messages it receives regardless of source Trap Community Enter the trap community which is the password sent with each public trap to the SNMP manager Destination Enter the IP address of the station to send your SNMP traps to 0 0 0 0 Once you have completed filling in Menu 22 SNMP Configuration press ENTER at the message Press ENTER to Confirm to save your configuration or press ESC to cancel 8 2 S
154. hat may be displayed in the Reason column of the firewall log are briefly described in Table 14 4 View Firewall Log 14 1 2 Attack Types Land In a LAND Attack hackers flood SYN packets into the network with a spoofed source IP address of the targeted system This makes it appear as if the host computer sent the packets to itself making the system unavailable while the target system tries to respond to itself IP Spoofing IP Spoofing may be used to break into systems to hide the hacker s identity or to magnify the effect of the DoS attack IP Spoofing is a technique used to gain unauthorized access to computers by tricking a router or firewall into thinking that the communications are coming from within the trusted network To engage in IP spoofing a hacker must modify the packet headers so that it appears that the packets originate from a trusted host and should be allowed through the router or firewall The ZyW ALL blocks all IP Spoofing attempts 14 2 Introducing the ZyWALL Firewall ZyWALL 10 Internet Security Gateway ICMP Echo A brute force attack such as a Smurf attack targets a feature in the IP specification known as directed or subnet broadcasting to quickly flood the target network with useless data A Smurf hacker floods a router with Internet Control Message Protocol ICMP echo request packets pings Since the destination IP address of each packet is the broadcast address of the network the router will b
155. hich includes connection information such as IP addresses TCP ports sequence numbers etc When any subsequent packet hits the box from the Internet or from the LAN its connection information is extracted and checked against the cache A packet is only allowed to pass through if it corresponds to a valid connection that is if it is a response to a connection which originated on the LAN 13 4 4 UDP ICMP Security UDP and ICMP do not themselves contain any connection information such as sequence numbers However at the very minimum they contain an IP address pair source and destination UDP also contains port pairs and ICMP has type and code information All of this data can be analyzed in order to build virtual connections in the cache For instance any UDP packet that originates on the LAN will create a cache entry Its IP address and port pairs will be stored For a short period of time UDP packets from the WAN that have matching IP and UDP information will be allowed back in through the firewall A similar situation exists for ICMP except that the ZyW ALL is even more restrictive Specifically only outgoing echoes will allow incoming echo replies outgoing address mask requests will allow incoming address mask replies and outgoing timestamp requests will allow incoming timestamp replies No other ICMP packets are allowed in through the firewall simply because they are too dangerous and contain too little tracking information Fo
156. his device must accept any interference received including interference that may cause undesired operations This equipment has been tested and found to comply with the limits for a CLASS B digital device pursuant to Part 15 of the FCC Rules These limits are designed to provide reasonable protection against harmful interference in a commercial environment This equipment generates uses and can radiate radio frequency energy and if not installed and used in accordance with the instructions may cause harmful interference to radio communications If this equipment does cause harmful interference to radio television reception which can be determined by turning the equipment off and on the user is encouraged to try to correct the interference by one or more of the following measures Reorient or relocate the receiving antenna Increase the separation between the equipment and the receiver Connect the equipment into an outlet on a circuit different from that to which the receiver is connected Consult the dealer or an experienced radio TV technician for help Notice 1 Changes or modifications not expressly approved by the party responsible for compliance could void the user s authority to operate the equipment Notice 2 Use of Shielded RS 232 cables is required to ensure compliance with FCC Part 15 and it is the responsibility of the user to provide and use shielded RS 232 cables FCC iii ZyWALL 10 Internet Security Gateway Infor
157. hooting the WAN interface Problem Corrective Action Cannot get WAN IP from the ISP The WAN IP is provided when the ISP recognizes the user as an authorized user after verifying the MAC address or Host Name or User ID Find out the verification method used by your ISP If the ISP checks the LAN MAC Address tell the ISP the WAN MAC address of the ZyWALL The WAN MAC can be obtained from menu 24 1 In case the ISP does not allow you to use a new MAC you can clone the MAC from the LAN as the WAN MAC and send it to the ISP using Menu 2 WAN Setup We recommend you configure this menu anyway even if your ISP presently does not require MAC address authentication If the ISP checks the Host Name enter host name in the System Name field in Menu 1 General Setup when you connect the ZyWALL to a cable xDSL modem If the ISP checks the User ID make sure that you have entered the correct Service Type user name in the My Login field and password in the My Password field in Menu 4 Internet Access Setup Can t connect to a remote node or ISP Check menu 24 1 to verify the line status If it indicates Down then refer to the section on the line problems 21 2 Troubleshooting ZyWALL 10 Internet Security Gateway 21 4 Problems with Internet Access Table 21 4 Troubleshooting Internet Access Problem Corrective Action Cannot access the Connect your Cable xDSL modem with the
158. ia the console port There are two components in the system the router firmware and the configuration file as shown below Figure 10 9 Menu 24 7 10 4 1 Uploading the Router Fir Menu 24 7 System Maintenance Upload Firmware 1 Upload Router Firmware 2 Upload Router Configuration File Enter Menu Selection Number System Maintenance Upload Firmware mware Menu 24 7 1 shows you the instructions for uploading the router firmware Follow the procedure below to upload the file Step 1 Enter y at the prompt to go into debug mode Step 2 Enter atur after the Enter Debug Mode message Step 3 Wait for the Starting XMOD your terminal EM upload message before activating Xmodem upload on Firmware and Configuration File Maintenance 10 5 ZyWALL 10 Internet Security Gateway Step 4 After successful firmware upload enter at go to restart the ZyWALL Menu 24 7 1 System Maintenance Upload Router Firmware To upload router firmware 1 Enter y at the prompt below to go into debug mode 2 Enter atur after Enter Debug Mode message 3 Wait for Starting XMODEM upload message before activating Xmodem upload on your terminal 4 After successful firmware upload enter atgo to restart the router Warning Proceeding with the upload will erase the current router firmware Do You Wish To Proceed Y N Figure 10 10 Menu 24 7 1 System Maintenance Upload Rout
159. ic Filter Rule in the Filter Type field in menu 21 4 1 1 and press ENTER to open Generic Filter Rule as shown below Menu 21 4 1 1 Generic Filter Rule Filter 4 4 1 Filter Type Generic Filter Rule Active No Offset 0 Length 0 Mask N A Value N A More No Log None Action Matched Check Next Rule Action Not Matched Check Next Rule Press ENTER to Confirm or ESC to Cancel Press Space Bar to Toggle Figure 7 11 Menu 21 4 1 1 Generic Filter Rule The following table describes the fields in the Generic Filter Rule Menu Filters 7 11 ZyWALL 10 Internet Security Gateway Table 7 4 Generic Filter Rule Menu Fields FIELD DESCRIPTION OPTIONS Filter This is the filter set filter rule co ordinates i e 2 3 refers to the second filter set and the third rule of that set Filter Type Use the SPACE BAR to select a rule type Parameters displayed below Generic Filter each type will be different TCP IP filter rules are used to filter IP packets Rule TCP IP while generic filter rules allow filtering of non IP packets Filter Rule Active Select Yes to turn on the filter rule or No to turn it off Yes Offset Enter the starting byte of the data portion in the packet that you wish to 0 compare The range for this field is from 0 to 255 Default Length Enter the byte count of the data portion in the packet that you wish to 0 compare The range for this field is O
160. ic and direct it to a number of specific systems The router need only allow application traffic destined for the application gateway and reject the rest 13 1 3 Stateful Inspection Firewalls Stateful inspection firewalls restrict access by screening data packets against defined access rules They make access control decisions based on IP address and protocol They also inspect the session data to assure the integrity of the connection and to adapt to dynamic protocols These firewalls generally provide the best speed and transparency however they may lack the granular application level access control or caching that some proxies support See section 13 4 for more information on Stateful Inspection Firewalls of one type or another have become an integral part of standard security solutions for enterprises 13 2 Introduction to ZyXEL s Firewall The ZyWALL firewall is a stateful inspection firewall and is designed to protect against Denial of Service attacks when activated in SMT menu 21 2 or in the ZyWALL Web Configurator The ZyWALL s purpose is to allow a private Local Area Network LAN to be securely connected to the Internet The ZyWALL can be used to prevent theft destruction and modification of data as well as log events which may be important to the security of your network The ZyWALL also has packet filtering capabilities The ZyWALL is installed between the LAN and a broadband modem connecting to the Internet This allows it
161. ignatures are created when someone generates a hash from a message then encrypts and sends both the hash and the message to the intended recipient The recipient decrypts the hash and original message makes a new hash on the message itself and compares the new hash with the old one If the hashes are the same the recipient knows that the message has not been changed Also see Public key encryption Domain Name System A database of domain names and their IP addresses DNS is the primary naming system for many distributed networks including the Internet The unique name that identifies an Internet site Domain Names always have 2 or more parts separated by dots The part on the left is the most specific and the part on the right is the most general Dynamic RAM that stores information in capacitors that must be refreshed periodically Digital Subscriber Line technologies enhances the data capacity of the existing twisted pair wire that runs between the local telephone company switching offices and most homes and offices There are actually seven types of DSL service ranging in speeds from 16 Kbits sec to 52 Mbits sec The services are either symmetrical traffic flows at the same speed in both directions or asymmetrical the downstream capacity is higher than the upstream capacity DSL connections are point to point dedicated circuits meaning that they are always connected There is no dial up There is also no switching which means tha
162. ination addresses This remembering is called saving the state When the outside system responds to your request the firewall compares the received packets with the saved state to determine if they are allowed in The ZyW ALL uses stateful packet inspection to protect the private LAN from hackers and vandals on the Internet By default the ZyWALL s stateful inspection allows all communications to the Internet that originate from the LAN and blocks all traffic to the LAN that originates from the Internet In summary stateful inspection Q Allows all sessions originating from the LAN local network to the WAN Internet 13 6 What Is a Firewall ZyWALL 10 Internet Security Gateway Q Denies all sessions originating from the WAN Internet to the LAN local network Protected WAN LAN ser Alinitiates a Telnet sessioh R turn traffic for User A s Telnet session is permitted ther Telnet traffic is blocked ZyWALL 10 Figure 13 5 Stateful Inspection The previous figure shows the ZyW ALL s default firewall rules in action as well as demonstrates how stateful inspection works User A can initiate a Telnet session from within the LAN and responses to this request are allowed However other Telnet traffic initiated from the WAN is blocked 13 4 1 Stateful Inspection Process In this example the following sequence of events occurs when a TCP packet leaves the LAN network through the firewall s WAN inte
163. information Action This is the specified action for that rule Note that Block Block means the firewall silently discards the packet Forward Log This field shows you if a log is created for packets that Match match the rule don t match the rule both or no log is Not Match created Both None Move Rule To Rule Number Move You may reorder your rules using this function Select by clicking on the rule you want to move The ordering of your rules is important as rules are applied in turn In this box type the number you want to move the rule to Click this command button to move the rule 16 6 Creating Custom Rules ZyWALL 10 Internet Security Gateway FIELD DESCRIPTION OPTIONS Click Apply to create a new firewall rule New firewall rules are added at the end after existing firewall rules Click Edit to edit an existing filter rule See section 16 5 for more details Click Delete to delete an existing firewall rule Note that subsequent firewall rules move up by one when you take this action Click Help for online HTML help on fields in this screen 16 5 Predefined Services The Available Services list box in the Rule Config uration screen see Figure 16 4 displays all predefined services that the ZyW ALL already supports Next to the name of the service two fields appear in brackets The first field indicates the IP protocol type TCP UDP or ICMP The second field
164. ing filters depending on the direction of the packet relative to a port Data filtering can be applied on either the WAN side or the LAN side Call filtering is used to determine if a packet should be allowed to trigger a call Remote node call filtering is only applicable when using PPPoE encapsulation Outgoing packets must undergo data filtering before they encounter call filtering as shown in the following figure Call Filtering im AG 1 N i N ive Data MES Built in 9 User defined Outgoing Data match gt default match Cal Eis Initiate call Packet gt Filtering Call Filters if applicable if line not up Send packet 1 n y and reset Match Match Match kie Timer Drop Drop packet Drop packet packet if line not up if line not up Or Or Send packet Send packet but do not reset but do not reset Idle Timer Idle Timer Figure 7 1 Outgoing Packet Filtering Process For incoming packets your ZyW ALL applies data filters only Packets are processed depending upon whether a match is found The following sections describe how to configure filter sets Filters 7 1 ZyWALL 10 Internet Security Gateway 7 1 1 The Filter Structure of the ZyWALL A filter set consists of one or more filter rules Usually you would group related rules e g all the rules for NetBIOS into a single set and gi
165. ing you should do is change the default system password by following the steps shown next Step 1 Enter 23 in the main menu to open Menu 23 System Password as shown below Menu 23 System Password Old Password New Password Retype to confirm Enter here to CONFIRM or ESC to CANCEL Figure 2 7 Menu 23 System Password Step 2 Enter your existing password and press ENTER Step 3 Enter your new system password and press ENTER Step 4 Re type your new system password for confirmation and press ENTER Note that as you type a password the screen displays an X for each character you type 2 6 1 Resetting the ZyWALL If you have forgotten your password or cannot access the SMT menu you will need to reinstall the configuration file Uploading the configuration file replaces the current configuration file with the default configuration file you will lose all configurations that you had before and the speed of the console port will be reset to the default of 9600bps with 8 data bit no parity and 1 stop bit 8n1 The password will be reset to the default of 1234 also Turn off the ZyW ALL and begin a Terminal session with the current console port settings Turn on the ZyW ALL again When you see the message Press Any key to enter Debug Mode within 3 seconds press any key to enter debug mode You should already have downloaded the correct file from your nearest ZyXEL FTP site See Chapter 9 for more information
166. intrusion UDP is a connectionless transport service that dispenses with the reliability services provided by TCP UDP gives applications a direct interface with IP and the ability to address a particular application process running on a host via a port number without setting up a connection session A widely used operating system in large networks Uniform Resource Locator URL is an object on the Internet or an intranet that resides on a host system Objects include directories and an assortment of file types including text files graphics video and audio A URL is the address of an object that is normally typed in the Address field of a Web browser The URL is basically a pointer to the location of an object Virtual Private Network These networks use public connections such as the Internet to transfer information That information is usually encrypted for security purposes Point where a system can be attacked Wide Area Network s link geographically dispersed offices in other cities or around the globe Just about any long distance communication medium can serve as a WAN link including switched and permanent telephone circuits terrestrial radio systems and satellite systems A program that automatically dials phone numbers looking for computers on the other end They catalog numbers so that hackers can call back and try to break in A term that describes Pirated Software on the Internet Warez include cracked games or other p
167. ion field in Menu 24 2 1 System Maintenance Information to confirm that you have uploaded the correct firmware version Firmware and Configuration File Maintenance 10 1 ZyWALL 10 Internet Security Gateway Table 10 1 Filename Conventions FILE TYPE INTERNAL EXTERNAL DESCRIPTION AT NAME NAME COMMAND Configuration Rom 0 rom This is the router configuration ATLC File filename on the ZyWALL Uploading the rom 0 file replaces the entire ROM file system including your ZyWALL configurations system related data including the console port speed and default password the error log and the trace log Firmware This is the generic name for the ZyNOS firmware on the ZyWALL 10 1 1 Firmware Development It is important to upgrade your firmware regularly especially if there are problems If you discover an unexpected behavior or bug see if your problem is mentioned in the release notes Load it according to instructions e g see if the default configuration file is needed also If the problem still exists e mail or call technical support 10 2 Backup Configuration Option 5 from Menu 24 System Maintenance allows you to backup the current ZyW ALL configuration to your workstation Backup is highly recommended once your ZyW ALL is functioning properly FTP and TFIP are the preferred methods for backing up your current workstation configuration to your computer since FTP and TFTP are faster You can also perfor
168. ions Bernie Node Filler Menu 15 2 Maul NAT Server Setup onfigure Dynamic DNS Menu 32 1 IPAlias Setup Menu 24 Nenu 22 Menu 24 5 d ae Menu 24 44 Sysern Maintenance SNMP Configuration Fiter and Firewall Setup SEHR Gran Maintenance Remote Management Menu21 1 Menu 212 Menu 24 1 VENT System Maintenance Filter Set Configuration Firewall Setup System Gatus Men u21 3 Vie wi Firewall Log Menu 26 1 System Maintenance Schedule Set Setup Time and Date Setting Menu 24 21 Menu 21 1x System Inf omatinn Filter Rules Summary Menu 24 9 4 TEER Menu 24 2 Budget Mara gerent System Maintenance Sydern Information and Nenu 21 1x y Generic Filte r Rule Console Port Speed Menu 24 22 AE Change Conso k Port Sheed Menu 244 ay TC RIP Filter Rule Menu 243 Menu 24 3 Menu 24 3 4 Commend Interpreter System Mbirtenan ce View Error Log Mode Log and Trace Nenu 24 32 Call History Menu 24 7 1 Ibload Router Finnware Menu 24 3 2 UNIX Syslog Menu 247 Menu 24 4 Nn u24 7 2 Systern Mailen ance System Maintenance T Men Upload Firmware Diagnostic Upload Router E 9 Menu 243 4 Contiquration Fle Call Triggering Packet Menu 246 Menu 24 5 System Maintenance System Maintenance Restore Configuration Backup Configuration Figure 2 6 SMT Menus at a Glance Hardware Installation amp Initial Setup ZyWALL 10 Internet Security Gateway 2 6 Changing the System Password The first th
169. is Backup Configuration screen Menu 24 5 Backup Configuration To transfer the configuration file to your workstation follow the procedure below 1 Launch the FTP client on your workstation 2 Type open and the IP address of your router Then type root and SMT password as requested 3 Locate the rom 0 file 4 Type get rom 0 to back up the current router configuration to your workstation For details on FTP commands please consult the documentation of your FTP client program For details on backup using TFTP note that you must remain in the menu to back up using TFTP please see your router manual Press ENTER to Exit Figure 10 4 Telnet into Menu 24 5 Backup Configuration Firmware and Configuration File Maintenance 10 3 ZyWALL 10 Internet Security Gateway 10 3 Restore Configuration Menu 24 6 System Maintenance Restore Configuration allows you to restore the configuration via the console port FTP and TFIP are the preferred methods for restoring your current workstation configuration to your ZyW ALL since FTP and TFTP are faster Please note that the system reboots automatically after the file transfer is complete Ready to restore Configuration via Xmodem Do you want to continue y n Figure 10 5 System Maintenance Restore Configuration 10 3 1 Example Restore Configuration Using HyperTerminal In menu 24 6 press y to continue Run the HyperTerminal program Click Tr
170. is acetates gh ee EE tete eet 3 6 Remote Management Setup 11 7 remote Node ssn e EE OE ME 4 1 Remote Node Remote Node Setup 2 7 Remote Node Eiter 4 9 Required fields eesseeseeeeessss 2 5 Resetting the ZyWALL AA 2 9 Restore Configuration sssssss 10 4 Return address 15 5 all EIE 3 3 3 6 4 7 4 9 ROM Filet it EE ESE SS NE EE NEE 10 6 Rule Checker 16 1 Rule Summary16 4 16 6 19 4 19 6 19 8 19 10 19 11 19 14 S Safety Instructons ees eek ee Re ee Re ee F saving the state sesse esse seen 13 6 Security In General 13 10 Index ZyWALL 10 Internet Security Gateway Security Hamificaitons sesse sesse ske ee ek 16 2 MURE EE AO N ES Send Alerts When Attacked 19 7 3 1 3 4 3 6 4 6 4 9 7 7 7 8 7 9 7 12 7 15 SERVE Meggie EER EE Ee EE 12 1 13 3 13 4 N Q R S V 3 1 3 9 4 2 6 3 6 4 6 7 6 9 6 12 6 13 6 TCP IP filter rie 7 7 14 6 16 6 17 11 6 N U V Teairdt p AE EE decal 13 4 14 4 ee RR MR N AE peaies vii 16 2 Televie ER OE re DE EN 12 1 Service Type 3 9 4 2 17 4 21 2 Telnet Configuration esses 12 1 Services Gupported sees ee ee 16 8 Telnet Under NAT ees ee se ee ee ee 12 1 SI pec 2 4 TFTP File Transfer AA 10 7 SMT Menus at a Glance 2 9 The Big Picture sees see ee ee ee ee ee 14 5 SMTP Error Messages
171. key used during encryption and a corresponding private key used during decryption Permanent Virtual Circuit A PVC is a logical point to point circuit between customer sites PVCs are low delay circuits because routing decisions do not need to be made along the way Permanent means that the circuit is preprogrammed by the carrier as a path through the network It does not need to be set up or torn down for each session The finding and observation of potential targets for a cracker to attack An RFC Request for Comments is an Internet formal document or standard that is the result of committee drafting and subsequent review by interested parties Some RFCs are informational in nature Of those that are intended to become Internet standards the final version of the RFC becomes the standard and no further comments or changes are permitted Change can occur however through subsequent RFCs Routing Information Protocol is an interior or intra domain routing protocol that uses the distance vector routing algorithms RIP is used on the Internet and is common in the NetWare environment as a method for exchanging routing information between routers A device that connects two networks together Routers monitor direct and filter information that passes between these networks Because of their location routers are a good place to install traffic or mail filters Routers are also prone to attacks because they contain a great deal of information abou
172. kts The number of received packets on this port Cols The number of collisions on this port Tx B s Shows the transmission speed in Bytes per second on this port Rx B s Shows the reception speed in Bytes per second on this port Up Time Total amount of time the line has been up LAN Ethernet Address The LAN port Ethernet address 9 2 System Information amp Diagnosis ZyWALL 10 Internet Security Gateway FIELD DESCRIPTION IP Address The LAN port IP address IP Mask The LAN port IP mask DHCP The LAN port DHCP role WAN Ethernet Address The WAN port Ethernet address IP Address The WAN port IP address IP Mask The WAN port IP mask DHCP The WAN port DHCP role System up Time The total time the ZyWALL has been on Name This is the ZyWALL s system name domain name assigned in menu 1 e g System Name xxx Domain Name baboo mickey com Names xxx baboo mickey com ZyNOS F W Version The ZyNOS Firmware version and the date created You Me enter 1 to drop the WAN connection 9 to reset the counters or ESC to return to menu 24 9 2 System Information and Console Port Speed This section describes your system and allows you to choose different console port speeds To get to the System Information and Console Port Speed Step 1 Enter 24 to go to Menu 24 System Maintenance Step 2 Enter 2 to open Menu 24 2 System Information and Console Port Speed
173. l eee 10 3 10 2 2 Backup Configuration Using Telnet nennen nennen nenne 10 3 10 3 Restore Configuration He feces ses IRL DEO eR ES e ites pel ERU PEE ptit EE 10 4 10 3 1 Example Restore Configuration Using HyperTerminal esee 10 4 10 4 Upload Firmware nec OE EE OE TE Utente sertis 10 5 10 4 1 Uploading the Router Fmware eese eee neren rennen 10 5 10 4 2 Example Xmodem Upload Using HyperTerminal eee 10 6 10 4 3 Uploading Router Configuration blei 10 6 10 5 TRIP File Transtet uve nee eR ae HUE Rs 10 7 10 5 1 Example TETP Command needed dep epe 10 8 10 6 RER File Transfer eterne EE EE OE heben 10 9 10 6 1 Using the FTP command from the DOS Prompt sese 10 11 Chapter 11 System Maintenance amp Information se ese Be Ee Se Ee Ee esses Be EG Be Be EG Bee Ge ee ee 11 1 11 1 Command Interpreter Mode 11 1 xii Table of Contents ZyWALL 10 Internet Security Gateway 11 2 Call Control SUppoOrt HE trt teer ete EE ER RIPE ape 11 2 11 21 Budget Management eer etr ther RERO e E RE EH EE Eve ce ER Ee SC 11 2 11 2 2 Call HIStory netten oe EE e REESE PRU 11 3 11 9 Fime and Date Setting zeit ote Ret E E HE ee UR UAE 11 4 How often does the ZyWALL update the time nennen nennen 11 6 11 4 Remote Management Setup ooo Eden 11 7 11 2 Boot Commands ss EER RS te tette N GR ee ete een eere EE d twos Ee Doe ee ed 11 8 Chapter 12 Telnet Configuration
174. l This field specifies the size or count of the IP address pool Type in the IP addresses of the DNS servers The DNS servers are passed to the DHCP clients along with the IP address and the subnet mask If Relay is selected in the DHCP field above then type in the IP address of the actual remote DHCP server here 192 168 1 33 32 Follow the instructions in the following table to configure TCP IP parameters for the LAN port Table 3 2 LAN TCP IP Setup Menu Fields FIELD DESCRIPTION EXAMPLE TCP IP Setup IP Address Enter the IP address of your ZyWALL in dotted decimal notation 192 168 1 1 default IP Subnet Mask Your ZyWALL will automatically calculate the subnet mask based on the IP address that you assign Unless you are implementing subnetting use the subnet mask computed by the ZyWALL 255 255 255 0 RIP Direction Press the SPACE BAR to select the RIP direction from Both In Both I None Only Out Only or None default Version Press the SPACE BAR to select the RIP version from RIP 1 RIP RIP 1 2B RIP 2M default 3 6 Internet Access ZyWALL 10 Internet Security Gateway FIELD DESCRIPTION EXAMPLE Multicast IGMP Internet Group Multicast Protocol is a session layer protocol None used to establish membership in a Multicast group The ZyWALL supports both IGMP version 1 IGMP v1 and version 2 IGMP v2 Press the SPACE BAR to enable I
175. l Check Routing Remote Node NAT Remote Node Filter Firewall Filter Table Protocol Filter DeviceF ilter WAN to LAN Inbound Traffic Figure 14 5 Big Picture Filtering Firewall and NAT 14 3 Packet Filtering Vs Firewall Below are some comparisons between the ZyW ALL filtering and firewall functions 14 3 1 Packet Filtering O The router filters packets as they pass through the router s interface according to the filter rules you designed Q Packet filtering is a powerful tool yet can be complex to configure and maintain especially if you need a chain of rules to filter a service Q Packet filtering only checks the header portion of an IP packet 14 6 Introducing the ZyWALL Firewall ZyWALL 10 Internet Security Gateway When To Use Filtering 1 To block allow LAN packets by their MAC address 2 To block allow special IP packets which are neither TCP UDP nor ICMP packets 3 To block allow both inbound WAN to LAN and outbound LAN to WAN traffic between the specific inside host network A and outside host network B If the filter blocks the traffic from A to B it also blocks the traffic from B to A Filters can not distinguish traffic originating from an inside host or an outside host by IP address 4 To block allow IP trace route 14 3 2 Firewall Q The firewall inspects packet contents as well as their source and destination addresses Firewalls of this type employ an inspection module
176. l ICMP packets to go through This is a popular Internet chat program This is another popular Internet chat program A protocol for news groups Network File System NFS is a client server distributed file service that provides transparent file sharing for network environments Network News Transport Protocol is the delivery mechanism for the USENET newsgroup service Remote Command Service A streaming audio service that enables real time sound over the web Remote Execution Daemon Remote Login Remote Telnet The Real Time Streaming media control Protocol RTSP is a remote control for multimedia on the Internet 16 8 Creating Custom Rules ZyWALL 10 Internet Security Gateway SERVICE DESCRIPTION SFTP TCP 115 SMTP TCP 25 SNMP TCP UDP 161 SNMP TRAPS TCP UDP 162 SQL NET TCP 1521 SSH TCP UDP 22 STRM WORKS UDP 1558 TACACS UDP 49 TELNET TCP 23 TFTP UDP 69 VDOLIVE TCP 7000 Simple File Transfer Protocol Simple Mail Transfer Protocol is the message exchange standard for the Internet SMTP enables you to move messages from one e mail server to another Simple Network Management Program Traps for use with the SNMP RFC 1215 Structured Query Language is an interface to access data on many different types of database systems including mainframes midrange systems UNIX systems and network servers Secure Shell Remote Login Program Stream Works Protocol
177. l Network Rule Summary 19 10 Cate SOTIES e Leere restet ete gore 20 1 EG 3 Rule Summary E 19 14 Customizilig oret emen 20 5 UIT 15 5 Days and Times ec 20 1 E mail Screen see 19 4 Index Y ZyWALL 10 Internet Security Gateway Sa UC ER ER HE ER 15 4 G Encapsulation PPP over Ethernet se se se se see se Ge Ge Ge GR Re ee A General Setup seen 2 9 Ethernet Encapsulation3 8 4 1 4 5 4 6 4 10 6 12 6 14 H Example E mail Log 15 6 Examples EE 19 1 Half Open Sessions eH 15 8 Hidden Menu s rere 2 5 F el RU annes 6 14 13 1 13 3 13 4 Q T W HyperTerminal program sss 10 3 Factory Default 2 ine eot 2 13 Filename Conventons ees ese ee ee 10 1 I Filet cnet te ee 2 14 4 9 7 1 Lond 7 1 ANA irit sto resa bac Te eee edere att co 3 2 Applying eet RE 7 16 ICMP echo ort Ee 13 6 14 3 Configuring En 7 4 GE 4 3 Example Roesgen ES ee EA IGMP Internet Group Multicast Protocol ede 3 3 Filter og ee Initial Screen 2 4 Generic Filter Rule Installation Requirements ssssss 2 3 NAT Lees Internet Hee SS ele 3 1 Structure Internet Access Setup 3 8 3 9 6 5 21 2 Filters Internet Assigned Numbers Authority See IANA Executing a Filter Rule 7 2 Internet Control Message Protocol ICMP 13 6 Logic Flow of an IP Filter esse seeks see ee 7 10 14 3 Firewall NET 3 2 3 6 Address Type suene usse Vigo
178. l Notice 192 168 10 10 RAS FW 172 21 1 25 2172 21 1 25 IGMP lt 2 gt default permit lt 2 0 gt B System Information amp Diagnosis 9 9 ZyWALL 10 Internet Security Gateway 9 3 3 Call Triggering Packet Call Triggering Packet displays information about the packet that triggered a dial out call in an easy readable format Equivalent information is available in menu 24 1 in hex format An example is shown next IP Frame ENETO RECV Size 44 44 Time 17 02 44 262 Frame Type IP Header IP Version s4 Header Length 20 Type of Service 0x00 0 Total Length 0x002C 44 Identification 0x0002 2 Flags 0x00 Fragment Offset 0x00 Time to Live OxFE 254 Protocol 0x06 TCP Header Checksum OxFB20 64288 Source IP 0xC0A80101 192 168 1 1 Destination IP 0x00000000 0 0 0 0 TCP Header Source Port 0x0401 1025 Destination Port 0x000D 13 Sequence Number 0x05B8D000 95997952 Ack Number 0x00000000 0 Header Length 24 Flags 0x02 9v Window Size 0x2000 8192 Checksum OxEO6A 57450 Urgent Ptr 0x0000 0 Options 0000 02 04 02 00 RAW DATA 0000 45 00 00 2C 00 02 00 00 FE 06 FB 20 CO A8 01 01 0010 00 00 00 00 04 O1 00 OD 05 B8 DO 00 00 00 00 00 0020 60 02 20 00 EO 6A 00 00 02 04 02 00 Press any key to continue Figure 9 9 Call Triggering Packet Example 9 4 Diagnostic The diagnostic facility allows you to test the different aspects of your ZyWALL to determine if it is working properly Menu 2
179. le just checked m Action Matched F means to forward the packet immediately and skip checking the remaining rules D means to drop the packet N means to check the next rule n Action Not Matched F means to forward the packet immediately and skip checking the remaining rules D means to drop the packet N means to check the next rule The protocol dependent filter rules abbreviation are listed as follows Table 7 2 Rule Abbreviations Used ABBREVIATION DESCRIPTION IP Pr Protocol SA Source Address SP Source Port number DA Destination Address DP Destination Port number 7 6 Filters ZyWALL 10 Internet Security Gateway ABBREVIATION DESCRIPTION GEN Off Offset Len Length Refer to the next section for information on configuring the filter rules 7 2 2 Configuring a Filter Rule To configure a filter rule type its number in Menu 21 1 Filter Rules Summary and press ENTER to open menu 21 1 1 for the rule To speed up filtering all rules in a filter set must be of the same class i e protocol filters or generic filters The class of a filter set is determined by the first rule that you create When applying the filter sets to a port separate menu fields are provided for protocol and device filter sets If you include a protocol filter set in a device filter field or vice versa the ZyW ALL will warn you and will not allow you to save
180. lease see our included disk for further information 21 1 Problems Starting Up the ZyWALL Table 21 1 Troubleshooting the Start Up of your ZyWALL Problem Corrective Action None of the LEDs are on when you turn on the ZyWALL Check the connection between the power adapter and the ZyWALL If the error persists you may have a hardware problem In this case you should contact technical support Cannot access the ZyWALL via the console port 1 Check to see if the ZyWALL is connected to your computer s serial port 2 Check to see if the communications program is configured correctly The communications software should be configured as follows VT100 terminal emulation 9600 bps is the default speed on leaving the factory Try other speeds in case the speed has been changed No parity 8 data bits 1 stop bit data flow set to none Troubleshooting ZyWALL 10 Internet Security Gateway 21 2 Problems with the LAN Interface Table 21 2 Troubleshooting the LAN Interface Problem Corrective Action Can t ping any workstation on the LAN Check the 10M 100M LEDs on the front panel One of these LEDs should be on If they are both off check the cables between your ZyWALL and hub or the station Verify that the IP address and the subnet mask are consistent between the ZyWALL and the workstations 21 3 Problems with the WAN interface Table 21 3 Troubles
181. legitimate owner for it Glossary of Terms ZyWALL 10 Internet Security Gateway Pirated Software Plain Text ZyWALL Web Configurator PNS POP Port H W Port POTS PPP PPTP Promiscuous Packet Capture This category of computer criminal includes several different types of illegal activities Making copies of software for others to use Distributing pirated software over the Internet or a Bulletin Board System Receiving or downloading illegal copies of software in any form Software that has been illegally copied or that is being used in violation of the software s licensing agreement Pirated software is often distributed through pirate bulletin boards or on the Internet In the internet underground it is known as Warez The opposite of Cipher Text Plain Text is readable by anyone This is a web based ZyWALL router not all configurator that includes an Internet Access Wizard Advanced and Firewall not all ZyWALL models configurations PPTP Network Server A PNS must have IP connectivity Post Office Protocol This is a common protocol used for sending receiving and delivering mail messages An interface on a computer for connecting peripherals or devices to the computer A printer port for example is an interface that is designed to have a printer connected to it Ports can be defined by specific hardware such as a keyboard port or through software An Internet port refers to a number that is
182. list entry previously created 7 The packet is inspected by a firewall rule and the connection s state table entry is updated as necessary Based on the updated state information the inbound extended access list temporary entries might be modified in order to permit only packets that are valid for the current state of the connection 8 Any additional inbound or outbound packets that belong to the connection are inspected to update the state table entry and to modify the temporary inbound access list entries as required and are forwarded through the interface 9 When the connection terminates or times out the connection s state table entry is deleted and the connection s temporary inbound access list entries are deleted 13 4 2 Stateful Inspection amp the ZyWALL Additional rules may be defined to extend or override the default rules For example a rule may be created which will i Block all traffic of a certain type such as IRC Internet Relay Chat from the LAN to the Internet ii Allow certain types of traffic from the Internet to specific hosts on the LAN iii Allow access to a Web server to everyone but competitors iv Restrict use of certain protocols such as Telnet to authorized users on the LAN These custom rules work by evaluating the network traffic s Source IP address Destination IP address IP protocol type and comparing these to rules set by the administrator The ability to define ZyWALL Web Configurato
183. llowing are some Internet firewall rule examples that allow DHCP negotiation between the ISP and the ZyWALL 10 and allow a syslog connection from the Internet Step 1 Follow the procedure shown next to first configure a custom port PORT CONFIG Custom ports show up with an before their names in the Services list box and the Rule CONFIGURATION INTERNEI after you ve created your custom port CUSTOM PORTS LOGS LOCAL NETWORK ur sl Summary list box Click Apply ol LOGOUT e Status Ready Figure 19 11 Custom Port for Syslog 19 12 Example Firewall Rules ZyWALL 10 Internet Security Gateway Step 2 Follow the procedures outlined in the previous examples to configure all your rules When finished your rule summary screen should look like the following EE RULE CONFIG MAIN MENU Internet to Local Network mo This is the address range Firewall of the syslog servers EET ource IP Address FS 0 0 0 10 10 0 0 15 CONFIGURATION EG Sosa sesse senes LOGOUT This is your POP TCP 110 Syslog UDP 514 Syslog Any TCP Any UDP custom port BGP TCP 179 BOOTP CLIENT UDP 68 Figure 19 12 Syslog Rule Configuration Example Firewall Rules 19 13 ZyWALL 10 Internet Security Gateway Step 3 On completing the procedure the Rule Summary for this Internet firewall rules should look like the following screen Don t forget to click Apply when you have finished configuring your rule
184. lnet Ggs into the ZyWALL Incoming Traffic Filter Figure 7 12 Telnet Filter Example Step 1 Enter 21 from the main menu to open Menu 21 1 Filter Set Configuration Step 2 Enter the index of the filter set you wish to configure say 3 and press ENTER Step 3 Enter a descriptive name or comment in the Edit Comments field and press ENTER Step 4 Press ENTER at the message Press ENTER to confirm to open Menu 21 1 1 Filter Rules Summary Step 5 Enter to configure the first filter rule the only filter rule of this set Make the entries in this menu as shown in the following figure Filters 7 13 ZyWALL 10 Internet Security Gateway Press the SPACE BAR to l choose this filter rule type The Filter 3 l first filter rule type determines Filter Type TCP IP Filter Rule Active Yes all subsequent filter types IP Protocol 6 P Source Route No within a set Destination Menu 21 1 1 TCP IP Filter Rule 3 1 Port 4 Comp Eer Select Yes to make the rule IP Mask 0 0 p active Port 0 6 is the TCP protocol Pyess ENTER to C to Cancel Port 4 Comp Press space Dar toAlosgle The port number for the telnet service TCP protocol is 23 See RFC 1060 for port numbers of well known services TCP Estab No Actign Not Match d Forward There are no more rules to Select Equal check here as you are looking for packets going to Select Drop
185. lt settings handy checklists information on setting up your PC and information on configuring your ZyW ALL for Internet access Packing List Card Finally you should have a Packing List Card which lists all items that should have come with your ZyWALL ZyXEL Web and FTP Server Sites You can access release notes for firmware upgrades and other information at ZyXEL web and FTP server sites Refer to the Customer Support page in this User s Guide for more information Syntax Conventions Enter means for you to type one or more characters and press the carriage return Select or Choose means for you to select one from the predefined choices The SMT menu titles and labels are in Bold Times font The choices of a menu item are in Bold Arial font A single keystroke is in Arial font and enclosed in square brackets for instance ENTER means the Enter or carriage return key ESC means the escape key and SPACE BAR means the space bar UP DOWN are the up down arrow keys For brevity s sake we will use e g as a shorthand for for instance and i e for that is or in other words throughout this manual xxviii Preface Getting Started Part Getting Started g 00L0 0MMLMLMM eeeMeeMeeMelMe eMeeeeMMeeeeeeeleeeeeeMeMeeMeeeMeeeseeeeeMeMeMMeeeeeeee e ZyWALL 10 Internet Security Gateway Chapter 1 Getting to Know Your ZyWALL This chapter introdu
186. m backup and restore using menu 24 through the console port Any serial communications program should work fine however you must use XMODEM protocol to perform the download upload and you don t have to rename the files see section 10 1 Please note that terms download and upload are relative to the workstation Download means to transfer from the ZyW ALL to the workstation while upload means from your workstation to the ZyW ALL Ready to backup Configuration via Xmodem Do you want to continue y n Figure 10 1 System Maintenance Backup Configuration 10 2 Firmware and Configuration File Maintenance ZyWALL 10 Internet Security Gateway 10 2 1 Example Backup Configuration Using HyperTerminal This section contains examples of backup configuration restore configuration and upload firmware using the HyperTerminal program Other serial communications programs should be similar In menu 24 5 enter y Run the HyperTerminal program Click Transfer then Receive File to display the following screen Receive File Type a location for storing the rom configuration file or use Browse Browse to look for one Place received file in the following folder C AZyXELS Contig rom Use receiving protocol Choose the Xmodem protocol Then click Receive Figure 10 2 Example Backup Configuration 10 2 2 Backup Configuration Using Telnet Telnetting into the ZyWall produces th
187. m devices on the network Passively watching a network for information that could be used to a hacker s advantage such as passwords Usually done while Camping Out A protocol that handles TCP traffic through proxy servers Unwanted e mail usually in the form of advertisements To forge something such as an IP address IP Spoofing is a common way for hackers to hide their location and identity Technology that allows you to send information that only the server can read SSL allows servers and browsers to encrypt data as they communicate with each other This makes it very difficult for third parties to understand the communications Twisted pair cable consists of copper core wires surrounded by an insulator Two wires are twisted together to form a pair and the pair form a balanced circuit The twisting prevents interference problems STP shielded twisted pair provides protection against external crosstalk A cable that wires a pin to its equivalent pin This cable connects two dissimilar devices for example a data terminal equipment DTE device and a data communications equipment DCE device A straight through Ethernet cable is the most common cable used Single User Account The ZyWALL s SUA Single User Account feature allows multiple user Internet access for the cost of a single ISP account see also NAT Transmission Control Protocol handles flow control and packet recovery and IP providing basic addressing and packet f
188. mation ee ge 209594 A eG System Maintenance9 1 9 2 9 3 9 4 9 5 9 6 9 j 7 9 11 9 12 10 2 10 4 10 5 10 6 10 7 10 8 10 10 11 1 11 2 11 3 11 5 W m DER OE EE EE es 2 11 WAN DHCP LLL 9 11 9 12 ystem Status HE N EO EF 9 1 System Timeout 12 2 WAN Gem 2 12 2 13 21 2 YN Oe EU IST WAN to LAN Rules A 16 8 Web CGontourator sesse ese ke ee ee 13 9 T Welcome screen essen 15 1 Ee te 15 8 15 11 WWWZYXEl COM ARE OE ter repete te FERE vii TOP Seet EE N N et 13 8 BB Index ZyWALL 10 Internet Security Gateway X xDSL modem 1 3 1 4 2 3 2 4 4 3 21 2 21 3 XMODEM porotoco esse see esse ee ee ee 10 2 ZyNOS 2 13 6 4 6 7 9 3 9 4 10 1 10 2 ZyNOS FAN Version 9 3 9 4 10 1 ZyWALL Firewall Application 13 3 ZyWALL Web Configurator sees ese ee ee 19 2 13 8 13 9 14 2 15 1 15 2 16 2 19 2 ZyXEL Limited Warranty Notes Mi vic RS e E vii ZVXEL WODSIIO cierto enne vii ZyXEL s Firewall Introduction e ete 13 2 Index CC
189. mation for Canadian Users The Industry Canada label identifies certified equipment This certification means that the equipment meets certain telecommunications network protective operation and safety requirements The Industry Canada does not guarantee that the equipment will operate to a user s satisfaction Before installing this equipment users should ensure that it is permissible to be connected to the facilities of the local telecommunications company The equipment must also be installed using an acceptable method of connection In some cases the company s inside wiring associated with a single line individual service may be extended by means of a certified connector assembly The customer should be aware that the compliance with the above conditions may not prevent degradation of service in some situations Repairs to certified equipment should be made by an authorized Canadian maintenance facility designated by the supplier Any repairs or alterations made by the user to this equipment or equipment malfunctions may give the telecommunications company cause to request the user to disconnect the equipment For their own protection users should ensure that the electrical ground connections of the power utility telephone lines and internal metallic water pipe system if present are connected together This precaution may be particularly important in rural areas Caution Users should not attempt to make such connections themselves bu
190. me enter the month and day that it ends on Once you have filled in this menu press ENTER at the message Press ENTER to Confirm or ESC to Cancel to save your configuration or press ESC to cancel How often does the ZyWALL update the time The ZyW ALL updates the time in three instances 1 On leaving menu 24 10 after making changes li When the ZyW ALL boots up and there is a time server configured in menu 24 10 iii 24 hour intervals after booting 11 6 System Maintenance amp Information ZyWALL 10 Internet Security Gateway 11 4 Remote Management Setup Telnet and FTP do not support encryption so for very strong security both services should be shut down This is done in Menu 24 11 Remote Management Control Enter 11 from menu 24 to bring up this menu AII Telnet and FTP activity both LAN and WAN may be disabled by selecting No press the SPACE BAR to select No in the two fields in this menu If you just wish to block certain users from using these activities then please use filtering see menu 21 1 Menu 24 11 Remote Management Control FTP service active Yes Telnet service active Yes Secured Client IP 0 0 0 0 Press ENTER to Confirm or ESC to Cancel Press Space Bar to Toggle Figure 11 8 Menu 24 11 Remote Management Control Remote management is only allowed from one single IP host Table 11 4 Menu 24 11 Remote Management Control FIELD DESCRIPTION EX
191. mit digital data over the hardware channel The device converts signals from bridges routers and multiplexors into the bipolar digital signals used by the digital lines Multiplexors mix voice signals and data on the same line Data Communications Equipment is typically a modem or other type of communication device The DCE sits between the DTE data terminal equipment and a transmission circuit such as a phone line The act of restoring an encrypted file to its original state Act of preventing customers users clients or other machines from accessing data on a computer This is usually accomplished by interrupting or overwhelming the computer with bad or excessive information requests Dynamic Host Configuration Protocol automatically assigns IP addresses to clients when they log on DHCP centralizes IP address management on central computers that run the DHCP server program DHCP leases addresses for a period of time which means that addresses are made available to assign to other systems Glossary of Terms ZyWALL 10 Internet Security Gateway Digital Signature DNS Domain Name DRAM DSL DSLAM DTE EMI Encryption Ethernet Digital code that authenticates whomever signed the document or software Software messages Email and other electronic documents can be signed electronically so that they cannot be altered by anyone else If someone alters a signed document the signature is no longer valid Digital s
192. mote Node Profile Rem Node Name ChangeMe Route IP Active Yes Encapsulation PPPoE Edit IP No Service Type Standard Telco Option Service Name Allocated Budget min 0 Outgoing Period hr 0 My Login Schedules My Password Nailed Up Connection No Authen CHAP PAP Session Options Edit Filter Sets No Idle Timeout sec 100 Press ENTER to Confirm or ESC to Cancel Press Space Bar to Toggle Figure 4 2 Menu 11 1 Remote Node Profile for PPPoE Encapsulation Outgoing Authentication Protocol Generally speaking you should employ the strongest authentication protocol possible for obvious reasons However some vendor s implementation includes specific authentication protocol in the user profile It will disconnect if the negotiated protocol is different from that in the user profile even when the negotiated protocol is stronger than specified If you encounter the case where the peer disconnects right after a successful authentication please make sure that you specify the correct authentication protocol when connecting to such an implementation Nailed Up Connection A nailed up connection is a dial up line where the connection is always up regardless of traffic demand The ZyW ALL does two things when you specify a nailed up connection The first is that idle timeout is disabled The second is that the ZyWALL will try to bring up the connection when turned on and whenever the connection is down A nailed up
193. mputer system or other device that acts as a translator between two systems that do not use the same communication protocols data formatting structures languages and or architecture Generally a hacker is anyone who enjoys experimenting with technology including computers and networks Not all hackers are criminals breaking into systems Some are legitimate users and hobbyists Nevertheless some are dedicated criminals or vandals HDLC High level Data Link Control is a bit oriented the data is monitored bit by bit link layer protocol for the transmission of data over synchronous networks Any computer on a network that is a repository for services available to other computers on the network It is quite common to have one host machine provide several services such as WWW and USENET Hyper Text Transfer Protocol The most common protocol used on the Internet HTTP is the primary protocol used for web sites and web browsers It is also prone to certain kinds of attacks Internet Assigned Number Authority acts as the clearinghouse to assign and coordinate the use of numerous Internet protocol parameters such as Internet addresses domain names protocol numbers and more The IANA Web site is at http www isi edu iana Internet Control Message Protocol is a message control and error reporting protocol between a host server and a gateway to the Internet ICMP uses Internet Protocol IP datagrams but the messages are processed by the T
194. n extension number called the TCP port or UDP port For example Web traffic by default uses TCP port 80 When computers communicate on the Internet they are using the client server model where the server listens on a specific TCP UDP port for information requests from remote client computers on the network For example a Web server typically listens on port 80 Please note that while a computer may be intended for use over a single port such as Web on port 80 other ports are also active If the person configuring or managing the computer is not careful a hacker could attack it over an unprotected port What Is a Firewall 13 3 ZyWALL 10 Internet Security Gateway Some of the most common IP ports are Table 13 1 Common IP Ports 21 FTP 53 i DNS 23 Telnet 80 HTTP 25 SMTP 110 i POP3 13 3 2 Types of DoS attacks There are four types of DoS attacks l e A 2 Those that exploit bugs in a TCP IP implementation Those that exploit weaknesses in the TCP IP specification Brute force attacks that flood a network with useless data IP Spoofing Ping of Death and Teardrop attacks exploit bugs in the TCP IP implementations of various computer and host systems 1 a Ping of Death uses a ping utility to create an IP packet that exceeds the maximum 65 536 bytes of data allowed by the IP specification The oversize packet is then sent to an unsuspecting system Systems
195. n Now click an available No rule number radio button then click Edit to bring up the Rule Config uration screen Now click on the DestAdd button under the Destination Address box and enter the IP of FTP server One 192 168 10 3 Follow the same procedure as shown in Figure 19 3and Figure 19 4 19 10 Example Firewall Rules ZyWALL 10 Internet Security Gateway Step 9 On completing the procedure the Rule Summary for this Internet firewall rules should look like the following screen Don t forget to click Apply when you have finished configuring your rule s to save your settings back to the ZyWALL P4 2 L wer 5 d IP address of the FTP server to EEN which traffic from the Internet MEEN This will block all other WAN nA will be forwarded to LAN traffic CONFIGURATION CH Default Set LOCAL NETWORK INTERNET CUSTOM PORTS LOGS M Configured Any v Ar E BOOTP_CLIENT UDP 68 Forward None LOGOUT Confgured Any x 192 168 10 3 v FTP TCP 20 21 7 Forward None Empty Empty Empty Empty Empty Empty Empty Empty Ds bles ede es dese is belese dee ee ee Gs ply Edit Delete 1 Move Click Apply to save your settings 4 back to the ZyWALL Status Ready Figure 19 10 Example Internet to Local Network Rule Summary Example Firewall Rules 19 11 ZyWALL 10 Internet Security Gateway 19 1 3 Example 3 DHCP Negotiation and Syslog Connection from the Internet The fo
196. n addition specific policies must be implemented within the firewall itself 13 1 Types of Firewalls There are three main types of firewalls Packet Filtering Firewalls 2 Application level Firewalls 3 Stateful Inspection firewalls 13 1 1 Packet Filtering Firewalls Packet filtering firewalls restrict access based on the source destination of the computer network address and the type of application 13 1 2 Application level Firewalls Application level firewalls restrict access by serving as proxies for external servers Since they use programs written for specific Internet services such as HTTP FTP and telnet they can evaluate network packets for valid application specific data Application level gateways have a number of general advantages over the default mode of permitting application traffic directly to internal hosts i Information hiding prevents the names of internal systems from being made known via DNS to outside systems since the application gateway is the only host whose name must be made known to outside systems What Is a Firewall 13 1 ZyWALL 10 Internet Security Gateway ii Robust authentication and logging pre authenticates application traffic before it reaches internal hosts and causes it to be logged more effectively than if it were logged with standard host logging Filtering rules at the packet filtering router can be less complex than they would be if the router needed to filter application traff
197. n below refers to both 16 6 1 Factors Influencing Choices for Timeout Values The factors influencing choices for timeout values are the same as the factors influencing choices for threshold values see section 15 4 1 Click on either Local Network or Internet then select the Timeout tab Figure 16 6 Timeout Screen 16 14 Creating Custom Rules ZyWALL 10 Internet Security Gateway Table 16 5 Timeout Menu FIELD DESCRIPTION DEFAULT VALUE TCP Timeout Values Connection Timeout This is the length of time the ZyWALL waits for a TCP 30 seconds session to reach the established state before dropping the session FIN Wait Timeout This is the length of time a TCP session remains open 60 seconds after the firewall detects a FIN exchange indicating the end of the TCP session This is the length of time of inactivity a TCP connection 3600 seconds remains open before the ZyWALL considers the 1 hour connection closed Idle Timeout UDP Idle Timeout This is the length of time of inactivity a UDP connection 60 seconds remains open before the ZyWALL considers the connection closed ICMP Timeout This is the length of time an ICMP session waits for the 60 seconds ICMP response When you have finished click on Apply to apply your changes or Reset to go back to the original settings Click Help for online HTML help on fields in this screen Creating Custom Rules 16 15 ZyWALL 10 Internet Sec
198. nd during the TFTP transfer For details on TFTP commands see following example please consult the documentation of your TFTP client program For UNIX use get to transfer from the ZyW ALL to the workstation put the other way around and binary to set binary transfer mode 10 5 1 Example TFTP Command The following is an example tftp command TFTP i host put zywall bin ras where i specifies binary image transfer mode use this mode when transferring binary files host is the ZyW ALL IP address put transfers the file source on the workstation zywall bin name of the firmware on the workstation to the file destination on the remote host ras name of the firmware on the ZyW ALL The following table describes some of the fields that you may see in third party TFTP clients Table 10 2 Third Party TFTP Clients General commands COMMAND DESCRIPTION Host Enter the IP address of the ZyWALL 192 168 1 1 is the ZyWALL default IP address when shipped Send Fetch Press Send to upload the file to the ZyWALL and Fetch to back up the file on your computer Local File Enter the path and name of the firmware file bin extension or configuration file rom extension on your computer 10 8 Firmware and Configuration File Maintenance ZyWALL 10 Internet Security Gateway COMMAND DESCRIPTION Remote File This is the filename on the ZyWALL The filenam
199. nd the IP address of your router Then type root SMT password as requested 3 Type put firmwarefilename ras where firmwarefilename is the of your firmware upgrade file on your workstation and ras is the remote file name on the router 4 The system reboots automatically after a successful firmware upload For details on FTP commands please consult the documentation of your FTP client program For details on uploading router firmware using TFTP note that you must remain on this menu to upload router firmware using TFTP please see your router manual Press ENTER to Exit Figure 10 13 Telnet into Menu 24 7 1 You see the following screen when you telnet into menu 24 7 2 Menu 24 7 2 System Maintenance Upload Router Configuration File To upload the router configuration file follow the procedure below 1 Launch the FTP client on your workstation 2 Type open and the IP address of your router Then type root and SMT password as requested 3 Type put configurationfilename rom 0 where configurationfilename is the name of your router configuration file on your workstation which will be transferred to the rom 0 file on the router 4 The system reboots automatically after the upload router configuration file process is complete For details on FTP commands please consult the documentation of your FTP client program For details on uploading router firmware using TFTP note that you must remain on this menu
200. ndices Glossary and Index AAA V Chapter 21 Troubleshooting eere crees cesse eene ee een Ge Ge EG EG Bee etas etas etas Se Bee ee sete EE Ge ease EG eg 21 1 21 1 Problems Starting Up the Zy WALL eeni eee nennen nennen een rennen ee ee ee 21 1 21 2 Problems with the LAN Interface 21 2 21 3 Problems with the WAN interface enne enne en nnne enne tnnt E nee 21 2 21 4 Problems with Internet ACCESS enne enne entren nnne en nnne tnit nentes 21 3 21 5 Problems with the Firewall 5 eio ett st tete tec ell SERA 21 3 Appendix A PPPOE m A Appendix B PPTP soseer sees sissies stisi ge Ese Es do oron iosi E S E Se dee se C Appendix C Hardware Specifications sesse sesse see see see Ee Bee Bee Se ee Bee Se ee ee Ee Ge GE GE EE Ge Ge Ge EG EG eg E Appendix D Important Safety Instructions eee eee eee Ee essen enata enses tuse Be Ee Be sns Be sesta statuae F Table of Contents XV ZyWALL 10 Internet Security Gateway Appendix E Firewall CLI Commands sesse eee ee ee eene Be tenen stata tasa enses tuse tatnen seta senes ense G Appendix F Power Adapter Specifications eere see se EG Be EE SEE EE enata tne Be sens Bee ee See Ge ense L Glossary Of TOPS cccccsscesccssesscsscssscssvascessossssessensesssovnsenssnevensasecssvasesaveosdsesssassasevenseacssvedsoaseesvesssesssosseusodsoukeos N GOS A E E O T Y xvi Table of Contents ZyWALL 10 Interne
201. nennen 9 2 Table 9 2 Fields in System Maintenance Information eese nennen nenne 9 4 Table 9 3 System Maintenance Menu Syslog Parameters esee nennen nene 9 7 Table 9 4 System Maintenance Menu Diagnostic eene nennen nennen rennen 9 12 Table 10 1 Filename Conventions nennen eene enne ee Ge ee ee ee Ge ee Re RR RA Re ene 10 2 Table 10 2 Third Party TFTP Clients General commands essere 10 8 Table 10 3 Third Party FTP Clients General Fields seen 10 12 Table 11 1 Budget Management 11 3 Table 11 2 Call History Fields tette eee een peer etn 11 4 Table 11 3 Time and Date Setting Fields ee He Oe Ge BE bee ee EE Be enne entente eterne tne brennen Ge Ee 11 6 Table 11 4 Menu 24 11 Remote Management Control 11 7 Table 13 1 Common IP Ports AR EE RE N EE ER EE EO N 13 4 Table 14 1 ICMP Commands That Trigger Alerte 14 3 Table 14 2 Legal NetBIOS Commands see se ee ee ee Ge Se GR RA RA Gee ee ee ee ee Ge ee Re Ge rennen ens 14 3 Table 14 3 Legal SMTP Commands cn mter Ete Re EHE e SR BEES EEEE o ERGER De Eri 14 3 Tabl e T44 View ExrewallLog etit etico deed 14 5 Table ESE IERE EE EE tele AU OE RE bate E ER erect 15 5 Table 15 2 SMTP E 15 6 Table 15 3 Attack IE OE RR RE EE EE EE RR 15 10 Table 16 1 Firewall Rules Summary First Screen 16 6 Table 16 2 Predefined Services tee ete reete e eH AEN 16 8 Table 16 3 Creating Editing A Firewall Rule 16 11 Table 16 4 Adding Editing Source and
202. nformation on the firewall Internet Access 3 13 Advanced Applications Part II Advanced Applications Chapters 4 6 describe advanced applications including Remote Node Setup IP Static routes and NAT ZyWALL 10 Internet Security Gateway Chapter 4 Remote Node Setup This chapter shows you how to configure a remote node A remote node is required for placing calls to a remote gateway A remote node represents both the remote gateway and the network behind it across a WAN connection Note that when you use menu 4 to set up Internet access you are actually configuring a remote node We will show you how to configure Menu 11 1 Remote Node Profile Menu 11 3 Remote Node Network Layer Options and Menu 11 5 Remote Node Filter 4 1 Remote Node Profile From the main menu select menu option 11 to open Menu 11 1 Remote Node Profile There are two variations of this menu depending on whether you choose Ethernet Encapsulation or PPPoE Encapsulation 4 1 1 Ethernet Encapsulation You must choose the Ethernet option when the WAN port is used as a regular Ethernet The first menu 11 1 screen you see is for Ethernet encapsulation shown next Menu 11 1 Remote Node Profile Rem Node Name ChangeMe Route IP Active Yes Encapsulation Ethernet Edit IP No Service Type Standard Session Options Service Name N A Edit Filter Sets No Outgoing My Login N A My Password N A Server IP N A Pre
203. nistrator To prevent confusion and discrepancy on the configuration your ZyWALL only allows one administrator to log in at any time Your ZyWALL also gives priority to the console port over telnet If you have already connected to your ZyW ALL via telnet you will be logged out if another user logs in to the ZyWALL via the console port Telnet 124 ZyWALL 10 Internet Security Gateway 12 3 2 System Timeout There is a system timeout of 5 minutes 300 seconds for either the console port or telnet Your ZyWALL will automatically log you out if you do nothing in this timeout period except when it is continuously updating the status in menu 24 1 or when sys stdio has been changed on the command line 12 4 Telnet Behind the Firewall Telnet over the WAN will not work if the firewall is active because the default firewall policies block all traffic from the WAN to the LAN To enable Telnet over the WAN you must turn the firewall off menu 21 2 or create a firewall rule to allow Telnet from the WAN Telnet will also not work when l 2 3 4 You have disabled Telnet service in menu 24 11 You have applied a filter in menu 3 1 LAN or in menu 11 5 WAN to block Telnet service The IP you entered in the Secured Client IP field in menu 24 11 does not match the client IP If it does not match the ZyWALL will disconnect the Telnet session immediately You have an SMT console session running The firewall is active The default fire
204. ns drops below another threshold max incomplete low When the rate of new connection attempts rises above a threshold one minute high the ZyW ALL starts deleting half open sessions as required to accommodate new connection requests The ZyWALL continues to delete half open sessions as necessary until the rate of new connection attempts drops below another threshold one minute low The rate is the number of new attempts detected in the last one minute sample period TCP Maximum Incomplete and Blocking Time An unusually high number of half open sessions with the same destination host address could indicate that a Denial of Service attack is being launched against the host Whenever the number of half open sessions with the same destination host address rises above a threshold TCP Maximum Incomplete the ZyW ALL starts deleting half open sessions according to one of the following methods 1 Ifthe Blocking Time timeout is 0 the default then the ZyWALL deletes the oldest existing half open session for the host for every new connection request to the host This ensures that the number of half open sessions to a given host will never exceed the threshold 2 Ifthe Blocking Time timeout is greater than 0 then the ZyWALL blocks all new connection requests to the host giving the server time to handle the present connections The ZyWALL continues to block all new connection requests until the Blocking Time expires The ZyWALL also sends ale
205. nt Filtering ZyWALL 10 Internet Security Gateway 20 4 Customizing Customize the content filter list by adding or removing specific sites from the filter list ER MAIN MENU Content Filter REGISTRY Figure 20 4 Customize Screen Content Filtering 20 5 ZyWALL 10 Internet Security Gateway 20 5 Keywords The ZyW ALL can also be configured to block certain web sites by using URL keywords Content Filter REGISTRY Free iCard CATEGORIES LIST UPDATE EXEMPT ZONE CUSTOMIZE URL WORD Delete Keyword Add Keyword Figure 20 5 Keyword Screen 20 6 Content Filtering ZyWALL 10 Internet Security Gateway 20 6 Log Records This screen records the results of your content filter policies Content Filter A no Content Filter Log existing REGISTRY Free iCard CATEGORIES LIST UPDATE LOGOUT Figure 20 6 Logs Screen Content Filtering 20 7 Troubleshooting Appendices Glossary and Index Part V Troubleshooting Appendices Glossary and Index Chapter 21 provides information about solving common problems followed by some Appendices a Glossary of Terms and an Index ZyWALL 10 Internet Security Gateway Chapter 21 Troubleshooting This chapter covers potential problems and possible remedies After each problem description some instructions are provided to help you to diagnose and to solve the problem P
206. nternal network protection and management as well Getting to Know Your ZyWALL 1 3 ZyWALL 10 Internet Security Gateway The firewall protects your LAN and the ZyWALL Firewall Cable Modem Figure 1 1 Secure Internet Access via Cable The firewall protects your LAN and the ZyWALL Firewall Figure 1 2 Secure Internet Access via DSL You can also use your xDSL modem in the bridge mode for always on Internet access and high speed data transfer 1 4 Getting to Know Your ZyWALL ZyWALL 10 Internet Security Gateway Chapter 2 Hardware Installation amp Initial Setup This chapter explains the LEDs and ports as well as how to connect the hardware and perform the initial setup 2 1 Front Panel LEDs and Back Panel Ports 2 1 1 Front Panel LEDs The LEDs on the front panel indicate the operational status of the ZyWALL ZyWALL INTERNET SECURITY GATEWAY Figure 2 1 Front Panel The following table describes the LED functions Table 2 1 LED functions LEDS FUNCTION INDICATOR ACTIVE DESCRIPTION STATUS PWR Power Green On The power adapter is connected to the ZyWALL SYS System Off The system is not ready or failed On The system is ready and running Flashing The system is rebooting 10M LAN LAN Green Off The 10M LAN is not connected On The ZyWALL is connected to a 10M LAN Flashing The 10M LAN is sending receiving packets 100M LAN Orange Off The 100M
207. o EO IE IP Address Assignment EE EE 4 6 4 8 ya C E IP Alias Setup E E ete 3 7 Connection Direction IP Multicast ee 1 2 3 3 Creating Editing Rules Internet Group Management Protocol IGMP 1 2 ne I eese eere ei IP Network Number ss 3 2 Guidelines For Enhancing Security IE Pool 2 E iti xe ie is 3 1 3 6 LOSS EE ERU IP POS Ee 13 4 POLICIES esu rte nete IP Spoofing icio 13 4 13 6 14 2 V Rule Logic IP Static BOUER ER ied 5 1 5 2 5 3 Rule Precedence SOLVICES E ES SMT EE K RRE UE Key Fields For Configuring Rules 16 2 RE ERA ER EE D e AG VS Eilterss ace saves ee Ee terree Web Configurator esee 15 1 L When TO Uses 14 7 LAN Setup ee ee ed 2 13 2 14 3 4 3 5 OW GODIEOL RE tr poe tert 2 3 Front Panel LEDs ee 2 4 e 16 3 LAND ESE ee me 13 4 13 5 14 2 FIP File Transfer ini 10 9 FTP Senet roit 1 3 6 18 nobel Network Z Index ZyWALL 10 Internet Security Gateway Rule Summary seegersi innne 16 4 jo 9 5 Log le AE TE RE metis 9 7 Log Screen demere ets 18 1 Login SCreeN ees seen 15 1 M MAC Address AA 2 13 21 2 Mail Seryver RE EE OE DEAN 15 5 Main Menu te tete OE N 2 6 maximum incomplete high 15 10 maximum incomplete low 15 10 max incomplete high ess 15 8 max incomplete low 15 8 15 11 Me
208. ol It displays information about past incoming and outgoing calls Enter 2 from Menu 24 9 System Maintenance Call Control to bring up the following menu System Maintenance amp Information 11 3 ZyWALL 10 Internet Security Gateway Menu 24 9 2 Call History Phone Number i Rate call Max Ts 2 ER 4 o 6 7 8 9t 0 m Enter Entry to Delete 0 to exit Figure 11 5 Call History Table 11 2 Call History Fields FIELD DESCRIPTION Phone Number The PPPoE service names are shown here Dir This shows whether the call was incoming or outgoing Rate This is the transfer rate of the call call This is the number of calls made to or received from that telephone number Max This is the length of time of the longest telephone call Min This is the length of time of the shortest telephone call Total This is the total length of time of all the telephone calls to from that telephone number You may enter an entry number to delete it or 0 to exit 11 3 Time and Date Setting There is no Real Time Chip RTC in the ZyWALL so there is a software mechanism to set the time manually or get the current time and date from an external server when you turn on your ZyW ALL Menu 24 10 allows you to update the time and date settings of your ZyW ALL The real time is then displayed in the ZyW ALL error logs and firewall logs If you do not choose a time service protocol th
209. om the WAN so to enable FTP over the WAN you must turn the firewall off menu 21 2 or create a firewall rule to allow FTP from the WAN 10 12 Firmware and Configuration File Maintenance ZyWALL 10 Internet Security Gateway Chapter 11 System Maintenance amp Information This chapter leads you through SMT menus 24 8 to 24 11 11 1 Command Interpreter Mode The Command Interpreter CI is a part of the main router firmware The CI provides much of the same functionality as the SMT while adding some low level setup and diagnostic functions The CI can be entered from the SMT by selecting menu 24 8 Access can be either by Telnet or by a serial connection to the console port although some commands are only available with a serial connection See the included disk or the zyxel com web site for more detailed information on CI commands Enter 8 from Menu 24 System Maintenance A list of valid commands can be found by typing help or at the command prompt Type exit to return to the SMT main menu when finished Menu 24 System Maintenance 1 System Status 2 System Information and Console Port Speed 3 Log and Trace 4 Diagnostic 5 Backup Configuration 6 Restore Configuration 8 Command Interpreter Mode 95 a e ie Time and Date Setting Remote Management Setup Enter Menu Selection Number Figure 11 1 Command Mode in Menu 24 Copyright c 1994 2001 ZyXEL Communications Corp ras Valid commands ar
210. on a physical network into logical networks over the same Ethernet interface The ZyW ALL supports three logical LAN interfaces via its single physical Ethernet interface with the ZyWALL itself as the gateway for each LAN network SNMP SNMP Simple Network Management Protocol is a protocol used for exchanging management information between network devices SNMP is a member of TCP IP protocol suite Your ZyW ALL supports SNMP agent functionality which allows a manager station to manage and monitor the ZyW ALL through the network The ZyWALL supports SNMP version one SNMPv1 Auto negotiating 10 100Mbps Ethernet The LAN interface automatically detects if it s on a 10 or a 100 Mbps Ethernet Network Address Translation NAT NAT Network Address Translation NAT RFC 1631 allows the translation of an Internet Protocol address used within one network to a different IP address known within another network DHCP Dynamic Host Configuration Protocol DHCP Dynamic Host Configuration Protocol allows the individual clients workstations to obtain the TCP IP configuration at start up from a centralized DHCP server The ZyW ALL has built in DHCP server capability enabled by default which means it can assign IP addresses an IP default gateway and DNS servers to Windows 9X Windows NT and other systems that support the DHCP client The ZyWALL can now also act as a surrogate DHCP server DHCP Relay where it relays IP address assignment from the ac
211. one call and relays the PPP frames to the PNS A PAC must have IP and dial up capability A filter that scans packets and decides whether to let them through Password Authentication Protocol PAP is a security protocol that requires users to enter a password before accessing a secure system The user s name and password are sent over the wire to a server where they are compared with a database of user account names and passwords This technique is vulnerable to wiretapping eavesdropping because the password can be captured and used by someone to log onto the system A program that uses a dictionary of words phrases names etc to guess a password A system of encrypting electronic files using a single key or password Anyone who knows the password can decrypt the file The encrypted password is not visible in the password file but stored in a shadow file that is only readable by root This prevents brute force attacks on the encrypted field to guess the password see e g http whatis com shadowpa htm Gaining access to computers or networks by bypassing security programs and passwords Breaking into phone or other communication systems Phreaking sites on the Internet are popular among crackers and other criminals An attack that slows down the network until it is unusable The attacker sends a ping command to the network repeatedly to slow it down See also Denial of Service Someone who steals or distributes software without paying the
212. onfig edit firewall set set gt rule rule gt srcaddr single ip address Description Edits whether a packet is dropped or allowed through when it does not meet a rule within the set Edits the time limit in seconds for an idle ICMP session before it is terminated Edits the time limit in seconds for an idle UDP session before it is terminated Edits the wait time in seconds for the SYN traffic in initiating a TCP session before it is terminated Edits the wait time in seconds for the FIN traffic in concluding a TCP session before it is terminated Edits the time limit in seconds for an idle TCP session before it is terminated Switches on off the logs for matching default permit Edits whether a packet is dropped or allowed through when it meets this rule Edits whether a rule is enabled or not Edits the protocol specification number made in this rule for ICMP currently Edits whether traffic that does match the rule doesn t match both or neither is logged Activates or deactivates the notification function for when a DOS attack occurs or there is a violation of any alert settings In case of such instances the function will send an e mail to the SMTP destination address and log an alert Selects and edits a source address of the traffic which comply to this rule CLI Commands ZyWALL 10 Internet Security Gateway Function CLI Syntax config edit firewall set s
213. onfiguration on a TCP IP Network AAA 12 1 Figure 13 1 ZyWALL Firewall Application rennen rennen enne ee ee ee ee ee 13 3 Figure 13 2 Three Way Handshake essent nennen eene nete entere tenere 13 5 Figure 13 3 SYN Flood ER OR UR OO ERU EE uit 13 5 Figure 13 4 Smurf Attack EECH 13 6 Figure 13 5 Stateful Inspection one cepere Dt teer ep OS EE EE Cope PE es 13 7 Figure 14 1 SMT Mam EI OE EL RE RE EE N 14 1 Figure 14 2 Menu 21 Filter and Firewall Sep 14 1 Figure 14 3 Menu 21 2 Firewall Setup 14 2 Figtire 14 4 View Firewall Log eines EEN ER EE ER OR EE ERE 14 4 Figure 14 5 Big Picture Filtering Firewall and NAT ese ese se ee se see Ge Re Gee Gee be ee ee ee ee ee ee 14 6 Figure 15 1 Login screen as seen in Netscape iese se se ee ee Ge ee ee ee Ge Se Ge GR RA GRA ee ee ee ee 15 1 Figure 15 2 ZyWALL Web Configurator Welcome Screen 15 2 Figure 15 3 Enabling the Firewall 5 ie eee RET HR ESE Oe RR Ee erheben 15 3 Figure 15 4 E mail Screen note rere ER ERR RU EE EE N a 15 4 Figure 15 5 E mail EA EE EE E E ERR eiii Sete EG 15 7 Figure 15 6 Attack Alert EE 15 9 Figure 16 1 LAN to WAN Traffic speise see see se ee ee nee enne Gee enne be ee ee ee Se o trennen enne 16 3 Figure 16 2 WAN to LAN Traffic iiie eere cete e DURER TRO IRURE e Ee ER ee rere 16 4 Figure 16 3 Firewall Rules Summary First Screen 16 5 Figure 16 4 Creating Editing A Firewall Rule 16 10 Figure 16 5 Adding Editing Source and
214. orwarding services Telnet is the login and terminal emulation protocol common on the Internet and in UNIX environments It operates over TCP IP networks Its primary function is to allow users to log into remote host systems Illegal interception of data from computers and video signals A device that allows you to send commands to a computer somewhere else At a minimum this usually means a keyboard and a display screen and some simple circuitry Software that pretends to be emulates a physical terminal and allows you to type commands to a computer somewhere else Glossary of Terms ZyWALL 10 Internet Security Gateway TFTP Trojan or Trojan Horse UDP UNIX URL VPN Vulnerability WAN War Dialer Warez Wire Tapping Worm WWW Trivial File Transfer Protocol is an Internet file transfer protocol similar to FTP File Transfer Protocol but it is scaled back in functionality so that it requires fewer resources to run TFTP uses the UDP User Datagram Protocol rather than TCP Transmission Control Protocol Like the fabled gift to the residents of Troy a Trojan Horse is an application designed to look innocuous Yet when you run the program it installs a virus or memory resident application that can steal passwords corrupt data or provide hackers a back door into your computer Trojan applications are particularly dangerous since they can often run exactly as expected without showing any visible signs of
215. owses a web site For example cookies are used to remember the items a shopper may have in a shopping cart Techniques programs or other tools that can protect your computer against threats Another term for hackers Generally the term cracker refers specifically to a person who maliciously attempts to break encryption software locks or network security Programs used to break into computers Cracker tools are widely distributed on the Internet They include password crackers Trojans viruses war dialers and worms The act of breaking into computers or cracking encryption A cable that wires a pin to its opposite pin for example RX is wired to TX This cable connects two similar devices for example two data terminal equipment DTE or data communications equipment DCE devices The act of analyzing or breaking into secure documents or systems that are protected with encryption Channel Service Unit Data Service Unit CSUs channel service units and DSUs data service units are actually two separate devices but they are used in conjunction and often combined into the same box The devices are part of the hardware you need to connect computer equipment to digital transmission lines The Channel Service Unit device connects with the digital communication line and provides a termination for the digital signal The Data Service Unit device sometimes called a digital service unit is the hardware component you need to trans
216. parated by commas The factory default filter set NetBIOS WAN can be applied in menu 11 5 to block local NetBIOS traffic from triggering calls to the ISP when you are using PPPoE or PPTP encapsulation only Enter 1 in protocol filters under Output Filter Sets when using Ethernet encapsulation and in the protocol filters field under Call Filter Sets when using PPPoE or PPTP encapsulation Apply them as shown in the following figure Menu 11 5 Remote Node Filter Input Filter Sets protocol filters device filters Output Filter Sets protocol filters 1 device filters Call Filter Sets protocol filters 1 device filters Enter here to CONFIRM or ESC to CANCEL Figure 7 17 Filtering Remote Node Traffic Apply Default Filter 1 Enter 1 in protocol filters under Output Filter Sets when using Ethernet encapsulation and under Call Filter Sets when using PPPOE or PPTP Encapsulation 7 17 ZyWALL 10 Internet Security Gateway Chapter 8 SNMP Configuration This chapter discusses SNMP Simple Network Management Protocol for network management and monitoring 8 1 About SNMP Your ZyWALL supports SNMP agent functionality which allows a manager station to manage and monitor the ZyWALL through the network Keep in mind that SNMP is only available if TCP IP is configured on your ZyWALL 8 2 Configuring SNMP To configure SNMP enter 22 from the main menu to open Menu 22 SNMP Configuration as shown in the fi
217. peed 9 3 Figure 9 4 Menu 24 2 1 System Maintenance Information sess 9 4 Figure 9 5 Menu 24 2 2 System Maintenance Change Console Port Speed 9 5 Figure 9 6 Menu 24 3 System Maintenance Log and Trace essen 9 6 Figure 9 7 Examples of Error and Information Messages esee eene enne 9 6 List of Figures xix ZyWALL 10 Internet Security Gateway Figure 9 8 Menu 24 3 2 System Maintenance UNIX Syslog esee 9 6 Figure 9 9 Call Triggering Packet Example ese se se Se Ge ee GR Gee RA GRA nennen 9 10 Figure 9 10 Menu 24 4 System Maintenance Diagnostic essere 9 11 Figure 9 11 WAN amp LANTER iiem e bere oe Ee ee ERR EUER ep pe Red 9 12 Figure 10 1 System Maintenance Backup Configuration sse 10 2 Figure 10 2 Example Backup Configuration se ese ee ee Ge Se ee Re nennen nennen nee nennen 10 3 Figure 10 4 Telnet into Menu 24 5 Backup Configuration se see see se see ee se ee ee ee Ge ee Ge Re ee 10 3 Figure 10 5 System Maintenance Restore Configuration sese 10 4 Figure 10 6 Example Restore Configuration sess en rennen trennen nennen een 10 4 Figure 10 8 Telnet into Menu 24 6 Restore Configuration essere nennen nenne 10 5 Figure 10 9 Menu 24 7 System Maintenance Upload Firmware see 10 5 Figure 10 10 Menu 24 7 1 System Maintenance
218. r Firewall Rules is a very powerful tool Using custom rules it is possible to disable all firewall protection or block all access to the I nternet Use extreme caution when creating or deleting Firewall Rules Test changes after creating them to make sure they work correctly Below is a brief technical description of how these connections are tracked Connections may either be defined by the upper protocols for instance TCP or by the ZyWALL itself as with the virtual connections created for UDP and ICMP 13 4 3 TCP Security The ZyWALL use state information embedded in TCP packets The first packet of any new connection has its SYN flag set and its ACK flag cleared these are initiation packets All packets that do not have this flag structure are called subsequent packets since they represent data that occurs later in the TCP stream If an initiation packet originates on the WAN this means that someone is trying to make a connection from the Internet into the LAN Except in a few special cases see Upper Layer Protocols shown next these packets are dropped and logged 13 8 What Is a Firewall ZyWALL 10 Internet Security Gateway If an initiation packet originates on the LAN this means that someone is trying to make a connection from the LAN to the Internet Assuming that this is an acceptable part of the security policy as is the case with the default policy the connection will be allowed A cache entry is added w
219. r Server IP if this field is left blank If it IP Address Assignment If your ISP did not assign you a fixed IP address select Dynamic otherwise select Static and enter the IP address amp subnet mask in the following fields Internet Access 3 9 ZyWALL 10 Internet Security Gateway FIELD DESCRIPTION IP Address Enter the fixed IP address assigned to you by your ISP Static IP Address Assignment is selected in the previous field IP Subnet Mask Enter the subnet mask associated with your static IP Gateway IP Address Enter the gateway IP address associated with your static IP Network Address Please see the NAT chapter for a more detailed discussion on the Network Translation Address Translation feature The choices are Full Feature None and SUA Only When you have completed this menu press ENTER at the prompt Press ENTER to Confirm to save your configuration or press ESC at any time to cancel 3 3 2 PPTP Encapsulation Point to Point Tunneling Protocol PPTP is a network protocol that enables secure transfer of data from a remote client to a private server creating a Virtual Private Network VPN using TCP IP based networks PPTP supports on demand multi protocol and virtual private networking over public networks such as the Internet The ZyWALL 10 supports only one PPTP server connection at any given time 3 3 3 Configuring the PPTP Client
220. r Types and NAT There are two classes of filter rules Generic Filter Device rules and Protocol Filter TCP IP rules Generic Filter rules act on the raw data from to LAN and WAN Protocol Filter rules act on the IP packets Generic and TCP IP filter rules are discussed in more detail in the next section When NAT Network Address Translation is enabled the inside IP address and port number are replaced on a connection by connection basis which makes it impossible to know the exact address and port on the wire Therefore the ZyW ALL applies the protocol filters to the native IP address and port number before NAT for outgoing packets and after NAT for incoming packets On the other hand the generic or device filters are applied to Filters 7 15 ZyWALL 10 Internet Security Gateway the raw packets that appear on the wire They are applied at the point when the ZyWALL is receiving and sending the packets i e the interface The interface can be an Ethernet port or any other hardware port The following diagram illustrates this LL Outgoing Figure 7 15 Protocol and Device Filter Sets 7 5 Firewall Firewall configuration is discussed in Part 4 of this manual Further comparisons are also made there between filtering NAT and the firewall 7 6 Applying a Filter and Factory Defaults This section shows you where to apply the filter s after you design it them Sets of factory default filter rules have been configured in m
221. r consumption 9 W Plug North American standards AC Power Adapter model AD48 1201200DUY Input power AC120Volts 60Hz Output power DC12Volts 1 2A Power consumption 9 W Plug North American standards Safety standards UL CUL UL1950 CSA C22 2 NO 234 M90 European Union AC Power Adapter model AD 1201200DV Input power AC230Volts 50Hz Output power DC12Volts 1 2A Power consumption 9 W Plug European Union standards AC Power Adapter model JAD 121200E Input power AC230Volts 50Hz Output power DC12Volts 1 2A Power consumption 9 W Plug European Union standards Safety standards TUV CE EN 60950 UK AC Power Adapter model AD 1201200DK Input power AC230Volts 50Hz Output power DC12Volts 1 2A Power consumption 9 W Plug United Kingdom standards Safety standards TUV CE EN 60950 BS7002 L Power Adapter Specifications ZyWALL 10 Internet Security Gateway Japan AC Power Adapter model JOD 48 1124 Input power AC100Volts 50 60Hz 27VA Output power DC12Volts 1 2A Power consumption 9 W Plug Japan standards Safety standards T Mark Australia and New Zealand AC Power Adapter model AD 1201200DS Input power AC240Volts 50Hz 0 2A Output power DC12Volts 1 2A Power consumption 9 W Plug Australia and New Zealand standards Safety standards NATA AS 3260 Power Adapter Specifications M ZyWALL 10 Internet Security Gateway
222. r instance ICMP redirect packets are never allowed in since they could be used to reroute traffic through attacking machines 13 4 5 Upper Layer Protocols Some higher layer protocols such as FTP and RealAudio utilize multiple network connections simultaneously In general terms they usually have a control connection which is used for sending commands between endpoints and then data connections which are used for transmitting bulk information Consider the FTP protocol A user on the LAN opens a control connection to a server on the Internet and requests a file At this point the remote server will open a data connection from the Internet For FTP to work properly this connection must be allowed to pass through even though a connection from the Internet would normally be rejected In order to achieve this the ZyW ALL inspects the application level FTP data Specifically it searches for outgoing PORT commands and when it sees these it adds a cache entry for the anticipated data connection This can be done safely since the PORT command contains address and port information which can be used to uniquely identify the connection Any protocol that operates in this way must be supported on a case by case basis You can use the ZyWALL Web Configurator s Custom Ports feature to do this 13 5 Guidelines For Enhancing Security With Your Firewall 1 Change the default password on the SMT and Web Configurator What Is a Firewall 13 9
223. r it is forwarded to the default server If the default is not defined the service request is simply discarded To make a server visible to the outside world specify the port number of the service and the insice IP address of the Server in Menu 15 SUA Server Setup Private Network IP Addresses Assigned by User 192 168 1 1 192 168 1 33 192 168 1 35 192 168 1 36 IP ADDRESS ASSIGNED The NAT network appears as BY ISP a single host on the Internet Figure 6 10 Multiple Servers Behind NAT 6 3 2 Configuring a Server behind NAT Follow the steps below to configure a server behind NAT Step 1 Enter 15 in the main menu to go to Menu 15 NAT Setup Step 2 Enter 2 to go to Menu 15 2 NAT Server Setup Step 3 Enter the service port number in the Port field and the inside IP address of the server in the IP Address field NAT 6 13 ZyWALL 10 Internet Security Gateway Step 4 Press ENTER at the Press ENTER to confirm prompt to save your configuration after you define all the servers or press ESC at any time to cancel If you re using Ethernet Encapsulation the SMT does not allow you to change the port 1026 entry The most often used port numbers are shown in the following table Please refer to RFC 1700 for further information about port numbers Please also refer to our included disk for more examples and details on NAT Menu 15 2 NAT Server Setup Port 4 IP Address 1 Default 2 21 9
224. r to your ZyWALL Connect the power adapter to the port labeled POWER on the rear panel of your ZyWALL Caution To prevent damage to the ZyWALL first make sure you have the correct AC power adapter Please see the Appendices for AC power adapter specifications for your region Step 4 Grounding the ZyWALL To ground the ZyWALL connect a grounded wire to the F G Frame Ground of the ZyWALL 2 3 Additional Installation Requirements In addition to the contents of your package there are other hardware and software requirements you need before you can install and use your ZyWALL These requirements include 1 A computer with an Ethernet NIC Network Interface Card installed 2 A computer equipped with communications software configured to the following parameters VTIOO terminal emulation 9600 Baud No parity 8 Data bits 1 Stop bit Flow Control set to None Hardware Installation amp Initial Setup 2 3 ZyWALL 10 Internet Security Gateway 3 Acable xDSL modem and an ISP account After the ZyWALL is properly set up you can make future changes to the configuration through telnet connections 2 4 Turn On Your ZyWALL At this point you should have connected the console port the LAN port the WAN port and the power port to the appropriate devices or lines Plug the power adapter into a wall outlet The Power LED should be on The SYS LED will come on after the system tests are complete The WAN LED and one o
225. rewall traffic log contents are sent sunday monday tuesday through e mail pertains to the weekly policy wednesday thursday friday saturday config edit firewall e mail hour Edits the hour of the day the current firewall traffic log 0 23 contents are sent through e mail pertains to the hourly daily amp weekly policies config edit firewall e mail Edits the minute of the hour the current firewall traffic log minute 0 59 contents are sent through e mail pertains to the hourly daily amp weekly policies Attack config edit firewall attack send Activates or deactivates the firewall DOS attack notification alert e mails yes no config edit firewall attack block Yes to block the traffics when exceeds the threshold of tcp yes no max incomplete No to delete the oldest half open session when exceeds the threshold of tcp max incomplete config edit firewall attack Only valid when sets block to be yes The unit is minute block minute 0 255 config edit firewall attack The threshold to start to delete the old half opened sessions minute high 0 255 to minute low config edit firewall attack The threshold to stop the deletion of the half opened minute low 0 255 sessions config edit firewall attack max The threshold to start to delete the old half opened sessions incomplete high 0 255 to max incomplete low config edit firewall attack max The threshold to stop the deletion of th
226. rface The TCP packet is the first in a session and the packet s application layer protocol is configured for a firewall rule inspection The packet travels from the firewall s LAN to the WAN 2 The packet is evaluated against the interface s existing outbound access list and the packet is permitted a denied packet would simply be dropped at this point 3 The packet is inspected by a firewall rule to determine and record information about the state of the packet s connection This information is recorded in a new state table entry created for the new connection If there is not a firewall rule for this packet and it is not an attack then The default action for packets not matching following rules field see Figure 16 3 determines the action for this packet 4 Basedon the obtained state information a firewall rule creates a temporary access list entry that is inserted at the beginning of the WAN interface s inbound extended access list This temporary access list entry is designed to permit inbound packets of the same connection as the outbound packet just inspected 5 The outbound packet is forwarded out the interface What Is a Firewall 13 7 ZyWALL 10 Internet Security Gateway 6 Later an inbound packet reaches the interface This packet is part of the connection previously established with the outbound packet The inbound packet is evaluated against the inbound access list and is permitted because of the temporary access
227. rload Local IP Start 192 168 1 10 End 192 168 1 12 Global IP Start 10 132 50 1 End 10 132 50 3 Press ENTER to Confirm or ESC to Cancel Figure 6 22 Example 4 Menu 15 1 1 1 Address Mapping Rule After you ve configured your rule you should be able to check the settings in menu 15 1 1 as shown next Menu 15 1 1 Address Mapping Rules Set Name Example4 Idx Local Start IP Local End IP Global Start IP Global End IP 192 168 1 10 192 168 1 12 10 132 50 1 1 2 3 4 5 6 7 8 9 0 Action Edit Select Rule Press ENTER to Confirm or ESC to Cancel Figure 6 23 Example 4 Menu 15 1 1 Address Mapping Rules NAT 6 21 Advanced Management Part III Advanced Management Chapters 7 12 provides information on ZyWALL Filtering SNMP Configuration System Information and Diagnosis Transferring Files System Maintenance and Telnet ZyWALL 10 Internet Security Gateway Chapter 7 Filter Configuration This chapter shows you how to create and apply filters 7 1 About Filtering Your ZyW ALL uses filters to decide whether to allow passage of a data packet and or to make a call There are two types of filter applications data filtering and call filtering Filters are subdivided into device and protocol filters which are discussed later Data filtering screens the data to determine if the packet should be allowed to pass Data filters are divided into incoming and outgo
228. roadcast the ICMP echo request packet to all hosts on the network If there are numerous hosts this will create a large amount of ICMP echo request and response traffic If a hacker chooses to spoof the source IP address of the ICMP echo request packet the resulting ICMP traffic will not only clog up the intermediary network but will also congest the network of the spoofed source IP address known as the victim network This flood of broadcast traffic consumes all available bandwidth making communications impossible ICMP Vulnerability ICMP is an error reporting protocol that works in concert with IP The following ICMP types trigger an alert Table 14 1 ICMP Commands That Trigger Alerts 13 TIMESTAMP REQUEST TIMESTAMP REPLY ADDRESS MASK REQUEST ADDRESS MASK REPLY Illegal Commands NetBIOS and SMTP The only legal NetBIOS commands are the following all others are illegal Table 14 2 Legal NetBIOS Commands MESSAGE REQUEST POSITIVE NEGATIVE RETARGET KEEPALIVE All SMTP commands are illegal except for those displayed in the following tables Table 14 3 Legal SMTP Commands Introducing the ZyWALL Firewall 14 3 ZyWALL 10 Internet Security Gateway Traceroute Traceroute is a utility used to determine the path a packet takes between two endpoints Sometimes when a packet filter firewall is configured incorrectly an attacker can traceroute the firewall gaining knowledge of the network topology inside the fire
229. rograms that software pirates distribute on the Internet Connecting to a network and monitoring all traffic Most wire tapping features can only monitor the traffic on their subnet A program that seeks access into other computers Once a worm penetrates another computer it continues seeking access to other areas Worms are often equipped with dictionary based password crackers and other cracker tools that enable them to penetrate more systems Worms often steal or vandalize computer data World Wide Web Frequently used when referring to The Internet WWW has two major meanings First loosely used the whole constellation of resources that can be accessed using Gopher FTP HTTP telnet USENET WAIS and some other tools Second the universe of hypertext servers HTTP servers Glossary of Terms ZyWALL 10 Internet Security Gateway Index Exempting Computers 20 4 A Filter Cist EE N M 20 1 AE EE EE AE 20 6 Action for Matched Packets Ee 16 11 Log Re cotds e SR gon Rek De EE eg sg ted avons 20 7 Activate The Firewall Ee 19 3 Restrict Web Features 20 1 Alert Schedule ETE EE EE EES 15 5 Update Lists tenete Ee ee De 20 3 Application level Firewalls 13 1 Custom Ports AT commande 10 1 Creating Editing eese 17 3 Attack IntrodUCtlOnz 5 5 eerie GEE Ee eked tae 17 1 de pta lute fred 18 2 Customer Support sse viii Attack Alert 15 7 15 8 15 9
230. rom or similar Once you have customized the ZyW ALL s setting they can be saved back to your computer under a filename of your choosing Choose something meaningful e g zywall cfg The ZyNOS firmware file sometimes referred to as the ras file is the file that contains the ZyXEL Network Operating System firmware and usually is the router model name with a bin extension e g zywall bin With serial XMODEM transfer the filenames on the computer are your choice With many ftp and tftp clients they are similar to those seen next ftp put zywall bin ras This is a sample ftp session showing the transfer of the computer file zywall bin to the ZyWALL ftp get rom 0 zywall cfg This is a sample ftp session saving the current configuration to the computer file zywall cfg If your t ftp client does not allow you have a destination filename different than the source you will need to rename them as the ZyWALL only recognizes rom 0 and ras Be sure you keep unaltered copies of both files for later use The following table is a summary Please note that the internal filename refers to the filename on the ZyWALL and the external filename refers to the filename not on the ZyWALL i e on your workstation local network or ftp site and so the name but not the extension will vary The AT command is the command you enter after you press y when prompted in the SMT menu to go into debug mode After uploading new firmware see the ZyNOS F W Vers
231. rts whenever TCP Maximum Incomplete is exceeded The global values specified for the threshold and timeout apply to all TCP connections Click on the Attack Alert tab to bring up the next screen 15 8 Introducing the ZyWALL Web Configurator ZyWALL 10 Internet Security Gateway ATTACK ALERT E Mail LOGOUT Status Ready Figure 15 6 Attack Alert The following table describes the fields in this screen Introducing the ZyWALL Web Configurator 15 9 ZyWALL 10 Internet Security Gateway Table 15 3 Attack Alert FIELD DESCRIPTION DEFAULT VALUES attack detected Generate alert when A detected attack automatically generates a log entry Check this box to generate an alert as well as a log whenever an attack is detected See the Logs Chapter for more information on logs and alerts Denial of Service Thresholds One Minute Low This is the rate of new half open sessions that causes the firewall to stop deleting half open sessions The ZyWALL continues to delete half open sessions as necessary until the rate of new connection attempts drops below this number 80 existing half open sessions One Minute High This is the rate of new half open sessions that causes the firewall to start deleting half open sessions When the rate of new connection attempts rises above this number the ZyWALL deletes half open sessions as required to accommodate new connection attempts 100 half op
232. rules you can have a maximum of 24 rules active for a single port Filters 7 3 ZyWALL 10 Internet Security Gateway 7 2 Configuring a Filter Set To configure a filter set follow the procedure below For more information on menus 21 2 and 21 3 please see Part 4 Step 1 Select option 21 Filter Set Configuration from the main menu to open menu 21 Menu 21 Filter and Firewall Setup Filter Setup Firewall Setup View Firewall Log Enter Menu Selection Number Figure 7 4 Menu 21 Filter and Firewall Setup Step 2 Enter to bring up the following menu Menu 21 1 Filter Set Configuration Set Comments Set Comments NetBIOS WAN NetBIOS LAN Enter Filter Set Number to Configure 0 Edit Comments N A Press ENTER to Confirm or ESC to Cancel Figure 7 5 Menu 21 1 Filter Set Configuration Step 3 Select the filter set you wish to configure 1 12 and press ENTER Step 4 Enter a descriptive name or comment in the Edit Comments field and press ENTER Step 5 Press ENTER at the message Press ENTER to confirm to open Menu 21 1 1 Filter Rules Summary 7 4 Filters ZyWALL 10 Internet Security Gateway Menu 21 1 1 Filter Rules Summary A Type Filter Rules Mmn 1 Y IP Pr 6 SA 0 0 0 0 DA 0 0 0 0 DP 137 NDN 2 Y TP Pr 6 SA 0 0 0 0 DA 0 0 0 0 DP 138 NDN 4 Y ER Pr 6 SA 0 0 0 0 DA 0 0 0 0 DP 139 NDN 4 Y IP Pr 17 SA 0 0 0 0 DA 0 0 0 0 DP 137 NDN 5 Y IR
233. rvices required to move mail from one system to another The current version is called POP3 Click Custom Ports and configure the screen as follows Example Firewall Rules 19 7 ZyWALL 10 Internet Security Gateway PORT CONFIG Type a name for this custom port CONFIGURATION LOCAL NETWORK and select TCP service Click Single and enter a port number of 110 LOGOUT 2 Di ma Click Apply when you ve finished Status Ready Figure 19 7 Configuring A POP Custom Port Step 4 Now you will create rules to block all outgoing traffic from the local network to the Internet except for traffic originating from the HTTP proxy server and our mail server Click Internet to see the Rule Summary screen Now click an available No rule number button then click Edit to bring up the next screen 19 8 Example Firewall Rules ZyWALL 10 Internet Security Gateway Step 5 Click SrcAdd under the Source Address box and enter the IP address of the mail server 192 168 10 2 in the same fashion as in Figure 19 4 RULE CONFIG Local Network to Internet He Soge IP Address SR e IP Address fifi bo PTT This is the IP address of your mail server ed seran soe Syslag UDP 514 PPOPCTCP 110 Any TCP SMTP TCP25 Any UDP BGP TCP 179 BOOTP CLIENT UDP 68 You select these mail C Forward services Note that the EIE customized service has Gel ae an before the name You want to forward to
234. s 4 Does this rule conflict with any existing rules Once these questions have been answered adding rules is simply a matter of plugging the information into the correct fields in the Rules screen in the ZyW ALL Web Configurator 16 2 3 Key Fields For Configuring Rules Action Should the action be to Block or Forward Block means the firewall silently discards the packet Service Select the service from the Service scrolling list box If the service is not listed it is necessary to first define it See section 16 5 for more information on services Source Address What is the connection s source address is it on the LAN or WAN Is it a single IP a range of IPs ora subnet Destination Address What is the connection s destination address is it on the LAN or WAN Is it a single IP a range of IPs ora subnet 16 2 Creating Custom Rules ZyWALL 10 Internet Security Gateway 16 3 Connection Direction This section talks about configuring firewall rules for connections going from LAN to WAN and WAN to LAN in your firewall 16 3 1 LAN to WAN Rules The default rule for LAN to WAN traffic is that all users on the LAN are allowed non restricted access to the WAN When you configure Policy gt LAN to WAN Rules you in essence want to limit some or all users from accessing certain services on the WAN See the following figure ZyWALL 10 By default all outgoing connections LAN to WAN are allowed unle
235. s field allows users to configure the WAN port s MAC address by either using the factory default or cloning the MAC address from a computer on your LAN Once it is successfully configured the address will be copied to the rom file ZyNOS configuration file It will not change unless you change the setting in menu 2 or upload a different rom file The following table contains instructions on how to configure your WAN setup Table 2 6 WAN Setup Menu Fields FIELD DESCRIPTION EXAMPLE MAC Address Assigned By Press the SPACE BAR to choose either of the two methods of Factory assigning a MAC Address Choose Factory Default to select the Default factory assigned default MAC Address Choose IP Address attached on LAN to use the MAC Address of that workstation whose IP you give in the following field IP Address This field is applicable only if you choose the IP Address attached 192 168 1 1 on LAN method Enter the IP address of the workstation on the LAN whose MAC you are cloning When you have completed this menu press ENTER at the prompt Press ENTER to Confirm to save your configuration or press ESC at any time to cancel 2 9 LAN Setup This section describes how to configure the LAN using Menu 3 LAN Setup From the main menu enter 3 to open menu 3 Hardware Installation amp Initial Setup 2 13 ZyWALL 10 Internet Security Gateway Menu 3 LAN Setup 1 LAN Port Filter Setup 2
236. s on a remote node basis They are reusable but only one set is allowed for each remote node The ZyWALL 10 supports 2 sets since there is only one remote node The second set SUA Only option in menu 15 1 is a convenient pre configured read only Many to One port mapping set sufficient for most purposes see section 6 4 for some examples and helpful to people already familiar with SUA in previous ZyNOS versions 6 1 6 NAT Application The following figure illustrates a possible NAT application where three inside LANs logical LANs using IP Alias behind the ZyWALL can talk to three distinct Internet destinations More examples follow at the end of this chapter 6 4 NAT ZyWALL 10 Internet Security Gateway Corporation B Server in Admin Network IP 1 IGA 1 Vvasvzer J9A19S LN LAN1 192 168 1 X Network Server Admin 192 168 1 1 Pes PC4 Corporation A PC1 PC Server in Pc2 LAN2 192 168 2 X Sales Network PC2 Network Server IP 2 IGA 2 Sales 192 168 2 1 PC3 PC3 NT Server PA 192 168 2 1 D g E Server in v v v v R amp D Network 9 a 9 Ze IP 3 IGA 3 25 LAN3 192 168 3 X e Network Server R amp D 192 168 3 1 WAN Addresses LAN Addresses Default IPs IGA 1 192 168 1 1 IGA 2 gt 192 168 2 1 IGA 3 gt 192 168 3 1 Figure 6 2 NAT Application 6 2 SMT Menus 6 2 1 Applying NAT in the SMT Menus You apply NAT via menus
237. s the SYN ACK it queues up all outstanding SYN ACK responses on what is known as a backlog queue SYN ACKs are moved off the queue only when an ACK comes back or when an internal timer which is set at relatively long intervals terminates the three way handshake Once the queue is full the system will ignore all incoming SYN requests making the system unavailable for legitimate users Client Server RE SE eg VER erue Figure 13 3 SYN Flood 2 b In a LAND Attack hackers flood SYN packets into the network with a spoofed source IP address of the targeted system This makes it appear as if the host computer sent the packets to itself making the system unavailable while the target system tries to respond to itself What Is a Firewall 13 5 ZyWALL 10 Internet Security Gateway 3 A brute force attack such as a Smurf attack targets a feature in the IP specification known as directed or subnet broadcasting to quickly flood the target network with useless data A Smurf hacker floods a router with Internet Control Message Protocol ICMP echo request packets pings Since the destination IP address of each packet is the broadcast address of the network the router will broadcast the ICMP echo request packet to all hosts on the network If there are numerous hosts this will create a large amount of ICMP echo request and response traffic If a hacker chooses to spoof the source IP address of the ICMP echo request packet
238. select this option the SMT will use Address Address Mapping Set 1 menu 15 1 see section Translation 6 2 3for further discussion You can configure any f th d bed in Table 6 2 When you select this option the SMT will use Address Mapping Set 255 menu 15 1 see section 6 2 3 Itis a convenient pre configured read only Many to One port mapping set sufficient for most purposes and helpful to people already familiar with SUA in previous ZyNOS versions Note that there is also a Server type whose IGA is 0 0 0 0 in this set 6 2 2 Configuring NAT To configure NAT enter 15 from the main menu to bring up the following screen Menu 15 NAT Setup Address Mapping Sets Server Set Enter Menu Selection Number Figure 6 5 Menu 15 NAT Setup 6 2 3 Address Mapping Sets and NAT Server Sets Use the Address Mapping Sets menus and submenus to create the mapping table used to assign global addresses to machines on the LAN Each remote node must specify which NAT Address Mapping Set to use The ZyWALL 10 has one remote node and so allows you to configure only one NAT Address Mapping Set You can see two NAT Address Mapping sets in menu 15 1 You can only configure Set 1 Set 255 is used for SUA When you select Full Feature in menu 4 or 11 3 the SMT will use Set 1 which supports all mapping types as outlined in Table 6 2 When you select SUA Only the SMT will use the pre configured Set 255 read only se
239. server and mail server on the LAN Step 8 Enter 15 from the main menu Step 9 Now enter 2 from this menu and configure it as shown in Figure 6 20 Menu 15 2 NAT Server Setup IP Address 2 9 10 0 0 145 0 0 0 12 RR Reserved Press ENTER to Confirm or ESC to Cancel Figure 6 20 Example 3 Menu 15 2 NAT 6 19 ZyWALL 10 Internet Security Gateway 6 4 4 Example 4 NAT Unfriendly Application Programs Some applications do not support NAT Mapping using TCP or UDP port address translation In this case it is better to use Many to Many No Overload mapping as port numbers do not change for Many to Many No Overload and One to One NAT mapping types The following figure illustrates this Mapping Rules 1 Game Players 1 to 3 lt gt IGAs 1to 3 Type Many Many No Ov ZyWALL Game Player 1 192 168 1 10 Game Player 2 192 168 1 11 10 132 50 1 IGA 1 10 132 50 2 2 IGA 2 10 132 50 3 2 IGA 3 Game Player 3 192 168 1 12 Figure 6 21 NAT Example 4 Other applications e g gaming programs are NAT unfriendly because they embed addressing information in the data stream These applications still won t work through NAT even when using One to One and Many to Many No Overload mapping types Follow the steps outlined in example 3 above to configure these two menus as follows 6 20 NAT ZyWALL 10 Internet Security Gateway Menu 15 1 1 1 Address Mapping Rule Type Many to Many No Ove
240. server that would still like to have a DNS name To use this service you must register with the Dynamic DNS client The Dynamic DNS Client service provider will give you a password or key The ZyWALL at the time of writing supports www ddns org and www dyndns org clients You can apply to either of these clients for Dynamic DNS service DYNDNS Wildcard Enabling the wildcard feature for your host causes yourhost dyndns org to be aliased to the same IP address as yourhost dyndns org This feature is useful if you want to be able to use for example www yourhost dyndns org and still reach your hostname 2 7 2 Procedure For Configuring Menu 1 Step 1 Enter 1 in the Main Menu to open Menu 1 General Setup Step 2 The Menu 1 General Setup screen appears as shown next Fill in the required fields Menu 1 General Setup System Name ZYWALL 10 Domain Name zyxel com tw Edit Dynamic DNS No Press ENTER to Confirm or ESC to Cancel Figure 2 8 Menu 1 General Setup 2 10 Hardware Installation amp Initial Setup ZyWALL 10 Internet Security Gateway Table 2 4 General Setup Menu Field FIELD DESCRIPTION EXAMPLE System Name Choose a descriptive name for identification purposes It is ZyWALL 10 recommended you enter your computer s Computer name in this field This name can be up to 30 alphanumeric characters long Spaces are not allowed but dashes and underscores are accepted Domain
241. sk This shows the IP mask of the ZyWALL DHCP This field shows the DHCP setting of the ZyWALL When finished viewing press ESC or ENTER to exit 9 4 System Information amp Diagnosis ZyWALL 10 Internet Security Gateway 9 2 2 Console Port Speed You can change the speed of the console port through Menu 24 2 2 Console Port Speed Your ZyWALL supports 9600 default 19200 38400 57600 and 115200 bps for the console port Use the SPACE BAR to select the desired speed in menu 24 2 2 as shown below Menu 24 2 2 System Maintenance Change Console Port Speed Console Port Speed 115200 Press ENTER to Confirm or ESC to Cancel Press Space Bar to Toggle Figure 9 5 Menu 24 2 2 System Maintenance Change Console Port Speed 9 3 Log and Trace There are two logging facilities in the ZyWALL The first is the error logs and trace records that are stored locally The second is the UNIX syslog facility for message logging 9 3 1 Viewing Error Log The first place you should look for clues when something goes wrong is the error trace log Follow the procedure below to view the local error trace log Step 1 Select option 24 from the main menu to open Menu 24 System Maintenance Step 2 From menu 24 select option 3 to open Menu 24 3 System Maintenance Log and Trace Step 3 Select the first option from Menu 24 3 System Maintenance Log and Trace to display the error log in the system
242. ss ENTER to Confirm or ESC to Cancel Figure 4 1 Menu 11 1 Remote Node Profile for Ethernet Encapsulation Remote Node Setup 4 1 ZyWALL 10 Internet Security Gateway Table 4 1 Fields in Menu 11 1 FIELD DESCRIPTION EXAMPLE Rem Node Name Enter a descriptive name for the remote node This field can be up to eight characters LAoffice Active Press SPACE BAR to select Yes activate remote node or No deactivate remote node Yes Encapsulation Ethernet is the default encapsulation Press the SPACE BAR if you wish to change to PPPoE encapsulation Ethernet Service Type Press SPACE BAR to select from Standard RR Toshiba RoadRunner Toshiba authentication method or RR Manager RoadRunner Manager authentication method Choose one of the RoadRunner methods if your ISP is Time Warner s RoadRunner otherwise choose Standard Standard Service Name This is valid only when you have chosen PPPoE encapsulation If you are using PPPoE encapsulation then type the name of your PPPoE service here poellc Outgoing My Login My Password Server IP This field is applicable for PPPoE encapsulation only Enter the login name assigned by your ISP when the ZyWALL calls this remote node Some ISPs append this field to the Service Name field above e g jim poellc to access the PPPOE server Enter the password assigned by your ISP when the ZyWALL calls this remote node
243. ss you create rules blocking certain LAN users Figure 16 1 LAN to WAN Traffic 16 3 2 WAN to LAN Rules The default rule for WAN to LAN traffic blocks all incoming connections WAN to LAN If you wish to allow certain WAN users to have access to your LAN you will need to create custom rules to allow it See the following figure Creating Custom Rules 16 3 ZyWALL 10 Internet Security Gateway By default NO incoming connections WAN to LAN are allowed unless you create rules allowing certain WAN users services access to your LAN ZyWALL Figure 16 2 WAN to LAN Traffic 16 4 Rule Summary The fields in the Rule Summary screens are the same for Local Network and Internet so the discussion below refers to both Click on Firewall then Local Network to bring up the following screen This screen is a summary of the existing rules Note the order in which the rules are listed The ordering of your rules is very important as rules are applied in turn 16 4 Creating Custom Rules ZyWALL 10 Internet Security Gateway ZyXEL LION LOCAL NETWORK MAIN MENU Local Network to Internet Timo Out Firewall CONFIGURATION ACL Default Set NETWORK LOCAL NETWORK M POP TCP 110 Forward None LT 3 x 4 1 Configured 192 168 10 2 LOGOUT Configured 192 168 10 5 7 Any z HTTP TCP 80 z Forward None Empty E E UR Empty s EI EI Empty s s Empty El s ml Empty o
244. sts available in menu 24 4 for your ZyW ALL and associated connections Table 9 4 System Maintenance Menu Diagnostic FIELD DESCRIPTION Ping Host Enter 1 to ping any machine with an IP address on your LAN or WAN Enter its IP address in the Host IP Address field below WAN DHCP Release Enter 2 to release your WAN DHCP settings WAN DHCP Renewal Enter 3 to renew your WAN DHCP settings Internet Setup Test Enter 4 to test the Internet Setup You can also test the Internet Setup in Menu 4 Internet Access Please refer to the nternet Access chapter for more details This feature is only available for dial up connections using PPPoE or PPTP encapsulation Reboot System Enter 11 to reboot the ZyWALL Host IP Address If you entered 1 above then enter the IP address of the machine you want to ping in this field Enter the number of the selection you would like to perform or press ESC to cancel 9 12 System Information amp Diagnosis ZyWALL 10 Internet Security Gateway Chapter 10 Firmware and Configuration File Maintenance This chapter tells you how to back up and restore your configuration file as well as upload new firmware and a new configuration file 10 1 Filename conventions The configuration file often called the romfile or rom 0 contains the factory default settings in the menus such as password DHCP Setup TCP IP Setup etc It arrives from ZyXEL with a name of zywall
245. t 11 1 EE OE ER RE N HOE EE Ae 4 2 Table 4 2 Fields in Menu 11 1 PPPoE Encapsulation Specifch ees esse esse esse esse ese ee ee ee Re Ge See Gee Gee se ee 4 4 Table 4 3 Fields in Menu 11 1 PPTP Encapsulation ener enrnen e 4 5 Table 4 4 Remote Node Network Layer Options Menu Fields sese 4 6 Table 4 5 Remote Node Network Layer Options Menu Fields serene 4 8 Table 5 1 IP Static Route Menu Fields sees enne ennt nne trennen 5 3 Table 6 1 NAT Definitions Este es ERGER Ee VEE N ey ee Eee uu e tee egere E etes 6 1 Table 6 2 NAT Mapping Types rte erp EE EE N EE 6 3 Table 6 3 Applying NAT in Menus 4 amp II 6 7 Table 6 4 SUA Address Mapping Rule 6 9 Table6 5 Fieldsin Menu 15 1 1 de bee ee eat Ge RE GE e eee es tidem is 6 11 Table 6 6 Menu 15 1 1 1 Configuring an Individual Rule 6 12 Table 6 7 Services amp Port numbers oet tt eee eet iet IPE de eg s 6 14 Table 7 1 Abbreviations Used in the Filter Rules Summary Menn 7 6 List of Tables xxiii ZyWALL 10 Internet Security Gateway Table 7 2 Rule Abbreviations Used neret pierden ir eripe ra bte Age basie ee 7 6 Table 7 3 TCP IP Filter Rule Menu Fields t etc eec e e GR eere 7 8 Table 7 4 Generic Filter Rule Menu beide 7 12 Table 8 1 SNMP Configuration Menu Fields iese ese se ee se se Ge Ge GRA GR Ge ee Ge ee ee nennen nennen nennen 8 2 Table 9 1 System Maintenance Status Menu Fields esee
246. t Name Enter a name for this set of rules This is a required NAT SET field Please note that if this field is left blank the entire set will be deleted Action There are four actions The default is Edit Edit means Edit you want to edit a selected rule see following field Insert Before means to insert a rule before the rule selected The rules after the selected rule will then be moved down by one rule Delete means to delete the selected rule and then all the rules after the selected one will be advanced one rule None disables the Select Rule item Select Rule When you choose Edit Insert Before or Delete in the 1 previous field the cursor jumps to this field to allow you to select the rule to apply the action in question You must press ENTER at the bottom of the screen to save the whole set You must do this again if you make any changes to the set including deleting a rule No changes to the set take place until this action is taken Be careful when ordering your rules as each rule is executed in turn beginning from rule 1 Selecting Edit in the Action field and then selecting a rule brings up the following menu Menu 15 1 1 1 Address Mapping Rule in which you can edit an individual rule and configure the Type Local and Global Start End IPs Menu 15 1 1 1 Address Mapping Rule Type One to One Local IP Start End Global IP Start End Press ENTER to Confirm or ESC to Cancel
247. t Security Gateway List of Figures Figure 1 1 Secure Internet Access via Cable sss nee een eere 1 4 Figure 1 2 Secure Internet Access Via DSL sees esel trosse siririn tiene Se ERGE EG ENER Geb ee Kees He ER Gegee 1 4 AD Front Panel casos o e n e dee ite N N RE N N EN 2 1 Figure 2 2 ZyWALL 10 Rear Panel and Connectons eese nennen RA ee ee ee 2 2 Figure 2 3 Initial Screen esiti peu o EE ss les Riot t eR E EE ert 2 4 Figure 2 4 Pass word Scte n ER EE ee EO re OE e ee EE 2 4 Figure 2 5 ZyWALL 10 Main Menu ettet ree i qe rh ce Perte es ek Gees che 2 6 Figuie 2 6 5MT Menus at a Glance oto iste Ue e Oeste D RE S Ee eg P d e 2 8 Figure 2 7 Menu 23 System Password 2 9 Figure 2 8 Menu 1 General Setup 2 10 Figure 2 9 Configure Dynamic DNS are eate ret teas ie rate eerie Ee ee eb ee SEE Reel ep ee HERR ese ERE 2 11 Figuie 2 10 Men 2 WAN Setups es ese ser seep ses sees eee ivre to roue de geo snes eet Eder Add Sie 2 13 Figure 2 11 Menu 3 LAN Setups iue UR E Eg bee Ge IE Ge EGO Ge Re EORR E pre Gebed eid 2 14 Figure 2 12 Menu 3 1 LAN Port Filter Sep 2 14 Figure 3 1 Physical Network ete eee Hedge EN OER ER ER AE N 3 4 Figure 3 2 Partitioned Logical Network A 3 4 Figure 3 3 Menu 3 LAN Setup iioc eR BIER Uere UR Ue Uer RU DE Be OE SG tiq ved 3 5 Figure 3 4 Menu 3 2 TCP IP and DHCP Ethernet Setup 3 5 Figure 3 5 Menu 3 2 1 IP Alias Setup nennen trennen trennen rennen enne 3 7 Figure 3 6 Menu 4
248. t a network In NetWare the SAP Service Advertising Protocol broadcasts information about available services on the network that other network devices can listen to A server sends out SAP messages every 60 seconds A server also sends out SAP messages to inform other devices that it is closing down Workstations use SAP to find services they need on the network A UNIX program that gathers information on networks and stores it in databases It is helpful in finding security flaws such as incorrect settings software bugs and poor policy decisions It shows network services that are running the different types of hardware and software on the network and other information It was written to help users find Glossary of Terms ZyWALL 10 Internet Security Gateway Server Shoulder Surfing SNMP Snooping SOCKS SPAM Spoofing SSL Secured Socket Layer STP Straight through Ethernet cable SUA TCP Telnet Tempest Terminal Terminal Software security flaws in their network systems A computer or a software package that provides a specific kind of service to client software running on other computers Looking over someone s shoulder to see the numbers they dial on a phone or the information they enter into a computer System Network Management Protocol is a popular management protocol defined by the Internet community for TCP IP networks It is a communication protocol for collecting information fro
249. t box to choose a time to send the alerts When Log is Full Hourly Daily Weekly None Sunday through Saturday When you have finished click Apply to save your customized settings and exit this screen Cancel to exit this screen without saving or Help for online HTML help on fields in this screen Introducing the ZyWALL Web Configurator 15 5 ZyWALL 10 Internet Security Gateway 15 3 3 SMTP Error Messages If there are difficulties in sending e mail the following error messages appear Please see the Support Notes on the included disk for information on other types of error messages E mail error messages appear in menu 24 3 1 as SMTP action request failed ret 2 is described in the following table Table 15 2 SMTP Error Messages 1 means ZyWALL out of socket 2 means tcp SYN fail 3 means smtp server OK fail 4 means HELO fail 5 means MAIL FROM fail 6 means RCPT TO fail 7 means DATA fail 8 means mail data send fail 15 3 4 Example E mail Log An End of Log message displays for each mail in which a complete log has been sent The following is an example of a log sent by e mail 15 6 Introducing the ZyWALL Web Configurator ZyWALL 10 Internet Security Gateway b Subject A C Firewall Alert From ZyWALL You may edit the mm j i Fri 07 Apr 2000 10 05 42 The us tornal e Tum here is user zyxel com Day Month Year user z
250. t need Deere verts 4 6 4 8 5 3 My WAN Address AAA 4 8 N nailed up CONNECTION secerneren 4 3 ME EE EE AE 4 6 4 8 7 15 Application DA Applying NAT in the SMT Menus esse sesse Config et DetifiitiOfs cte Hr e Re Examples e nn How NAT Works Mapping Types sses Multiple Servers eee decies Non NAT Friendly Application Programs 6 20 Ordering Rules eser 6 10 What NAT does eisses nitet 6 1 NetBIOS commande ees ee ee ee ee ee 14 3 Network Address Translation NAT 1 2 6 1 12 1 O one minute high esses 15 10 one minute Owi 15 10 one minute huot 15 8 Online Registration ees ee Re ee vii P Packet Filtering Firewalls 13 1 Packet Information esses 18 2 Packet Triggered 9 7 Packing List Card xxviii PAP RE DER 4 4 PasSWOFd ice rct Pp Poi T ra adus 2 4 2 9 Pifig EE ER ai 9 12 Ping of Death esse ees se ee ee ee de ee ee 13 4 ae eei pecie 13 3 13 4 Port Configuration ee ee ee Re ee 17 4 Power Adapter ees ee Re ee ee 2 3 PPP log RENE ER aa 9 7 PPPoE Encapsulation3 8 3 11 4 1 4 3 4 4 4 9 4 10 PPTP Encapsulation 1 2 3 10 4 4 4 7 Private 3 2 3 3 4 7 4 9 5 3 W Private IP Addresees sesse esse ee ee ee ee ee 3 2 R Read Me Eret ese ees ee ee ee ee RR ee ee EE ee xxviii Rear Panel 1 renonce 2 2 Related Documentation xxviii Relays a
251. t should contact the appropriate electrical inspection authority or electrician as appropriate Note This digital apparatus does not exceed the class A limits for radio noise emissions from digital apparatus set out in the radio interference regulations of Industry Canada iv Canadian Users ZyWALL 10 Internet Security Gateway Declaration of Conformity We the Manufacturer Importer ZyXEL Communications Corp No 6 Innovation Rd Il Science Based Industrial Park Hsinchu Taiwan 300 R O C declare that the product ZyWALL 10 is in conformity with reference to the specification under which conformity is declared Standard Standard Item Version e EN 55022 Radio disturbance characteristics Limits and method of 1994 measurement e EN 61000 3 2 Disturbance in supply system caused by household appliances 1995 and similar electrical equipment Harmonics e EN 61000 3 3 Disturbance in supply system caused by household appliances 1995 and similar electrical equipment Voltage fluctuations e EN 61000 4 2 Electrostatic discharge immunity test Basic EMC Publication 1995 e EN 61000 4 3 Radiated radio frequency electromagnetic field immunity test 1996 e EN 61000 4 4 Electrical fast transient burst immunity test Basic EMC 1995 Publication e EN 61000 4 5 Surge immunity test 1995 e EN 61000 4 6 Immunity to conducted disturbances induced by radio freguency 1996 fields e EN 61000 4 8 1993 e EN 61000 4 11
252. t the line is a direct connection into the carrier s frame relay ATM Asynchronous Transfer Mode or Internet connect system A Digital Subscriber Line Access Multiplexer DSLAM is a network device usually at a telephone company central office that receives signals from multiple customer Digital Subscriber Line connections and puts the signals on a high speed backbone line using multiplexing techniques Depending on the product DSLAM multiplexers connect DSL lines with some combination of asynchronous transfer mode ATM frame relay or IP networks Originally the DTE data terminal equipment meant a dumb terminal or printer but today it is a computer or a bridge or router that interconnects local area networks ElectroMagnetic Interference The interference by electromagnetic signals that can cause reduced data integrity and increased error rates on transmission channels The act of substituting numbers and characters in a file so that the file is unreadable until itis decrypted Encryption is usually done using a mathematical formula that determines how the file is decrypted A very common method of networking computers in a LAN There are a number of adaptations to the IEEE 802 3 Ethernet standard including adaptations with data rates of 10 Mbits sec and 100 Mbits sec over coaxial cable twisted pair cable and fiber optic cable The latest version of Ethernet Gigabit Ethernet has a data rate of 1 Gbit sec Glossary of Terms
253. tBIOS smtp illegal command traceroute teardrop or syn flood Section 14 1 2 and Chapter 13 have more detailed discussion of what these attacks mean Action This field displays whether the packet was Block Forward blocked i e silently discarded forwarded or neither Block Forward or None None means that no action is dictated by this rule or None Click Previous Page or Next Page to view other pages in your log Click Refresh to renew the log screen or Clear to clear all the logs Click Help for online HTML help on fields in this screen When you have finished viewing this screen click another link to exit 18 2 Example Firewall Rules ZyWALL 10 Internet Security Gateway Chapter 19 Example Firewall Rules This chapter gives examples for configuring various rules for WAN to LAN and LAN to WAN 19 1 Examples Whenever you open a hole in the firewall to forward a service from the Internet to the local network and NAT is also enabled you may have to also configure a server behind NAT using SMT menu 15 2 Please see the NAT chapter for more detailed information and also see Figure 14 5 for a view of how filtering the firewall and NAT interact 19 1 1 Example 1 Firewall Rule To Allow Web Service From The Internet Let s say you have one server on the local network with an IP of 10 100 1 2 supporting FTP HTTP Telnet and mail services The only traffic allowed from the Internet is web ser
254. te 15 4 153 3 SMTE Error Messages ceo oh tena eiae eege ee 15 6 15 34 Examiple E mail LOS ss eto Ree Rr en eere En rele eet ee ree dE 15 6 DA Attack Alert eelere 15 7 TISAY Threshold EE 15 7 15 42 Half Op n SESSIONS eerte e niaise raara o ek ie ee sp ee cea eroe Lese EOM 15 8 Chapter 16 Creating Custom Rules sesse ese sesse se see eee eene Se EE EE SE EE Ee SE EE Ee SR EE Ee SR EE Be SR EE Ee SR EE Ee Re ee 16 1 16 I Rules OVERVIEW SR AR EA EE ER OE EE ER OE N URS 16 1 16 2 Rul Logic OV rView 5 EE EE EE OE ER N 16 1 16 2 1 Rule Checklist OR EO ine RE RO 0 16 1 16 22 Security Ramifications ei ss ees See Se REGEER RE Dennerle ue Se ERG GE be 16 2 16 2 3 Key Fields For Configuring Rules 2 0 0 0 esse esse es see ee ee ee GR ee EE EE ee GR be aTa 16 2 16 5 Connection Direction uou ene eere ie rote D el teur m eee Ee ER Cote OON ge GE RR 16 3 16 31 EAN to WAN Rules deii ede dote ipit eid due d pid pie evite 16 3 16 3 2 WANtoLDAN Rulesz edid eere e ege edere ee epe e pt ee teda 16 3 T64 Rule SUMMALY edd ee iier tre he ORE ORE ER ERA etatis 16 4 16 5 Predefined Services ia ca eL dete DUREE TEE ERG DE ERE APER EE ie tego Ese 16 7 16 5 1 Creating Editing Firewall Rules eese nennen ener nnne 16 10 16 5 2 Source and Destination Adresses 16 12 16 6 Timeouts OE EE EO EE ER RI Rp BU 16 14 16 6 1 Factors Influencing Choices for Timeout Values esee 16 14 Chapter 17 Custom POrts
255. the other hand if you are part of a much larger organization you should consult your network administrator for the appropriate IP addresses Regardless of your particular situation do not create an arbitrary IP address always follow the guidelines above For more information on address assignment please refer to RFC 1597 Address Allocation for Private I nternets and RFC 1466 Guidelines for Management of I P Address Space 3 1 5 RIP Setup RIP Routing Information Protocol RFC1058 and RFC 1389 allows a router to exchange routing information with other routers The RIP Direction field controls the sending and receiving of RIP packets When set to Both or Out Only the ZyWALL will broadcast its routing table periodically When set to Both or In Only it will incorporate the RIP information that it receives when set to None it will not send any RIP packets and will ignore any RIP packets received The Version field controls the format and the broadcasting method of the RIP packets that the ZyW ALL sends it recognizes both formats when receiving RIP 1 is universally supported but RIP 2 carries more information RIP 1 is probably adequate for most networks unless you have an unusual network topology Both RIP 2B and RIP 2M sends the routing data in RIP 2 format the difference being that RIP 2B uses subnet broadcasting while RIP 2M uses multicasting Multicasting can reduce the load on non router machines since they generally do not list
256. ting one of the IP static routes as shown below Enter 12 from the main menu Menu 12 IP Static Route Setup ees 2 3 4 5 6 Tes 8 Enter selection number Figure 5 2 Menu 12 IP Static Route Setup Now enter the index number of one of the static routes you want to configure Menu 12 1 Edit IP Static Route Route 4 1 Route Name Active No Destination IP Address IP Subnet Mask Gateway IP Address Metric 2 Private No Press ENTER to CONFIRM or ESC to CANCEL Figure 5 3 Menu 12 1 Edit IP Static Route The following table describes the IP Static Route Menu fields 5 2 IP Static Route Setup ZyWALL 10 Internet Security Gateway Table 5 1 IP Static Route Menu Fields FIELD DESCRIPTION Route This is the index number of the static route that you chose in menu 12 Route Name Enter a descriptive name for this route This is for identification purposes only Active This field allows you to activate deactivate this static route Destination IP Address This parameter specifies the IP network address of the final destination Routing is always based on network number If you need to specify a route to a single host use a subnet mask of 255 255 255 255 in the subnet mask field to force the network number to be identical to the host ID IP Subnet Mask Enter the IP subnet mask for this destination Gateway IP Address Enter the IP address of the g
257. tiple local IP addresses to shared global IP addresses 4 Many to Many No Overload In Many to Many No Overload mode the ZyWALL maps the each local IP addresses to unique global IP addresses 5 Server This type allows you to specify inside servers of different services behind the NAT to be accessible to the outside world Port numbers do not change for One to One and Many to Many No Overload NAT mapping types The following table summarizes these types Table 6 2 NAT Mapping Types TYPE IP MAPPING SMT ABBREVIATION One to One ILA1 IGA1 1 1 Many to One SUA PAT ILA1 IGA1 M 1 ILA2 5 IGA1 Many to Many Overload ILA1 amp IGA1 M M Ov ILA2 IGA2 ILA3 IGA1 ILA4 IGA2 Many to Many No Overload ILA1 IGA1 M M No Ov ILA2 IGA2 ILA8 lt gt IGA3 NAT 6 3 ZyWALL 10 Internet Security Gateway TYPE IP MAPPING SMT ABBREVIATION Server Server 1 IP amp IGA1 Server Server 2 IP IGA1 Server 3 IP gt IGA1 6 1 5 SUA Single User Account Versus NAT SUA Single User Account in previous ZyNOS versions is a subset of NAT that supports two types of mapping Many to One and Server See section 6 2 5 for a detailed description of the NAT set for SUA The ZyWALL now has Full Feature NAT support to map global IP addresses to local IP addresses of clients or servers using all mapping types as outlined in Table 6 2 The ZyW ALL supports NAT set
258. to upload router firmware using TFTP please see your router manual Press ENTER to Exit Figure 10 14 Telnet into Menu 24 7 2 System Maintenance To transfer the firmware and the configuration file follow these examples 10 10 Firmware and Configuration File Maintenance ZyWALL 10 Internet Security Gateway 10 6 1 Using the FTP command from the DOS Prompt Step 1 Step 2 Step 3 Step 4 Step 5 Step 6 Step 7 Launch the FTP client on your workstation Type open and the IP address of your ZyWALL Press ENTER when prompted for a username Type root and your SMT password as requested The default is 1234 Type bin to set transfer mode to binary Use put to transfer files from the workstation to the ZyWALL e g put zywall bin ras transfers the firmware on your computer zywall bin to the ZyWALL and renames it ras Similarly put zywall rom rom 0 transfers the configuration file on your computer zywall rom to the ZyWALL and renames it rom 0 Likewise get rom 0 zywall rom transfers the configuration file on the ZyWALL to your computer and renames it zywall rom See section 10 1 for more information on filename conventions Type quit to exit the ftp prompt 331 Enter PASS command Password 230 Logged in ftp bin 200 Type I OK ftp put zywall bin ras 200 Port command okay 150 Opening data connection for STOR ras 226 File received OK ftp 327680 bytes sent in 1 10Seconds 297 89Kb
259. tocol that provides datagram services Internet Relay Chat IRC was developed in the late 1980s as a way for multiple users on a system to chat over the network Today IRC is a very popular way to talk in real time with other people on the Internet However IRC is also one avenue hackers use to get information from you about your system and your company Moreover IRC sessions are prone to numerous attacks that while not dangerous can cause your system to crash Internet Service Providers provide connections into the Internet for home users and businesses There are local regional national and global ISPs You can think of local ISPs as the gatekeepers into the Internet Local Area Network is a shared communication system to which many computers are attached A LAN as its name implies is limited to a local area This has to do more with the electrical characteristics of the medium than the fact that many early LANs were designed for departments although the latter accurately describes a LAN as well LANs have different topologies the most common being the linear bus and the star configuration A version of the UNIX operating system designed to run on IBM Compatible computers A virus that only activates itself when certain conditions are met Logic bombs usually damage files or cause other serious problems when they are activated On a local area network LAN or other network the MAC Media Access Control address is your computer
260. tual real DHCP server to the clients 1 2 Getting to Know Your ZyWALL ZyWALL 10 Internet Security Gateway Full Network Management This feature allows you to access the SMT System Management Terminal through the console port or telnet connection RoadRunner Support In addition to standard cable modem services the ZyW ALL supports Time Warner s RoadRunner Service Time and Date Setting This new feature Menu 24 10 allows you to get the current time and date from an external server when you power up your ZyW ALL The real time is then displayed in the ZyW ALL error logs and firewall logs If you do not choose a time service protocol that your timeserver will send when the ZyW ALL powers up you can enter the time manually but each time the system is booted the time and date will be reset to 2000 01 0100 00 00 Logging and Tracing Built in message logging and packet tracing Unix syslog facility support Upgrade ZyWALL Firmware via LAN The firmware of the ZyW ALL 10 can be upgraded via the LAN Embedded FTP and TFTP Servers The ZyW ALL s embedded FTP and TFTP Servers enable fast firmware upgrades as well as configuration file backups and restoration 1 3 Applications for ZyWALL 10 1 3 1 Broadband Internet Access via Cable or xDSL Modem A cable modem or xDSL modem can connect to the ZyW ALL 10 for broadband Internet access via Ethernet port on the modem It provides not only high speed Internet access but secured i
261. uded in RIP broadcast If No the route to this remote node will be propagated to other hosts through RIP broadcasts RIP Press the SPACE BAR to select the RIP direction from Both None None In Only Out Only Please see the R P Setup section for more information on RIP The default for RIP on the WAN side is None It is recommended that you do not change this setting Version Press the SPACE BAR to select the RIP version from RIP 1 RIP None 2B RIP 2M or None Multicast IGMP Internet Group Multicast Protocol is a session layer protocol IGMP v2 used to establish membership in a Multicast group The ZyWALL supports both IGMP version 1 IGMP v1 and version 2 IGMP v2 Press SPACE BAR to enable IP Multicasting or select None to disable it See the previous Part for more information on this feature Once you have completed filling in the Network Layer Options Menu press ENTER to return to menu 11 Press ENTER at the message Press ENTER to Confirm to save your configuration or press ESC at any time to cancel 4 2 1 Editing TCP IP Options with PPTP Encapsulation Make sure that Encapsulation is set to PPTP in menu 11 1 Then move the cursor to the Edit IP field in menu 11 1 press the SSPACE BAR to toggle No to Yes Press ENTER to open Menu 11 3 Network Layer Options Remote Node Setup 4 7 ZyWALL 10 Internet Security Gateway Menu 11 3 Remote Node Network Layer Options IP Ad
262. urity Gateway Chapter 17 Custom Ports This chapter covers creating viewing and editing custom ports 17 1 Introduction Configure customized ports for services not predefined by the ZyWALL see Figure 16 4 Fora comprehensive list of port numbers and services visit the IANA Internet Assigned Number Authority website For further information on these services please read section 16 5 To configure a custom port click Custom Ports to bring up the following screen Customized Services CONFIGURATION Syslog LOCAL NETWORK ol O cC e cC e C 9 c c Figure 17 1 Custom Ports The next table describes the fields in this screen Custom Ports 17 1 ZyWALL 10 Internet Security Gateway Table 17 1 Custom Ports FIELD DESCRIPTION Customized Services No This is the number of your customized port Status Indicates whether ports have already been configured or are still empty Name This is the name of your customized port Protocol This shows the IP protocol TCP UDP or Both that defines your customized port Port This is the port number or range that defines your customized port Add a New Entry Click this button to create a new service custom port Click a custom port number option box No and then click Edit to edit an existing service custom port or Delete to delete that service custom port Click Help for online HTML help on fields in this screen When you ha
263. ve finished viewing this screen click another link to exit 17 2 Custom Ports ZyWALL 10 Internet Security Gateway 17 2 Creating Editing A Custom Port Click Edit to create a new custom port or edit an existing one This displays the following screen ARM PORT CONFIG MAIN MENU Firewall CONFIGURATION ko o ooo fe E LOCAL NETWORK INTERNET CUSTOM PORTS LOGOUT po wa Figure 17 2 Creating Editing A Custom Port The next table describes the fields in this screen Custom Ports 17 3 ZyWALL 10 Internet Security Gateway Table 17 2 Creating Editing A Custom Port FIELD DESCRIPTION OPTIONS Service Name Enter a unique name for your custom port Service Type Choose the IP port TCP UDP or Both that TCP defines your customized port from the drop UDP down list box Both Port Configuration Type Click the Single button to specify one port Single only or Range radio button to specify a Bak span of ports that define your customized ande service Port Number Enter a single port number or the range of port numbers that define your customized service When you have finished click Apply to save your customized settings and exit this screen Cancel to exit this screen without saving or Help for online HTML help on fields in this Screen 17 4 Custom Ports ZyWALL 10 Internet Security Gateway Chapter 18 Logs This chapter contains information
264. ve applied a filter in menu 3 1 LAN or in menu 11 5 WAN to block Web service LA You have an SMT console session running After a successful login you will see the Welcome screen shown next Introducing the ZyWALL Web Configurator 15 1 ZyWALL 10 Internet Security Gateway ZyXEL WIZARD SETUP Welcome to the ZyWALL Router Web Based Configurator You can click on the Wizard Setup panel or topics on the Main Menu located in the left frame SUA NAT STATIC ROUTE FIREWALL The Wizard Setup will lead you through your ZyWALL router CONTENT FILTER configuration step by step Advanced users can click on the items on MAINTENANCE the Main Menu panel for more system status LOGOUT Figure 15 2 ZyWALL Web Configurator Welcome Screen 15 2 Introducing the ZyWALL Web Configurator ZyWALL 10 Internet Security Gateway 15 2 Enabling the Firewall Click Firewall then Configuration then the Rule Config tab to enable the firewall as seen in the following screen EMail Attack Alert CONFIGURATION LOCAL NETWORK LOGOUT Figure 15 3 Enabling the Firewall 15 3 E mail This screen allows you to specify your mail server where e mail alerts should be sent as well as when and how often they should be sent 15 3 1 What are Alerts Alerts are reports on events such as attacks which you may want to know about right away You can choose to generate an alert when an attack is detected in the Attack Alert screen
265. ve it a descriptive name The ZyW ALL allows you to configure up to twelve filter sets with six rules in each set for a total of 72 filter rules in the system You cannot mix device filter rules and protocol filter rules within the same set You can apply up to four filter sets to a particular port to block multiple types of packets With each filter set having up to six rules you can have a maximum of 24 rules active for a single port Sets of factory default filter rules have been configured in menu 21 to prevent NetBIOS traffic from triggering calls and to prevent incoming telnetting A summary of their filter rules is shown in the figures that follow The following figure illustrates the logic flow when executing a filter rule See also Figure 7 10 for the logic flow when executing an IP filter 7 2 Filters ZyWALL 10 Internet Security Gateway Packet into filter Fetch First Filter Set Filter Set aca ae gt Fetch Next Fetch First Filter Set Filter Rule Fetch Next i Filter Rule Yes A Yes Next filter is ity 4 No Rule No AD Available Yes Y Execute No H Filter Rule Check Next Rule ee DR Forward Drop Figure 7 2 Filter Rule Process You can apply up to four filter sets to a particular port to block multiple types of packets With each filter set having up to six
266. vice You want to be able to forward all traffic initiated from the local network You want to know who accesses your server and send e mail alerts when this happens Assume for example your mail account is user zyxel com Another network administrator has an e mail address of user2 zyxel com Here are the steps you would follow Example Firewall Rules 19 1 ZyWALL 10 Internet Security Gateway Step 1 Activate the firewall You may activate the firewall through the ZyWALL Web Configurator as shown next click Configuration the Config tab then check the Firewall Enabled box or through SMT menu 21 2 You can only configure the firewall using the ZyW ALL Web Configurator or CI commands see Appendices When the firewall is active the default rules allow all traffic from the local network to the WAN Internet and block all traffic from the Internet to the local network EMail Attack Alert Check here to activate the firewall You may also activate the firewall in SMT menu 21 2 Figure 19 1 Activate The Firewall 19 2 Example Firewall Rules ZyWALL 10 Internet Security Gateway Step 2 Configure your E mail screen as follows Click the E mail tab to bring up the next screen SC Enter 10 100 1 2 the IP address of the mail server here CONFIGURATION LOCAL NETWORK INTERNET 8 CUSTOM PORTS Enter a subject for LOGS these e mails here user zyxel com tw LOGOUT user2 zyxel com tw This is where we Weekly s
267. wall Teardrop Teardrop attacks exploit weaknesses in the reassembly of IP packet fragments As data is transmitted through a network IP packets are often broken up into smaller chunks Each fragment looks like the original IP packet except that it contains an offset field that says for instance This fragment is carrying bytes 200 through 400 of the original non fragmented IP packet The Teardrop program creates a series of IP fragments with overlapping offset fields When these fragments are reassembled at the destination some systems will crash hang or reboot SYN Flood SYN Attack floods a targeted system with a series of SYN packets Each packet causes the targeted system to issue a SYN ACK response While the targeted system waits for the ACK that follows the SYN ACK it queues up all outstanding SYN ACK responses on what is known as a backlog queue SYN ACKs are moved off the queue only when an ACK comes back or when an internal timer which is set at relatively long intervals terminates the three way handshake Once the queue is full the system will ignore all incoming SYN requests making the system unavailable for legitimate users Attack types and some background are described in more detail in Chapter 13 Time Packet Information Reason Action TOm 122 1 8 t 2 e re9 e ot matc TCP src port 01060 dest port 00119 lt 2 01 gt protocol From 192 168 1 2 To 10 100 6 66 match UDP src port 01053 dest port 00053 1 02
268. wall policies block all traffic from the WAN so to enable FTP over the WAN you must turn the firewall off menu 21 2 or create a firewall rule to allow FTP from the WAN 12 2 Telnet Firewall and Content Filters Part IV Firewall and Content Filters Chapters 13 20 define the term Firewall introduce the ZyWALL Firewall and ZyWALL Web Configurator describe how to create Custom Rules and configure customized ports explain Logs and provide Example Firewall Rules Chapter 20 explains Content Filtering and how to use the ZyWALL 10 Internet Security Gateway Chapter 13 What is a Firewall This chapter gives some background information on Firewalls Originally the term firewall referred to a construction technique designed to prevent the spread of fire from one room to another The network term firewall is typically defined as a system or group of systems that enforces an access control policy between two networks It may also be defined as a mechanism used to protect a trusted network from an untrusted network Of course firewalls cannot solve every security problem A firewallis one of the mechanisms used to establish a network security perimeter in support of a network security policy It should never be the only mechanism or method employed For a firewall to guard effectively you must design and deploy it appropriately This requires integrating the firewall into a broad information security policy I
269. ytes sec ftp quit Figure 10 15 FTP Session Example The system reboots after a successful upload The following table describes some of the fields that you may see in third party FTP clients Firmware and Configuration File Maintenance 10 11 ZyWALL 10 Internet Security Gateway Table 10 3 Third Party FTP Clients General Fields COMMAND DESCRIPTION Host Address Enter the address of the host server Login Type Anonymous This is when a user D and password is automatically supplied to the server for anonymous access Anonymous logins will work only if your ISP or service administrator has enabled this option Normal The server requires a unique User ID and Password to login Transfer Type Transfer files in either ASCII plain text format or in binary mode Initial Remote Specify the default remote directory path Directory Initial Local Specify the default local directory path Directory FTP over WAN will not work if 1 2 3 gu You have disabled Telnet service in menu 24 11 You have applied a filter in menu 3 1 LAN or in menu 11 5 WAN to block Telnet service The IP you entered in the Secured Client IP field in menu 24 11 does not match the client IP If it does not match the ZyW ALL will disconnect the Telnet session immediately You have an SMT console session running The firewall is active The default firewall policies block all traffic fr
270. yxel com To 192 1168 1 1 To 192 168 1 255 default permit The date format src port 00520 dest port 00520 1 00 here is Month Day 192 168 1 131 To 192 168 1 255 default permit 3 Year The time src port 00520 dest port 00520 1 00 format is Hour 168 1 6 To 10 10 10 10 match forward Mi d src port 03516 dest port 00053 1 01 nute Second 681 yd To 192 168 1 255 Src port 00520 dest port 00520 168 1 131 To 192 168 1 255 End of Log sre port 00520 dest port 00520 message shows that EB 22 a complete log has forward 0105130 port 00520 been sent End of Firewal Figure 15 5 E mail Log 15 4 Attack Alert The first defense against DOS attacks In this screen you may choose to generate an alert whenever an attack is detected For DoS attacks the ZyWALL uses thresholds to determine when to drop sessions that do not become fully established These thresholds apply globally to all sessions You can use the default threshold values or you can change them to values more suitable to your security requirements 15 4 1 Threshold Values Tune these parameters when something is not working and after you have checked the firewall counters These default values should work fine for normal small offices with ADSL bandwidth Factors influencing choices for threshold values are 1 The maximum number of opened sessions 2 The minimum capacity of server backlog in your LAN network 3 The C

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