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EXP Computer PathBuilder S200 User's Manual

1. Range 1 to 64 stations Default 1 Description Entry number used to reference this table Boot Type N A Local MAC Address Range 00 00 00 00 00 01 to 7F FF FF FF FF FF Default 00 00 00 00 00 80 Description MAC address must match the source MAC address of the frame received from the LAN port or the destination MAC address of a frame received from the WAN for the session to be spoofed If you are using Local Termination Autolearn specify the remote MAC address Boot Type LLC LT Station Bridging T0008 16F 107 Release 5 2M LLC2 Local Termination Local SAP Range 01 to FE hexadecimal Default 04 Description This SAP must match the source SAP of the frame received from the LAN port for the session to be spoofed If you are using Local Termination Autolearn specify the remote Host SAP for the local MAC Boot Type LLC LT Station LLC Profile Name Range 0 to 8 alphanumeric space blanks field Default Blank Description Local Term Station Table references this parameter for the T1 T2 TI N2 N3 and TW values If no profile name is specified then default values are used Boot Type LLC LT Station Configuring the LT These parameters make up the LT WAN Parameters Table WAN Parameters T1Reply Timer Range 1 to 25 seconds Default 3 Descript
2. Boot Type Changes to this parameter require a Node Boot to take effect Bridging Configuring the PathBuilder S200 Series Switch for Bridging Operation Encapsulation Type Range RFC 877 RFC 1294 Default CODEX Description Specify the type of encapsulation used over this LAN connection Encapsulation types supported include e CODEX Codex Proprietary Encapsulation e RFC 877 1356 RFC 877 1356 X 25 protocol encapsulation for IP e RFC 1294 1490 RFC 1294 1490 multiprotocol encapsulation over Frame Relay Boot Type Changes to this parameter require a Table and Node Record boot to take effect Autocall Mnemonic Range 0 to 8 alphanumeric characters Default 0 blank Description Specify the mnemonic name used when the LAN connection is configured to autocalling A corresponding entry must be made in the Mnemonic Table A blank entry means autocalling will not be initiated by this LAN connection entry The LAN connector at the remote device must initiate the call If configured the Autocall Mnemonic references a remote address which will be called by the LAN connection Specifically it must equal the node address of the node to which the remote LAN is attached the LAN to which we want to bridge The LAN connection subaddress configured in the node record is appended to this address to form the complete called address of an X 25 call
3. LCON Queue Limit Range 0 to 65536 Default 16000 Description The LCON Queue Limit parameter specifies the maximum number of bytes that are queued for this LAN before transmission on the WAN link Set this parameter for two seconds of data on the WAN link Bridging T0008 16F 33 Release 5 2M Configuring the PathBuilder S200 Series Switch for Bridging Operation 34 Billing Records Range OFF ON Default OFF Description Enables or disables the creation storing and printing of billing records for the LAN connection e ON Billing records are generated e OFF Billing records are not generated Traffic Priority Range LOW MED HIGH EXP Default HIGH Description Specify the Traffic Priority level of this LAN Connection e LOW One Low Priority packet is sent for every Traffic Priority Step number of Medium priority packets e MED One Medium priority packet is sent for every Traffic Priority Step number of High priority packets e HIGH High is the first level of priority packets sent if no expedite priority packets are sent e EXP Expedite priority packets have the highest priority and use all of the link bandwidth that they need Any remaining bandwidth is shared by the high medium and low priority packets Bridging Configuring the PathBuilder S200 Series Switch for Bridging Operation Limiting Bridge Frame Sizes O
4. Forwarding Database e MAC Address 6 byte value of MAC Address parameter from the MAC Filter Table Indicates a MAC Address for the list of entries in the forwarding database displayed by the status statistics screen e Bridge Link Number Indicates the corresponding bridge link number used to forward a frame with the given MAC Address e Status Indicates how the forwarding entry was learned e CONF This entry was learned from the permanent learned station address stored in CMEM e LEARN This entry was learned from the received frames on bridge links 133 Release 5 2M Bridge Statistics Transparent Bridge Detailed Bridge Link Statistics Detailed Bridge Link Statistics Detailed Bridge Link Statistics Terms Transparent Bridge Second Page 134 Figure 63 shows page 2 of the Detailed Bridge Statistics screen This page reflects Transparent Bridging statistics when TB is configured on the node Node Address Date Time Detailed Bridge Link Statistics Bridge Link 01 Page 2 of 2 TB Frames Discarded link not in Forwarding State Inbound Discards 0 Outbound Discards 0 TB Frames Discarded due to unicast link protect being set Inbound Discards 0 Outbound Discards 0 TB Frames Discarded due to multicast link protect being set Inbound Discards 0 Outbound Discards 0 Filter Discards In Out RIF Error Discards Source MAC Address Dest MAC Address Protocol Filtered Total Filter Di
5. During Forwarder Module initialization the Forwarder creates the sockets to connect to other modules in the node such as sockets used to communicate with the network handlers It also defines MACRO services in the Forwarder Module Descriptor to export the socket addresses to the outside world 51 Release 5 2M Transparent Bridging for Ethernet LANs Forwarder and STPE Learn Only Period Aging 52 The Forwarder cleans up all entries in the Forwarding Table when there are spanning tree topology changes taking place These actions are considered services the Forwarder provides to the Spanning Tree Protocol Entity STPE The Forwarder provides these services through MACRO routines so that they are accessible to the entire system m Note The Forwarder is not required to pass STPE traffic to the handlers The STPE is considered to be an independent entity and similar to all the forwarders in the system It has its own interface with the network handlers and it uses this interface passing PDUs to the network via the handlers For example it forwards Spanning tree PDUs directly to the handler and does not go through the Forwarder The Learn Only Period is a timer you can set from the CTP This timer is started whenever the node boots Until this timer expires the bridges learn only LAN station addresses and place them into the forwarding database The bridges do not forward any frames during this interval When the timer ex
6. The Bridge Link Parameters menu appears Bridging T0008 16F 115 Release 5 2M Mixed LAN Operation Statistics IP and IPX Support 116 Step Action continued Result Description 9 Type and press Return The record is saved 10 Perform a Bridge Link boot from This enables the bridge link the Boot menu 11 Configure the WAN bridge link to This enables TB and SR on the support Transparent Bridging and WAN link Source Route Bridging Select Bridge Link Parameters and type in a WAN entry number from 5 to 36 to display the Bridge_Type parameter Enter the string BOTH_SR_AND TB 12 Type and press Return The record is saved 13 Perform a Node boot to implement Your changes are implemented your changes m Note Duplicate bridge link or router interface numbers results in only the lowest numbered port being initialized Bridge link statistics for the WAN bridge link show the status of Mixed LAN links as Both TB and SRB Active when the WAN bridge link is configured as BOTH_SR_AND_TB and the Ethernet port successfully initialized The statistics screen displays information on both the Transparent Bridging operation and the Source Route Bridging operation on the WAN link If the node is booted with only one port configured or active then the statistics screen displays TB Active or SR Active only A PathBuilder 24x 26x and 27x switch performing a Mi
7. Dual LAN Ethernet section on page 117 Bridging Basic Remote Bridging Examples Basic Remote Bridging Examples Introduction This section shows some common examples of bridging applications using PathBuilder S200 series switches Remote Bridging Figure 9 shows a common Source Route Bridging operation for PathBuilder S200 Across a WAN series switches where two Token Ring LANs are attached across a WAN For example two LANs could be bridged using two PathBuilder S200 series switches interconnected by an X 25 or Frame Relay link Bridged traffic flows between the bridges over a Switched Virtual Circuit SVC that connects them together across the WAN or Permanent Virtual Circuit PVC for Frame Relay X 25 Frame Relay Figure 9 PB S200s Connecting LANs via an X 25 Frame Relay Link Extended Bridging If more than two remote LANs are involved in your bridging application the bridge for Multiple LANs arrangement can be extended so that individual LAN pairs are connected by different bridges as shown in Figure 10 Node 1 Node 2 Bridge 1 Bridge 1 Token Ring 2 Bridge 2 Bridge 3 SVC Connectors PVC for Frame Relay Bridge 2 Bridge 3 Figure 10 Two Port Bridges Connecting Multiple Token Ring LANs In this example each pair of LANs is connected by a single bridge formed by bridge pairs e Bridge 1 interconnects Token Ring 1 and Token Ring 2 e Bridge 2 interconnec
8. Notice continued Proprietary Material Information and software in this document are proprietary to 3Com or its Suppliers and without the express prior permission of an officer of 3Com may not be copied reproduced disclosed to others published or used in whole or in part for any purpose other than that for which it is being made available Use of software described in this document is subject to the terms and conditions of the 3Com Software License Agreement This document is for information purposes only and is subject to change without notice Part No TO008 16 Rev F First Printing October 1998 Manual is current for Release 5 2M Overview Functionality Remote Bridging Solutions Bridging Bridging PathBuilder S200 series switches support bridging of data traffic for Ethernet LANs Bridging LAN traffic minimizes your networking costs by eliminating the need for redundant networks and maximizes the availability of dedicated facilities such as servers and printers as well as public Frame Relay and X 25 services across multiple LANs PathBuilder S200 series switches are intended for use in remote bridging solutions This means the PathBuilder S200 series switch is best used to connect a remote LAN to the WAN to connect to other remote LANs in your network as shown in Figure 1 Ethernet Token PB S200 Ring PB S200 PB S200 Ethernet Figure 1 PathBuilder S200 Series Swi
9. Entry Number Range 1 to 300 Default 1 Description Entry number used to reference this table record for filtering action m Note If you do not wish to determine filter action for this link through the MAC Address Filter Table select NONE in the Bridge Link record MAC Address Range 00 00 00 00 00 00 to FF FF FF FF FF FF Canonical Default 00 00 00 00 00 00 Description Frames with MAC Addresses that match this MAC Address are filtered as specified in the following parameters For an example of MAC Address Filtering refer to MAC Address Filtering Examples in this guide Incoming Source Address Link Action Range PASS BLOCK PASSLIST BLOCKLIST Default PASS Description Incoming source means that the frame is entering the bridge entity from the LAN that includes the MAC address the source Therefore a given source frame will be incoming from the LAN to the Bridge and outgoing from the Bridge to the WAN provided it does not get blocked due to filtering Refer to Figure 31 e PASS Pass incoming frames with this MAC Address value on all links that are referencing this table If this value is chosen skip the List of Links e BLOCK Block incoming frames with this MAC Address value on all links that are referencing this table If this value is chosen skip the List of Links e PASSLIST If this value is used a pass list is specified by the followi
10. Functional Address Mask Range 00000000 to 7FFFFFFF hexadecimal Default 0000001A Description Used to enable or disable the LSS servers and represents a 31 bit map of functions where a specific bit identifies a function such as Configuration Report Server CRS Relevant bits should be set if the node supports these functions e Configuration Report Server CRS 00 00 00 10 e Ring Parameter Server RPS 00 00 00 02 e Ring Error Monitor REM 00 00 00 08 Note The LSS contains an LBS that is always enabled A Node Boot is required to enable or disable the servers 123 Release 5 2M Bridge Statistics Bridge Statistics Introduction The Bridge Statistics section provides information about the LAN Port Bridge Links LAN Connection and the Spanning Tree Figure 57 shows the Bridge Statistics Menu screen Node Address Time Menu Bridge Statistics Path Main STPE Status Detailed Bridge Link Stats Reset Detailed Bridge Link Stats Bridge Link Filters Status TB Forwarding Table Stats LLC LT Session Summary Stats LLC LT Detailed Session Stats L Reset LLC LT Detailed Session Stats Figure 57 The Bridge Statistics Menu Screen 124 Bridging Bridge Statistics Spanning Tree Statistics Spanning Tree STPE Status Figure 58 shows the information displayed by the Spanning Tree Status report Node Spanning Tree Statistics STPE Br
11. TB Frame Summary Received Transmitted Unicast 0 0 Multicast 0 0 Broadcast 0 0 Frame Totals 0 0 Press any key to continue ESC to exit 01 MAY 1993 04 19 05 Time Page 1 of 2 Node Detailed Bridge Link Statistics Bridge Link 01 Address Date Figure 59 Detailed Bridge Link Statistics First Page TB Frames Discarded link not in Forwarding State Inbound Discards 0 Outbound Discards Time Page 2 of 2 0 TB Frames Discarded due to unicast link protect being set Inbound Discards Inbound Discards Filter Discards Source MAC Address Dest MAC Address Protocol Filtered Total Filter Discards 0 0 In 0 0 0 0 Outbound Discards 0 TB Frames Discarded due to multicast link protect being set Outbound Discards 0 Out oooo Press any key to continue ESC to exit RIF Error Discards Segment Mismatch 0 Duplicate Segment 0 Hop Count Exceeded 0 Figure 60 Detailed Bridge Link Statistics Second Page Release 5 2M Bridge Statistics Description of This table describes Detailed Bridge Link Statistics terms Screen Terms Term Description Bridge Link Status Following are the possible states e Not Configured This record is not configured e No LAN Port No physical LAN Port e Active Link is operational e Congestion Link is operational but congested e Disabled Disabled by Bridge Link disable command e S
12. What is It What You Need to Configure Passwords Ring Error Monitor Configuration Report Server Ring Parameter Server 120 The LAN Server Subsystem LSS software lets PathBuilder S200 series switches such as the PathBuilder S200 series switch communicate with an IBM LAN Manager to provide the following support for Token Ring Source Route Bridging applications e Ring Error Monitor REM e Configuration Report Server CRS e Ring Parameter Server RPS e LAN Bridge Server The LAN Server Subsystem LSS Record is configured for the Token Ring Source Route Bridging LAN port A Node boot is required to restart the LSS or implement LSS parameter changes The default LSS link passwords for links 0 through 3 are initially set to PASSWORD This password is used by the IBM LAN Network Manager to establish a connection to the 3Com bridge s LSS Default passwords can be changed by the LAN Manager There is no facility to examine or change the passwords from the bridge s human interface Also it is recommended that you leave the parameter Calculation Interval at the default setting of 10 seconds to avoid conflict with the LNM A REM observes collects and analyzes hard error and soft error reports sent by stations on a single ring and assists in fault isolation and correction One or more ring error monitors can reside on a ring If no REMs are on a particular ring it is not possible to monitor errors f
13. for WAN Operation over a WAN you must configure the following two parameters in the Node record for the bridge node In most cases use default values e Codex Proprietary Protocol ID e LAN Connection Subaddress You also need to configure the LAN Connection Table Entries in this table are for the WAN Adapter and specify connections going across a wide area network such as X 25 Frame Relay or other proprietary protocols Codex Proprietary The Protocol Identifier ID is placed on the Call User Data field of the Call Request Protocol ID Bridging T0008 16F packet This packet is generated by the Autocall used to establish a circuit for a bridge link If the bridge link is not configured to initiate an autocall then this configured value is matched with that found in an Incoming Call packet to determine if the call should be established To define the Codex Proprietary Protocol ID select a value within the designated range Normally you would not configure a value different from the default value The only reason to use a different value is if the default value conflicts with one already in use It is recommended that the Protocol ID value in all network nodes be the same 19 Release 5 2M Setting Up WAN Operation for Bridging LAN Connection The LAN Connection Subaddresses identifies all LAN Connections Incoming calls Subaddress with a network address consisting of the Node Address specified in the Node record and
14. per node If you perform automatic spanning tree in a Mixed LAN implementation SPTE may prohibit traffic from passing between LANs by blocking some bridge links to avoid bridge looping e You must install Release 4 90 or above operating software on all PathBuilder S24x 26x and 27x switches in your network to perform Mixed LAN opera tion on any node in the network If you have a mixture of nodes running ear lier operating software releases mixed LAN operation will cause node crashes A PathBuilder S24x 26x and 27x switch used as a router and config ured for Mixed LAN operation is not impacted by this limitation Bridging Mixed LAN Operation Steps to Configure To perform mixed LAN bridging operation in a PathBuilder 24x 26x and 27x Mixed LAN switch configure a unique bridge link and router interface number for each LAN Bridging Operation interface from the Port record You must also configure the WAN bridge link to sup port Transparent Bridging and Source Route Bridging Follow these steps to configure Mixed LAN Bridging as shown in Figure 54 Step Action Result Description 1 Make a local CTP connection to a PathBuilder S24x 26x and 27x switch The CTP is physically connected to the device you are configuring Select Configure gt Port from the CTP Main menu The Port record appears Configure the Port record as you normally do for an Ethernet LAN connection Two new paramet
15. 00 00 40 Incoming Source Address Link MAC Address 10 00 5A 00 00 40 Outgoing Destination Address Link MAC Address 10 00 5A 00 00 40 1 LAN Token Ring 2 WAN Node 100 File Server MAC Address 10 00 5A 00 00 40 Figure 33 Example of Address Links Bridging Bridge Filtering MAC Wildcard Filtering What Is It PathBuilder S200 Series Switch Support How MAC Wildcard Filtering works Bridging T0008 16F MAC wildcard filtering is an enhancement to the Motorola Network Access Products MAC Filter table MAC wildcard filtering lets you configure the MAC filter tables and use wildcards to designate numeric pieces of the MAC address The MAC Address filter lets you configure a table of MAC Address filters each filter contains a MAC address which is a string of 12 characters from the range 0 9 A F The table is searched for each incoming and outgoing frame on the LAN WAN link to find a match in the table for the MAC address in the frame This enhancement lets you use the wildcard character in any of the 12 character positions while configuring a filter The wildcard character matches any of the valid characters allowed in a MAC address 0 9 A F when it is used to filter a given MAC Address MAC wildcard filtering lets you configure a smaller MAC Address Filter table if you configure MAC Address filters where one or more of the 12 character positio
16. C9 10 98 E5 04 Up 5 2 10 00 5A E1 A2 C4 F4 10 00 7C 00 04 Al F4 Up 6 2 10 00 5A E1 A2 C4 F4 10 00 7C 00 C4 C2 F4 Up 7 2 10 00 5A E1 A2 C4 F4 10 00 7C 00 04 E5 F4 Up Press any key to continue ESC to exit Figure 68 Session Summary Statistics Screen This table describes the screen terms for the Session Summary Statistics screen as shown in Figure 68 Heading Description Session Session number assigned between the MAC addresses Maximum number of sessions supported is 64 Stn Refers to the entry number assigned to the LT session for the local MAC address during configuration Maximum number of stations available is 64 Local MAC ADDR Refers to the MAC address assigned to the locally attached device to be spoofed local is in reference to the bridge you are taking statistics from SAP Refers to the Service Access Point used by the local MAC address for this session REMOTE MAC ADDR Refers to the MAC address assigned to the remotely attached device to be spoofed remote is in reference to the bridge you are taking statistics from SAP Refers to the Service Access Point that is used by the remote MAC address for this session 141 Release 5 2M Bridge Statistics 142 Heading continued Description Status Indicates the session between the local and remote MAC addresses e UP MAC addresses are communicating using Local Termination
17. Filters MAC Address e MAC Address 6 byte value of MAC Address parameter from the MAC Filter Table e Source In Value PASS or BLOCK from the MAC Filter Table Action to be taken on an inbound frame having the indicated MAC Source address Source Out Value PASS or BLOCK from the MAC Filter Table Action to be taken on an outbound frame having the indicated MAC Source address Destination In Value PASS or BLOCK from the MAC Filter Table Action to be taken on inbound frame for the indicated MAC Destination Address Destination Out Value PASS or BLOCK from the MAC Filter Table Action to be taken on outbound frame for the indicated MAC Destination address Active Filters Protocol Class Protocol Class Value DSAP or SNAP of Protocol Class parameter of a Protocol Filter Table Value Represents the value of the Protocol parameter of a Protocol Filter Table This value can be 1 byte DSAP or 5 bytes SNAP depending upon which type of protocol is involved in the frame Incoming Value PASS BLOCK from the Protocol Filter Table Action to be taken on outbound frame for the indicated protocol value Outgoing Value PASS BLOCK from the Protocol Filter Table Action to be taken on outbound frame for the indicated protocol value m Note This screen can be several pages long depending on configuration Bridging T0008 16F 131 Release 5 2M Bridge Statistics Transparen
18. PathBuilder S200 series switch family supports many types of protocols for bridging operations Some of the supported protocols include e Async e SDLC e Bisync e Transparent Polled Async e HDLC e X 25 e Frame Relay e Burroughs Poll Select e NCR Bisync Bridging In This Manual Topic See Page Bodems Features and Capabuines sessccesioncanctnicinnintiassiaieasiacwanciauinielas 3 Toka Rine LAN serrare a an A AA A ESA 6 Etema LAN roconioonradinioniir ennu A E A A 8 Mired LAN BUONE srona ihein aa ET DEE E 10 VEAL PORCINE ararnar e a E NOO ON 11 LIC Loeil Termit eaaa a a 12 Aut learn for Local Terminal ofi ccsrnninsirei a 13 VEIE A a iT ATEA A AAE S MENEE P E E AEA 14 ie emit Ties Proroci accise EAA RE 15 Prol Ebern LANE aroc E T R aa 16 Basie Remote Bidag ELampiEs mirorrione isnin A 17 Bridge Hardware Components in PathBuilder S200 Series Switches 19 Setting Up WAN Operation for Bridging scic cccccscenccsussnsecentsrneenenineevecatacnnentan 20 Configuring the PathBuilder S200 Series Switch for Bridging Operation 22 Bidee TOME EIS rera a A 23 Budos Link Paramete ES nirani ian ra eE EER af LAN Connection TADIG seiccsisintistcaencne A A 32 Liming Bridge Frame SIOS sarro dansncengaueontsas cans oa ansugatchanaetsta aarti 36 Configuring Translational Bridging iiccsssscteiasesiciondsiedacniciaieriateisaieteione 38 Source Route Bridging for Token Ring LANS 0 eee eeeeseeeeeeeeeceeeeeeeees 40 Bidee Pirate Pig eniai
19. This appendix describes these services Information contained in this appendix is correct at time of publication For the very latest 3Com recommends that you access the 3Com Corporation World Wide Web site 3Com offers worldwide product support 24 hours a day 7 days a week through the following online systems e World Wide Web site e 3Com FIP site e 3Com Bulletin Board Service 3Com BBS 3ComFacts automated fax service Access the latest networking information on the 3Com Corporation World Wide Web site by entering the URL into your Internet browser http www 3com com This service provides access to online support information such as technical documentation and software library as well as support options ranging from technical education to maintenance and professional services Download drivers patches and software across the Internet from the 3Com public FIP site This service is available 24 hours a day 7 days a week To connect to the 3Com FIP site enter the following information into your FTP client e Hostname ftp 3com com or 192 156 136 12 e Username anonymous e Password lt your Internet e mail address gt m Note A user name and password are not needed with Web browser software such as Netscape Navigator and Internet Explorer 3Com Bulletin Board Service 3ComFacts Automated Fax Service Support from Your Network Supplier A 2 The 3Com BBS contains patches software and drive
20. Time Menu Configure Bridge Path Bridge Parameters Bridge Link Parameters MAC Address Filter Table Entry Number MAC Address Incoming Source Address Link Action Outgoing Source Address Link Action Incoming Destination Address Link Action Outgoing Destination Address Link Action Figure 35 MAC Address Filter Table Menu MAC Addresses can fall into four categories e Incoming Source e Outgoing Source e Incoming Destination e Outgoing Destination Every node bridge has one MAC Address Filter Table Every bridge link can be configured to determine whether or not frames passing on that bridge link are to be filtered according to the entries in the MAC Address Filter Table The filter table is examined to see if there is a match If a match is found table and frame additional table parameters determine when to pass or block the frame If there is no match the decision is dependent upon the Bridge Link record to determine whether to pass or block Action is then taken on what is specified in this record pass or block rather than the filter table when there is no match to an entry in this filter table m Note A Table boot is required to make MAC Address Filter parameters part of an active configuration Booting is nondisruptive to data or call connections Bridging Parameters Bridging T0008 16F Bridge Filtering These parameters make up the MAC Address Filter Table
21. anaa A 41 Soure Route Bidens Operai ON orrira i 42 Configuring Source Route Bridging Operation eee eeeeeseeeteeeeeeees 45 Connecting a Station to a Server in Source Route Bridging 47 Transparent Budeme for Ethernet LANS ssciscccorsnieminiienncaemedeuneas 53 Forwarder Database and Spanning Tree oc cecissicccsssneseensaeiscenasbieees vesvenesense 58 UES TE aL Des eo ete eee eee E E serene 59 Transparent Bridge Configuration Parameters 20 0 0 scescesceseeeeseeeeeeees 61 Pabe gy hoa a cae eee ene ter ete er teree ry neue ONOS 62 MAL Address Firin Os cia ceecnina vhs chs a a a 63 MAC Address Filtering Px Apes ccmicnroionrsiesaci sanni 67 Identifying Address Links for MAC Addressing sseseeeeeeeeeerereee 72 MAL ot PG ni eri once me aE A E E T3 Configuring the MAC Address Filter Table esssrssirsiiisrisssiionisissnsseriuooiseis 74 Pioc PINETE vecii rearni na ea A R AA 78 Config rine the Protocol Filter Tale sesir iu tonike sein 79 NeR IGS Name FUTTE sciana ATO 84 Configuring NetBIOS Name Filtering siisiiisssoroiiniirioinioeusitainiioni 86 NetBIOS Name Piltene Statistics ascsiiicnieeudtccani esi 92 NetBIOS Facket FOTIS sicisacrssssesvicnsmnunesiansburcstonnarvanennes aereeeeranumnansanvencia 93 Spanning Thee Protocol Entity STPE siccin 94 STPE Parameter Setting Considerations sristi 97 De As LOT eal Eisai TOETS age eee ee neta re enn rere ree ert Teta Teen arr eeee rere enn rir tre 103 Bridge Forward Delay TIMET scsscsscisa
22. bit must be set in the source MAC Address of the frame e If the frame is non broadcast the local ring number bridge number and remote ring number must match the bridge s stored values for these numbers and the routing field must have less than 7 to 14 LAN bridge couplets depending on the configured maximum allowed e Ifthe frame is single route broadcast and forwarding of single route broadcast is enabled then the Routing Information field must not contain the remote ring number since the frame has already been on the forward ring If single route broadcast is disabled the frame is not copied e Ifthe frame is All Route Broadcast then the Routing Information field must not contain the remote ring number These rules apply to frames with either locally or universally administered addresses and for frames with either individual or group addresses When the All Route Broadcast frame is received from the LAN and initiated by another device on the LAN it is sent to all remote bridges on all SVCs The single route broadcast frame is sent only to the remote bridge that is part of the spanning tree The specific route frame is sent to the remote bridge via the single SVC that connects the bridges When received from the WAN broadcast frames are sent to the Token Ring They are sent to the other SVCs for general or spanning tree distribution as appropriate after the LAN port removes the frame from the local ring When a specif
23. continued Local Station Session Summary TX Window Transmit window size obtained from the configuration for the local station Protocol State Number of the state for current session with local device Characters In Number of user data characters received by the spoofer from the locally attached LAN station Characters Out Number of user data characters transmitted by the spoofer to the locally attached LAN station Info Number of information frames received or transmitted by the local spoofer from or to the local device RR Number of RR frames received or transmitted by the local spoofer from or to the local device RNR Number of RNR frames received or transmitted by the local spoofer from or to the local device REJ Number of REJ frames received or transmitted by the local spoofer SABME Number of SABME frames received or transmitted by the local spoofer from or to the local device UA Number of UA frames received or transmitted by the local spoofer to or from local device UI Number of UI frames received by the local spoofer from the local device TEST Number of Test frames received by the local spoofer from the local device XID Number of XID frames received by the local spoofer from the local device DISC Disconnect DM Number of DM frames received or transmitted by the local spoofer from or to the local device FRMR Number of FRMR frames recei
24. e DOWN MAC addresses are not communicating Session is the process of coming up or going down Bridging Bridge Statistics LLC2 LT Detailed Session Statistics Sample of Detailed Figures 69 and 70 show samples of the LLC2 LT Detailed Session Statistics report Session Statistics Node Address Date Time LLC LT Detailed Session Stats Page 1 of 2 Session Number 1 Station Number 1 LLC Profile Name HOSt Local MAC 40 00 10 00 00 00 Local SAP 04 WAN Queue Depth 0 Remote MAC 00 00 C9 10 88 C3 Remote SAP 04 LAN Queue Depth 0 RIF 0620 0021 0010 Last Statistics Reset Date Time Local Station Session Summary TX Window 7 Protocol State 4 Characters In 3740798 Characters Out 36107 Frame Type In Out Frame Type In Out Info 17682 3980 UI 0 RR 4018 6827 TEST 0 RNR 0 1 XID 1 REJ 0 0 DISC 0 0 SABME 1 0 DM 0 0 UA 0 1 FRMR 0 0 Frames received out of sequence 0 Bad Frames received 0 Frames dropped 0 ress any key to continue ESC to exit Figure 69 Detailed Session Statistics Screen Page 1 Node Address Date Time LLC LT Detailed Session Stats Page 2 of 2 Remote Spoofer Session Summary TX Window 7 Protocol State 4 Frame Type In Out Frame Type In Out Info 3982 17691 UI 0 RR 6114 4064 TEST 0 RNR 0 0 XID 2 REJ 0 0 DISC 0 0 SABME 0 1 DM 0 0 UA 1 0 Frames received out of sequence 0 Bad Frames received 0 Frames dropped 0 P
25. frames are used The Spanning Tree is manually configured on a bridge link basis using the Bridge Link STPE Link State parameter FORWARD BLOCK When you configure a node for bridging operation the spanning tree parameters that appear on the Bridge Parameters Record and Bridge Link Record depend on whether you configure manual or automatic spanning tree Configuration STPEControl AUTO STPE Control MANUAL Menu Bridge Record STPE Control Auto STPE Control Manual Bridge Priority Bad Hello Threshold Max Age Bad Hello Count Hello Time Forward Delay Bridge Link STPE Priority STPE Link State Record STPE Path Cost m Note All bridges in a network must operate in the same mode either all automatic or all manual One Custom Software Key CSK enables both the Source Route Bridging and the Spanning Tree Protocol Entity Bridging Bridge Links Forwarding and Blocking States Topology Change Notification Bridging T0008 16F Spanning Tree Protocol Entity STPE There are three types of bridge links within a given spanning tree network e The Root Bridge Link The link representing the best path to the root bridge A root link is always on the spanning tree e The Designated Bridge Links All the other bridge links on the spanning tree e The Standby Bridge Links All other bridge links which are not on the spanning tree All the bridge links of the root bridge are in the spanning
26. if the WAN lines are all 19 2 kbps and the links are directly connected with a single SVC hop then their incremental cost for WAN links can be set to STPE Path Cost 3536 Therefore B3 will see messages from other bridge links resulting in the following cost to the root bridge e From bridge 1 link 6 root is bridge 1 cost to root 3536 e From bridge 4 link 8 root is bridge 1 cost to root 7072 3536 3536 e From bridge 5 link 9 root is bridge 1 cost to root 14154 3536 10 3536 3536 3536 Based on these numbers B3 determines B1 to be the root bridge because B1 s bridge ID is lower than all reported root bridges including B3 s own bridge ID B3 also designates bridge link 6 as the root link since it has the least cost to the root Bridging 91 T0008 16F Release 5 2M Spanning Tree Protocol Entity STPE Consider the Nature and Expected Number of SVCs 92 A further consideration for setting path cost is the nature and expected number of SVCs that the bridge link uses to achieve its connectivity and adjust the value of incremental path cost accordingly For example consider the topology shown in Figure 45 Bridge 1 Bridge 2 Bridge 3 Bridge 4 Figure 45 Bridge Links Within Network Bridge 2 is linked to bridge 1 by two separate links The link through Node B must traverse two separate SVC hops while the direct link has only a single hop If the speed of the li
27. is chosen skip the List of Links parameter e BLOCK Block outgoing frames with this MAC Address value on all links that are referencing this table If this value is chosen this filter is fully configured and the next prompt would wrap to MAC Address to allow further configuration of this record If this value is chosen skip List of Links parameter e PASSLIST If this value is used a pass filtering list is specified by the parameter List of Links Links in this list pass the frame Links not in this list block the frame e BLOCKLIST If this value is used a block filtering list is specified by the parameter List of Links Links in this list block the frame Links not in this list pass the frame List of Links Range 1 5 to 36 Default no entry Description Each entry is a bridge link number in the range 1 5 to 36 The individual numbers correspond to the links that filter according to the preceding parameter If the preceding parameter is e PASSLIST The listed links pass the frame and unlisted links block the frame e BLOCKLIST The listed links block the frame and unlisted links pass the frame This parameter appears only when the parameter Outgoing Destination Address Link Action PASSLIST or BLOCKLIST Bridging T0008 16F 69 Release 5 2M Bridge Filtering Protocol Filtering What is It 70 Protocol filtering is used to prevent nodes operating with a certain p
28. last reset or restart Bridge Link Number of specified bridge link Bridging T0008 16F 125 Release 5 2M Bridge Statistics 126 Term continued Description State The STPE view of the link s current state The possible states are e Disabled The STPE is disabled If STPE Control parameter is MAN e Blocking The STE frames are blocked on this bridge link e Listening The STE frames are blocked Listening to STPE PDUs e Learning The STE frames are blocked Learning the topology from STPE PDUs e Forwarding The STE frames can be forwarded on this bridge link Priority The value of STPE Priority parameter of the bridge link Path Cost The value of STPE Path Cost parameter of the bridge link A weight that is added to the overall links in a particular Ring to Ring path The path with the lowest cost determines which path will be chosen between the Rings Bridging Detailed Bridge Link Statistics Introduction Bridging T0008 16F Bridge Statistics Figure 59 and Figure 60 show sample statistics screens Node Address Detailed Bridge Link Statistics Bridge Link 01 Date Bridge Link Status Inactive Bridge Type SRT ST Status forwarding Bridge Link Type LAN Last Stat Reset Max Frame Size 205 Max Hop Count 7 Local Ring Number 1 SR Frame Summary Received Transmitted SRF 0 0 ARE 0 0 STE 0 4 Frame Totals 0 4
29. path back to the source The RIF also sets three bits in the Routing Type field that indicate the frame is to be specifically routed and not broadcast 10 When the response TEST frame reaches the source PC the PC now knows what route to use to send its frames to the server 46 Bridging Configuring the PathBuilder S200 Series Switch for Bridging Operation Attaching a Station This table describes how a station attaches to a ring to a Ring Bridging T0008 16F Step Action Result Description 1 The station requests values for the ring s operational parameters from the RPS 2 An attaching station also sends the RPS its adapter software level as well as its Upstream Neighbor Address If Then An RPS is It responds to The RPS then notifies the LAN present on the ring the station s request by sending it the current values for the ring s operational parameters managers that a new station has attached to the ring An RPS is not present on the ring The ring station uses the values assigned by the program using the ring station or the default values for its operational parameters An RPS has a functional address of C00000000002 47 Release 5 2M Transparent Bridging for Ethernet LANs Transparent Bridging for Ethernet LANs Introduction Learning Transparent Bridge Forwarder 48 A transparent bridge also known as a spanning tree brid
30. that can be set greater than the LLC protocol timers LLC2 LT supports intermediate Token Ring networks between spoofers For example Figure 53 shows Local Termination running in the edge point nodes of this network to provide spoofing across multiple Token Rings Spoofing Intermediate Ring FEP X 25 EP End 1 Station hit LT enabled with MAC LT enabled with MAC Address of FEP 1 and Address of FEP 2 and 104 SAP value being used SAP value being used Figure 53 Example of LT Spoofing Bridging Traffic Priority amp Local Termination Bridging T0008 16F LLC2 Local Termination You can significantly optimize your spoofing operations by prioritizing Local Termination traffic and regular bridge traffic By assigning a separate lower priority to spoofer traffic the regular bridge traffic is queued quicker The extra delay of spoofer traffic does not affect the acknowledgments of frames on the LAN See Configuring Local Termination section on page 106 for details on setting the LLC LT WAN Data Priority parameter record 105 Release 5 2M LLC2 Local Termination Configuring Local Termination Configuring for Local Termination Before You Begin Configuring the Bridge 106 Perform the following procedures to configure Local Termination on a Bridge node Step Action 1 Configure the node 2 Configure the ports 3 Configure the route selection ta
31. the LAN Connection Subaddress specified in the LAN Connection Table are verified and allowed to connect to the WAN Adapter in order to reach the LAN bridges The LAN Connection Subaddress is appended to the calling address of the Call Request packet if generated and sent by the WAN Adapter Use the default value unless it conflicts with an address already in use Refer to the LAN Connection Table section on page 31 for more details 20 Bridging Configuring the PathBuilder S200 Series Switch for Bridging Operation Configuring the PathBuilder S200 Series Switch for Bridging Operation Introduction This section shows you how to configure a PathBuilder S200 series switch for bridging operation What You Need to When you are performing a Transparent Bridging operation configure the following Configure records in the bridge node Node Record LAN Port Record Bridge Record Bridge Link Record LAN Connection Table Optional Filter Tables LAN Server Subsystem LSS Record optional Autocall Mnemonic Table Some of the WAN Adapter connections are configured to Autocall Routing Table At the destination node a LAN Connection LCON entry is needed for the WAN Adapter For general details on configuring the Node record and the LAN Port record refer to the PathBuilder S200 Series Basics Protocols For details on LAN Server Subsystem configuration see the LAN Server Subsystem section on page 120 The follow
32. to the configuration example in the next section Figure 18 shows an example of a PathBuilder S24x 26x and 27x switch configured for Translational Bridging between an Ethernet and Token Ring Network within the same node The records and parameters that need to be configured for Translational Bridging are shown a Note In this example the parameters in Bridge Link 1 and Bridge Link 2 records remain at their default values However to implement the default settings you need to call up the records from the CTP and then save them 37 Release 5 2M Configuring the PathBuilder S200 Series Switch for Bridging Operation Port 13 PB S200 Switch Port 19 Station A Station B Bridge Transparent Link5 LCON PVC Source Bridge 1 Bridge Port 13 Port Type ETH Bridge Link Number 1 Ethernet Token Ring Port 19 Port Type TR Ring Number 1 Bridge Link Number 2 Bridge Link 6 Bridge Type SR Link Mode TRANS Virtual Ring Number 2 LAN Connection 2 LAN Forwarder Type BRID Bridge Link Number 6 Network Services PVC Setup Table Source LCON 1 Destination LCON 2 Bridge Link 5 Bridge Type TB LAN Connection 1 LAN Forwarder Type BRID Bridge Link Number 5 Figure 18 Translational Bridging Example Figure 19 shows a situation where a PathBuilder S24x 26x and 27x switch is configured for translational bridging with SVCs PVCs originating from two re
33. traffic e BRID Bridged LAN traffic is transported across this connection e ROUT Routed LAN traffic is transported across this connection e BROUT Both bridged and routed LAN traffic are transported across this connection Boot Type Changes to this parameter require a Node Boot to take effect LAN Connection Type Range PT_to_PT GROUP Default PT_to_PT Point to Point Description Specify whether this LAN Connection defines a point to point connection across the WAN or is part of a group of LAN Connections If configured as GROUP multiple LAN Connections can use the same Router Interface number If configured as PT_to_PT the Router Interface configured must be unique to this LAN Connection E Note This parameter appears if the LAN Forwarder Type is configured as ROUT or BROUT Boot Type When changing from GROUP to PT_PT a Node boot is required Otherwise a Table and Node Record boot is required Router Interface Number Range 5 to n where n 36 to 254 Default 5 Description Specifies a Router Interface using this LAN Connection record This connection makes it possible to pass LAN data through the WAN network to a remote router The allowable range of values reflect the maximum number of IP or IPX interfaces set in the IP or IPX Parameters Menu m Note This parameter appears if the LAN Forwarder Type is configured as ROUT or BROUT
34. tree and are designated bridge links After the spanning tree is determined all root links and all designated links are placed in a forwarding state and standby links are placed in a blocking state These states refer to the action that a link performs on data frames For Source Route Bridging forwarding and blocking refer to Spanning Tree Explorer data frames Specifically Routed Frames and All Route Explorer frames are not subjected to blocking forwarding by this link state When a link is in blocking state it still monitors and passes to its own bridge the Hello message from the adjacent designated bridge link Bridge links are not put into a forwarding state immediately upon determining their link classification Forwarding Delay is used to allow the determination of the spanning tree network to stabilize This prevents the network from sending information frames into temporary routing loops The Topology Change Notification Bridged Packet Data Unit BPDU is used by a bridge that notices a topology change to send a notification in the direction of the Root Bridge This occurs only during Automatic spanning tree operation When the Root Bridge finally gets this notification it sets the topology change notification bit in the BPDU that it periodically generates This informs all bridges that there has been a change in topology and that they should expect that station locations might have changed In a manual spanning tree all th
35. 3Com Corporation PathBuilder S200 Series Switch Bridging Notice 1998 3Com Corporation 5400 Bayfront Plaza Santa Clara CA 95052 8145 408 326 5000 All rights reserved Printed in U S A Portions reprinted with the permission of Motorola Inc Restricted Rights Notification for U S Government Users The software including firmware addressed in this manual is provided to the U S Government under agreement which grants the government the minimum restricted rights in the software as defined in the Federal Acquisition Regulation FAR or the Defense Federal Acquisition Regulation Supplement DFARS whichever is applicable If the software is procured for use by the Department of Defense the following legend applies Restricted Rights Legend Use duplication or disclosure by the Government is subject to restrictions as set forth in subparagraph c 1 ii of the Rights in Technical Data and Computer Software clause at DFARS 252 227 7013 If the software is procured for use by any U S Government entity other than the Department of Defense the following notice applies Notice Notwithstanding any other lease or license agreement that may pertain to or accompany the delivery of this computer software the rights of the Government regarding its use reproduction and disclosure are as set forth in FAR 52 227 19 C Unpublished rights reserved under the copyright laws of the United States
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37. 6x and 27x switch as shown in Figure 6 If you happen to configure two Ethernet LAN interfaces in the same node instead of a mix of one Ethernet and one Token Ring you can perform local Transparent bridging between the two Ethernet LANs Ethernet 1 Ethernet 1 Port 13 l l l IPB S200 l l Port 19 Ethernet 2 Ethernet 2 Figure 6 Example of Mixed LAN Bridging in PathBuilder S24x 26x and 27x Switch m Note Mixed LAN operation does not support translational bridging meaning you cannot pass LAN traffic from an Ethernet LAN to a Token Ring LAN without using some sort of conversion software Refer to the Mixed LAN Operation section on page 114 for more details Bridging Bridging Features and Capabilities MAC Addressing What Is It Bridges whether they using Transparent Bridging operate at the Data Link Layer which is concerned with MAC addressing The MAC Address is a 6 byte MAC Media Access Control address that identifies stations on a LAN The IEEE administers distribution of the MAC address to ensure no duplicates occur in MAC addressing This is accomplished by assigning a unique MAC address to each manufacturer Each manufacturer then assigns sequential values to the lower three bytes for each interface manufactured For More Details For more details on MAC Address filtering see the section MAC Address Filtering section on page 58 in t
38. Action Block HOME_FILE_01 NetBIOS Name Filter Table String Type ASCII NetBIOS Name HOME Incoming NetBIOS Name Link Action PASS Outgoing NetBIOS Name Link Action PASS Figure 39 NetBIOS Name Filtering Configuration Example What Is NetBIOS Network Basic Input Output System NetBIOS is a session level protocol standardized by IBM that serves as one of the main Application Programming Interfaces APIs for local area network software Software such as SNA 3270 emulation packages and Lotus Notes operate on top of the NetBIOS layer Microsoft LAN Manager uses NetBIOS extensively for identifying clients and servers NetBIOS is based on 16 character named services that connect to each other Servers advertise their implementation of a named service and clients try to find servers by transmitting broadcast frames that contain the name of the service they want 76 Bridging Forcing a Local Domain With NetBIOS Name Filters Wildcard Name Patterns Another Use of Name Filters Checking NetBIOS Broadcasts Bridging T0008 16F Bridge Filtering The NetBIOS Name Filtering feature can also force a local domain or context of a NetBIOS name All branch offices for example may connect to an SNA gateway function in OS 2 by accessing a gateway local to the branch Under normal bridging conditions you configure the SNA gateway NetBIOS server with a different name for each branch office and every workstation to att
39. Figure 32 Frames with Outgoing Source Address A are passed at link 5 to server B but not passed on link 6 to server C Bridging 63 T0008 16F Release 5 2M Bridge Filtering Identifying Address Links for MAC Addressing Why it is Important Identifying the address links is an important step in configuring MAC Address Example of Address Links 64 filtering A Source Address link allows a device on the LAN to send frames A Destination Address link allows a device on the LAN to receive frames The Incoming Source Address link provides a path for a frame to go from the Token Ring to the bridge The Outgoing Source Address link provides a path for a frame to go from the bridge to the WAN The Incoming Destination Address link provides a path for a frame to go from the WAN to the bridge The Outgoing Destination Address link provides a path for a frame to go from the bridge to the LAN Figure 33 shows that link 5 serves as both the Outgoing Source Address link and the Incoming Destination Address link In this example Outgoing Source Address link 5 allows the File Server with MAC Address 10 00 5A 00 00 40 the source to send frames to the WAN via link 5 Incoming Destination Address link 5 allows the File Server with MAC Address 10 00 5A 00 00 40 the destination to receive frames from the WAN via link 5 Outgoing Source Address Link MAC Address 10 00 5A 00 00 40 Incoming Destination Address Link MAC Address 10 00 5A
40. NetBIOS broadcasts except those to or from a list of servers NetBIOS Name Filtering compares NetBIOS broadcasts to a pattern that may have a wild card character at the end For example if all servers have a naming convention with the first part of the name the same for example SVR then you can complete only one entry in the NetBIOS Filter Table to permit broadcasts to and from the SVR name pattern With NetBIOS Name Filters you can block the local service name for example SNA_GW on the WAN link so that NetBIOS broadcasts to and from that name are not forwarded across to the internetwork This feature lets the branches use the same name for their local SNA service and you can configure all the workstations to access the same local SNA name Refer to NetBIOS Name Filtering section on page 76 in this guide Protocol filtering prevents nodes operating with a certain protocol from operating outside their intended scope Refer to the Protocol Filtering section on page 70 for more details Bridging Bridging Features and Capabilities Spanning Tree Protocol What Is It Automatic amp Manual Spanning Tree Support For More Details Bridging T0008 16F Spanning Tree Protocol reduces multiple bridge paths between LANs to a single path Instead of a mesh network with several paths to a destination the Spanning Tree Protocol remaps the network so that only one path is a
41. PathBuilder S24x 26x and 27x switch the system initializes only the first two ports you configure during system powerup In a Transparent Bridging environment if you connect both Ethernet LAN ports to the same Ethernet segment you must enable Spanning Tree Failure to enable Spanning Tree in this configuration is a violation of the rules of Transparent Bridging 117 Release 5 2M Dual LAN Ethernet Routing How to Configure Dual Ethernet LAN 118 In IP IPX or AppleTalk routing environments do not connect both Ethernet LAN ports to the same Ethernet segment with identical routing decision values This is not supported Follow these steps to configure a node for Multiple Ethernet LAN Step Action Result Description 1 Make a local CTP connection toa The CTP is physically connected to PathBuilder S24x 26x and 27x the device you are configuring switch 2 Select Configure gt Port from the The Port record appears CTP Main menu 3 Configure the Port record as you Two new parameters Bridge Link normally do for an Ethernet LAN Number and Router Interface connection appear in the record 4 At the Bridge Link Number This matches this port configuration parameter type in a number 1 4 to to a specific bridge link number identify the bridge link and press within the bridging configuration If Return the bridge link you select is already m Note used a warning m
42. Specifies the action to take on the incoming protocol Link Action Actions include Pass Block Passlist and Blocklist Outgoing Protocol Specifies the action to take on the outgoing protocol Link Action Actions include Pass Block Passlist and Blocklist List of Links Specifies the links associated with the preceding link action parameters in this table When Passlist PL is specified the associated listed links pass the frame and the unlisted links block it Conversely when Blocklist BL is specified the associated listed links block the frame and the unlisted links pass it 75 Release 5 2M Bridge Filtering NetBIOS Name Filtering Introduction The NetBIOS Name Filtering feature compares NetBIOS broadcasts to a pattern that may have a wild card character at the end For example if all servers have a naming convention with the first part of the name the same for example SVR then you can complete only one entry in the NetBIOS Filter Table to permit broadcasts to and from the SVR name pattern Example of Figure 39 shows an example of how to configure NetBIOS Name Filtering in a NetBIOS Name Token Ring Source Rout Bridging application however the same is true for Ethernet Filtering Transparent Bridging Boston Branch Office Home Office PB S200 Bridge Link Parameters BOSTON_FILE_01 NetBIOS Name Filter
43. W Disables Disabled by the operating software because of internal error e Inactive Waiting to be Active after restart Bridge Type Configured value of Bridge Type parameter of the Bridge Link ST Status Spanning Tree state of a bridge link This state controls what action a link takes on reception of a source route Spanning Tree Explorer Frame e STPE Control MAN The configured value of the STPE state parameter is displayed e STPE Control AUTO STPE view of the link s current state is displayed e Disabled LAN or WAN connection is inactive e Blocking The STE frames are blocked on this Bridge Link e Listening The STE frames are blocked Learning the topology from STPE PDUs e Forwarding The STE frames can be forwarded on this bridge link Bridge Link Type e LAN If Bridge Link number is 1 e WAN If Bridge Link number is 5 to 36 Last Stat Reset Date and time of the last statistics reset Resetting the link statistics does not clear the last call information from the port statistics screens This information is only cleared by a node boot Max Frame Size The maximum size of the frame that this bridge link is configured to send and receive Max Hop Count The maximum number of routing hops allowed in a source routed frame Local Ring Number The ring number to which this bridge is locally attached Next Ring Number The next Ring Number of the LAN to which the b
44. ach to the name for its branch office With NetBIOS Name Filters you can block the local service name for example SNA_GW on the WAN link so that NetBIOS broadcasts to and from that name are not forwarded across to the internetwork This feature lets the branches use the same name for their local SNA service and you can configure all the workstations to access the same local SNA name Name filter patterns may contain wildcard characters such as that matches any character or at the end of the pattern that matches all remaining characters As a result a single filter record can pass or block a large set of NetBIOS names Unlike current MAC Filter and Protocol filters for a bridge a packet may match more than one filter record For this reason NetBIOS Name Caching operates using an ordered list of name matching records A packet is compared against each name matching string in order and the action for the first match is taken If a packet does not match any NetBIOS Name Filter record the Default NetBIOS Filter Action is taken Another way of using NetBIOS Name Filters is to pass all NetBIOS broadcasts except those that are identified in the NetBIOS Name Filter table This can be used for example to restrict access to a particular server to the local segment The NetBIOS Name Filtering feature does not check every NetBIOS packet It only checks the NetBIOS broadcast packets that are used to initiate a
45. attempts count Number of auto call attempts Specifies the number of times the WAN Adapter attempted to autocall before it either succeeded or failed in establishing the connection Last clear cause code This is the cause code in the call clear packet last received by the LAN connection and explains why the last call was cleared e Last clear diagnostic code This is the diagnostic code in the call clear packet last received by the LAN connection and explains why the call was cleared 138 Bridging Bridging T0008 16F Bridge Statistics Term continued Description Packet Summary e Data Summary of each packet sent on the WAN and received from the WAN bridge link e Call Request Specifies the total number of Call Request Packets sent on the WAN and received from the WAN e Call Accept Specifies the total number of Call Accept Packets sent on the WAN and received from the WAN e Clear Request Specifies the total number of Clear Request Packets sent on the WAN e Clear Confirm Specifies the total number of Clear Confirmation Packets sent on the WAN and received from the WAN e Reset Request Specifies the total number of Reset Request Packets sent on the WAN and received from the WAN e Reset Confirm Specifies the total number of Reset Confirmation Packets sent on the WAN and received from the WAN Last Statistics Reset The date and time of the last statistics reset Resetting
46. be performed to implement changes to the Protocol Filter Table parameters Figure 36 shows the Protocol Filter Table parameters Node Address Date Time a Menu Configure Bridge Path Bridge Parameters Bridge Link Parameters MAC Address Filter Table Protocol Filter Table V Entry Number Protocol Type Protocol Value t Incoming Protocol Link Action Outgoing Protocol Link Action Figure 36 Configure Protocol Filter Table Menu These parameters make up the Protocol Filter Table Record Entry Number Range 1 to 100 Default 1 Description Entry number used to reference this table record 71 Release 5 2M Bridge Filtering T2 Protocol Type Range DSAP SNAP Default DSAP Description Indicates what type of protocol is involved in the frame DSAP Destination Service Access Point The protocol value to be filtered is the Destination SAP field of the 802 2 LLC formatted frame This type includes Protocol SAP hex value Banyan BC used only for 802 5 Novell IPX EO used only for 802 5 NetBIOS FO ISO Connectionless Internet FE SNAP Sub Network Access Protocol The Protocol Value to be filtered is specified by the SNAP header which identifies the 3 byte Organizationally Unique Identifier OUD and 2 byte Protocol Type used for the frame This type includes Protocol OUIMIP hex value AppleTalk Phas
47. ble 4 Configure the LAN connection table 5 Configure the Mnemonic Table and PVC Setup table 6 Configure the bridge for Local Termination Go to Configuring the Bridge section on page 106 for details on configuring the bridge table for Local Termination Connect to the node using Control Terminal Port CTP access Obtain the following information e MAC Address of the device being spoofed e SAP value of the device being spoofed Follow these steps to configure bridge parameters to enable Local Termination on a node Step Action Result 1 Select Configure gt Configure The Configure Bridge Record Bridge from the Main menu menu appears Note Bridge must be configured for source routing Bridge Type SR Bridging LLC2 Local Termination Step Action continued Result Configure all of these LT configu ration options Choose one to begin e LLC LT Station Table Then Go to Configuring the LT Station Table for details e LLC LT WAN Parameters Then Go to the section Configuring the LT WAN Parameters e LLC LT Profile Table Then Go to the section LLC LT Profile Table Configuration LLC LT Station Table Configuration appears LLC LT WAN Configuration appears LLC LT Profile Table Configuration appears Configuring the LT These parameters make up the LT Station Table Station Table Entry Number
48. cal Termination enabled at the network s edge points Bridging Proper LT configuration LLC Protocol LLC Frame Description LLC2 Frame Description Bridging T0008 16F LLC2 Local Termination Figure 52 shows a Token Ring LAN properly configured for Local Termination LLC2 Keepalives Acks LLC2 Keepalives Acks LLC2 Keepalives Acks Figure 52 Example of Proper LT Configuration Local Termination running on PathBuilder S200 series switch bridges 1 2 and 3 at the edge points of the network provide a simple solution to congestion and bandwidth problems across the entire network LLC is a link layer protocol used in IBM environments and defined in the IEEE802 2 LAN model Its function is to establish maintain and terminate the logical link between adjacent stations in a network There are three types of LLC operations Type Name Description Type 1 LLC1 Unacknowledged connectionless services Type 2 LLC2 Connection oriented services Type 3 LLC3 Acknowledged connectionless services Logical Link Control 2 LLC2 is a connection oriented acknowledged protocol LLC2 requires a connection setup between two LAN devices LLC2 is based on the HDLC protocol and is used to transport SNA traffic as well as other protocols 103 Release 5 2M LLC2 Local Termination Spoofing Local termination or spoofing of LLC protocol means that acknowledgmen
49. cal link will be declared down inoperative Boot Type LLC LT WAN Parameters N3 ACK Delay Count Range 1 to 15 Default 3 Description The Receive Count is used with T2 to reduce the number of acknowledgments a station generates The receive count is used by a station to determine how many frames it receives from the remote station while withholding acknowledgment of these frames This reduces the number of acknowledgments generated by a link station When this count expires the link station immediately sends an acknowledgment for all received frames not yet acknowledged Boot Type LLC LT WAN Parameters Bridging 109 T0008 16F Release 5 2M LLC2 Local Termination LLC LT Profile Table Configuration 110 Tx Window Size Range 1 to 15 Default 7 Description Transmit window size is the maximum number of I frames a station may transmit without acknowledgment Boot Type Node Boot LCC LT WAN Data Priority Range HIGH MEDIUM LOW Default HIGH Description Specifies the transmission priority of the LLC LT data Boot Type LLC LT WAN Parameters These parameters make up the LLC LT Profile Table Entry Number Range 1 to8 Default 1 Description Entry number used to reference this table record Boot Type N A LCC Profile Name Range 0 to 8 alp
50. col Entity STPE Introduction Automatic Spanning Tree Manual Spanning Tree What You Need to Configure Custom Software Key 86 The Spanning Tree Protocol Entity STPE is part of the PathBuilder S200 series switch Source Route Bridge functionality The parameters that control Spanning Tree Protocol operation are in the Bridge Record and Bridge Link Record In the Bridge Record the STPE Control parameter setting determines whether Automatic or Manual Spanning Tree is used For detailed information about the parameters in the Bridge Record and in the Bridge Link Record refer to the Bridge Parameters and Bridge Link Parameters sections earlier in this guide Automatic Spanning Tree is dynamic and involves more parameters that enable and control the Spanning Tree Protocol messages that communicate between the bridges By processing these messages the bridges automatically determine a spanning tree for the network These messages are continually updated so the spanning tree automatically adjusts to the current topology These messages consume a small amount of the bandwidth The automatic version is redundant since PathBuilder S200 series switch has the capability of re autocalling the destination thereby rerouting over another link Manual Spanning Tree is static and cannot adjust to bridge network topology changes However the process is more straightforward and does not consume network bandwidth no Hello
51. ctive for traffic between any source station and any destination station The other paths block any frames between the LANs A spanning tree network eliminates parallel paths and traffic loops The PathBuilder S200 series switch implementation of the Spanning Tree Protocol Entity SPTE conforms to IEEE 802 ID specifications Refer to the IEEE 802 ID specification for more detailed information on Spanning Tree Protocol operation PathBuilder S200 series switch support both automatic and manual spanning tree operations If you do not want to configure spanning tree operation yourself you can use the automatic spanning tree creation option Remember that a all bridges in your network must be configured to automatic spanning tree operation to allow for the spanning tree protocol to determine the spanning tree See the Spanning Tree Protocol Entity STPE section on page 86 13 Release 5 2M Bridging Features and Capabilities Dual Ethernet LANs What Is It For More Details The PathBuilder S24x 26x and 27x switch supports up to two Ethernet LANs in t he same node This means you can connect up to two Ethernet LANs to a single PathBuilder S24x 26x and 27x switch to perform bridging and routing of LAN traffic across the WAN to multiple Ethernet LANs Before Dual Ethernet LAN the PathBuilder S24x 26x and 27x switch supported only one Ethernet LAN port for remote bridging and routing of LAN traffic See the
52. d maintaining SVC PVC for Frame Relay connections to remote LAN bridge forwarders so that virtual circuits can be formed between the forwarders The bridge sees the LAN and the WAN by means of the WAN Adapter as networks it is attached to by links There are a total of 36 links four LAN links and 32 WAN links The PathBuilder S200 series switch supports only one LAN per node so only one link is needed for the LAN port connection link number 1 The PathBuilder S24x 26x and 27x switch supports up to two Ethernet LANs per node See Dual LAN Ethernet section on page 117 for more details on this functionality On the PathBuilder S200 series switch links numbered 2 to 4 are not used and are reserved for future configurations WAN links are numbered 5 to 36 and provide up to 32 WAN connection links which correspond to potential bridges 17 Release 5 2M Bridge Hardware Components in PathBuilder S200 Series Switches 18 Bridging Setting Up WAN Operation for Bridging Setting Up WAN Operation for Bridging Introduction With the 3Com Bridging Protocol option you can use PathBuilder S200 series switches to connect remote LANs across a Wide Area Network WAN as shown in Figure 13 Codex Proprietary Protocol ID LAN Connection Subaddress Figure 13 Interface Connections Between WAN and LAN Critical Parameters Before you can use a PathBuilder S200 series switch as a bridge to connect LANs
53. d protocols include e Novell Netware e DECnet e Banyan Vines Figure 3 shows the basic frame formats for Ethernet frames supported by PathBuilder S200 series switches Ethernet Frame Format Sa 8 6 6 2 45 1500 Octets a 64 1518 Figure 3 Frame Format for Ethernet Frames Figure 4 shows the supported 802 3 Ethernet MAC Frame format 802 3 MAC Frame Format Sad ee ad IDSAP SSAP Higher Layer Information i uoe a 42 1497 Octets 802 3 LLC Figure 4 802 3 Ethernet MAC Frame Format Example Bridging Example of Ethernet Bridge Operation For More Details Bridging T0008 16F Bridging Features and Capabilities Figure 5 shows an example of two Ethernet LANs connected across a WAN using two PathBuilder S200 series switches as bridges The example shows a Frame Relay WAN application but you can also bridge across an X 25 WAN Frame Relay PB S200 Figure 5 Ethernet Bridge Example For more details on bridging Ethernet LAN traffic see Transparent Bridging for Ethernet LANs on page 48 Release 5 2M Bridging Features and Capabilities Mixed LAN Bridging What is It For More Details PathBuilder S24x 26x and 27x switches support a mixture of Token Ring and Ethernet interfaces configured in the same node This means the PathBuilder S24x 26x and 27x switch is able to perform remote Transparent bridging for Ethernet LANs from the same PathBuilder S24x 2
54. d entries as they occur if there are stations active that are not in the initial database they will be added as they are learned Such an expanded database can be written to the CMEM by a CTP update command This has the effect of converting the entire forwarding table in running memory to permanent entries and creating a new permanent table in CMEM equal to the running configuration If the spanning tree is configured for automatic configuration then the operation of the forwarding database is as noted previously The permanent database offers a means of quickly obtaining a forwarding database without the bridge having to broadcast frames for which it does not know the destination link However since the bridge topology can change in an unpredictable way corresponding to unpredictable network failures it is best that the entries in the database are all aged Aging all entries allows the forwarding database to remain current even with topology changes Therefore it is recommended that if such changes are expected the system administrator should not use permanent forwarding entries However there is no reason that they cannot be used and the full set of editing and saving commands still apply when the spanning tree is in automatic operation Forwarding table entries can be deleted from CMEM by CTP command If the system administrator changes the topology changes bridges or stations the CMEM record edit delete add can be updated and t
55. d on link 6 Source Address PB S200 PB S200 Outgoing Source Outgoing 6 Source PB S200 Incoming Source Address Pass Link 1 Outgoing Source Address Pass Link 5 Do Not Pass Link 6 Block Figure 32 Example of Bridge Links Configured to Filter Selected MAC Address Frames To configure something similar to Figure 32 complete the Bridge Link record for the bridge and the MAC Address Filter Table as shown in these tables Configuring the Bridge Link Record Parameter Values Entry Number 1 5 6 MAC Address Filter Action Pass Pass Pass Bridging Bridge Filtering Configuring the MAC Address Filter Table Parameter Values Entry Number 1 MAC Address A Incoming Source Address Action Passlist List of Links 1 Outgoing Source Address Action Passlist List of Links 5 In a Bridge Link Record Pass or Block tells the system to check the MAC Address Filter Table to find out what filtering to perform If the Bridge Link Record specified None then the frame would pass without any filtering If the frame MAC Address is in the MAC Address Filter Table filtering is performed on the frame as specified in this table The MAC Address Filter Table used in this example specifies the filtering to be performed on MAC Address A as the incoming source address to the bridge Frames with Incoming Source Address A are passed at link 1 see
56. ddress link function 64 Outgoing Destination Address Link Action parame ter function 59 Outgoing Protocol Link Action parameter description 75 Outgoing Source Address example 62 link 64 Outgoing Source Address Link Action parameter function 58 P Pass application 61 filtering action 59 Passlist 59 Protocol LLC 103 Protocol Filter Table 122 configuring 71 use 70 Protocol filtering use 12 70 Protocol formats bridge filtering 57 DSAP 57 SNAP 57 Protocol ID in SNAP 74 Protocol ID DSAP in LLC field 74 Protocol Type parameter description 75 Protocol Value parameter description 75 R Records deleting 113 REM 120 Reset Bridge statistics 147 returning products for repair A 4 RIF 42 Ring Error Monitor 120 Ring Parameter Server see RPS Root bridge link 87 Routing Info Indicator bit description 43 Routing Information Field 39 42 function 43 remote ring number 39 Routing Information Present bit 39 Routing TEST frame Routing Type field 46 RPS 120 S SDLC 2 Sessions maximum number of LT sessions 104 SNAP description 74 Source Address link example 64 function 64 Source Route bridging example of use 43 Spanning tree configuration 53 manual 87 single route broadcast 39 Spanning Tree STPE Status 125 Spanning Tree Protocol Entity STPE 23 Specific route frame 39 Specific Routed TEST frame example 46 Spoofing described 10 100 104 SRB Source Route Bridging 43 Standby bridge links 87 Stati
57. dware maintenance application training and support services When you contact your network supplier for assistance have the following information ready e Product model name part number and serial number e A list of system hardware and software including revision levels e Diagnostic error messages e Details about recent configuration changes if applicable Technical Support If you are unable to contact your network supplier see the following section on how to contact 3Com Support from If you are unable to obtain assistance from the 3Com online technical resources or 3Com from your network supplier 3Com offers technical telephone support services To find out more about your support options please call the 3Com technical telephone support phone number at the location nearest you When you contact 3Com for assistance have the following information ready e Product model name part number and serial number e A list of system hardware and software including revision levels e Diagnostic error messages e Details about recent configuration changes if applicable Below is a list of worldwide technical telephone support numbers Country Telephone Number Country Telephone Number Asia Pacific Rim Australia 1 800 678 515 PR of China 10800 61 00137 or Hong Kong 800 933 486 021 6350 1590 India 61 2 9937 5085 Singapore 800 6161 463 Indonesia 001 800 61 009 S Korea Japan 0031 61 6439 From anywhere in S Korea 82 2 3455 64
58. e II 08 00 07 80 9B Apple ARP Phase II 00 00 00 80 F3 Proteon Proprietary AppleTalk 00 00 93 80 02 Phase I for FDDI Proteon Proprietary AppleTalk 00 00 93 80 02 ART Phase I for FDDI m Note The protocols listed here represent only some of those that are currently available for DSAP and SNAP Protocol Value Range 00 to FF If Protocol Type DSAP 0000000000 to FFFFFFFF If Protocol Type SNAP Default 00 If Protocol Type DSAP 0000000800 If Protocol Type SNAP Description Indicates the hexadecimal value of the protocol that is filtered or forwarded Bridging Bridging T0008 16F Bridge Filtering Incoming Protocol Link Action Range PASS BLOCK PASSLIST BLOCKLIST Default PASS Description Specifies the action to be taken on the incoming protocol These actions include PASS BLOCK PASSLIST or BLOCKLIST e PASS If this value is used incoming frames with the specified protocol value are passed on all links All other protocols are blocked on incoming links If this value is chosen skip the List of Links parameter e BLOCK If this value is used incoming frames with the specified protocol value are blocked on all links All other protocols are passed on incoming links If this value is chosen skip the List of Links parameter e PASSLIST If this value is used a pass list is specified by the List of Links parameter Links in this lis
59. e bridge network determine the tree by algorithm However even with automatic spanning tree determination you must study the possible arrangements of resulting trees and assign the bridge priorities accordingly to avoid unreasonable performance due to long data paths In fact this responsibility points out a major disadvantage of using a bridge network in a mesh topology instead of a router The spanning tree protocol does not allow the bridges to determine optimal paths and to route frames along them Trying to handle this task manually by configuring bridges and bridge links quickly becomes unwieldy as soon as additional loops are possible and one tries to maintain optimal traffic routing when faced with a variety of possible link or bridge failures Bridging Spanning Tree Protocol Entity STPE STPE Parameter Setting Considerations Introduction This section discusses how the bridge and bridge link parameters can be used to influence the design of a bridge network and to show how they relate to overall PathBuilder S200 series switch configuration during spanning tree operation a Note You should thoroughly understand the spanning tree protocol and how its parameters influence performance before you consider changing SPTE related these parameters in a PathBuilder S200 series switch network Otherwise because of the critical nature of the timers involved the spanning tree topology may become unstable It may become difficult to trace t
60. e local spoofer from the remote spoofer TEST Number of Test frames received by the local spoofer from the remote spoofer XID Number of XID frames received by the local spoofer from the remote spoofer DISC Disconnect DM Disconnect node Frames received out of sequence Number of frames received out of sequence from the remote spoofer Bad frames received Number of bad frames received from the remote spoofer Frames dropped Frames from the remote spoofer dropped due to congestion LAN queue full Bridging Bridge Statistics Reset Statistics How to Reset Port Statistics Consistent with PathBuilder S200 series switch the reset port statistics prompts you to enter the number of the port to be reset For TR port Number 55 all the statistical counters are set to zero Reset Bridge Link Stats This command prompts you to enter the number of the bridge link to be reset All the statistical counters of the selected bridge link are set to Zero Reset All Stats This command resets all the statistics of the PathBuilder S200 series switch This includes statistics of the TR port and all bridge links Bridging 147 T0008 16F Release 5 2M Bridge Statistics 148 Bridging Online Technical Services World Wide Web Site 3Com FTP Site Technical Support Appendix A Technical Support 3Com provides easy access to technical support information through a variety of services
61. e single paths are manually assigned No Hello frames are exchanged between bridges rather each bridge port in the network is configured to either forward or block all Spanning Tree Explorer frames If a link or bridge goes down then that path stays broken until the problem is fixed No topology change notification occurs in manual spanning tree operation You have to adjust the spanning tree to changes in your network either by reconfiguring the spanning tree or wait until the lost path is restored A manual spanning tree forms fixed single route paths between LANs and cannot dynamically reestablish an alternate path for the broken one However the PathBuilder S200 series switch LAN option can use its SVC rerouting capability to overcome this problem The PathBuilder S200 series switch senses the break drops the original SVC between the bridged nodes and re autocalls creating another SVC connection using a different path across the WAN Since a manual spanning tree does not send Hello messages between bridges it minimizes network bandwidth overhead An automatic spanning tree requires sending and receiving BPDUs which consumes processing cycles from the CPU of a node and therefore increases CPU use A manual spanning tree avoids this usage 87 Release 5 2M Spanning Tree Protocol Entity STPE Tips on Spanning Tree 88 Determining a spanning tree in order to set up a manual tree may seem more labor intensive than letting th
62. ease 5 2M Bridge Filtering DSAP Values The DSAP is a 1 byte ID found in the LLC field see Figure 37 You set this value in the Protocol Value parameter of the Protocol Filter Table Examples of DSAPs include IBM 04 08 e Banyan Vines BC e Novell IPX E0 IBM NetBIOS FO LLC Field A L N E TT f Figure 37 Protocol ID DSAP Located in LLC Field SNAP Protocol ID The SNAP is five bytes and is also found in the LLC field The first three bytes are OUI and the last two bytes are the Protocol ID Figure 38 LLC Field 4 ee N DSAP SSAP Control 5 Bytes 03 OUI Type 00 00 00 2 Bites Indicates SNAP Format as Unnumbered Information OUI Organizationally Unique Identifier Type 2 Byte Protocol ID Figure 38 SNAP Protocol ID The SNAP format is used to identify Ethernet and pre IEEE 802 protocol IDs that do not fit the 1 byte ID 74 Bridging Example of Protocol Filter Table Bridging T0008 16F Bridge Filtering This table provides an overview of the Protocol Filter Table parameters Parameter Action s Entry Number Used to reference this table record Protocol Type Indicates what type of protocol is involved in the frame Selections include NONE DSAP and SNAP Protocol Value Indicates the value of the protocol that is filtered or forwarded Range 00 OxFF DSAP 0000000000 FF FF SNAP Incoming Protocol
63. eatures and capabilities of PathBuilder S200 series switches As mentioned earlier Bridging extends the size and coverage of a Local Area Network LAN PathBuilder S200 series switches provide bridging support for up to two 802 3 Ethernet LAN interfaces per node or one 802 5 Token Ring LAN interface per node and up to 32 remote bridge connections A PathBuilder S200 series switch bridge can be connected to a WAN backbone made up of X 25 Frame Relay or both as shown in Figure 2 PB S200 PB S200 Figure 2 Example of Typical PathBuilder S200 Series Switch Bridging Application PathBuilder S200 series switches are best suited for remote bridging operations where traffic flows from one LAN through a WAN bridged by at least two PathBuilder S200 series switches to another LAN Release 5 2M Bridging Features and Capabilities Ethernet LAN What Is It PathBuilder S200 Series Switch Support for Ethernet Example of Basic Ethernet Frame Format 802 3 MAC Frame Format Ethernet is a common implementation of LAN topology wherein stations are connected using a bus topology Stations access the Ethernet using Carrier Sense with Multiple Access and Collision Detection CSMA CD PathBuilder S200 series switch Ethernet functionality complies with the IEEE 802 3 specifications and provides Transparent Bridging to transport many different protocols over the Wide Area Network WAN to remote destinations Supporte
64. ed link is the link that is responsible for issuing the bridge messages when more than one link is involved in a network For example in the network in Figure 43 Bridge 5 and bridge 6 are connected to LAN 5 and will both issue each other spanning tree messages until they determine which one of them is the designated bridge for LAN 5 Once determined the designated bridge issues bridge messages and the other bridge only listens unless it has received another message from another link that would make its link the designated bridge such a message must have higher priority than the one it receives from its designated adjacent Another case where there is contention and resolution to a designated bridge is link 8 between bridge 3 and bridge 4 To determine which link becomes designated the same set of priority parameters are used as in determining the root link In this case the designated link is the link issuing the message that e Identifies the root bridge with the lowest numerical bridge ID e Has the lowest cost to the root assuming there is a tie in reporting the root bridge e Identifies itself with a higher priority ID assuming there is a tie in reporting the root bridge and the cost to the root bridge e Has the higher priority link assuming all of the above are tied In this network bridge 5 link 1 is the designated link for LAN 5 because between bridge 5 link 1 and bridge 6 link 1 bridge 5 link 1 generates a message with a low
65. elete LT session configuration records Step Action Result 1 Select Delete Record from the The Delete Record menu appears CTP Main menu and press Return 2 Select Delete Bridge from the The Delete Bridge menu appears Delete Record menu 3 Select Entry number 1 appears e LLC LT Station Table Entry Or e LLC LT Profile Table Entry 4 Press Return to delete entry Proceed Y N appears number or type in another entry number 5 Type Y to delete the entry Record Deleted appears Bridging 113 T0008 16F Release 5 2M Mixed LAN Operation Mixed LAN Operation Overview PathBuilder S24x 26x and 27x switches support a mixture of Token Ring and Ethernet interfaces configured on the same node This means the PathBuilder S24x 26x and 27x switch is able to perform remote Transparent bridging for Ethernet LANs and remote Source Route Bridging from the same PathBuilder S24x 26x and 27x switch as shown in Figure 54 Ethernet 1 Ethernet 1 Port 13 l l l l PB S200 l l Mixed LAN Environment Limitations 114 Port 19 Ethernet 2 Ethernet 2 Figure 54 Example of Mixed LAN Bridging in PathBuilder S24x 26x and 27x Switch These limitations apply when you perform Mixed LAN bridging in a PathBuilder S24x 26x and 27x switch e The PathBuilder S24x 26x and 27x switch is limited to only one Spanning Tree Entity SPTE
66. en the message with the higher priority reporting adjacent should be given priority In this case B2 has been configured to have a higher priority lower Bridge ID than B3 so B4 selects link 7 as its root link The second consideration occurs when two links on the same bridge are receiving messages from the same adjacent bridge and the messages report the same root bridge and the same cost to the root bridge This could occur if there were two links between B3 and B4 The bridge will choose the link with the lower bridge link priority The priority for the link is a 2 byte number formed by concatenating the value of the parameter STPE Priority with the link number 1 LAN3 1 I Bridge 3 Tl Bridge 4 LAN4 Figure 46 Two Bridge Links Between B3 and B4 For example B3 sends messages to B4 that the root bridge is B1 and that the cost to the root is 10608 353643536 To cause bridge 4 to favor link 11 over link 8 configure link 8 STPE Priority 128 80 hex link 11 STPE Priority 64 40 hex In this example should a link between bridge 3 and bridge 4 be necessary for a spanning tree bridge 4 will favor link 11 and remove link 8 from the tree Bridging 93 T0008 16F Release 5 2M Spanning Tree Protocol Entity STPE 94 The same priority mechanisms that determine the root link are also applied in determining which links become designated links a root link is never a designated link The designat
67. ept 0 0 Clear Request 0 0 Clear Confirm 0 0 Reset Request 0 0 Reset Confirm 0 0 Press any key to continue ESC to exit Figure 66 Detailed LAN Connection Statistics Second Page Bridging 137 T0008 16F Release 5 2M Bridge Statistics Description of This table describes screen terms for pages 1 and 2 of the Detailed LAN Connection Screen Terms Statistics shown in Figures 65 and 66 Term Description Call Summary This field provides information about the following e Connection Type Specifies whether the connection is an SVC or a PVC e Connection State Specifies the current state of the PVC or SVC Possible states are Unconfigured Calling Waiting Connected Autocall Failure Software Disabled Operator Disabled Congested This means either the Frame Relay link is receiving BECNSs or the node is running low on Data Buffers Or if the LCON queue backs up due to too much traffic passing from the LAN to the WAN the connection state may be Congested Forwarders Connected Specifies which forwarders are currently connected to this LAN Connection Source Route Spanning Tree Remote Address Specifies the called address of the remote WAN Adapter LAN Connection for connected SVCs The possible states are Blank for PVCs blank for disconnected SVCs No Mnemonic for autocall SVCs whose mnemonic does not exist in the Mnemonic Table Max Attempts for Autocall SVCs that reached their autocall maximum
68. er cost to the root than bridge 6 link 1 they both have the same root Between bridge 3 and bridge 4 on link 8 bridge 3 link 8 becomes the designated link because it has a lower cost to the link Links that are not root links or are not designated links are not part of the spanning tree Links that are not on the spanning tree do not forward data packets or spanning tree explorer frames in source route bridging However they are constantly receiving bridge messages on these links from the designated bridges and comparing these messages to those they originate This action allows the bridge to detect failures and adjust the spanning tree should this become necessary Bridging Spanning Tree Protocol Entity STPE Spanning Tree Timers Introduction Timer Parameters Hello Timer Max Age Bridging T0008 16F If the spanning tree converges to a final topology it usually does but misconfiguration as discussed below can cause instability and lack of convergence the topology is maintained by timed messages initiated by the root bridge and sent out its designated links Subsequently bridges receive the message on their root link and in turn pass the message along the spanning tree by transmitting it on their designated links The root bridge message has timer parameter values that all bridges should copy and use These timers are e Message Age e Max Age Bridge Parameters Record e Hello Time Bridge Parameters Rec
69. ers Bridge Link Number and Router Interface appear in the record At the Bridge Link Number parameter type in a number 1 4 to identify the bridge link and press Return For example you can configure the Ethernet port as bridge link 1 E Note The default value for this parameter is 1 This matches this port configuration to a specific bridge link number within the bridging configuration If the bridge link you select is already used a warning message appears but your input is retained in the CMEM At the Router Interface Number parameter type in a number 1 4 to identity the router interface For example you can configure the Ethernet port as router interface 1 The default value for this parameter is 1 This matches this port configuration to a router link number within the router configuration If the router interface number you select is already used a warning message appears but your input is retained in the CMEM Type and press Return to save the record This saves the record Perform a Node boot from the Boot menu This implements your changes but if you want the new bridge link to be active you must configure the Bridge Link record under the Configure Bridge menu Go to the following step By default the bridge link is not activated until you activate it Select Configure Bridge gt Bridge Link Parameters from the CTP Main menu to activate the bridge link
70. essage appears The default value for this hs input is retained in the parameter is 1 f 5 At the Router Interface Number This matches this port configuration parameter type in a number 1 4 to to a router link number within the identity the router interface router configuration If the router u Note interface number you select is The default value for this already used a warning message parameter is 1 appears but your input is retained in the CMEM 6 Type and press Return to save the This saves the record record 7 Perform a Node boot from the Boot This implements your changes but menu if you want the new bridge link to be active you must configure the Bridge Link record under the Configure Bridge menu Go to the following step By default the bridge link is not activated until you activate it 8 Select Configure Bridge gt The Bridge Link Parameters menu Bridge Link Parameters from appears the CTP Main menu to activate the bridge link 9 Type and press Return The record is saved Bridging Dual LAN Ethernet Step Action continued Result Description 10 Perform a Bridge Link boot from This enables the bridge link the Boot menu For Details on See the PathBuilder S200 Series Basic Protocols for details on Ethernet LAN port Parameters parameters for Multiple LAN Ethernet operation Bridging 119 T0008 16F Release 5 2M LAN Server Subsystem LAN Server Subsystem
71. eter If there is no match between the frame MAC Address and any entry in the MAC Address Filter Table then filtering action on that frame is not controlled by the MAC Address Filter Table When the filtering action is not controlled by the MAC Address Filter Table the action taken by the bridge is determined by the MAC Address Filter Action parameter in the Bridge Link Table the action is to either PASS the frame or BLOCK it The MAC Address Filter Action parameter determines if the filter table is enabled on a bridge link This same parameter is used to define the action taken PASS or BLOCK when no match is made in the MAC Address Filter Table For a detailed description of the MAC Address Filter parameters refer to Configuring the MAC Address Filter Table section on page 66 Incoming and The filtering action is applied to each link The frames passing on a link can be either Outgoing Frames incoming or outgoing see Figure 31 Incoming means that the frame is entering the bridge from elsewhere either from the LAN or WAN Outgoing means the frame is leaving the bridge Therefore a given frame can be incoming on one link and outgoing on another link provided it does not get blocked due to filtering Filtering can be applied at each of those links For any link the PASS or BLOCK attribute can be set for either the source address or the destination address This method allows you to individually configure every combinati
72. eters Bridge Link Parameters MAC Address Filter Table Protocol Filter Table LSS Parameters M Virtual Port s MAC Address Virtual Bridge ID Path Trace Control Functional Address Mask Figure 56 LAN Server Subsystem LSS Record Menu Parameters These parameters make up the LSS Record Virtual Port s MAC Address Range 00 00 00 00 00 00 to FE FF FF FF FF FF Default 00 00 00 00 00 00 Description Specifies the MAC address of the virtual LAN port of the virtual ring This value defaults to a universally administered second address that is supplied by 3Com in the TRIM card PROM This PROM address is called the Burned in Address BIA A value of zero 00 00 00 00 00 00 is used as the default when hardware is absent When hardware is present and the MAC Address is configured to zero it will be overwritten by the BIA The LAN port can also be configured to a locally administered MAC address 122 Bridging Bridging T0008 16F LAN Server Subsystem Virtual Bridge ID Range 0 to 15 Default 0 Description Represents the bridge ID of a virtual source routing bridge that connects the local TR LAN to the virtual TR LAN Path Trace Control Range ENABLE DISABLE Default DISABLE Description Specifies whether or not the LBS is enabled to send the Path Trace notification frames to the IBM LAN Network Manager
73. exceeds the value of this parameter The event is generated only once during the Bad Hello Time m Note If STPE Control parameter is set to MAN the following parameter appears Bad Hello Timeout Range 10 to 30 Default 15 Bridging T0008 16F 23 Release 5 2M Configuring the PathBuilder S200 Series Switch for Bridging Operation Bad Hello Timeout continued Description Represents the timeout value in minutes The Bad Hello counter is reset when the timeout expires and can be used to control how frequently the Hello counter reaches its alarm threshold Learn Only Period used for Ethernet only Range 2 to 604800 Default 10 Description The time in seconds that a bridge is prevented from forwarding frames after the forwarding is cleared due to a node boot Aging Period used for Ethernet only Range 2 to 1000000 Default 10 Description Specify the time in seconds that a learned entry in the Forwarding Table is allowed to remain in the table without being updated relearned If the entry is not updated within this time period it is discarded from the table Bridge WAN Data Priority used for Ethernet only Range EXP HIGH MED LOW Default HIGH Description Specify the transmission priority of the bridged data over the WAN 24 Bridging Configuring the Pa
74. following are true e The bridged packet is a MAC level multicast or broadcast that is the first transmitted bit of the destination is set e The bridged packet contains an 802 2 LLC field that is on Ethernet implementation the packet does not use an EtherType code to distinguish the packet format e The LLC DSAP SSAP CTL fields are OxFO OxFO x03 The first byte following the above LLC layer is considered offset 0 of the NetBIOS PDU protocol data unit e The two bytes at NetBIOS offset 2 3 are OxFF and OxFE NetBIOS frame delimiter Filtering Either one of the following is true The NetBIOS command byte at offset 4 is 00 Add_Group_Name or 01 Add_Name Query The packet field to be compared to the NetBIOS Name Filter list is the SOURCE name field occupying the 16 bytes starting an offset Ox1C in the NetBIOS PDU e The NetBIOS command byte at offset 4 is 08 Datagram or Ox0A Name Query The packet field to be compared to the NetBIOS Name Filter list is the DESTINATION name field occupying the 16 bytes starting at offset OxOC of the NetBIOS PDU When Filters Are NetBIOS name filters are applied to the broadcast packets that are transmitted in Applied order to initiate NetBIOS sessions and to broadcast datagrams Application of NetBIOS filters does not halt the operation of any NetBIOS sessions already in progress Bridging 85 T0008 16F Release 5 2M Spanning Tree Protocol Entity STPE Spanning Tree Proto
75. for the primary LAN interface The WAN bridge links start at entry 5 Enter the number of the link that you are defining and complete the NetBIOS Name Filter Action parameter using the description in the Parameters section that follows Parameter NetBIOS Name Filter Action The NetBIOS Name Filter Action parameter is in the Bridge Link Parameters record Range PASS BLOCK NONE Default NONE Description When using NetBIOS Name Filters set the NetBIOS Name Filter Action to BLOCK on Bridge Link 1 the LAN link Then define the NetBIOS Name Filter Table records with patterns for each of the server names that you want to access e PASS Passes all frames with a NetBIOS name that is not listed in the NetBIOS Name Filter Table e BLOCK Blocks all frames with a NetBIOS name that is not listed in the NetBIOS Name Filter Table e NONE Indicates no NetBIOS name filtering for the link Bridging T0008 16F 179 Release 5 2M Bridge Filtering Configure NetBIOS Figure 41 highlights the NetBIOS Name Filter Table selection in the Configure Name Filter Table Bridge menu Node Address Date Time Menu Configure Bridge Path Main 5 22 Bridge Parameters Bridge Link Parameters MAC Address Filter Table Protocol Filter Table NetBIOS Name Filter Table LSS Parameters LLC LT Station Table LLC LT WAN Parameters LLC LT Pr
76. ge decides where to relay Ethernet LAN frames by using the spanning tree protocol to develop and maintain a loop free topology Using spanning tree you can add a bridge anywhere in the Ethernet LAN without creating loops The network devices are not involved in this decision process which is transparent to them A transparent bridge monitors Ethernet LAN traffic learns the source address of each frame it receives and maintains a database also known as the Forwarder of source addresses and associated bridge connections A transparent bridge uses a timeout process to purge its database of what it considers inactive addresses For the PathBuilder S200 series switch to learn where MAC stations are located in relation to themselves they use a hardware accelerator a transparent bridging forwarder and a transparent bridging forwarding table A transparent bridge learns based upon the MAC source address This address is placed into the transparent bridging forwarder table along with the link that the PathBuilder S200 series switch received the frame on if the address is not to be filtered When a transparent bridge receives a frame it checks its database for the frame address and performs one of the following actions e If the frame s MAC destination address is not found in the TB forwarding table then the bridge sends the frame on all bridge connections except for the connection on which it arrived e If the brid
77. ge modify the Bridge Priority value appropriately For example Bridge ID equals Bridge Priority Value in hex MAC Address The default bridge priority value is 32768 8000 in hex So a bridge with a MAC address of 08 00 3E 02 53 8F and a default bridge priority value would have this bridge ID 80 00 08 00 3E 02 53 8F Bridge Priority AC Adda Figure 44 Example of Bridge ID and MAC Address A Root Link is the Bridge Link on a particular bridge that is the preferred path to the Root Bridge A Designated Link is all other links that are part of the spanning tree In Automatic mode the Root Link is determined by summing path costs from a bridge to the Root Bridge Path costs are configured in the Bridge Link Record If there are multiple paths to the Root Bridge the bridge selects the route with the least cost to the root as the preferred link Root Link All other links associated with the bridge become Designated Links For example in the network in Figure 43 bridge 3 receives messages from bridges 1 4 and 5 because these bridges are adjacent directly connected by links If the cost of traversing any of the WAN links is equal and bridges 1 4 and 5 are reporting B1 as the root and that they know how to get to it then bridge 3 will choose link 6 as the preferred link to the root because this path will have the least cost to the root m Note The fewest number of links involved yields the lowest cost the fact
78. ge has learned the destination address meaning the frame s MAC destination address is found in the TB forwarding table then the frame is sent out on the learned link unless there is a filter set on the link e The Hardware Accelerator discards local traffic before it reaches the node The Forwarder initiates the Learning process of the transparent bridge logic for frames received from the LAN and WAN ports After receiving an Ethernet frame the Forwarder applies bridging logic routes the frame to the appropriate Handler and sends the frame to the outgoing link which is a path to the frame s MAC destination address The Forwarder e Initiates WAN frame learning e Initiates LAN frame learning e Filters the frame using the filtering facility Information sent to the Hardware Accelerator includes e Source address e Destination address Bridging Transparent Bridging for Ethernet LANs Transparent Bridge Figure 27 shows how the Forwarder and the Hardware Accelerator process a frame Forwarder Example A frame arrives at the TB Forwarder Drop the frame YES YES n Is the inbound flag for a Unicast or Multicast frame Is the MAC Source Address in the forwarding NO Learn the Source Address YES NO TB Forwarder checks if any filters are set Source Address on the Permanent Station Address List Destination Address in the forwarding table YES NO TB Fo
79. hanumeric space blanks field Default blank Description Local Term Station Table references this parameter for the T1 T2 TI N2 N3 and TW values Boot Type Tables and Node Record Bridging LLC2 Local Termination T1 Reply Timer Range 1 to 25 seconds Default 1 Description This Ack timer is used by a station to detect a failure of the remote station to acknowledge an outstanding I frame or supervi sory frame with the pole bit set to 1 Boot Type Tables and Node Record T2 Rx ACK Timer Range 1 to 255 tenths of seconds Default 1 Description Specifies how long the station withholds acknowledgment of a frame from the remote station that requires acknowledgment This reduces the number of acknowledgments generated by a link station When the timer expires the link station immediately sends an acknowledgment for all received frames not yet acknowledged Boot Type Tables and Node Record Ti Inactivity Timer Range 2 to 255 seconds Default 30 Description The Idle Timer is used by a station to detect an inoperative condition of the logical link This timer starts when the link is idle no data to pass and no outstanding acknowledgments When the timer expires the station sends a supervisory frame with the poll bit set to 1 Boot Type Tables and Node Record N2 Retry Count Range 1 to 20 Defaul
80. he LAN to the WAN The WAN links are numbered 5 to 36 and provide up to 32 WAN connection links which correspond to potential bridges These links pass the LAN traffic from the LAN Bridge to the WAN Adapter Refer to the sections on Bridge software modules and links for more information e WAN Adapter The WAN Adapter adapts LAN traffic to WAN protocols It also provides other WAN services for the bridge such as establishing network calls via a set of configurable records Bridging 41 T0008 16F Release 5 2M Configuring the PathBuilder S200 Series Switch for Bridging Operation Connecting a Station to a Server in Source Route Bridging Introduction The following is an example of the process involved in establishing a connection between a station on one Token Ring LAN with a server on a remote Token Ring LAN for a Source Route Bridging operation Procedure These steps describes the process of how a a station to server connection is set up 1 The PC station source on LAN AAA requests a session to a server destination located on remote LAN CCC Figure 21 PB S200 Bridge PB S200 Bridge PB S200 Bridge Figure 21 Example of a Station to Server Configuration Server PB S200 Bridge 2 The PC assumes the server is on the local LAN and the PC sends an LLC frame typically an LLC1 TEST frame around its local LAN AAA looking for a response from the server The TEST frame has a destination MAC Addre
81. he table booted to get a cleaned up version of the database in working memory This boot does not disrupt bridge operation other than a momentary disruption to forwarding traffic The entire forwarding table in CMEM can also be deleted by a single CTP command This lets you make substantial changes to the topology then boot the bridge network with no permanent forwarding table entries to let the bridge learn station locations After a suitable learning time you can update the entries to permanent CMEM entries using the update command From that point on the permanent forwarding table will contain valid entries for the configuration 33 Release 5 2M Transparent Bridging for Ethernet LANs Using Filters Support Incoming Source Address Filter Incoming Destination Address Filter Outgoing Source Address Filter Outgoing Destination Address Filter Unicast Link Protect Flag 54 The Forwarder provides its own filtering facility which is used to reduce unnecessary traffic and to provide security The filtering facility supports the following types of filters e Incoming Source Address Filter e Incoming Destination Address Filter e Outgoing Source Address Filter e Outgoing Destination Address Filter The Incoming Source Address Filter filters packets are based on their source address and incoming links Frames with a source address found in the Incoming Source Address Filter List are discarded without applying b
82. hen to discard information about the Root Bridge and the link to the Root Bridge 95 Release 5 2M Spanning Tree Protocol Entity STPE Other Considerations 96 One important consideration is based on the fact that any bridge downstream from the root bridge copies the message received on the root link which is also passed along designated links and the retained copy is constantly aged If the age of the message reaches the value of Max Age the bridge discards the stored message and chooses another link as the root link Potentially this could result in a different bridge selected as the root bridge and in turn cause it to recalculate the root root link and designated links recalculate the spanning tree Since the root port generates the update message every Hello Time period in seconds it is obvious that the parameter Max Age should not have a value less than or in fact near the value of Hello Time The spanning tree protocol IEEE 802 1D dictates that a bridge should enforce the following relationship Max Age gt 2 x Hello Time 1 In the PathBuilder S200 series switch this rule is not strictly enforced by CTP configuration checks You should check that the values are satisfactory for the operational environment The Max Age range of values is 6 to 40 and the default is 20 The Hello Time range of values is 1 to 4 and the default is 2 seconds These values allow the enforcement of timer relationships for any reasonab
83. his behavior as the effect might occur only occasionally and only in certain types of traffic patterns Example of a Figure 43 shows a bridge network composed of six PathBuilder S200 series switches Bridge Network and five LANs The links that are in the blocking state have been selected to achieve With Spanning Tree the shortest path for the bulk of the expected data flow Bridge 1 MAC Address OF 00 3E 00 10 50 08 00 3E 00 10 60 5 LAN1 IBridge 1 Bridge 2 LAN 2 6 7 08 00 3E 00 20 30 08 00 3E 00 20 40 LAN3 I Bridge 3 i Bridge 5 08 00 3E 00 30 10 08 00 3E 00 30 20 LAN 5 Figure 43 Example of a Bridge Network Bridging 89 T0008 16F Release 5 2M Spanning Tree Protocol Entity STPE Setting the Root Bridge of the Spanning Tree Determining Root Links and Designated Links 90 The bridge with the lowest Bridge ID becomes the root bridge in a spanning tree network The Bridge ID is made up of two parts the Bridge Priority and the MAC address of the LAN port You modify these elements during bridge configuration from the Bridge Priority parameter in the Bridge Parameters record and the MAC Address parameter in the LAN Port record All bridges have the same default priority value 32768 So without any changes to this value the MAC address of the LAN port determines the root bridge in a network If you want to control which bridge becomes the root brid
84. his manual Bridging 9 T0008 16F Release 5 2M Bridging Features and Capabilities LLC2 Local Termination LLC2 Local Termination LT Example LLC2 Keepalives Acks For More Details PathBuilder S200 series switch support includes LLC2 Local Termination for your Bridging operations when passing SNA SDLC data traffic LLC2 Local Termination lets specific Token Ring ports generate and respond to LLC2 polls with local acknowledgments thereby preserving bandwidth and preventing session timeouts Local Termination also referred to as spoofing provides an efficient means for carrying out an LLC2 session between two SNA end stations attached to separate Token Ring LANs connected by a Wide Area Network WAN Additionally Local Termination provides detailed statistics on LLC2 sessions Figure 7 shows a network where running LLC2 Local Termination at the edge point PathBuilder S200 series switches enables spoofing from one side of the network to the other across multiple Token Rings LLC2 Keepalives Acks LLC2 Keepalives Acks LLC2 Keepalives Acks LLC2 Keepalives Acks Figure 7 Local Termination Example See LLC2 Local Termination section on page 100 in this guide Bridging Bridging Features and Capabilities Autolearn for Local Termination What Is It Example Local Termination Autolearn reduces the amount of configuration you need to do by let
85. ically routed frame is received from the WAN it is sent to the Token Ring if the next bridge listed in the Routing Information field does not correspond to a bridge formed by a local SVC Otherwise it is forwarded to the proper SVC for additional bridging without being sent to the LAN This keeps transit traffic off rings where it can be avoided 39 Release 5 2M Configuring the PathBuilder S200 Series Switch for Bridging Operation Configuring Source Route Bridging Operation Introduction Configuring the Node for SRB Operation Individual Bridge Links 40 You configure a node for Source Route Bridging during normal bridge configuration Refer to Configuring the PathBuilder S200 Series Switch for Bridging Operation section on page 21 for more details This section provides some guidelines you should consider when configuring a node for Source Route Bridge operation The Node must be enabled for Bridge operation and some general parameters established in the Software Key and Node Record sections of the configuration menu e Make sure the CSK is entered for Source Route Bridging SRB e The subaddress within the node for the bridge module should be specified This allows the bridge connections to other nodes to be targeted to the right subaddress upon entering the node e A Codex Proprietary Protocol ID must be specified in the Node Record to ensure that calls for other traffic types if mistakenly c
86. idge ID Root Path Cost Max Age Last Topological Change Topological Changes 0 Bridge Link Address Date Time Page 1 of 1 00 f ff 00 00 00 00 Root Bridge ID OO ff ff ff ff ff ff f 03 Root Port Bridge Link 0 Forward Delay 0 09 AUG 1993 08 21 33 1 5 State Priority Path Cost Forwarding 128 1 Forwarding 128 1 Figure 58 Spanning Tree Status Descriptions for the Spanning Tree Status report This table describes the screen terms for the Spanning Tree Statistics report Term Description STPE Control Configured value of STPE Control If STPE is configured for MAN the rest of the parameters are not displayed STPE Bridge ID The value of the bridge ID which is transmitted by the bridge in STPE PDUs Root Bridge ID The root of the spanning tree as determined by the STPE Root Path Cost The cost of the path to the root as seen from this bridge Root Port The bridge link number that offers the lowest cost path from this bridge to the root bridge Max Age The actual Max Age timeout value that this bridge is currently using Forward Delay The actual Forward Delay value that this bridge is currently using The amount of time before sending a regular non spanning tree frame Last Topological Change The time when the last topological change was detected Topological Changes The number of topological changes since the
87. ination LANs This form of broadcast ensures that at least one copy of the frame arrives at the destination e Routing Information Field RIF shows the path LAN number Bridge number LAN number Bridge number etc that each ARE frame took on its search between the source and the destination Bridging 43 T0008 16F Release 5 2M Configuring the PathBuilder S200 Series Switch for Bridging Operation 5 The PathBuilder S200 series switch transfers a copy of the ARE frame from the LAN Port across LAN Bridge Link number 1 to the Bridge Figure 24 Since the frame is an All Routes Explorer the Bridge broadcasts the frame across each of the existing WAN Bridge Links 32 max to the WAN Adapter module 6 The WAN Adapter transmits each ARE frame to a separate already established SVC which connects it across the WAN to a remote node Figure 25 Note that in the node attached to LAN AAA three bridge links 5 6 and 7 to the WAN side are necessary because they go to the three remote LANs to establish complete bridges to those LANs The three right hand nodes really need only one WAN Bridge Link each but two additional ones are shown they could be attached to other bridges in other nodes not shown LAN Bridge Link ARE Frame WAN Bridge Links SVCs PVCs for Frame Relay Figure 24 PathBuilder S200 Series Switch Transfers a Copy of ARE Frame to the Bridge Module 44 Bridging Configuring
88. ing sections describe how to configure the records and tables critical for performing bridging on a PathBuilder S200 series switch Bridging T0008 16F 21 Release 5 2M Configuring the PathBuilder S200 Series Switch for Bridging Operation Bridge Parameters Bridge Port Record After you configure the Node record and the LAN Port record for the bridge node Parameters configure the Bridge parameters Figure 14 shows the parameters that make up the Bridge Parameters record Node Address Menu Configure Bridge Bridge Parameters V Max Number of Bridge Links STPE Control Bad Hello Threshold Bad Hello Timeout Learn Only Period Aging Period Bridge WAN Data Priority Bridged Protocols L Local Bridge ID Figure 14 Configure Bridge Parameters Parameters These parameters make up the Bridge Parameter Record Maximum Number of Bridge Links Range 36 to 250 Default 36 Description Specifies the maximum number of bridge links allowed Boot Type A change to this parameter requires a Node boot to take effect 22 Bridging Configuring the PathBuilder S200 Series Switch for Bridging Operation STPE Control Range AUTO MAN Default MAN Description The Spanning Tree Protocol Entity STPE module in the Path Builder S200 series switch provides automatic calculation of the spanning tree Spanning tree allows fo
89. ion NETBIOS Name Filter Action STPE Link State Link Mode __ Virtual Ring Number Figure 15 Configure Bridge Link Menu 26 Bridging Parameters Bridging T0008 16F Configuring the PathBuilder S200 Series Switch for Bridging Operation These parameters make up the Bridge Link Record Entry Number Range 1 5 to 36 Default 1 Description Specify the Bridge Link number that references this record Two Ethernet LANs can be configured on the PathBuilder S24x 26x and 27x switch using 1 and 2 Links 1 4 are reserved for LAN port connections There are 32 possible WAN Bridge Links numbered 5 to 36 Bridges are formed by PVC SVC connections to WAN bridge links in remote PathBuilder S200 series switch Each bridge link used in a WAN connection is connected to a remote bridge link and such an arrange ment forms a bridge between the two LANs At the destination node the routing table must have an entry that lists the destination port as LCON LAN Connection This allows the call to be directed to a connection on the WAN Adapter m Note The following parameter appears if you enter 5 top 36 at the Entry Number parameter Bridge_Type Range SR TB BOTH_SR_AND_TB Default TB Description This is the bridge type for links connecting to WANs It defines the kind of bridging that will be employed on the link It applies only to WAN links number 5 to 36 the maximum number of li
90. ion This Ack timer is used by a station to detect a failure of the remote station to acknowledge an outstanding I frame or supervisory frame with the pole bit set to 1 Boot Type LLC LT WAN Parameters T2 Rx Ack Timer Range 1 to 255 tenths of seconds Default 1 Description The Receive Ack timer is used by a station to determine how long it will withhold acknowledgment of a frame from the remote station that requires acknowledgment This is a method of reducing the amount of acknowledgments generated by a link station When this timer expires the link station should immediately send an acknowledgment for all received frames not yet acknowledged 108 Bridging LLC2 Local Termination T2 Rx Ack Timer continued Boot Type LLC LT WAN Parameters Ti Inactivity Timer Range 2 to 255 seconds Default 30 Description The Idle Timer is used by a station to detect an inoperative condition of the logical link This timer is started when the link becomes idle no data to pass and no outstanding acknowledgments and if it expires the station sends a supervisory frame with the pole bits set to 1 Boot Type LLC LT WAN Parameters N2 Retry Count Range 1 to 20 Default 8 Description This count defines the number of times an I frame or supervisory frame with pole bits set to 1 will be transmitted due to T1 acknowledgment timeout before the logi
91. le choice of values The factor of two between Max Age and Hello Time allows one of the hello messages to be lost due to for example congestion In general increasing the value of Max Age lessens the chance of a false timeout due to a delay of the hello message When bridge traffic must compete with other traffic on WAN links setting this value can become an important consideration On the other hand beyond a certain point a large value for Max Age may cause the detection of a true fault to be prolonged beyond what is desired The Hello Time should be considered similarly e Too low a value causes frequent transmission of the message resulting in network overhead e Too long an interval between transmissions forces a longer Max Age which results in lack of responsiveness to failure situations In spite of the overhead a short Hello Time helps in cases where the message might be inadvertently lost in the network not likely or where a short convergence time for the spanning tree is desired Bridging Spanning Tree Protocol Entity STPE Bridge Forward Delay Timer Forward Delay For transparent bridges the bridge Forward Delay is used to allow the spanning tree algorithm to converge to a stable topology before the bridging process is allowed to proceed Spanning tree topology determination is an iterative process and requires time to converge The bridge should not forward packets during this time because temporary loops might ca
92. link 129 Release 5 2M Bridge Statistics Bridge Link Filter Summary Example of Bridge Figure 61 shows the information displayed by the Bridge Link Filter Summary The filters from MAC Address Filter Tables and Protocol Filter Tables are sorted for a Link Filter Summary Description of Screen Terms bridge link and displayed Address Date Node Bridge Link Filter Summary Bridge Link 5 Bridge Link Filter Action MAC Address Block Protocol Pass Active Filters Press any key to continue ESC to exit Time Page 1 of 1 MAC Address Source In Source Out Dest In Dest Out 080AB546787C PASS BLOCK PASS PASS 01287D46787C BLOCK BLOCK BLOCK PASS Protocol Class Value Incoming Outgoing DSAP 8F PASS PASS SNAP 0000010808 BLOCK BLOCK Figure 61 Bridge Link Filter Summary Status This table provides descriptions of the screen terms in the Bridge Link Filter Summary Term Description Bridge Link Filter Action e MAC Address This field reports on the activity of the MAC filtering action If the MAC Address Filter Action parameter is set to NONE filtering is disabled Pass or Block Enabled e Protocol This field reports on the activity of the Protocol filtering action If the Protocol Filter Action parameter is set to NONE fil tering is disabled Pass or Block Enabled 130 Bridging Bridge Statistics Term continued Description Active
93. ll free numbers select option 2 and then option 2 Austria Belgium Denmark Finland France Germany Hungary Ireland Israel Italy Netherlands Norway Poland Portugal South Africa Spain Sweden Switzerland U K Latin America U S A and Canada 3 26 98 A 4 06 607468 0800 71429 800 17309 0800 113153 0800 917959 0130 821502 00800 12813 1800553117 177 3103794 1678 79489 0800 0227788 800 11376 00800 3111206 05 05313416 0800 995014 900 983125 020 795482 0800 55 3072 0800 966197 1 408 326 2927 1 800 876 3266 option 2 1 408 764 6883 1 408 764 7120 Technical Support Numerics 3Com bulletin board service 3Com BBS A 2 3Com URL A 1 3ComFacts A 2 A All Route Broadcast frame 39 All Route Explorer ARE TEST frame 43 ARE frame transfer example 44 ARE TEST frame 43 Async traffic 2 Autolearn Local Termination 11 Banyan Vines 74 Bisyne 2 Block application 61 Blocklist 59 Bridge filtering MAC Address filtering 58 protocol filtering 70 protocol formats 57 sequence 57 types of 57 uses 57 Bridge frame size considerations 35 Bridge Link 17 127 Bridge Link parameters 26 Bridge Link Record application 63 Bridge Link Table function 58 MAC Address filtering 58 Protocol Filter table 70 Bridge links configuring 26 LAN WAN 40 Bridge parameters Incoming Protocol Link Action 73 Outgoing Protocol Link Action 73 Protocol Type 72 Protocol Value 72 Bridge Statistics 124 Bridging Index con
94. locations if a topology change occurs due to node or link failures Note that the topological change messages are sent at the same rate as the Hello Time interval This limits the speed and gives the lower time boundary so that bridges can adjust to the change 99 Release 5 2M LLC2 Local Termination LLC2 Local Termination LLC2 Local LLC2 Local Termination lets specific Token Ring ports generate and respond to Termination LLC2 polls with local acknowledgments thereby preserving bandwidth and preventing session timeouts in a Bridging application Local Termination also referred to as spoofing provides an efficient means for carrying out an LLC2 session between two SNA end stations attached to separate Token Ring LANs connected by a Wide Area Network WAN Additionally Local Termination provides detailed statistics on LLC2 sessions LT Example For example Figure 48 shows a network where running LLC2 Local Termination at the edge point PathBuilder S24x 26x and 27x switches enables spoofing from one side of the network to the other across multiple Token Rings LLC2 Keepalives Acks LLC2 Keepalives Acks LLC2 LLC2 Keepalives Acks Keepalives Acks Figure 48 Local Termination Example 100 LLC2 Keepalives Acks L Bridging Before Local Termination After Local Termination Bridging T0008 16F LLC2 Local Termination Without Local Termination netw
95. matching MAC frame address and take the filtering action specified by this filter table If no matching entry is found this value indicates that this frame should be passed e BLOCK Look in the MAC Address Filter Table for an entry with a matching MAC frame address and take the filtering action specified by this filter table If no matching entry is found this value indicates that this frame should be blocked Bridging Configuring the PathBuilder S200 Series Switch for Bridging Operation Protocol Filter Action Range NONE PASS BLOCK Default NONE Description Functions similarly to the MAC Address Filtering Action parameter The filtering is applied to each link Frames passing on a link can be either incoming or outgoing e NONE No Protocol filtering using the Protocol Filter Table is to be performed for this link e PASS Look in the Protocol Filter Table for an entry with a matching frame address and take the filtering action specified by this filter table If no matching entry is found this value indicates that this frame should be passed e BLOCK Look in the Protocol Filter Table for an entry with a matching frame address and take the filtering action specified by this filter table If no matching entry is found this value indicates that this frame should be blocked NETBIOS Name Filter Action Range PASS BLOCK NONE Default NONE Description Specif
96. meter is configured to disable filtering NONE selected then the frame is allowed to pass and no filtering is applied If the parameter is configured with another value either PASS or BLOCK this signifies that the MAC Address Filter Table is to be checked to determine whether filtering action is to be performed In this situation the frame is checked to see if a match occurs between the MAC address in the frame and an address contained in an entry in the MAC Address Filter Table 59 Release 5 2M Bridge Filtering MAC Filtering Process 60 Figure 30 shows the MAC Filtering process Check Bridge Link Record or Entry NONE MAC Address Filtering Action Setting Pass frame without filtering PASS or BLOCK Check MAC Address Filter Table for match of frame MAC Address Frame MAC Address in MAC Address Filter Table YES Apply Table Filter PASS or BLOCK Check Bridge Link Table MAC Address Filtering Action Setting BLOCK Block the PASS frame Figure 30 MAC Address Filtering Action Bridging Bridge Filtering Mac Filtering As shown in Figure 30 if a match is detected the system applies the filtering action Process configured for that entry The filtering action is to either PASS the frame or BLOCK the frame for all links or for a configured list of links This filtering action overrides the action specified in the MAC Address Filter Action param
97. motes Multiple remote Ethernet and Token Ring LANs may attach to the local Token Ring via the PathBuilder S24x 26x and 27x switch with Translational Bridging PB 8200 Switch w Translational PB S200 Node 100 Node 200 Bridge Station A Link 5 Transparent X 25 FR Annex G Bridge f 1 F SVC Port 13 Port Type ETH Bridge Link Number 1 Port 13 Bridge Link 5 Ethernet Token Ring Port 19 Port Type TR Ring Number 1 Bridge Link Number 1 Bridge Link 5 Bridge Link 5 Bridge Type TB Bridge Type SR Link Mode TRANS Virtual Ring Number 2 LAN Connection 1 LAN Forwarder Type BRID Bridge Link Number 5 LAN Connection 1 LAN Forwarder Type BRIDG Bridge Link Number 5 Remote ID 1 Figure 19 Translational Bridging Point to Point Example 38 Bridging Configuring the PathBuilder S200 Series Switch for Bridging Operation Bridge Frame Handling Introduction How Frame Handling Works Broadcast Frame Handling Routed Frame Handling Bridging T0008 16F This section summarizes how PathBuilder S200 series switches handle frames during Source Route Bridge operation Once a PathBuilder S200 series switch station connected to a Token Ring and is operating normally non MAC frames are copied from the ring as they pass through the bridge station only if they satisfy these requirements e The Routing Information Present
98. n A Destination Address link allows a device on a Token Ring to receive frames An Incoming Destination Address link provides a path for a frame to go from the WAN to the bridge e PASS Pass incoming frames with this MAC Address value on all links that are referencing this table If this value is chosen skip the List of Links e BLOCK Block incoming frames with this MAC Address value on all links that are referencing this table If this value is chosen skip the List of Links e PASSLIST If this value is used a pass filtering list is specified by the following parameter List of Links Links in this list pass the frame Links not in this list block the frame e BLOCKLIST If this value is used a block filtering list is specified by the following parameter List of Links Links in this list block the frame Links not in this list pass the frame Bridging Bridge Filtering Outgoing Destination Address Link Action Range PASS BLOCK PASSLIST BLOCKLIST Default PASS Description The Outgoing Destination Address link provides a path for a frame to go from the bridge to the LAN It allows a device on a Token Ring to receive frames e PASS Pass outgoing frames with this MAC Address value on all links that are referencing this table If this value is chosen this filter is fully configured and the next prompt would wrap to MAC Address to allow further configuration of this record If this value
99. n on the t 0 line For simplicity the bridge ID is a two digit number and the couplet such as 01 3561 should be interpreted as root_ID cost_to_root The messages sent to the LAN attached to B1 and B4 are irrelevant to this discussion and are not shown At the end of this first iteration after the bridges have compared messages sent and received on the various links they conclude the following e B1 will continue to see itself as the root bridge Its link 5 and link 1 to the LAN not shown will be set as designated links e B2 will continue to see itself as the root bridge temporarily Its link 1 and link 6 will be set as designated links e B3 will determine B1 as the root bridge Its link 5 is its root link and its link 1 is a designated link e B4 will temporarily see B2 as the root bridge Its link 6 is its root link and its link 1 not shown is a designated link At t Hello Time the root bridges issue the spanning tree hello message After the bridges have compared the new messages they form the following conclusion e B1 will continue to see itself as the root bridge Its link 5 and link 1 will be set as designated links e B2 will determine B1 as the root bridge Its link 1 will be the root link and link 6 will be set as a designated link e B3 will determine B1 as the root bridge Its link 5 is its root link and its link 1 is a designated link e B4 will temporarily still see B2 as the root bridge Its link 6 is it
100. ncoming Protocol Link Action parameter description 75 Incoming Source Address example 62 link 64 Incoming Source Address Link Action parameter function 58 IPX 74 L LAN port connection 41 LAN Bridge Server 120 LAN Connection 136 LAN Connection Subaddress defining 22 LAN Connection Table 31 configuring 31 Index 2 LAN connections example 42 LAN Forwarder Type 32 LAN links 17 LAN Server Subsystem Configuration Report Server 120 Ring Error Monitor 120 Ring Parameter Server 120 See LSS 120 LAN Server Subsystem LSS 120 List of Links parameter function 59 Protocol filtering description 75 LLC1 TEST frame 42 LLC2 recovery procedures 36 Local Termination autolearn 11 configuring 106 described 10 100 example 10 100 supported topologies 102 LSS LAN Server Subsystem 120 LSS Record 120 configuring 122 MAC Address Filter Table 58 configuring 66 function 58 MAC Address filtering description 58 examples 62 process 60 MAC Address Filtering Action parameters application 61 Block 59 None 59 Pass 59 MAC Address parameter function 58 MAC Wildcard Filtering 65 Manual spanning tree 87 Multicast Protect Flag 55 N NCR Bisyne 2 NetBIOS description 76 NetBIOS Name Filtering Configuring 78 network supplier support A 2 Node enabling for TR operation 40 Non broadcast frames 39 None filtering action 59 Novell IPX 74 O online technical services A 1 OUI in SNAP 74 Outgoing Destination A
101. ne network the PathBuilder 24x 26x and 27x switch s Source Route translates the data into a translational bridge format that can be used by the other network For Translational Bridging to function several conditions must exist e The Token Ring network must conform to IEEE standard 802 5 and the Ethernet network mst conform to 802 3 e The PathBuilder S24x 26x and 27x switch must contain a 4 Meg FLASH and be using one of these software options Option 71 to 75 m Note In a single node Translational Bridging performance is limited to 350 packets per second To enable Translational Bridging you need to set the parameter Link Mode TRANS in the Bridge Link Parameters Record Also be sure the parameter Virtual Ring Number is set to a unique value These factors should be considered when configuring your PathBuilder S24x 26x and 27x switch for Translational Bridging e Only one link in a PathBuilder S24x 26x and 27x switch can have the param eter Link Mode TRANS e Only Bridge Link with Bridge Type SR can have Link Mode TRANS e LLC Termination is not supported between Token Ring and Ethernet when using Translational Bridging e You can increase the value of the parameter Aging Period in the Bridge Parameters Record to limit the relearning of the entries in the Translational Bridging MAC Address For more information about configuring a PathBuilder S24x 26x and 27x switch for Translational Bridging refer
102. necting LANs via X 25 link 15 connecting multiple Token Ring LANs 15 example of SVC arrangement 16 frame handling 39 transit time 36 Broadcast function 57 bulletin board service A 2 Burroughs Poll Select 2 C Codex Proprietary Protocol ID defining 22 Configuration bridge parameters 106 improper configuration 102 Local termination for PathBuilder S24x 26x 27x and 29x switch 106 proper configuration 103 Translational Bridging 37 Configuration Report Server 120 Configure Bridge Link menu list 58 D Designated bridge links 87 Destination Address link example 64 function 64 Destination MAC Address example 43 DSAP examples 74 Protocol Value parameter 74 E Entry Number parameter Protocol filtering description 75 Ethernet 1 74 F fax service 3ComFacts A 2 Filtering action block 59 none 59 pass 59 Filters transparent bridge 54 Index 1 Forwarding delay 87 Frame handling All Route Broadcast 39 duplicate frames 36 single route broadcast 39 Frame passing example 61 Frames between spoofers 104 frame types not spoofed 104 frame types spoofed 104 LLC description 103 LLC1 TEST 42 LLC2 description 103 Frames Discarded Congestion message 36 H HDLC 2 Hop bridge 16 IBM NetBIOS 74 IBM LAN Manager functionality 120 IBM LAN Network Manager Bridge View Figure 121 LSS Record 123 Incoming Destination Address link function 64 Incoming Destination Address Link Action parame ter function 58 I
103. nes are all equal then the cost for the bridge link through Node B should be higher than the cost for the direct link On the other hand if the amount of traffic due to sources other than bridging traffic causes added delay for the direct route or if the direct route has a lower speed it might be better to use the direct route as a backup Therefore one would set the cost for the direct route higher than for the Node B route For the multipoint line connecting bridges 2 3 and 4 the cost for each link should be increased in proportion to the amount of bandwidth sharing involved This also accounts for the fact that a slave node such as Node D or Node E must wait to be polled before it can pass data to its master thus adding some extra delay Bridging Spanning Tree Protocol Entity STPE Other There are two final considerations when selecting links on the basis of reported cost Considerations for when the costs and indicated root bridge on different links are the same The first is Selecting Links the case where for example B4 receives a message on link 8 from B3 designating B1 as the root bridge with a cost of 10608 to the root At the same time B4 receives a message on link 8 from B2 designating B1 as the root bridge with a cost of 7072 In this case B4 will select link 7 as the root link because the spanning tree algorithm dictates that if more than one message has the same root bridge indicated at the same cost to the root th
104. ng Aging Timer Bridging T0008 16F Spanning Tree Protocol Entity STPE The Aging Timer is a configurable parameter found in the Bridge Parameters Record It allows learned station addresses to be aged in the station address cache and deleted once their age has reached the value of the Aging Timer parameter This allows automatic updates for certain dynamic conditions such as when a station is physically moved from one part of the network to another Provided the Aging Timer is low enough to age out the station that is being moved the entry is deleted and once the station becomes active at its new location the bridge relearns its new location and forwards packets to it properly The Aging Timer is also used when there is a topological change to the network Generally if a bridge based on the automatic spanning tree algorithm notices that a link must be moved to or from a block state moved to or from the spanning tree then the bridge informs the root bridge by means of a special message sent out the root port This message includes a flag that indicates a topological change has occurred The root bridge in turn informs all the bridges in the network that a change has occurred by setting a flag in the hello message Once a bridge is informed of a change in the topology by the hello flag it switches the timer value used in aging to a value equal to the Forward Delay time This allows the bridge to more quickly relearn new station
105. ng parameter List of Links Links in this list pass the frame Links not in this list block the frame e BLOCKLIST If this value is used a block list is specified by the parameter List of Links Links in this list block the frame Links not in this list pass the frame 67 Release 5 2M Bridge Filtering 68 Outgoing Source Address Link Action Range PASS BLOCK PASSLIST BLOCKLIST Default PASS Description Outgoing source means that the frame is leaving the bridge for the WAN Therefore a given source address frame will be outgoing from bridge to WAN and incoming from LAN to bridge provided it does not get blocked due to filtering e PASS Pass outgoing frames with this MAC Address value on all links that are referencing this table If this value is chosen skip the List of Links e BLOCK Block outgoing frames with this MAC Address value on all links that are referencing this table If this value is chosen skip the List of Links e PASSLIST If this value is used a pass list is specified by the following parameter List of Links Links in this list pass the frame Links not in this list block the frame e BLOCKLIST If this value is used a block list is specified by the parameter List of Links Links in this list block the frame Links not in this list pass the frame Incoming Destination Address Link Action Range PASS BLOCK PASSLIST BLOCKLIST Default PASS Descriptio
106. nks allowed Choose e TB to perform Transparent Bridging e BOTH_SR_AND_TB when you perform mixed LAN bridging operation This lets the node perform TB and SRB operations simultaneously Bridge ID Range 0 to 15 Default 1 Description A bridge number uniquely identifies a bridge when more than one bridge is used to span the same two segments This should match the Bridge ID of the remote Bridge half 27 Release 5 2M Configuring the PathBuilder S200 Series Switch for Bridging Operation 28 Hop Count Limit Range 0 to7 Default 7 Description Specifies the maximum number of bridges through which a broadcast frame may pass on the way to its destination Largest Frame Size Range 516 1500 2052 4472 Default 2052 Description Specifies the maximum size of the INFO field that this Bridge Link can send and receive The minimum value of this parameter or of adjacent Bridge Link or values of Largest Frame Size of bridge wide parameter is used to determine whether a modification of the Routing Control field of RIF is necessary MAC Address Filter Action Range NONE PASS BLOCK Default NONE Description Specify how the MAC Address Filter Table is used e NONE No MAC address filtering using the MAC Address Filter Table is performed for this link e PASS Look in the MAC Address Filter Table for an entry with a
107. ns can be allowed to take any value in the permissible range For example with the existing functionality if the Bridge had to be configured to block all the frames with MAC addresses in the range 080004001F00 to 080004001FFF you would have to configure 256 filters Now you can simply specify 080004001F PathBuilder S200 series switches support the MAC wildcard feature on the Ethernet Figure 34 shows a typical MAC wildcard filtering application 080004001F05 080004001F01 080004002F01 080004001F04 080004001F02 080004001F03 Figure 34 Example of How MAC Wildcard Filtering Works With the old filtering system if you do not want any of the devices shown on the LAN on the left to access the WAN you would need to configure all five entries With the MAC wildcard filtering only one entry is required For example you can specify 080004001F to prevent all devices from accessing the WAN 65 Release 5 2M Bridge Filtering Configuring the MAC Address Filter Table Introduction The MAC Address Filter Table controls which frames are allowed to pass on to different links and lets you control proprietary information that you may not want to go to another LAN It is also useful in controlling the unnecessary proliferation of broadcast frames in the LAN network MAC Address Filter Figure 35 shows the MAC Address Filter Table parameters Table Parameters Categories 66 Node Address Date
108. ofile Table Enter Selection Figure 41 Configure Bridge Menu Configuring To configure the NetBIOS Name Filter Table follow these steps NetBIOS Name Filter Table Step Action Result 1 Select Configure gt Configure The first entry of the NetBIOS Bridge gt NetBIOS Name Filter Name Filter Table appears Table from the CTP Main menu a Note You can enter up to 255 entries in the table Each entry can be a wildcard pattern that matches a class of servers used in an organization 2 Complete the record by configuring the parameters using the description shown in the Parameters section on page 81 80 Bridging Typical Filtering Parameters Bridging T0008 16F Bridge Filtering For the typical case where you filter client broadcast traffic by default and pass server traffic as discussed in the Typical Filtering section on page 81 e Define only the NetBIOS Name field e Define one record for each wildcard pattern that encompasses all NetBIOS service names These parameters make up the NetBIOS Name Filter Table record String Type Range ASCII Hex Default ASCII Description This parameter determines how you enter the 16 character NetBIOS name for this record ASCII means that you enter ASCII characters for the name The name is left justified blank filled to the 15th byte and the 16th byte is ignored Hex means that you enter hexadecimal values for up to all 16 byte
109. on of Screen Terms shown in Figure 67 This table describes the screen terms for the LAN Connection Summary Statistics Term Description LAN Connection Specifies the LAN Connection entry number and current state of a configured LAN Connection The possible states are Not Properly Configured Not Connected Calling Waiting for Call Connected Waiting for Clear Confirmation Disabled Bridge Link Specifies the WAN Bridge Link number associated with this LAN connection The possible current states of the WAN Bridge Link are Not Applicable Empty Mismatch Inactive Active Congested Software Disabled User Disabled Connection Type Specifies whether the LAN Connection is a PVC a Calling SVC or a Called SVC Remote Destination Specifies the remote destination that this LAN Connection is connected to including the Remote Connection ID 140 Bridging Bridge Statistics LLC2 LT Session Summary Statistics Sample of Session Figure 68 shows a sample of the LLC2 LT Session Summary Statistics report Summary Statistics Description of Screen Terms Bridging T0008 16F Node Address Date Time LLC LT Session Summary Stats Page 1 of 1 Session Stn LOCAL MAC ADDR SAP REMOTE MAC ADDR SAP Status 1 1 40 00 10 00 00 00 04 00 00 C9 10 88 C3 04 Up 2 1 40 00 10 00 00 00 04 00 00 C9 10 A0 8A 04 Up 3 1 40 00 10 00 00 00 04 00 00 C9 10 CB 2B 04 Up 4 1 40 00 10 00 00 00 04 00 00
110. on of in out and source destination to either a pass or a block action for any link Bridge Links Token Ring 1 Outgoing Frame from Bridge to Bridge Incoming Frame Frames passing on a link can be either incoming or outgoing The same frame can be incoming on one link and outgoing on another link Figure 31 Example of a Frame Passing on a Bridge Link The source address incoming or outgoing refers to the frame having the indicated MAC source address The destination address incoming or outgoing refers to the frame having the indicated MAC destination address Bridging 61 T0008 16F Release 5 2M Bridge Filtering MAC Address Filtering Examples Introduction First Example How To Configure the Example in Figure 32 62 This section shows two filtering examples Figure 32 shows how the source address can be used to filter frames Figure 35 shows how the MAC Address Filter Table can be used to filter frames by combining multiple source and destination addresses In Figure 32 the source address MAC Address represented by A is used to filter frames passing in or out of the bridge via links 1 5 and 6 Figure 32 Frames originating from the station with MAC Address A are to be sent to server B but not server C Figure 32 shows that for bridge link 1 Incoming Source Address frames with MAC Address A are passed and Outgoing Source Address frames with MAC Address A are passed on link 5 but blocke
111. onnected to the bridge subaddress are rejected Only similar remote bridges must identify themselves with this ID For details on configuring the Node record refer to the PathBuilder S200 Series Basic Protocols Once you complete node and port configuration individual bridge links to other nodes must be established up to a maximum of 32 per node Figure 20 shows LAN WAN Bridge Links used in a PathBuilder S200 series switch LAN network LAN Bridge Link WAN Bridge Link Numbered 5 to 36 for Numbered 1 only 1 32 possible WAN Links One link for each link is operational connection to a remote half bridge Port X 25 MX 25 FR or XDLC Token LAN WAN Ring Bridge Adapter LAN SVCs Connect each half bridge across the WAN to a remote half bridge Figure 20 LAN WAN Bridge Links Used in PathBuilder S200 Series Switch LAN Network To assist you in configuring the node the LAN bridge oriented parameters are considered separate from the WAN oriented parameters Bridging Configuring the PathBuilder S200 Series Switch for Bridging Operation e LAN Side The LAN port connection consists of one link To configure the bridge module requires that you configure the LAN Port the LAN Bridge and the LAN Bridge Link which passes the LAN traffic from the LAN Port to the LAN Bridge always numbered 1 e WAN Side The WAN Adapter default subaddress 94 is used to make the transition from t
112. or that ring One or more REMs can report to a LAN manager A REM has a functional address of CO00000008 A CRS accepts commands from the LAN Manager to get station information set station parameters and remove stations from its ring It also collects and forwards configuration reports generated by stations on its ring to the LAN manager Information such as reporting a new active monitor and reporting a stored upstream address change are sent to the CRS A configuration report server has a functional address of CO0000000010 An RPS resides on each ring in a multiple ring environment for which operational parameters are being managed and provides three main services e Sends initialization information to new stations that are attaching to the ring e Ensures that stations on the ring have consistent values for operational parameters e Forwards registration information to LAN managers from stations attaching to the ring Bridging LAN Server Subsystem Statistics and Statistics and status alarm thresholds maintained by the LSS are specific for the IBM Alarms LNM and can be accessed by the IBM LNM but not from the CTP Bridging 121 T0008 16F Release 5 2M LAN Server Subsystem Configuring the LSS Record Example of LCC Figure 56 shows the LSS Record parameters used to configure a PathBuilder S200 Record series switch for LSS operation Node Address Date Time i Menu Configure Bridge Path Bridge Param
113. ord e Forward Delay Bridge Parameters Record Notice that the last three are parameters configured for each bridge Once the root bridge is determined however all the other bridges use the value in the root bridge initiated message rather than their own configured values The Max Age and Hello Time are the two principal timers used by the spanning tree protocol for detecting a fault condition When selecting values to configure these two parameters consider the fact that the bridge network is when X 25 WAN circuits are used overlaid onto an underlying network which has its own timers and recovery procedures It is important that the two networks do not interfere with each other s protocols especially where timer considerations are involved Hello messages are sent by the Root Bridge at specific time intervals These intervals are determined by the Hello Timer parameter configured in the Bridge Parameters record If the bridges in the network receive these Hello messages then this indicates to the bridges that the Root Bridge is functioning and the path from the bridge to the Root Bridge is functional as well If a bridge does not receive a Hello message from the Root Bridge within the time allowed by the Max Age Timer parameter then that bridge begins the process of recalculating the spanning tree for the network The Max Age is a configurable parameter on the Bridge Parameters Record This parameter indicates to a bridge w
114. orks face significant problems with bandwidth usage and session timeouts due to polling overhead between the host and terminal as well as network delays For example Figure 49 shows a terminal session on a source route bridged Token Ring LAN connected to a host without Local Termination During the terminal session LLC2 polls such as ACKs and keepalives are exchanged between the host and the terminal session causing e Inefficient use of the WAN bandwidth e Increased session timeouts e Ongoing tuning of network parameters to fix session timeouts sna L Keepalives Acks U Before Figure 49 Before Local Termination Example You can increase timer values to reduce the number of session timeouts experienced on a network but configuring large numbers of stations makes such a solution impractical Moreover it does not solve the problem with keepalives slowing down network traffic The best solution to such network traffic problems is to locally terminate the LLC2 session at the Token Ring interface as shown in Figure 50 Keepalives Acks Keepalives Acks After Figure 50 After Local Termination Example Using LLC2 LT you can spoof traffic on a Token Ring LAN reducing the polling overhead by minimizing session timeouts Ack and keepalive messages traverse the network between spoofers they are controlled in frequency by the WAN parameters 101 Release 5 2M LLC2 Local Termination Suppor
115. packets are forwarded more quickly by intermediate nodes resulting in the end system receiving several short frames in less time than a long frame How much improvement is achieved depends on the transmission times and line speeds involved The trade off in this case is that even though the transit delay is reduced the packet per second load is increased on all three nodes and two end systems involved In this case the factor is at least three if continuous streams of packets are involved Release 5 2M Configuring the PathBuilder S200 Series Switch for Bridging Operation Standard Frame Sizes Bridge Transit Time 36 Increasing the frame size also causes the reduction in frame overhead If a 1000 byte data packet required a 50 byte header frame IP TCP then if 2000 bytes were placed in the frame with the same frame the difference in overhead is 50 1000 5 versus 2 5 As the size of the data increases the overhead becomes even less However at these levels the gain is marginal Other factors may reduce this method of gain considerably For example intermediate systems have a limit on how large a frame they can handle As the size of the frame becomes larger there is a corresponding increase in the time the frame spends in transmission media The error rate of transmission media is finite and becomes a problem when the time for transmitting a frame becomes long enough that the probability of an error occurring during the tran
116. pires the bridges forward frames in the usual way The default setting for this parameter is 10 seconds This timer is not to be confused with the Forward Delay timer of the spanning tree protocol entity STPE The STPE timer is used to control how long a bridge link withholds a link from going into the forward state once it is determined that the link should be part of the spanning tree This timer is set to avoid bridge topology loops from forming The Learn Only Period timer prevents the bridge from sending broadcasts as part of the learning process when the bridge first comes up and has a sparse forwarding database Aging is an important process associated with the learned database entries When a new entry is learned and placed in the forwarding database a timer is set that indicates the station with the MAC address is still active If the timer expires for an entry the entry is removed from the database The aging time for learned entries in the forwarding table is configurable by the system administrator This parameter is located in the Bridge Parameters menu The default setting for this parameter is 3600 seconds 1 hour The Forwarder starts the Aging Timer for the learned addresses in the Forwarding Table The purpose for aging database entries is to allow changes in the network configuration to be automatically accounted for in the forwarding table If a station is moved from one LAN to another the station becomes reachable
117. ption This is a virtual ring number that is used by the Bridge Link for connecting to another Bridge or Frame Relay Access Device via RFC1294 or RFC1490 Bridging It must match the virtual ring number of the connecting Bridge or Frame Relay Access Device 30 Bridging Configuring the PathBuilder S200 Series Switch for Bridging Operation LAN Connection Table Introduction LAN Connection Table Parameters Parameters Bridging T0008 16F The LAN Connection Table provides information about the connections that cross over the WAN Figure 16 shows the LAN Connection Table parameters am Address Date Time Menu Configure Path Node Port LAN Connection Table M Entry Number LAN Forwarder Type LAN Connection Type Router Interface Number Encapsulation Type Autocall Mnemonic LCON Queue Limit Billing Records Traffic Priority Figure 16 LAN Connection Table Menu These parameters make up the LAN Connection Table Record Entry Number Range 1 to 32 Default 1 Description Specify the entry number used to reference this table record 31 Release 5 2M Configuring the PathBuilder S200 Series Switch for Bridging Operation 32 LAN Forwarder Type Range ROUT BRID BROUT Default ROUT Description Specify if the LAN Connection is to pass bridged routed and or brouted
118. r Links that are listed block the frame Links that are not listed pass the frame An empty list means that all links pass frames m Note If you chose PASS or BLOCK skip the List of Links parameter Incoming NetBIOS Name List of Links Range 1 5 to 36 Default The individual numbers correspond to the links that you filter according to the preceding parameter Description The following describes the options that you can define for the link e PASSLIST Passes all incoming frames on the links that are listed Blocks all the incoming frames on the links that are not listed An empty list means that all links block the frames e BLOCKLIST Blocks all incoming frames on the links that are listed Passes all the incoming frames on the links that are not listed An empty list means that all links pass the frames You can enter a range of link numbers for example 1 6 8 12 indicates 1 6 8 9 10 11 and 12 82 Bridging Bridge Filtering Outgoing NetBIOS Name Link Action Range PASS BLOCK PASSLIST BLOCKLIST Default PASS Description These are the options that you can define for the link e PASS Passes outgoing frames with the specified NetBIOS name on all links All outgoing frames with other NetBIOS names are blocked on all links e BLOCK Blocks outgoing frames with the specified NetBIOS name on all links All outgoing frames with other Ne
119. r the proper support of single route broadcast frames that occur in LANs This parameter controls how a bridge determines the Spanning Tree either automatically using the STPE or manually using additional parameters in the bridge link record e AUTO The bridge participates in Spanning Tree Protocol STP and automatically determines the single path between LANs using the Path Costs assigned to the different links Bridge protocol data units BPDUs are special frames used to continually communicate this information between bridges e MAN The Spanning Tree is configured by the network administrator This is done using the STPE Link State parameter found in the next section Bridge Link Parameters Configure all bridges in your network to MANual if you are not an expert user of Spanning Tree protocol operation This prevents problems in operation especially when lower speed WAN links are involved in forming bridges m Note If STPE Control parameter is set to MAN the following parameter appears Bad Hello Threshold Range 10 to 30 Default 15 Description Use this parameter to generate alarms when some bridges are configured AUTO and others are configured MAN in order to detect nonmatching configurations A Bad Hello counter is incremented when a HELLO Protocol Data Unit PDU is received while the STPE Control parameter is configured to MAN An event alarm is generated when the counter
120. ress any key to continue ESC to exit Figure 70 Detailed Session Statistics Screen Page 2 Bridging 143 T0008 16F Release 5 2M Bridge Statistics Description of Screen Attributes 144 This table describes the screen attributes for the Detailed Session Statistics screens as shown in Figures 69 and 70 Heading Description Session Number Refers to the entry number assigned between MAC addresses Maximum number of sessions is 64 Station Number Entry Number on LLC LT Station Table of local MAC SAP LLC Profile Name Profile name table that this station uses which references the T1 T2 Ti N2 N3 TW values Local MAC MAC address of the local device Remote MAC MAC address of the remote device Local SAP SAP being used by local device Remote SAP SAP being used by the remote device WAN Queue Indicates the number of packets queued for transmission to Depth the WAN or waiting for acknowledgment from the remote spoofer LAN Queue Depth Indicates the number of packets queued for transmission to the LAN or waiting for acknowledgment from the local device RIF Routing information field used in all frames transmitted between the devices This field contains the routing control field ring number and bridge number information Last Statistics Reset Last time statistics were reset Bridging Bridge Statistics Heading Description
121. ridge Filtering Parameter Action continued Outgoing Perform filtering action on an outbound frame for the Destination Address indicated MAC Destination address Link Action List of Links Specifies the links associated with the preceding link action parameters in this table When Passlist PL is specified the associated listed links pass the frame and the unlisted links block it Conversely when Blocklist BL is specified the associated listed links block the frame and the unlisted links pass it This table lists the filtering actions available for the MAC Address Filtering Action parameter Parameter Action Value Pass P Look in the MAC Address Filter Table for an entry with a matching MAC frame address and perform the filtering action specified by this entry If no matching MAC frame address is found pass the frame Block B Look in the MAC Address Filter Table for an entry with a matching MAC frame address and perform the filtering action specified by this entry If no matching MAC frame address is found block the frame None N No filtering to be performed pass the frame When filtering is performed the system checks the Bridge Link Table of the bridge link involved with the frame to see if the MAC Address Filtering Action parameter is configured to disable all filtering on that bridge link Figure 30 shows the process involved in MAC Address filtering If the para
122. ridge logic This filter may be applied to all links or selected links The Incoming Destination Address Filter filters packets based on their destination address and the incoming ports Frames with a destination address found in the Incoming Destination Address Filter List are discarded without applying bridge logic This filter may be applied to all links or selected links The Outgoing Source Address Filter filters packets based on their source address and the outgoing links Frames with a source address found in the Outgoing Source Address Filter List are discarded This filter may be applied to all links or selected links The Outgoing Destination Address Filter filters packets based on their destination address and the outgoing links Frames with a destination address found in the Outgoing Destination Address Filter List are discarded This filter may be applied to all links or selected links When a frame comes from a link with the Unicast Link Protect Flag set and if its source address is not found in the Permanent Station Address list the frame is dropped When a frame is being sent out over a link with the Unicast Link Protect Flag set and if its destination address is not found in the Permanent Station Address List the frame is dropped Once the Unicast Link Protect Flag is set for a link source address learning for Unicast frames is stopped for that link and all the addresses that were learned before are moved in
123. ridge route is bridging This is the ring number to which the 3Com remote bridge is attached 128 Bridging Bridging T0008 16F Bridge Statistics Term continued Description SR Source Route Frame Summary Received Transmitted The number of Source Route frames received sent by the bridge e SRF Specifically Routed Frames e ARE All Route Explorer Also called all route broadcast e STE Spanning Tree Explorer Also called Single Route Explorer SRE or single route broadcast Frame Totals The total number of frames received and transmitted by the bridge Filter Discards In Out The number of frames that were discarded due to filtering action e Source MAC Address Filter discard due to source MAC Address match in filter table e Dest MAC Address Filter discard due to destination MAC Address match in filter table e Protocol Filtered Filter discard due to Protocol type MAC Address match in filter table Total Filter Discards The total number of frame discards due to filter action RIF Error Discards The number of frames that were discarded due to incorrect RIF e Segment Mismatch Frame is discarded because next ring indicated in RIF is not correct e Duplicate Segment Frame is discarded because the RIF listed the same LAN segment more than once e Hop Count Exceeded Frame is discarded because RIF exceeded maximum Hop Count Limit configured for the
124. rotocol from operating outside their intended scope For protocol filtering the same fundamentals apply as with MAC Address Filtering except the Bridge Link record specifies Protocol Filtering Action This table shows how to configure the Bridge Link record for protocol filtering Parameter Values Entry Number 1 5 6 Protocol Filtering Action Pass Pass Pass When protocol filtering is performed the system checks the Bridge Link Table of the bridge link involved with the frame to see if the Protocol Filtering Action parameter is configured to disable all filtering on that bridge link Figure 30 which describes the MAC Address filtering process is also applicable to protocol filtering For example if the parameter is configured to disable filtering NONE selected then the frame is allowed to pass and no filtering is applied The Protocol Filter Table is used with the Bridge Link Table to specify filtering action It includes the link action parameters used to apply filtering action to every link Bridging Bridge Filtering Configuring the Protocol Filter Table Introduction Protocol Filter Table Parameters Parameters Bridging T0008 16F The Protocol Filter Table prevents stations operating with a certain protocol from operating outside their intended scope This filtering action is applied to that part of the frame that defines the protocol carried by the frame m Note A Table boot must
125. rs for 3Com products This service is available through analog modem or digital modem ISDN 24 hours a day 7 days a week Access by Analog Modem To reach the service by modem set your modem to 8 data bits no parity and 1 stop bit Call the telephone number nearest you Country Data Rate Telephone Number Australia Up to 14 400 bps 61 2 9955 2073 Brazil Up to 14 400 bps 55 115181 9666 France Up to 14 400 bps 33 1 6986 6954 Germany Up to 28 800 bps 4989 62732 188 Hong Kong Up to 14 400 bps 852 2537 5601 Italy Up to 14 400 bps 39 2 27300680 Japan Up to 14 400 bps Mexico Up to 28 800 bps P R of China Up to 14 400 bps Taiwan Up to 14 400 bps R O C U K Up to 28 800 bps U S A Up to 28 800 bps Access by Digital Modem 81 3 3345 7266 52 5 520 7835 86 10 684 92351 886 2 377 5840 44 1442 438278 1 408 980 8204 ISDN users can dial in to the 3Com BBS using a digital modem for fast access up to 56 Kbps To access the 3Com BBS using ISDN use the following number 1 408 654 2703 The 3ComFacts automated fax service provides technical articles diagrams and troubleshooting instructions on 3Com products 24 hours a day 7 days a week Call 3ComFacts using your Touch Tone telephone 1 408 727 7021 If additional assistance is required contact your network supplier Many suppliers are authorized 3Com service partners who are qualified to provide a variety of services including network planning installation har
126. rwarder checks 7 ae if any filters are set the frame Drop TB Forwarder gives the the frame frame to the handlers that are in the forwarding state TB Forwarder gives the frame to the appropriate Handler sends handler as found in the the frame forwarding table Figure 27 How the Forwarder and Hardware Accelerator Process a Frame Forwarder In addition the Forwarder collects the following types of statistics Statistics i Filteting e LAN link e WAN link e Link error Bridging 49 T0008 16F Release 5 2M Transparent Bridging for Ethernet LANs Forwarder Figure 28 shows the relationship of the Forwarder and Hardware Accelerator to the Hardware LAN and WAN Handlers Accelerator and TB Forwarder LAN WAN Handlers Accelerator Figure 28 Relationship of Forwarder and Hardware Accelerator to LAN and WAN Handlers LAN Handler 5 WAN Handler Hardware The Hardware Accelerator performs these functions Accelerator e Discards local traffic before it reaches the node Functions e Participates in the learning process for LAN traffic e Participates in the aging process for LAN traffic The Hardware Accelerator applies the aging process to the learned addresses on a LAN port It needs to e Set the aging timer bit for each address learned on the LAN link e Reset the aging timer bit for the entry whenever a frame with the same source address passes through
127. s Source MAC Address e IN This counter is incremented when the inbound frame on a Bridge Link is not forwarded because of MAC Address Table filtering on the source address e OUT This counter is incremented when the outbound frame on a Bridge Link is not forwarded because of MAC Address Table filtering on the source address e Destination MAC Address e IN This counter is incremented when the inbound frame on a Bridge Link is not forwarded because of MAC Address Table filtering on the destination address e OUT This counter is incremented when the outbound frame on a Bridge Link is not forwarded because of MAC Address Table filtering on the destination address e Protocol Filter e IN This counter is incremented when the inbound frame on a Bridge Link is not forwarded because of Protocol Table Filtering e OUT This counter is incremented when the outbound frame on a Bridge Link is not forwarded because of Protocol Table Filtering e Total Filter Discards e IN This counter is the sum of Source MAC Address in Destination Address in and Protocol filter in e OUT This counter is the sum of Source MAC Address out Destination Address out and Protocol filter out 135 Release 5 2M Bridge Statistics LAN Connection Statistics Example of LAN Connection Statistics Menu Example of Detailed LAN Connection Statistics 136 The LAN Connection Statistics Menu screen is shown in Figure 64 Selec
128. s Banyan 74 Virtual Port s MAC Address 122 W WAN 41 links 17 source route bridging 6 WAN Adapter description 17 transmits ARE frame 44 WAN links 41 Wildcard filtering 65 wildcard 65 Wildcard filtering 65 World Wide Web WWW A 1 X X 25 2 Index 5
129. s L Bridge Link Number Figure 29 Transparent Bridge TB Forwarding Table Menu Parameters These parameters make up the Transparent Bridge Forwarding menu Entry Number Range 1 to 8000 Default 1 Description Entry used to reference this table record Local MAC Address Range 00 00 00 00 00 01 to FF FF FF FF FF FF Default 00 00 00 00 00 01 Description MAC Address that is to be used for forwarding Bridge Link Number Range 1 5 to 36 Default 1 Description The bridge link to forward a frame with the associated MAC Address Boot Type Perform a node boot to implement changes to this parameter 56 Bridging Bridge Filtering Bridge Filtering What is It How Filtering is Used Bridging T0008 16F Bridge filtering prevents extraneous traffic from traversing the WAN and stops the unintentional proliferation of traffic onto other remote LAN segments In Ethernet Transparent Bridging the broadcast feature lets stations determine routes to other end stations Broadcasting to the entire network can unnecessarily degrade performance because of broadcasts traversing LAN segments that are not in any part of the network where the target station resides Therefore you can use bridge filtering methods such as MAC Address Filtering Protocol Filtering and NetBIOS Name Filtering to control broadcast traffic and reduce overhead Filtering i
130. s The string is left justified and the remaining bytes are ignored NetBIOS Name Range 0 to 16 ASCII characters if parameter String Type ASCII Blank set to null 2 to 32 hexadecimal digits if parameter String Type hex Default lt blank gt Description This name string is matched against NetBIOS packets ASCII type strings are case sensitive They may contain the wildcard character that matches any character or as the last character that matches all remaining characters Hex type strings may contain the sequence for a byte position to indicate a wildcard match of any byte value 81 Release 5 2M Bridge Filtering Incoming NetBIOS Name Link Action Range PASS BLOCK PASSLIST BLOCKLIST Default PASS Description The following describes the options that you can define for the link e PASS Passes all incoming frames with a specified NetBIOS name on all links e BLOCK Blocks all incoming frames with a specified NetBIOS name on all links Passes incoming frames with other NetBIOS names on all links e PASSLIST If you choose this value you need to specify a pass list in the List of Links parameter Links that are listed pass the frame Links that are not listed block the frame An empty list means that all links block frames e BLOCKLIST If you choose this value you need to specify a block list in the List of Links paramete
131. s MAC addresses of any Host MAC LAN devices with matching destination MAC address addresses Sas 40 00 00 00 10 88 PB S200 PB S200 FEP 6 The local PB S200 running Local Termination Autolearn automatically learns MAC addresses of stations on local LAN Figure 8 Example of Local Termination Autolearn 11 Release 5 2M Bridging Features and Capabilities Filtering What Is It Mac Address Filtering NetBIOS Name Filtering Protocol Filtering Filtering lets you restrict data traffic from certain segments of your network There are different methods used to filter data traffic on a bridged network PathBuilder S200 series switch support for filtering includes e MAC Address Filtering e NetBIOS Name Filtering e Protocol Filtering MAC Addressing is important in a bridging operation because one of the most common tasks in a bridging environment is to provide filtering of data frames Filtering provides a way of stopping certain devices from communicating with other devices in a network One way to filter traffic through a bridge is by identifying the devices you want to block by their MAC Addresses For more details on MAC Address filtering see the section MAC Address Filtering section on page 58 in this manual The NetBIOS Name Filtering feature of PathBuilder S200 series switches lets you restrict or filter all
132. s root link and its link 1 is a designated link Att 2 x Hello Time there is only one root bridge B1 to issue the spanning tree hello message This message is passed along the tree and at this iteration B4 finally sees B1 as the root bridge and the spanning tree has converged From this example it is seen that the convergence time is dependent on how many link hops the farthest bridge is from the root bridge and how frequently the hello message is sent Until the bridges converge no bridge should learn station locations nor forward data frames therefore the forward delay the time the bridge should wait before learning should be set to a value that might be at least as high as the hello time multiplied by the network diameter With special consideration this time might be considerably reduced For example in the preceding network if B2 and B3 are interchanged the spanning tree will converge at t Hello Time half the time of the original network a Note The Forward Delay time is used a second time to allow the bridge to learn station locations before allowing the bridge to forward frames When the spanning tree is configured for manual operation no spanning tree protocol needs to converge but the station locations still must be learned For manual operation a different timer is used only for setting the Learn Only Period This timer is used by the bridge to set the time it will learn only after the bridge has booted Bridgi
133. s screen There are separate counts for the number discarded on incoming and outgoing directions for each bridge link Check Detailed Figure 42 shows the detailed statistics screen that includes counts of the number of Bridge Link Stats NetBIOS broadcasts filtered on the link Node Address Date Time Detailed Bridge Link Statistics Bridge Link 01 Page 2 of 2 Filter Discards In Out RIF Error Discards Source MAC Address 0 0 Segment Mismatch 0 Dest MAC Address 0 0 Duplicate Segment 0 Protocol Filtered 0 0 NETBIOS Filtered 46 0 Hop Count Exceeded 0 Total Filter Discards 46 0 Press any key to continue ESC to exit Figure 42 Detailed Bridge Link Statistics For More Details Refer to the Detailed Bridge Link Statistics section on page 127 84 Bridging Bridge Filtering NetBIOS Packet Formats Introduction NetBIOS Name Filtering operates only on the Microsoft or IBM compatible NetBIOS implementations which represents the majority of NetBIOS implementations It does not recognize at this time Novell s implementation of NetBIOS over IPX nor does it recognize the packet format of NetBIOS over TCP RFC 1000 NetBIOS Name Filtering operates on Ethernet LANs IBM NetBIOS IBM NetBIOS formats are documented in the IBM publication LAN Technical Formats Report for IEEE 802 2 and NetBIOS Interfaces SC 303587 When to Use Configure NetBIOS Name Filtering when NetBIOS Name All of the
134. s used to e Reduce unnecessary traffic affecting the performance of LAN segments Filtering broadcasts can help to reduce this overhead e Control the unnecessary proliferation of application level broadcasting used on Novell and NetBIOS applications e Restrict access to certain LAN segments for security reasons e Prevent unnecessary traffic from proliferating onto the WAN where bandwidth is limited This can help to reduce congestion and minimize delay for traffic that must cross the WAN e Prevent stations using a certain protocol from operating outside their intended scope Protocol formats that are filtered include DSAP and SNAP You can filter the MAC address contained in a frame or a protocol The system applies MAC address filtering first and then follows with protocol filtering if appropriate MAC Address filtering can be performed on either the source address or destination address 57 Release 5 2M Bridge Filtering MAC Address Filtering What Is It MAC Address Filter Table Parameters 58 This feature lets you filter bridge traffic based on MAC address The Bridge Link Table and the MAC Address Filter Table are used to configure MAC Address filtering The Bridge Link Table specifies e Whether or not any filtering action is to be performed e The filtering action to perform when the MAC frame address is not found in the MAC Address Filter Table The Bridge Link Table contains these parameters incl
135. sascictavsaartharecacaapeialag rand tenciaisaninestunasnes 105 LEC Local TOMOA A A AO 108 Confieurne Local Teri ain esnan ana a a cares 114 Deletine ET Contisisation Recotds as ccssiccasesrsteiemeuniaaneusicbiondielenintas 121 Ded ANC eraLO ainsi enivnat dent vanivuaavaiacreadnnaesaaiienid en nciaan mawsinnaeupuarenar 122 PELAN EENS eaa Connersnc ener ratetr Frente erent frre 125 LAN Serer SUNS MIN eoi sce casas east nes can anes O carci vaean banca N 128 Coniencine the LSS Rcd onirici alate 130 Bridging 3 T0008 16F Release 5 2M In This Notice Topic See Page continued Palee on fol fs gree erate cee ee Pere re eco ne rec ene rime te tree creas ter Carer rer ety meron errr 132 Spanmine Tres SCANS HOS estaas RAT A RA manag 133 Detaled Bridge Link SUSU sicnenninencienscteuitatnaineneinauee 135 Bridge Link Filter Sanya c vss ascxsasventdansbacasrneseuaur bene cde bens nE 138 Transparent Bridge Forwarding Table Statistics 00 eee eeeeeeseeeneeeees 140 Transparent Bridge Detailed Bridge Link Statistics 10 0 0 ee eeeeeeeeeeeeeee 142 LAN Onre ction SBU opani A AE 144 LLC2 LT Session Summary Stats UCS seiersrus siidine ieri eaareniveases 149 LECZ LY Detaled Session SPMSUCS secssconiecccscactes eteinneicledenlanns 151 Rosero e a A A A 155 4 Bridging Bridging Features and Capabilities Bridging Features and Capabilities Introduction Bridging Primer Token Ring Bridging T0008 16F This section describes bridging f
136. scards Segment Mismatch 0 Duplicate Segment 0 0 0 0 Hop Count Exceeded 0 0 oooo Press any key to continue ESC to exit Figure 63 Detailed Bridge Link Statistics TB Second Page This table describes the attributes for page 2 of the Detailed Bridge Link Statistics screen shown in Figure 63 Term Description STPE State Learning The STPE frames are blocked Learning the topology from STPE PDUs Bridging Bridging T0008 16F Bridge Statistics Term Description continued TB Frame Summary Frames Received Transmitted e Unicast This is a count of frames received transmitted with an individual non group MAC level address e Multicast This is a count of the number of frames received transmitted with a group MAC level address Broadcast This is a count of the number of frames received transmitted with the broadcast MAC level address FF FF FF FF FF FF e Frame Totals This is a count of the number of frames received transmitted of all types on this link TB Frames Discarded e Inbound This counter indicates the number of received frames that are discarded due to the bridge link being in a non forwarding state due to spanning tree configuration e Outbound This counter indicates the number of transmitted frames that are discarded due to the bridge link being in a non forwarding state due to spanning tree configuration TB Filter Discard
137. session Activating NetBIOS Name Filtering does not affect NetBIOS sessions already in progress 17 Release 5 2M Bridge Filtering Configuring NetBIOS Name Filtering Introduction This section describes how to use the Control Terminal Port CTP to configure NetBIOS Name Filtering How to Configure Follow these steps NetBIOS Name Filtering Step Action 1 Configure the NetBIOS Name Filter Action parameter in the Bridge Link Parameters 2 Configure the parameters in the NetBIOS Name Filter Table record Bridge Link Figure 40 highlights the parameter NetBIOS Name Filter Action in the Bridge Link Parameters Record Parameters record Address Date Time Path Node Menu Configure Bridge Bridge Parameters Bridge Link Parameters Entry Number Hop Count Limit Largest Frame Size MAC Address Filter Action Protocol Filter Action NetBIOS Name Filter Action STPE Link State Figure 40 Bridge Link Parameters Record 78 Bridging Bridge Filtering Configuring NetBIOS Name Filtering To access the NetBIOS Name Filter Action parameter follow the steps below Step Action Result 1 Select Configure gt Configure Bridge gt Bridge Link Parameters from the CTP Main menu Entry Number 1 appears m Note The table has one entry for each logical bridge link in the bridge node Bridge Link Entry 1 is reserved
138. smission time is likely An error on a large frame with its subsequent retransmission means the media are used with unproductive transmissions and reduced efficiency In general these industry standards can be used as a guideline for selecting the maximum frame size Max Frame Size Line Speed Range kbps 512 9 6 to 38 4 1500 38 4 to 56 2052 56 to 1544 4472 1544 The transit time for bridged traffic within a PathBuilder S200 series switch is fixed to an upper bound of approximately one second If the time is exceeded the frame is discarded This avoids extra traffic being sent especially due to LLC2 recovery procedures Duplicate frames will frustrate normal recovery procedures and cause extra traffic to be generated When a frame is discarded in this manner the port statistic in the Detailed Port Stat screen displays Frames Discarded Congestion Bridging Configuring the PathBuilder S200 Series Switch for Bridging Operation Configuring Translational Bridging Introduction What is Translational Bridging Parameter Configuration Guidelines Configuration Examples Bridging T0008 16F This section explains how to configure your PathBuilder S24x 26x and 27x switch to implement the Translational Bridging feature Translational Bridging allows a PathBuilder S24x 26x and 27x switch to bridge traffic between Ethernet and Token Ring networks Upon receiving traffic from o
139. ss equal to the server s MAC Address Since the server is not on the local ring no station responds to the server s destination MAC Address Figure 22 This TEST frame does not have the Routing Information Indicator bit RID set the high order bit in the Source MAC Address and as a result it does not build a Routing Information Field RIF to trace the path to the destination 42 Bridging Configuring the PathBuilder S200 Series Switch for Bridging Operation Figure 22 Server s Destination MAC Address Not on LAN AAA 3 After receiving no response on the local LAN the PC uses Source Route Bridging SRB to find the path to the remote server The PC can resend the TEST frame indicating that the frame is to be bridged over all routes The PC resends an All Route Explorer ARE TEST frame via its SRB software Figure 23 PC LAN AAA Figure 23 All Route Explorer ARE Frame Searches the Network for the Server PB S200 ARE Frame 4 The TEST frame includes the following e Destination Address is server s MAC Address e Routing Information Indicator bit RID is set to one This bit is the most significant bit in the source address indicating this frame has a Routing Information Field RIF e Three bits in the Routing Information Field RIF indicate this is an ARE This instructs all bridges that encounter this frame to forward the frame to their dest
140. stics Reset Bridge 147 samples 141 143 Statistics menu LAN Connection Summary Statistics 140 Supported topologies guidelines 102 T technical support 3Com URL A 1 Index 3 bulletin board service A 2 fax service A 2 network suppliers A 2 product repair A 4 TEST frame 42 description 43 RII bit 42 Specific Route type 46 Token Ring Configuration Bridge parameters 22 MAC Address Filter Table 66 Token Ring Port Record 22 Topology Change Notification BPDU 87 TR Bridge parameters Autocall Mnemonic 33 Bad Hello Threshold 23 Bad Hello Timeout 23 Billing Records 34 Entry Number Bridge link 27 Entry Number LAN Connection Table 31 Entry Number MAC Address Filter Table 67 Entry Number Protocol Filter Table 71 Incoming Destination Address Link Action 68 Incoming Source Address Link Action 67 MAC Address 67 MAC Address Filter Action 28 Outgoing Destination Address Link Action 69 Outgoing Source Address Link Action 68 Protocol Filter Action 29 STPE Control 23 TR Records and Parameters 21 Traffic Priority described 105 Translational Bridging 2 37 configuration example 37 38 configuration guidelines 37 Transparent 2 Transparent bridge aging 52 filters 54 learning 48 Multicast Protect flag 55 Unicast Link Protect flag 54 Transparent Bridge TB Forwarding Table Menu 56 Transparent bridge forwarder 48 Transparent Bridge Forwarding Table Statistics 132 U Unicast Link Protect Flag 54 URL A 1 Index 4 V Vine
141. t Bridging T0008 16F This section describes bridge hardware configuration and connections for the PathBuilder S200 series switch Figure 12 shows the physical connections of the modules that provide bridging functionality for PathBuilder S200 series switch This figure shows a LAN port module and supporting WAN Adapter module within a PathBuilder S200 series switch The LAN port module is broken out into a driver and a forwarder to show the concept of bridge links At each end node the bridge has connections referred to as bridge links Bridge links that connect to the LAN are referred to as LAN bridge links Bridge links that connect to remote bridges across the WAN are referred to as WAN bridge links LAN Link Numbers range from 1 to Up to 32 WAN links can be defined 4 up to two LAN connections are numbered 5 to 36 one for each supported for Ethernet bridge connection over an SVC PVC for Frame Relay LAN Port Module f X 25 SVCs connected to Driver Bridge SVCs on network ports Forwarder PVCs for Frame Relay Figure 12 LAN Port Module and WAN Adapter Module Logical View The LAN port consists of low level drivers and the bridge forwarder This can be viewed as the functioning bridge The WAN Adapter is closely associated with the bridge The WAN Adapter provides the network services that the bridge requires in order to function over the WAN network The principal service is establishing an
142. t 8 Description Specifies the number of times an I frame or supervisory frame with poll bit set to 1 is transmitted due to T1 acknowledgment timeout before the logical link is declared down inoperative Boot Type Tables and Node Record 111 Release 5 2M LLC2 Local Termination 112 N3 ACK Delay Count Range 1 to 15 Default 3 Description The Receive Count is used with T2 to reduce the number of acknowledgments a station generates The receive count is used by a station to determine how many frames it receives from the remote station while withholding acknowledgment of these frames This reduces the number of acknowledgments generated by a link station When this counter expires the link station immediately sends an acknowledgment for all received frames not yet acknowledged Boot Type Tables and Node Record Tx Window Size Range 1 to 15 Default 7 Description Specifies the maximum number of I frames a station may transmit without acknowledgment Boot Type Tables and Node Record Bridging LLC2 Local Termination Deleting LT Configuration Records Overview You can delete the following LLC2 LT configuration records if you no longer use them LT Station Table LT Profile Table Before You Begin Choose List Bridge from the CTP Main menu to obtain a list of the configured LT session records Procedure This procedure describes how to d
143. t Bridge Forwarding Table Statistics TB Forwarding TB Forwarding Table statistics are shown in Figure 62 Stats Example Node Address Date Time TB Forwarding Table Stats Page 1 of 1 Learned Entry Discards 0 Learned Entries 0 Available Entries 7997 Maximum Entries 3 Aging Timer 3600 Forwarding Database MAC Address Bridge Link Number Status 03 00 FF FF FF FF Other 08 00 3E 00 1B 96 Other FF FF FF FF FF FF Other Press any key to continue ESC to exit Figure 62 Transparent Bridge Forwarding Table Statistics TB Forwarding This table describes Transparent Bridging Forwarding Table Statistics attributes Stats Descriptions shown in Figure 62 Term Description Learned Entry The number of Learned Address List entries that have been Discards discarded due to lack of room in the forwarding database the database size had been at its maximum allowed when the entry was learned Learned Entries The total number of entries currently in the forwarding database learned station table The maximum number of entries is 8000 Available Entries The amount of space in entries that the forwarding database currently has available for additional entries Maximum Entries The amount of space in entries that the forwarding database has available for entries since the last node boot 132 Bridging Bridging T0008 16F Bridge Statistics Term continued Description
144. t pass the frame Links not in this list block the frame An empty list means all links will block e BLOCKLIST If this value is used a block list is specified by the List of Links parameter Links in this list block the frame Links not in this list pass the frame An empty list means all links will pass Outgoing Protocol Link Action Range PASS BLOCK PASSLIST BLOCKLIST Default PASS Description Specifies the action to be taken on the outgoing protocol These actions include PASS BLOCK PASSLIST or BLOCKLIST e PASS If this value is used outgoing frames with the specified protocol value are passed on all links All other protocols are blocked on outgoing links If this value is chosen skip the following parameter List of Links e BLOCK If this value is used outgoing frames with the specified protocol value are blocked on all links All other protocols are passed on outgoing links If this value is chosen skip the following parameter List of Links e PASSLIST Pass list If this value is used a pass filtering list is specified by the following parameter List of links Links in this list pass the frame Links not in this list block the frame e BLOCKLIST Block list If this value is used a block filtering list is specified by the following parameter List of Links Links in this list block the frame Links not in this list pass the frame An empty list means all links will pass T3 Rel
145. t the appropriate number to view a particular screen Node Address Time Menu Lan Connection Statistics Path Main 5 9 LAN Connection Stats LAN Connection Summary Stats Reset LAN Connection Stats Figure 64 LAN Connection Statistics Menu Screen Figures 65 and 66 show the Detailed LAN Connection Statistics Node Address Date Time Detailed LAN Connection Statistics LCON 5 Page 1 of 2 Last Statistics Reset Date Time Transmit Data Summary Number of Packets Transmitted 0 Average Transmit Packet Size 0 Current Transmit Queue Depth 0 Maximum Transmit Queue Depth 0 at Date Time Receive Data Summary Number of Packets Received 0 Average Receive Packet Size 0 Discard Summary Transmit Packets Discarded Due to Max Frame Size Exceeded 0 Transmit Packets Discarded Due to Node Transit Delay 0 Transmit Packets Discarded Due to Congestion 0 Press any key to continue ESC to exit Figure 65 Detailed LAN Connection Statistics First Page Bridging Bridge Statistics Node Address Date Time Detailed LAN Connection Statistics LCON 5 Page 2 of 2 Call Summary Connection Type svc Connection State Improper Config Forwarders Connected Remote Address Number of auto call attempts 0 Last clear cause code 0 Cleared by other end Last clear diagnostic code 0 No more information Packet Summary Transmit Receive Data 0 0 Call Request 0 0 Call Acc
146. tBIOS names are passed on all links e PASSLIST Passes all outgoing frames on the links that you listed in the List of Links parameter Blocks all the outgoing frames on the links that are not listed An empty list means that all links block the frames e BLOCKLIST Blocks all outgoing frames on the links that you listed in the List of Links parameter Passes all the outgoing frames on the links that are not listed An empty list means that all links pass the frames m Note If you chose PASS or BLOCK skip the List of Links parameter Outgoing NetBIOS Name List of LInks Range 1 5 to 36 Default The individual numbers correspond to the links that you filter according to the preceding parameter Description The following describes the options that you can define for the link e PASSLIST Passes all outgoing frames on the links that are listed Blocks all the outgoing frames on the links that are not listed An empty list means that all links block the frames e BLOCKLIST Blocks all outgoing frames on the listed links Passes all the outgoing frames on the links that are not listed An empty list means that all links pass the frames Bridging T0008 16F 83 Release 5 2M Bridge Filtering NetBIOS Name Filtering Statistics Introduction For each bridge link you can display the number of packets discarded due to matching a NetBIOS name filter on a bridge filter statistic
147. tain links e Whether the frame is a multicast or broadcast frame and if it is to which links the frame should be sent out The Forwarder attempts to send the multicast or broadcast frame over to all links which are in forwarding state except the link where the frame arrived Before sending the frame out to each link the Forwarder checks with the filtering facility to see if filters are to be applied to the frame at that link If not the Forwarder sends the frame over to the link A multicast Broadcast frame is a frame with the Least Significant Bit of its destination address being set to 1 e Whether the received non multicast and non broadcast frame should be dropped without sending it out The Forwarder drops the frame due to filtering when the link is unconfigured or the link is not in forwarding state Two types of forwarding database entries that are kept in running memory are e Learned dynamic e Permanent static The learned entries of the forwarding database are obtained from the source address of frames that are received by the bridge entity This relies on the end stations sending frames so that the bridge learns the station location from the source address contained in the frame The permanent entries are obtained from a CMEM record that is configurable by the system administrator They are loaded into the database whenever the node or the table is booted The permanent entries are maintained by the system administrator
148. tch Bridge Combining Traffic from Serial Devices Figure 1 shows PathBuilder S200 series switches acting as remote bridges to combine data traffic from Ethernet LANs to the WAN to connect to other remote LANs in the network Mixed LAN Support PathBuilder S200 series switches support mixed LAN bridging meaning you can Translational Bridging No Local Bridging Transparent Bridging Supported Traffic configure an Ethernet interface in the same node Refer to the Mixed LAN Bridging section on page 8 for more details PathBuilder S200 series switches can use the Translational Bridging feature to bridge traffic between Ethernet Networks Translational Bridging provides a PathBuilder S200 series switch with the capability to bridge non routable protocols For information about enabling and configuring Translational Bridging refer to the Configuring Translational Bridging section on page 37 As mentioned earlier PathBuilder S200 series switches are not intended for use in local bridging applications where one LAN is connected directly to another LAN It is not recommended you use PathBuilder S200 series switches to perform local bridging Transparent Bridging TB is the method used by PathBuilder S200 series switches to bridge Ethernet LAN traffic from one Ethernet LAN to another one across a WAN Refer to Transparent Bridging for Ethernet LANs on page 48 for more details on these bridging operations The
149. ted Topologies Improper LT Configuration 102 Local Termination is supported only on Token Ring topologies configured for Source Route Bridging And there are two important guidelines to remember when you are planning your Local Termination strategy e When you turn on Local Termination in your network the MAC address SAP value you assign is always locally terminated e You must have a PathBuilder S200 series switch running Local Termination positioned at both ends of your network to provide spoofing from one edge point to another For example Figure 51 shows a Token Ring network improperly configured for Local Termination Figure 51 Example of Improper LT Configuration The cluster controller CC using non PathBuilder S200 series switch bridge 3 in Figure 51 is source route bridged to the FEP The local PathBuilder S200 series switch bridge 1 at the FEP use location tries to locally terminate the session since all frames bearing the MAC address of the FEP are to be spoofed However the non PathBuilder S200 series switch bridged cluster controller will never come up unless Local Termination is disabled entirely The cluster controller on PathBuilder S200 series switch bridge 2 will come up because it runs Local Termination PathBuilder S200 series switch bridge 2 is unable to spoof traffic unless it originates from its own Token Ring For spoofing to work you must use PathBuilder S200 series switches with Lo
150. thBuilder S200 Series Switch for Bridging Operation m Note If STPE Control parameter value is AUTO this parameter appears Bridged Protocols Range None IP IPX Default None Description Specify the routable protocols that can be bridged across BROUT or BRID links None specifies no routable protocols IP IPX will be bridged IP specifies that IP packets can be bridged IPX specifies that IPX packets can be bridged m Note Any combination of the available selections may be specified by summing such as IP IPX Bridging 25 T0008 16F Release 5 2M Configuring the PathBuilder S200 Series Switch for Bridging Operation Bridge Link Parameters Introduction The bridge uses Bridge Links as connections to the LAN and WAN networks The LAN Bridge Link connects the bridge directly to the local LAN and its parameters control the characteristics of this connection The WAN Bridge Link parameters let you establish and maintain SVC connections to a remote LAN bridge The bridge views the LAN bridge links and the WAN bridge links as links to the networks attached to it Bridge Link Figure 15 shows the Bridge Link parameters Parameters Node Address Menu Configure Bridge Bridge Parameters Bridge Link Parameters Entry Number Bridge Type Bridge ID Hop Count Limit Largest Frame Size MAC Address Filter Action Protocol Filter Act
151. that the link is directly attached to the root bridge is coincidental in this example The path cost to the root bridge has an influence on the spanning tree topology The bridge link parameter called STPE Path Cost is the parameter that sets the incremental path cost to the root should that bridge link be followed to the root bridge In general the speed of the bridge link is the most important factor that determines the path cost increment Bridging Spanning Tree Protocol Entity STPE Determining Path Bridges use Path Cost to determine their Root Link The range of Path Cost is 0 to Costs 65535 The lower the path cost the more likely this path will be used Use This table to determine the path costs for each type of link in your network Type of Network Speed STPE Path Cost 802 3 10 Mbps 10 802 5 4 Mbps 25 802 5 16 Mbps 6 serial 1 54 Mbps 65 serial 384 kbps 260 serial 56 kbps 1768 serial 19 2 kbps 3536 For speeds not listed interpolate to reasonable values The valid range for path cost is 0 to 65535 so that when values are determined they should not be such that the total path cost along any reasonable route adds up to more than 65535 Some bridge manufacturers may list a different set of values for path cost increment It is important that the same rule be applied to all bridges involved in the spanning tree calculation Returning to the mesh network in Figure 43 look at bridge B3
152. the statistics does not clear the last call information from the detailed port statistics screen This information is cleared only on a node boot Transmit Data Summary This field provides information on the transmission of packets and those awaiting transmission to the WAN Totals are provided for the number of packets transmitted the average transmitted packet size in bytes and the current and maximum transmit queue depths in packets Receive Data Summary This field provides information on the number of packets received and the average size of the packets received from the WAN Totals are provided for the number of packets received and the average received packet size in bytes Discard Summary This field provides the following totals for packets discarded due to the following reasons Transmit Packets Discarded Due to Max Frame Size Exceeded Transmit Packets Discarded Due to Node Transit Delay e Transmit Packet Discarded Due to Congestion data was buffered more than 1 second Release 5 2M Bridge Statistics Example of LAN Connection Summary Statistics Node LAN Connection Summary Status Figure 67 shows the LAN Connection Summary Statistics Address Date LAN Bridge Conn Remote Connection Link Type Destination 1 Waiting 5 Configured svc Press any key to continue ESC to exit Page 1 of 1 Figure 67 LAN Connection Summary Statistics Descripti
153. the PathBuilder S200 Series Switch for Bridging Operation PB S200 WAN Adaptor PC J WAN Bridge Link Server plat PB S200 B WAN ri T WAN o 6 Adaptor N m o Adaptor l A Ai J LAN Bridge Link PB S200 WAN Adaptor Figure 25 WAN Adapter Transmits Each ARE Frame Across the WAN 7 One ofthe ARE frames finds the destination server and the server recognizes the MAC address in the TEST frame Bridging 45 T0008 16F Release 5 2M Configuring the PathBuilder S200 Series Switch for Bridging Operation 8 The server issues a Specific Route TEST frame also called a non broadcast frame in response using the route indicated in the ARE TEST frame Note that the server does not have to broadcast use ARE to get the TEST response back to the PC it uses a Specifically Routed TEST frame Figure 26 Server PB S200 PB S200 a Bridge Bridge WAN WAN Adaptor Adaptor Figure 26 Server Responds with Specifically Routed TEST Frame 9 The response TEST frame also has a Routing Information Field RIF with the same path trace as the original ARE TEST frame except the Direction bit is set to 1 This reverses the direction in which the RIF sequence is read and indicates the
154. the bridge e Decrement the aging timer bit when it receives periodic timeout notification from the Forwarder e Remove all the aged out entries from the Hardware Accelerator database The statistics which show the number of local traffic frames discarded by the Hardware Accelerator are displayed on the LAN port Statistic CTP menu 50 Bridging Forwarder Functions Forwarder Initialization Bridging T0008 16F Transparent Bridging for Ethernet LANs The Forwarder bridging logic includes decisions such as e Which Link s the frame should be sent to If the destination address of the frame exists in the Forwarding Table and there is a link number associated with it then the Forwarder checks whether filters should be applied to the frame and cause the frame to be dropped If all these conditions are satisfied and no filters apply the Frame is sent over to the link via the Handler e Whether the frame should be broadcast to all ports even though the frame is not a multicast or broadcast frame If the destination address of the frame did not exist in the Forwarding Table such as when this is the first time the bridge learns the source address of the frame the Forwarder attempts to send the frame out over all links which are in Forwarding state except the link where the frame arrived Before the Forwarder sends the frame out it also checks whether filters are to be applied to this frame The frame may get filtered at cer
155. ting you spoof remote sessions without configuring a MAC address and a Service Access Point SAP for each station running a session to the host Front End Processor FEP Since Local Termination supports up to 256 sessions for the PathBuilder S24x 26x and 27x switch Local Termination Autolearn can save you considerable time during the configuration process Local Termination Autolearn is a default feature with PathBuilder S200 series switches operating software meaning it requires no special configuration other than configuring the remote host MAC address in the PathBuilder S200 series switch Local Termination LT Station tables It does not interfere with previously configured Local Termination spoofing sessions Figure 8 shows how a PathBuilder S200 series switch automatically learns the address of PCs connected to the local bridge so you can pass data traffic to the host without configuring entries in the Local Termination Station table for each PC session The PC s destination MAC address must match the MAC address configured in the remote Host FEP for local PB S200 to automatically learn LAN MAC addresses ye ae Destination MAC addresses set up 40 00 00 00 10 88 Bridging T0008 16F Configure the Host FEP MAC address and SAP in the LT station tables of the local and remote bridges PB S200 automatically learn
156. to the Permanent Station Address List Setting or Clearing of Unicast Link Protect Flag is performed via the LAN Control menu located in the Main menu Bridging Multicast Link Protect Flag Bridging T0008 16F Transparent Bridging for Ethernet LANs When a multicast broadcast frame comes from a link with the Multicast Protect Flag set and if its source address is not found in the Permanent Station Address list the frame is dropped When a multicast broadcast frame is sent out over a link with the Multicast Protect Flag set and if its destination address is not found in the Permanent Station Address List the frame is dropped Once the Multicast Protect Flag is set for a link source address learning for multicast broadcast frames is stopped for that link totally and all the addresses that were learned before are moved into the Permanent Station Address List Setting or Clearing of Multicast Link Protect Flag is performed using the LAN Control menu located in the Main menu 53 Release 5 2M Transparent Bridging for Ethernet LANs Transparent Bridge Configuration Parameters TB Forwarding Figure 29 shows the Transparent Bridge Forwarding Table parameters Table Node Address Date Time Menu Configure Bridge Path Bridge Parameters Bridge Link Parameters MAC Address Filter Table Protocol Filter Table NETBIOS Name LSS Parameters TB Forwarding Table Entry Number Local MAC Addres
157. ts Token Ring 1 and Token Ring 3 e Bridge 3 interconnects Token Ring 2 and Token Ring 3 Bridging 15 T0008 16F Release 5 2M Basic Remote Bridging Examples A Less Complex Extended Bridge Figure 11 shows a possible arrangement of SVCs PVCs for Frame Relay that produces the same bridge arrangement as shown in Figure 10 Node 1 Node 2 Bridge 1 Bridge 1 Bridge 2 Bridge 2 Node 3 Bridge 3 SVC Connectors Bridge 3 Figure 11 Example of Bridges in an SVC Arrangement Token Ring 2 In this arrangement all LAN segments are one hop away from each other since they are directly attached by a single pair of bridges In Figure 11 Token Ring 1 is one bridge away from Token Ring 2 and Token Ring 3 and the same applies for the other rings From a bridged network point of view Token Ring 1 is one bridge away from Token Ring 3 but Node 1 is not directly connected to Node 3 Traffic between Token Ring 1 and Token Ring 3 does not have to pass through Token Ring 2 This is an important advantage in configuring bridge networks with the PathBuilder S200 series switch because you can form a minimal bridge network to accomplish the desired interconnectivity Bridging Bridge Hardware Components in PathBuilder S200 Series Switches Bridge Hardware Components in PathBuilder S200 Series Switches Introduction Bridge Configuration and Connections LAN Interface Suppor
158. ts to information frames and certain supervisory frames are handled locally by the spoofer The spoofer the LT software in a PathBuilder S200 series switch ensures the acknowledged information frames are reliably delivered to the destination peer spoofer and that any flow control issues are handled appropriately Because of local acknowledgment spoofing of LLC frames may enhance network performance and allows for reliable Token Ring to Token Ring connectivity This table describes the types of frames Local Termination spoofs Local Termination spoofs All Specifically Routed LLC frames such as I frames and Supervisory frames Local Termination does not spoof e Route Explorer frames such as ARE or STE e Internally matched frames coming in from the LAN port e Frames generated by LSS LLC in the bridge going out to the LAN port e WAN to WAN frames Maximum Sessions The maximum number of sessions you can spoof at one time is 64 If you reach the Spoofed What Happens between Spoofers Intermediate Frames between Spoofers maximum number of sessions Local Termination does not establish additional spoofing sessions nor does it source route bridge the additional sessions Local Termination runs a subset of LLC2 protocol between spoofers to ensure that frame traffic reliably passes from one edge point node to another edge point node in your network The subset protocol uses separate timers and retry counts
159. uding the MAC Address Filtering Action parameter which lets you specify the filtering actions to be applied at the bridge link These parameters are located under the Configure Bridge Link menu selection e Entry Number e Bridge ID e Hop Count Limit e Largest Frame Size e MAC Address Filter Action e Protocol Filter Action e STPE Link State e STPE Priority e STPE Path Cost The MAC Address Filter Table specifies e The MAC Address of the frame to be filtered e The filtering action to perform on the frame This table is used in conjunction with the Bridge Link Table to specify filtering action and includes the link action parameters which allow you to apply filtering action to every link This table describes the MAC Address Filter Table parameters Parameter Action MAC Address Frames that have MAC Addresses matching this MAC Address are filtered as specified by the parameters in this table Incoming Source Perform filtering action on an inbound frame having the Address Link Action indicated MAC Source address Outgoing Source Perform filtering action on an outbound frame having the Address Link Action indicated MAC Source address Incoming Perform filtering action on an inbound frame for the Destination Address indicated MAC Destination address Link Action Bridging MAC Address Filtering Action Parameter Selections What Happens During Filtering Bridging T0008 16F B
160. use forwarded packets to be exponentially duplicated and disable the network Once the topology has stabilized the bridge should not forward packets immediately since initially it will not have learned station locations and will have to broadcast packets when it does not find the entry in its local station cache Once the bridge has built up its cache by listening for a short period of time it can forward packets directly rather than using high overhead broadcasts The Forward Delay is used twice once to allow the topology to stabilize and during this time to process only spanning tree protocol messages and then again to allow the bridge to learn station locations during which time data packets are received but not forwarded To understand how long it takes to converge a spanning tree consider the following simplified network shown in Figure 47 together with the message events shown as a timed sequence below the network Bridge IDs Link Numbers t 0 01 3536 gt lt 02 25 02 3536 gt lt 03 3536 03 25 gt 04 3536 y t Hello Time 01 3536 gt 02 25 02 3536 01 3561 gt t 2x Hello I ime 01 3536 gt 01 3561 gt 01 7097 gt Figure 47 Message Events in Network Bridging 97 T0008 16F Release 5 2M Spanning Tree Protocol Entity STPE 98 Suppose all bridges come up at the same time Initially at t 0 all bridges think they are the root and they issue the messages show
161. ved or transmitted by the local spoofer from the local device Frames received out of sequence Information frames received out of sequence from the local device Bad frames received Bad frames received from the local device These frames are improper for various reasons Frames dropped Frames from the local device dropped due to congestion due to WAN queue full 145 Release 5 2M Bridge Statistics 146 Heading Description continued Remote Spoofer Session Summary TX Window Transmit window size obtained from the configuration for LLC WAN parameters Protocol State Number of the state for current session with remote spoofer Info Number of information frames received or transmitted by the local spoofer to or from the remote spoofer RR Number of RR frames received or transmitted by the local spoofer to or from the remote spoofer RNR Number of RNR frames received or transmitted by the local spoofer to or from the remote spoofer REJ Number of REJ frames received or transmitted by the local spoofer from or to the remote spoofer SABME Number of SABME frames received or transmitted by the local spoofer from or to the remote spoofer UA Number of Unnumbered Acknowledgment UA frames received or transmitted by the local spoofer to or from the remote spoofer UI Number of Unnumbered Information UT frames received by th
162. verview Example of Frame Sizes Bridging T0008 16F Although there are valid reasons for using larger frame sizes on bridges there are limiting factors that must be considered when selecting a maximum frame size There are several reasons for limiting the maximum size of the frame especially where bridging is done remotely across a WAN e The larger the frame the longer it takes to transmit the frame on a WAN link e Increasing the frame size also causes a reduction in frame overhead Conversely the smaller the frame the less time it takes to transmit the frame Since a smaller frame cannot be forwarded by an intermediary node until it is fully received a large frame cannot be forwarded for the time it takes to transmit and receive it over a given link On a LAN this time is less of an issue where the link speed is approximately 10 Mbps On a WAN link it becomes an issue because the transmission times for large frames become significant Figure 17 shows the effect on transit delay across a network for two cases in one an end system sends a large packet as a single frame and in the other the same large packet is sent as three smaller packets End End System Node 1 Node 2 Node 3 System A B Large Packet Total Transit Time End End System Node 1 Node 2 Node 3 System A B Small Packet e ee Total Transit Laa I Time Figure 17 How Packet Size Affects Transit Delay Small
163. when the entry ages out and is replaced with a new entry that indicates new forwarding information Aging does not apply to the permanent entries in the forwarding table These entries are maintained by the system administrator and kept in CMEM They are never aged out of the forwarding database and they are never corrected If a frame arrives on an unexpected link with a source address in the permanent part of the forwarding table the table is not changed Bridging Transparent Bridging for Ethernet LANs Forwarder Database and Spanning Tree How They Work Together Deleting Forwarding Table Entries Bridging T0008 16F There is a close relationship between the forwarding database and the spanning tree The spanning tree can be manually configured This is a reasonable thing to do in the case where a stable environment exists since it saves CPU processing by eliminating aging timers and the broadcasting that is employed when the forwarding table does not have a suitable entry In this case when the node is booted bridges will form a spanning tree always the same one provided all equipment remains operational and a permanent forwarding database can be loaded from CMEM that is required for the configuration This also allows a quick method for the bridge to become operational The learning process continues even if the forwarding table is formed initially from permanent CMEM entries That is the forwarding database adds learne
164. xed LAN operation supports IP and IPX routing of traffic with no additional configuration needed Bridging Dual LAN Ethernet Dual LAN Ethernet What Is It Sample Application Limitations Bridging Bridging T0008 16F The Dual LAN Ethernet feature lets your PathBuilder S24x 26x and 27x switch support up to two Ethernet LAN interfaces to perform bridging and routing of LAN traffic across multiple LANs Before Multiple Ethernet LAN the PathBuilder 24x 26x and 27x switch supported only one Ethernet LAN port for remote bridging and routing of LAN traffic However with the Multiple Ethernet LAN feature you can bridge and route LAN traffic locally and remotely using up to two LAN ports on each PathBuilder 24x 26x and 27x switch as shown in Figure 55 Note It is recommended that you configure the first LAN card in your device as Bridge Link Number 1 or Router Interface Number 1 Failure to do so may cause your device to perform continuous resets when you power up the device after reinstalling an earlier release of operating software Figure 55 shows a sample application for the Multiple Ethernet LAN feature Ethernet 1 Ethernet 1 PB S200 Ethernet 2 Ethernet 2 Figure 55 Example of Multiple Ethernet LAN The PathBuilder S24x 26x and 27x switch supports only two Ethernet LAN ports at one time If you configure more than two Ethernet ports on a
165. y how NetBIOS Name Filter is used on this node e PASS Pass all frames with NETBIOS name not listed in NETBIOS Name Filter Table BLOCK Block all frames with NETBIOS name not listed in NETBIOS Name Filter Table e NONE No NETBIOS name filtering to be performed for this link STPE Link State Range FORWARD BLOCK Default FORWARD Description Specify whether to forward or block data frames when the STPE Control parameter is configured to MAN Bridging T0008 16F 29 Release 5 2M Configuring the PathBuilder S200 Series Switch for Bridging Operation Link Mode Range NORMAL RFC1294 TRANS Default NORMAL Description Specify one of the following e NORMAL Bridge link connects to another Bridge using the Link Control Protocol to determine remote Ring Number This option is not supported for PVC connections Use another option for PVC connections e RFC1294 Bridge link uses RFC1294 or RFC1490 bridging to connect to another Bridge or Frame Relay Access Device A Bridge Link Virtual Ring Number is required e TRANS Translational Bridging support for PathBuilder S24x 26x and 27x switch only Boot Type A change to this parameter requires a node boot to take effect m Note The following parameter appears if you set Link Mode to RFC1294 Virtual Ring Number Range 0001 OFFF hexadecimal Default 0000 Descri

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