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LinkBuilder® FDDI Workgroup Hub User Guide

1. Figure 3 2 Dual Attachment Hubs DACs in Wrap State 3 4 Configuring the Hub Single Attachment Hub A single attachment hub SAC is never attached directly to the dual trunk ring Instead it is attached to another hub which is connected to the main ring Figure 3 3 shows a single attachment hub connected to the network via a dual attachment hub The single attachment hub in this example is connected to three single attachment stations Primary ring j lt Rees Secondary ring aoe TSAS Ne DAC yf SAC SAS SAS SAS Figure 3 3 Single Attachment Hub SAC Configuring the Hub 3 5 Null Attachment Hub A null attachment hub NAC functions as a self contained FDDI network It is an FDDI backbone but is not connected to a dual ring backbone The network is concentrated in the hub and all of the attached devices communicate through it using FDDI Null attachment hubs do not support A B or S ports Figure 3 4 shows a null attachment hub with several connected devices SAC Figure 3 4 Null Attachment Hub NAC and Connected Stations SAS and DAS 3 6 Configuring the Hub Dual Homing Dual homing DH configuration provides two attac
2. Se eo S Figure 2 4 Media Module Keys Identified by Port Type 2 10 Installing the Hub Use of media module keys is optional They can be used to ensure that the correct cable is inserted into each fiber transceiver Once a key is in place you can only insert the cable connector specified by that key into the transceiver However if the cable connector is universally keyed it will fit into any transceiver regardless of its inserted key You should insert the keys into the transceivers before installing the fiber module Insert one key into the top of each transceiver as described below and shown in Figure 2 5 1 Determine the type of configuration that you want for the two attachment ports on the fiber module Refer to the sections Planning Connections later in this chapter and Port Connections in Chapter 3 for help in determining your hub connection plan 2 Choose the appropriate key A B M or S The key types are identified by letters on the top of the key 3 Insert the tabbed end of the key through the opening in the top of the transceiver receptacle and fit it in place Figure 2 5 Inserting a Type M Key into a Fiber Transceiver Installing the Hub 2 11 4 Push the back of the key down until it snaps into place The key sits flush with the top of the tran
3. later in this chapter for a discussion of downloading procedures The console command set provides for setting and displaying TCP IP related addresses To display these addresses enter the show ip command IP Address The IP address is a unique 32 bit identifier for a specific TCP IP host or other device Contact your network administrator for the IP addresses that you need a To set the IP address type set ip followed by the hub s IP address the netmask optional and the broadcast IP address optional For example type set ip 128 45 87 25 255 255 0 0 128 45 255 255 Enter Your input is echoed after you press Enter as shown below IP address 2 128 45 87 25 Netmask P2004 2004 0 0 Broadcast 2 128 45 255 255 m Ifyou type only set ip this usage message appears Usage set ip address netmask broadcast where address is the IP address for this hub netmask is the IP network mask optional broadcast is the IP broadcast address optional e g set ip 128 45 87 25 255 255 0 0 0 0 255 255 a Ifyou type set ip followed by only one IP address the netmask and broadcast address are automatically calculated as shown below set ip 128 45 87 25 IP address 2128 45 87 25 Netmask 25537255030 Broadcast 128 45 255 255 4 4 Setting Up the Hub La NOTE In this manual the address format used three digits in each octet is assumed to be decimal representation If you prefer hexadecimal representation th
4. To order call Computer Library at 800 827 7889 extension 515 Outside the U S call 212 503 4400 or use fax number 212 503 4487 Support from Your Network Supplier 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 hardware maintenance application training and support services U S and Canada Call the following number to locate your local 3Com sales office US 1 800 NET 3Com The 3Com sales office will refer you to the nearest 3Com authorized service partner Outside the U S and Canada To locate a 3Com authorized service partner near you contact your local 3Com sales office Australia 61 2 959 3020 Belgium Netherlands 31 25 032 2120 France 33 1 698 66800 Germany 49 89 678210 Hong Kong 852 868 9111 Italy 39 22 7302041 Japan 81 3 546 62233 D 4 Technical Support Nordic 46 8 703 4870 Singapore 65 321 8929 Taiwan 886 2 775 4352 U K 44 628 890 670 When you contact a 3Com authorized service partner for assistance have the following information ready a Diagnostic error messages a A list of system hardware and software including revision levels a Detail on recent configuration changes if applicable 3Com s service partner will determine what action needs to be taken to resolve the problem 3Com service partne
5. UTP PORT MODULE lt z z z s STP PORT MODULE S z ol GBD FIBER PORT MODULE ve o gt amao MANAGEMENT MODULE M LON LinkBuilder FDDI WORKGROUP HUB IO O O ka O Keal m O Peon O Figure 1 2 The LinkBuilder FDDI Workgroup Hub Site Selection The hub is housed in a 16 8 x 11 6 x 5 2 inch chassis that can be placed on a tabletop or easily mounted in an Electronics Industries Association EIA standard 19 inch rack You can mount more than one hub in a rack depending on your network needs Included with the chassis are four small rubber pads to be inserted on the bottom four corners for tabletop placement and two attachable brackets to be attached on two sides for rack mounting for your choice of placement When selecting a site for the hub remember that the hub can be connected to an external terminal for initial configuration In this case you will need room in front of the chassis to place and access the terminal Instead of attaching a terminal to the hub you can configure the hub over the network by using the TCP Telnet protocol You can also access the hub via a modem attached to the serial port Overview 1 9 Typical FDDI Ring Setups The hub can be used singly or in groups to bring FDDI to the desktop Figure 1 3 show
6. a LER Rejects 7 LER Count show rev Syntax show rev Description The show rev command displays the version number and the release date of the EPROM firmware and software C 14 Commands show ring Syntax show ring Description The show ring command displays the Ring Management RMT state fddiMACRMTState for the MAC on the primary ring The possible RMT states are listed below n Isolated m Non_Op a Ring_Op E Detect E Non_Op_Dup a Ring_Op_Dup 7 Directed E Trace show sid Syntax show sid Description The show sid command displays the 64 bit FDDI station identifier fddiSMTStationId the 48 bit MAC address fddiMACSMT Address and the 48 bit LLC address show tmax Syntax show tmax Commands C 15 Description The show tmax command displays the value of T Max fddiMACT Max the maximum length of time allowed for the token to move around the ring show tneg Syntax show tneg Description The show tneg command displays the current value of T Neg fddiMACT Neg the ring s operational Target Token Rotation Time show tnotify Syntax show tnotify Description The show tnotify command displays the value of T Notify fddiSMTT Notify for the hub which determines how frequently Neighbor Information Frames NIFs are broadcast to the ring show treq Syntax show treq Description The show treq command displays the value of T Req fddiMACT Req which is the requested Target To
7. 0 0 255 0 0 0 0 255 255 255 0 0 0 0 0 0 0 0 LOCAL Null Null 9600 3 8 Configuring the Hub You can operate the hub using its default configuration without making any changes whatsoever However you may want to change various parameters to suit your particular network environment Refer to Chapters 4 and 5 and Appendix C for information about making changes to the hub s default configuration If you should want to return the hub to its default configuration after making changes use the set defaults command which is accessible only in the primitive command mode Accessing Configuration Commands You can configure the hub using the commands in two command modes a Management console commands n Primitive console commands Management Console Commands Management console commands allow you to a Display current parameter settings and configuration information a Setor change certain configuration related parameters a Display a list and descriptions of the command set a __ Invoke several TCP IP network troubleshooting commands You can access the management console command mode by doing one of the following a Attaching a terminal to the RS 232 serial port on the management module a Connecting a Hayes compatible modem to the RS 232 serial port on the management module a Using the TCP Telnet protocol over the network Configuring the Hub 3 9 Primitive Console Commands The primitive console commands
8. A 6 unpack the hub 2 1 use station management parameters SMT 4 7 use Telnet to access the hub 2 19 use the reset function 5 15 Index hub accessing 2 16 attachment options 3 1 configuring 3 1 connecting to the ring 2 24 connecting to a terminal 2 16 default configuration 3 7 disconnecting from the ring 5 22 displaying IP addresses 5 3 features and functions 1 6 information 5 1 to 5 11 installing modules 4 2 12 package contents 2 2 5 rack mounting 2 2 resetting 5 15 setting the password 4 5 site selection 1 8 station management parameters 4 7 unpacking 2 2 1 hub commands 4 1 help descriptions 4 2 hub modules fiber 1 12 management 1 11 media 1 12 STP 1 14 UTP 1 14 l image downloading 4 12 installation battery 2 7 cascade connector 3 18 fiber port keys 2 10 hub 2 5 image 4 12 modem 2 18 modules 4 2 12 optical bypass switch 2 26 IP address 4 3 5 3 3 4 index K keys fiber port module 2 9 L LEDs 5 11 ATTACH 3 16 5 12 FAN FAIL 5 12 5 14 HI TEMP 5 12 5 14 Link Error 5 17 LOW BATT 5 12 5 14 management module 5 11 media modules 5 16 Port State 5 17 PWR 5 12 Signal Detect 5 17 STATUS 5 12 TOKEN 5 12 5 22 WRAP 5 12 5 13 LEM Count 5 10 LEM Rejects 5 10 LER alarm 4 8 5 9 LER cutoff 4 10 5 9 LER Estimate 5 9 Link Error LED 5 17 Link Error Monitor LEM 4 8 Link Error Rate LER 4 8 5 9 LinkBuilder FDDI Workgro
9. If you enter 0 zero for the slot number this message appears There are no ports in the management module slot If you do not specify a slot number you will be prompted for one Figure 5 7 shows the results of entering this command with a fiber media module in slot 1 and two additional modules in the remaining slots gt sh ports 1 odule 1 of 3 Port 1 2 3 4 PMD Class Fiber Fiber Fiber Fiber PHY Type B A M M Neighbor A B U U PCM State Active Active Connect Connect ConnectState Active Active Connect Connect LER Alarm 10 E 08 10 E 08 10 E 08 10 E 08 LER Cutoff 10 E 07 10 E 07 10 E 07 10 E 07 LER Estimate 10 E 11 10 E 09 10 E 09 10 E 11 LEM Rejects 0 0 0 0 LEM Count 0 0 0 0 Figure 5 7 Example of show ports Command Information 5 6 Using the Hub The Station Management SMT acronyms and other line items used in the show ports display are defined below along with the values that may appear Module Designation The first line in the show ports display gives the slot number of the module represented by the display and the number of modules installed in the hub These combinations are possible a lofl one module installed display describes module in slot 1 a lof2 two modules installed display describes module in slot 1 a lof3 three modules installed display describes module in slot 1 a 2o0f2 two modules installed display describes module in slot 2 a 2o0f3 three modules installed displ
10. a Attachment options supported by the hub Default configuration of the hub and its modules a Console command access modes a Rules for media module port connections Attachment Options The LinkBuilder FDDI Workgroup Hub supports four types of standard configurations m Dual attachment concentrator DAC m Single attachment concentrator SAC m Null attachment concentrator NAC m Dual homing DH NOTE 3Com uses the standard acronyms shown above but calls the concentrator a hub Each type of configuration is discussed in this section Refer to the section Configuring Modules later in this chapter for information about using the set attach command to configure the hub 3 2 Configuring the Hub Dual Attachment Hub A dual attachment hub DAC attaches to both the primary and the secondary rings Figure 3 1 shows a hub functioning as a dual attachment hub Primary ring trunk ring Secondary ring Legend lt Primary ring gt Secondary ring Figure 3 1 Dual Attachment Hub DAC Configuring the Hub 3 3 You can place a dual attachment hub directly on the trunk ring This allows it to participate in ring wrapping if a segment of the trunk fails Figure 3 2 shows dual attachment hubs in wrap state DAC fe ax DAC DAS Fault occurred in dual attached station
11. again 3 10 Configuring the Hub If you do not press the RESET button during the 10 seconds that the STATUS LED is flashing amber green you are denied access to the primitive console command mode and this message appears Primitive console entry has timed out Press RESET again This message appears Press Ctrl P to enter Primitive Console Hold down the Control and P keys The hub is now in the primitive console command mode The STATUS LED flashes amber green continuously while you are in the primitive console command mode If you do not enter a primitive console command within 15 seconds an inactivity timeout will cause the hub to return to the management console command mode If you do not press Ctrl P within 10 seconds the system times out If your attempt to enter the primitive console command mode fails and the timeout occurs you can try again by following the steps above Configuring the Hub 3 11 Returning to the Management Console Command Mode To return to the management console command mode without reattempting to enter the primitive console command mode follow these steps 1 Press Enter This message appears 3Com LinkBuilder FDDI Workgroup Hub The password prompt appears 2 Enter the password and press Enter To return to the management console command mode from the primitive console command mode reset the hub Port Connections The two leftmost ports on any module installed
12. attachment ports The remaining two ports are M master ports by default Overview 1 13 Figure 1 6 Fiber Media Port Module Front Panel If you insert the module in slots 2 or 3 all ports are automatically configured as M ports With three fiber modules installed in the hub 12 fiber MIC ports are available The fiber media port module is shipped with dust plugs inserted in its transceivers to protect the fiber optic connectors from contamination Keep a dust plug in each port until you are ready to insert a fiber cable into the port Figure 1 7 shows how to remove a dust plug from a fiber transceiver Figure 1 7 Removing a Dust Plug from a Fiber Transceiver 1 14 Overview STP Media Port Module Figure 1 8 shows the front panel of the six port STP media port module All of its ports are configured as M ports by default You can specify any port configuration for the attachment ports but you must use a special connector called the STP cascade connector to configure the leftmost attachment port as S To configure the attachment ports as B and A requires two cascade connectors Refer to Chapter 2 for additional information on the STP cascade connector STP PORT MODULE eof Rea o Figure 1 8 STP Media Port Module Front Panel If you install an STP module in each of the three hub slots 18 STP ports are ava
13. for your response For example Current LER Alarm exponent 8 Current LER Cutoff exponent 7 LER alarm 7 15 2 Enter the new LER alarm value For example type 7 Enter If you enter an alarm value that is less than the current cutoff value this message appears Error The alarm exponent must be gt current cutoff exponent Set alarm exponent gt 7 or change the cutoff value 4 10 Setting Up the Hub LER_Cutoff This threshold is the link error rate at which a faulty or poor link connection will be broken The factory set default is 10 E 07 10 7 If the LER exceeds the limits set by this option the hub will automatically reestablish the connection to this port If this is not possible the port will be bypassed until the fault is corrected To change the LER_Cutoff parameter follow these steps 1 Enter the set ler cutoff command Type set ler cutoff Enter You are prompted for the module number and the port number Module Port The current LER values are displayed followed by a prompt for your response For example Current LER Alarm exponent 8 Current LER Cutoff exponent 7 LER cutoff 4 8 Enter the new LER cutoff value For example type 7 Enter If you enter a cutoff value that is more than the current alarm value this message appears Error The cutoff exponent must be lt current alarm exponent Set cutoff exponent lt 8 or
14. in the B receptacle and the B connector in the A receptacle 2 Plug the A and B MIC connectors of the optical bypass switch into the A and B ports on the FDDI hub A to A and B to B DAC e FDDI h B A ub 6 Pin mini DIN gt A B O G Optical bypass switch DAS B A DAS D a Network devices gt A B DAC Figure 2 11 Cabling for Installing an Optical Bypass Switch 2 28 Installing the Hub 3 Plug the optical bypass switch s power connector a 6 pin mini DIN plug into the optical bypass interface receptacle on the management module If you are installing the hub in a rack you can purchase a cable tray to support the optical bypass switch unit as shown in Figure 2 12 or you can rest the unit on one of the rack mounted components vHvaHKHaAS ge A VBURUOABADAADA Le eE S S e S a a e E E i a E a a E gt To network device gt or another hub WBHUDAUADDIDIDIADIA DUIADAADA Figure 2 12 Rack Mounting a Hub with an Attached Optical Bypass Switch Chapter 3 Configuring the Hub After you have installed the hub and its modules and physically connected it to the ring you can configure the hub to operate in your network environment This chapter discusses the following topics
15. installing the management module and one or more media modules one or two empty slots may remain in the base unit Insert a blanking plate into each of these empty slots This keeps objects from falling into the hub and prevents RF emissions from an open slot 6 Quick Start Connecting to the Ring After installing the modules and plugging in the power cord you are ready to connect the hub to the ring by attaching the appropriate cables to the attachment ports which are the two leftmost ports on the module installed in slot 1 To complete the connection to the ring you must configure the attachment ports For detailed information on connecting the hub to the ring see the references in the Road Map to Hub Operations section earlier in this chapter Chapter 1 Overview The 3Com LinkBuilder FDDI Workgroup Hub brings Fiber Distributed Data Interface FDDI high speed LAN technology to the desktop Throughout this guide the LinkBuilder FDDI Workgroup Hub will be referred to as the hub The hub supports remote management via Station Management SMT 7 3 or Telnet protocol Local management is provided via a console interface or a modem attached to the management module s serial port The SMT 7 3 standard specifies the format of management information so that it is consistent with the object oriented approach defined by OSI management standards The standard SMT Management Information Base MIB variables are present in th
16. is determined by the link error monitor LEM Show Ring State To determine the Ring Management RMT state of the primary MAC enter the show ring command Figure 5 8 shows a sample MAC RMT state in which the ring is operational gt sh ring Current RMT state Ring_Op Figure 5 8 Display of a MAC s Ring Management State The Ring Management RMT values that can appear in the show ring display are defined in Table 5 7 Using the Hub 5 11 Table 5 7 Ring Management States Ring Management State Isolated Non_Op Ring_Op Detect Non_Op_Dup Ring_Op_Dup Directed Trace Interpreting the LEDs Definition The initial RMT state The MAC is participating in ring recovery and the ring is not operational The MAC is part of an operational FDDI ring The ring has not been operational for a specified period The address of the MAC under control duplicates the address of another MAC on the ring The ring is not operational The address of the MAC under control duplicates the address of another MAC on the ring The ring is operational The MAC under control is sending beacon frames notifying the ring of a stuck condition RMT has discovered a stuck beacon condition and is initiating a trace to recover The LEDs located on the faceplates of the management module and the various media modules provide information about the configuration and operation of the hub Management Module LEDs The interp
17. is on a ring wrap condition exists on the hub To determine where the wrap has occurred enter the show cfm command This command displays the Configuration Management CFM state of the dual ring inside the hub Table 5 9 defines the possible CFM states A path in this definition represents the segment of a logical ring that passes through a station Table 5 9 CFM State Values Displayed by the show cfm Command CFM State Definition Wrap_a The secondary path is wrapped to the A port Wrap_b The primary path is wrapped to the B port Wrap_s The primary path is wrapped to the S port C_wrap_a The primary and secondary paths are joined internally to the station and wrapped to the A port C_wrap_b The primary and secondary paths are joined internally to the station and wrapped to the B port C_wrap_s The primary and secondary paths are joined internally to the station and wrapped to the S port Isolated The MAC or port is not inserted into any path Thru The primary path enters the A port and emerges from the B port The secondary path enters the B port and emerges from the A port This is normal FDDI operation Not all wrap conditions activate the WRAP LED The WRAP LED lights when a wrap condition involves a peer mode connection A B and S ports are considered peer ports and any connection between two peer ports is a peer mode connection An S to S connection is the exception and is not considered a peer mode connection A
18. media port module supporting level 5 and screened level 5 data grade unshielded twisted pair UTP cabling system per the ANSI TP PMD standard a Upgradeability You can easily change from copper media to fiber media and vice versa using the available port modules a Configurability You can configure the two leftmost ports of the slot 1 module to meet any one of four network configurations dual attachment single attachment null attachment and dual homing a _ Serviceability with power on insertion You can insert and remove the media port modules without removing power from the hub a Flash EPROM The presence of the flash EPROM makes the hub s software easily upgradeable because future software images can be downloaded into flash memory over the network via the Trivial File Transfer Protocol TFTP See the section Downloading New Images in Chapter 4 for information on downloading images into the flash EPROM a FDDI benefits You can take advantage of the many benefits provided by FDDI technology including Increased data rate of 100 Mbps Longer distance between nodes via fiber optic cable Immunity to electronic noise fiber only Support of large networks comprising up to 500 nodes Fault tolerance and fault isolation Improved network management 1 8 Overview Figure 1 2 shows the LinkBuilder FDDI hub with the management module and all three types of media modules installed
19. rules Creates two logical token rings provides a consistent designation of the primary ring among all stations Exists when an M to M connection is formed It isolates a portion of the network onto a separate token ring nested in the tree of rings continued Configuring the Hub 3 15 Table 3 4 Definitions for the Port Connection Rules continued Condition Port Connection Definition of Port Indicator Condition Condition W Wrap state Exists when a break in the primary ring occurs and the stations on either side of the break join the primary and secondary rings It can also indicate that the ring is wrapped at a particular port T Twisted ring Exists when an A to A or a B to B connection is formed It divides the network into two groups of stations that disagree on which token ring is the primary ring The connections listed below are not allowed a MtoM anillegal connection AtoA an undesirable connection that creates a twisted ring a BtoB an undesirable connection that creates a twisted ring The connection rules do not necessarily prevent undesirable connections An undesirable connection designation reflects the connection status of the sending node only The connection can still be made if the receiving node exhibits an acceptable connection status Configuring Modules You can only configure the module inserted in slot 1 and you can only configure the two leftmost ports the attachment p
20. setup See installation shielded twisted pair See STP show command C 10 C 21 show attach command 5 1 C 7 C 21 show baud command C 7 C 21 show boot command C 7 C 21 show boot load command 4 14 C 7 show boot method command 4 14 C 7 show cfm command 5 13 C 8 show commands 4 2 C 7 show fstats command 5 1 C 9 show gateway command C 9 C 21 show help command C 10 C 21 show ip command 4 3 5 3 C 10 C 21 show log command 5 21 C 10 C 21 show log last command 5 21 C 10 show mib counters command 5 3 C 10 show neigh command 5 4 C 11 show obs command C 11 C 22 show ports command 5 5 C 12 show rev command C 13 C 22 show ring command 5 10 C 14 show sid command 5 4 C 14 C 22 show tmax command C 14 show tneg command C 15 show tnotify command C 15 C 22 show treq command C 15 C 22 show tvx command C 15 C 22 Signal Detect LED 5 17 single attachment hub SAC 3 4 SMT functions 1 6 maximum token rotation time 4 11 negotiated time 4 11 neighbor notification timer 4 7 target token rotation time 4 8 valid transmission timer 4 11 software image downloading 4 12 specifications B 1 station identifier 5 4 station management parameters SMT 4 7 Station Management SMT 1 3 MIB 1 1 remote management 1 1 STATUS LED 5 12 STP cabling rules 2 20 media port module 1 14 module cascade connector 2 11 pin assignments 2 21 subnet mask 4 4 system messages A 1 system soft
21. the port number indicated by p Do not use this port 3Com recommends replacing the entire module Backplane error You must replace the backplane Software error Check for the correct version number and the last download status Appendix B Technical Specifications This appendix provides the physical electrical and environmental specifications for the LinkBuilder FDDI Workgroup Hub Physical Characteristics Width Depth Height Weight empty Weight fully loaded Power Requirements AC line frequency Current consumption Environmental Requirements Storage temperature Operating temperature Altitude Storage humidity Operating humidity Battery Specifications 3V 2450 lithium 16 8 in 42 6 cm 11 6 in 29 4 cm 5 2 in 13 3 cm 15 Ib 2 oz 6 86 kg 19 1b 8 5 kg 100 to 240 Vac 47 to 63 Hz 3 2 amps RMS 115 Vac 240 watts 22 to 194 F 30 to 90 C 32 to 122 F 0 to 50 C To 10 000 ft 3 050 m 5 95 noncondensing 104 F 40 C 5 95 noncondensing 104 F 40 C Approved manufacturers are Duracell Sanyo Renata and Seiko B 2 Technical Specifications Standards Compliance FCC approval FCC VDE Class B for LinkBuilder FDDI Management Module Fiber Optic Module and STP SDDI Module FCC approval FCC Class A for LinkBuilder FDDI UTP Module If no UTP modules are installed in the hub the hub complies with the limits of a Class B digital device If a UTP m
22. this service you may choose to access CardFacts containing adapter information or 3ComFacts containing network system product information a CardFacts provides adapter installation diagrams configuration drawings troubleshooting instructions and technical articles Document 9999 provides you with an index of adapter documents m 3ComFacts provides data sheets and technical articles on 3Com s hub bridge router terminal server and software products Document 8888 provides you with an index of system product documents Ask3Com On line Service SM Ask3Com is an on line service located on CompuServe This service is accessible worldwide Ask3Com contains extensive technical and marketing information on all 3Com products To use Ask3Com you must first obtain a CompuServe account To open an account contact your local CompuServe office To use Ask3Com log into CompuServe type GO THREECOM and press Enter to see the Ask3Com main menu Technical Support D 3 3Com Documentation on CD ROM An extensive library of 3Com product documentation is available in CD ROM format through Support on Site for Networks subscription service This multivendor CD ROM service offered by Computer Library a division of Ziff Communication contains technical information and documentation from major data networking hardware and software manufacturers Stand alone and concurrent user network subscriptions are available
23. to change the baud rate of the serial port The serial port s default baud rate is 9600 To display the serial port s baud rate enter the show baud command Installing the Hub 2 17 To change the hub s baud rate to match the baud rate of a terminal or modem follow these steps 1 Enter the set baud command Type set baud This selection prompt appears Select one of the following 1 1200 2 2400 3 4800 4 9600 Baudrate 2 Type a number to select a baud rate For example type 3 Enter This confirmation appears Baud rate changed to 4800 3 Reset the hub by pressing the recessed RESET button on the management module front panel The new baud rate will take effect when the self tests are finished 2 NOTE The other default parameters of the serial port are Parity None Data oY Bits 8 and Stop Bits 1 2 18 Installing the Hub b Installing an Optional Modem If you want to access the hub via a Hayes modem you must prepare the modem correctly for use with the hub Follow these steps 1 If necessary change the hub s baud rate to match the modem s baud rate Refer to the preceding section Changing the Serial Port s Baud Rate for instructions on changing the baud rate NOTE Before you install a modem you should set a password to restrict access to the hub 2 Log out from the hub by entering the logout command Type logout Enter Be sure the modem is tu
24. type 1 Enter These confirmation lines appear Current configuration M M Initialize attachment as B A Reset the hub by pressing the recessed RESET button on the management module front panel The attachment ports will be initialized as B A 2 26 Installing the Hub Installing an Optical Bypass Switch In many network environments mission critical devices such as bridges routers and hubs should be connected to the primary dual ring only if they are equipped with an optical bypass switch OBS An optical bypass switch is a device that prevents ring wrap in the event a node is powered off Using an optical bypass switch protects the integrity of the dual ring by rerouting the signal in case of a station malfunction the trunk ring is not broken If you want the protection provided by an optical bypass switch purchase an optical bypass switch with the plug configuration shown in Figure 2 10 3Com does not supply this device 6 Pin mini DIN MIC connectors Figure 2 10 Optical Bypass Switch Installing the Hub 2 27 To detect the presence of an optical bypass switch on your system enter the show obs command To install an optical bypass switch with the configuration shown in Figure 2 11 follow these steps 1 Plug the A and B Media Interface Connectors MIC connectors from a network device or another hub into the B and A receptacles on the optical bypass switch The device s A connector must be placed
25. which are a subset of the management console commands are accessible in case of unusual system situations For example you can access the primitive console command mode if a You forget the password You do not need a password to access the primitive console command mode Once in this mode you can set a new password a You have downloaded a faulty image into the flash EPROM and you must reset the hub a You have configured the hub with illegal parameters and nothing can operate You must reset the hub Unlike the management console command mode when the primitive console command mode is active no connection to the ring exists In primitive mode you can change only those parameters that involve nonvolatile RAM You can access the primitive console command mode only via a terminal attached to the serial port on the management module Remote access through a modem or via Telnet is not supported Accessing the Primitive Console Command Mode To access the primitive console command mode follow these steps 1 Press the RESET button once The RESET button is recessed on the management module Use a bent paper clip or other small pointed object to press the RESET button NOTE You cannot access the primitive console command mode by typing the reset command 2 Watch the STATUS LED on the management module The STATUS LED is normally amber When the STATUS LED flashes amber green you have 10 seconds to press the RESET button
26. 2 Cross over Connections on a UTP Cable 2 21 UTP Cabling Distances per ANSI Standards 2 22 Direction of Data Flow Through a Hub and Stations 2 24 Optical Bypass Switch 2 26 Cabling for Installing an Optical Bypass Switch 2 27 Rack Mounting a Hub with an Attached Optical Bypass Switch 2 28 3 1 3 2 3 3 3 4 3 5 3 6 3 7 5 1 5 2 5 3 5 4 5 5 5 6 5 7 5 8 5 9 Dual Attachment Hub DAC 3 2 Dual Attachment Hubs DACs in Wrap State 3 3 Single Attachment Hub SAC 3 4 Null Attachment Hub NAC and Connected Stations SAS and DAS 3 5 Dual Homing Connections 3 6 Upstream and Downstream Neighbors 3 13 Using Two STP Cascade Connectors to Allow a Dual Attachment Configuration 3 18 Display of Attachment Port Configuration 5 1 Display of MAC Frame Statistics 5 2 Display Produced by show IP Command 5 3 Display Produced by show MIB counters Command 5 3 Display of Neighbors Addresses 5 4 Display of Station Identifier 5 4 Example of show ports Command Information 5 5 Display of a MAC s Ring Management State 5 10 LEDs on the STP Module 5 16 XV Tables 2 1 2 2 2 3 3 1 3 2 333 3 4 3 5 4 1 5 1 5 2 5 3 5 4 5 5 5 6 5 7 5 8 5 9 5 10 DB 9 STP Connector Pin Assignments 2 21 RJ 45 UTP Connector Pin Assignments 2 22 FDDI Port Types 2 23 LinkBuilder FDDI Workgroup Hub Default Configuration 3 7 Selecting Port Configurations for Attachment Types 3 12 Port Connec
27. 20 set pwd C 20 set tnotify C 20 set treq C 21 Display Commands C 21 show attach C 21 show baud C 21 show boot C 21 show gateway C 21 show helpl C 21 show ip C 21 show log C 21 show obs C 22 show rev C 22 show sid C 22 show tnotify C 22 show treq C 22 show tvx C 22 Miscellaneous Commands C 22 clear C 22 help C 22 reset C 22 Appendix D Technical Support On line Product Support D 1 CardBoard Bulletin Board Service D 1 Automated Fax Service D 2 Ask3Com On line Service D 2 3Com Documentation on CD ROM D 3 Support from Your Network Supplier D 3 U S and Canada D 3 Outside the U S and Canada D 3 Returning Products for Repair D 5 Glossary Index xiii Figures 1 1 1 2 1 3 1 4 1 5 1 6 1 7 1 8 1 9 2 1 2 2 2 3 2 4 2 5 2 6 2 7 2 8 2 9 2 10 2 11 2 12 Ring Wrap 1 3 The LinkBuilder FDDI Workgroup Hub 1 8 Physical Topology for Typical FDDI Ring 1 9 FDDI Ring of Trees 1 10 Management Module Front Panel 1 11 Fiber Media Port Module Front Panel 1 13 Removing a Dust Plug from a Fiber Transceiver 1 13 STP Media Port Module Front Panel 1 14 UTP Media Port Module Front Panel 1 14 Attaching Mounting Brackets to the Hub 2 3 LinkBuilder FDDI Workgroup Hub Installed in a Distribution Rack 2 4 Battery Location on the Management Module 2 8 Media Module Keys Identified by Port Type 2 9 Inserting a Type M Key into a Fiber Transceiver 2 10 STP Module Cascade Connector 2 1
28. 3Com s LinkBuilder FDDI Workgroup Hub Please fill out and return the enclosed registration card to start your one year warranty period Customers in the countries shown below should send the completed registration card to the appropriate address France Spain Portugal Greece 3Com France Marketing Department ZA de Courtaboeuf 25 Ave de la Baltique B P 609 91945 Les Ulis Cedex France Italy 3Com Mediterraneo Srl Marketing Department Via Michelangelo Buonarroti 1 20093 Cologno M onzese M1 Milano Italia United Kingdom Eire 3Com UK Ltd Marketing Department Pacific House Third Avenue Globe Park M arlow on Thames Buckinghamshire SL7 1YW United Kingdom Sweden Finland Norway Denmark 3Com Nordic AB Marketing Department Box 1110 164 22 Kista Sweden Germany Austria Switzerland 3Com GmbH M arketing Department Gustav Heinemann Ring 123 8000 M uenchen 83 Germany Belgium Netherlands Luxembourg 3Com Benelux Marketing Department Planetenweg 80 2nd Floor 2132 HP Hoofddorp Netherlands Customers in other non U S locations should send the registration card to the U S address on the front of the card Quick Start Use this Quick Start procedure if You are experienced in installing and operating LinkBuilder FDDI hubs You have an FDDI segment running with other network devices attached to it Road Map to Hub Operations The steps listed below summarize the procedures n
29. 5 11 WRAP LED 5 13 FAN FAIL LED 5 14 HITEMPLED 5 14 LOW BATT LED 5 14 Dangerous Environmental Conditions Display 5 14 RESET Function 5 15 Media Module LEDs 5 16 Using Miscellaneous Commands 5 17 Diagnosing Network Problems 5 17 ping Command 5 18 route Command 5 19 arp Command 5 20 show log and clear log Commands 5 21 Using Connectivity Commands 5 22 connect and disconnect Commands 5 22 logout Command 5 22 Appendix A System Messages Error Messages A 1 Download Messages A 4 Fault Log Error Code Messages A 6 Appendix B Technical Specifications Appendix C Commands Management Console Commands C 1 Set Commands C 1 set attach C 1 set baud C 2 set boot C 3 set gateway C 4 sethelp C 4 setip C 4 setler C 5 set pwd C 6 set tnotify C 6 set treq C 6 Show Commands C 7 show attach C 7 show baud C 7 show boot C 7 show cfm C 8 show fstats C 9 show gateway C 9 show help C 10 show ip C 10 show log C 10 show mib counters C 10 show neigh C 11 show obs C 11 show ports C 12 show rev C 13 show ring C 14 xi show sid C 14 show tmax C 14 show tneg C 15 show tnotify C 15 show treq C 15 show tvx C 15 Diagnostic and Connectivity Commands C 16 arp C 16 clear C 16 connect C 17 disconnect C 17 help C 17 logout C 17 ping C 18 reset C 18 route C 18 Primitive Console Commands C 19 Set Commands C 20 set attach C 20 set baud C 20 set boot C 20 set defaults C 20 set gateway C 20 set help C 20 setip C
30. CardBoard D 1 2 index C continued CardFacts D 2 cascade connector 2 11 3 18 CFM 5 13 clear alarm command 5 15 C 17 clear command C 16 C 22 clear log command 5 21 C 16 commands See under individual command names Computer Library D 3 configuration attachment ports 3 11 3 12 4 6 hub 3 1 3 7 modules 3 15 configuration commands 3 8 Configuration Management CFM 5 13 connect command 5 22 C 17 Connect State 5 9 connecting to the dual ring 2 24 console command modes 2 16 3 8 D dangerous environmental conditions 5 14 data flow direction 2 23 DB 9 STP connector pin assignments 2 21 default configuration 3 7 default gateway address 4 4 disconnect discon command 5 15 5 22 C 17 distribution rack 2 2 documentation on CD ROM D 3 download messages A 4 download status 4 14 downloading from TFTP 4 12 downloading software images 4 12 dual attachment hub DAC 3 2 dual homing DH 3 6 dual ring connections 2 24 dust plug 1 13 E electrical specifications B 1 environmental specifications B 1 error messages A 1 F factory default configuration 3 7 FAN FAIL LED 5 12 5 14 fault log 5 21 fault log error code messages A 6 fax service 3ComFacts D 2 FCC standards compliance B 2 FDDI benefits 1 7 cabling rules 2 20 connection rules 3 12 self paced study course 1 2 standard attachment options 3 1 technology 1 2 FDDI ring connecting to 2 24 data flow spe
31. Description The show baud command displays the baud rate for the serial port show boot Syntax show boot method load Description The show boot method command displays the boot parameters method image filename and IP address of the boot server The show boot load command displays the status of the last download C 8 Commands The boot method can be one of the following LOCAL Runs flash EPROM default a TFTP Uses the TFTP protocol and local configuration parameters to load a new image across the network The show boot load command displays the parameters used and the status of the last download to the flash EPROM show cfm Syntax show cfm Description The show cfm command displays the Configuration Management CFM state fddiSMTCF State of the dual ring inside the hub Values CFM states are listed below a Wrap_A Wrap_B a Wrap_S 7 C_Wrap_A n C_Wrap_B 7 C_Wrap_S 1 Isolated n Thru Commands C 9 show fstats Syntax show fstats Description The show fstats command displays the following raw frame statistics for the hub s MAC a Total transmit frames a Total received frames a Total transmit SMT frames a Total received SMT frames a Total transmit LLC frames a Total received LLC frames a Total received short frames a Total received invalid frames a Total aborts a Received resets a Directed beacon entered 7 Directed beacons sent show gateway Syntax show gatewa
32. LinkBuilder FDDI Workgroup Hub User Guide A member of the LinkBuilder FDDI family For 3Com User Group Information 1 800 NET 3Com or your local 3Com office Manual Part No 09 0447 000 Published July 1993 Printed in the U S A 3Com Corporation 5400 Bayfront Plaza Santa Clara California USA 95052 8145 3Com Corporation 1993 All rights reserved No part of this manual may be reproduced in any form or by any means or used to make any derivative work such as translation transformation or adaptation without permission from 3Com Corporation 3Com Corporation reserves the right to revise this publication and to make changes in content from time to time without obligation on the part of 3Com Corporation to provide notification of such revision or change 3Com Corporation provides this guide without warranty of any kind either implied or expressed including but not limited to the implied warranties of merchantability and fitness for a particular purpose 3Com may make improvements or changes in the product s and or the program s described in this manual at any time If you are a government agency then this software and documentation is provided to you subject to the following restricted rights For units of the Department of Defense 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 Soft
33. Meaning Nonvolatile RAM error on the management module Action Check LOW BATT LED If the battery is low replace it and try the operation again If the problem persists contact 3Com support 01xxxxxx Meaning Action 0XXXXXXX Meaning Action 1PXXXXXX Meaning Action 2PXXXXXX Meaning Action System Messages A 7 Flash memory error on the management module Contact 3Com support Management module failure Replace the module Media module failure in slot 1 If p is O or a value greater than the maximum number of ports on this module replace this module If p is a value between 1 and the maximum number of ports on the module an error exists on the port number indicated by p Do not use this port 3Com recommends replacing the entire module Media module failure in slot 2 If p is O or a value greater than the maximum number of ports on this module replace this module If p is a value between 1 and the maximum number of ports on the module an error exists on the port number indicated by p Do not use this port 3Com recommends replacing the entire module A 8 System Messages 3pXXXXxx Meaning Action 8XXXXXXX Meaning Action FEXxxxxx Meaning Action Media module failure in slot 3 If p is O or a value greater than the maximum number of ports on this module replace this module If p is a value between 1 and the maximum number of ports on the module an error exists on
34. ON MAINTENANCE USE PERFORMANCE FAILURE OR INTERRUPTION OF ITS PRODUCTS EVEN IF 3COM OR ITS AUTHORIZED RESELLER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES Some states do not allow the exclusion of implied warranties or the limitation of incidental or consequential damages for consumer products so the above limitations and exclusions may not apply to you This warranty gives you specific legal rights which may vary from state to state 3Com Corporation 5400 Bayfront Plaza Santa Clara CA 95052 8145 408 764 5000 6 15 92 b WARNING This equipment 3C781 3C782 3C783 has been tested and found to comply with the limits for a Class B digital device pursuant to Part 15 of the FCC Rules These limits are designed to provide reasonable protection against harmful interference in a residential installation This equipment generates uses and can radiate radio frequency energy and if not installed and used in accordance with the instructions may cause harmful interference to radio communications However there is no guarantee that interference will not occur in a particular installation If this equipment does cause harmful interference to radio or television reception which can be determined by turning the equipment off and on the user is encouraged to try to correct the interference by one or more of the following measures n Reorient or relocate the receiving antenna n Increase the separation between the equipment and receiv
35. P download request could not be completed because the requested server did not respond Action Check the server s IP address Check also to be sure the server is connected to the network and is operational If the server is on a remote network check the gateway s IP address that is saved in nonvolatile RAM TFTP Abort Flash memory error Meaning The requested image could not be written to flash memory because of a flash chip problem You no longer have an executable image in flash Action Contact 3Com technical support Refer to Appendix D for instructions on getting 3Com support A 6 System Messages TFTP Abort invalid NVRAM parameters Meaning The TFTP download request could not be completed because the requested IP address server IP address or image filename was incorrect The existing image will not be changed Action Make sure that you have entered the correct the IP addresses or image filename Then reissue the download request TFTP Attempt using NVRAM parameters Meaning The TFTP download request was interrupted The existing image will not be changed Action Check to be sure the TFTP server is operating properly and reissue the download request TFTP download completed successfully Meaning The software image has been downloaded successfully Action Proceed with normal hub operations Fault Log Error Code Messages The x s in each designation represent any hexadecimal digit OOxxxxxx
36. The beacon process can indicate either a station hardware or software failure A packet delivery system that delivers a copy of a given packet to all hosts that attach to it The ability of a node to optically isolate itself from the FDDI network while maintaining the continuity of the cable plant See also Optical bypass The agreed upon bit order of transmission Canonical addressing is when the least significant bit of the most significant byte is always transmitted first The FDDI hub s LLC logical link control address appears in canonical order when the show sid command is issued Copper Distributed Data Interface FDDI over twisted pair copper wire 2 Glossary Concentrator DAC DAS Dotted decimal notation Downstream Dual counter rotating ring Dual ring Dual homing A sophisticated multiplexer or hub device that has additional ports beyond those required for its own attachment to the main ring of an FDDI network These additional ports are for attaching other FDDI nodes including single attachment stations SASs and other concentrators in a tree topology Concentrators may be stand alone null attachment and not connected to the main ring they may support only the interconnection of a few SASs Dual Attachment Concentrator A concentrator with A and B ports for attachment to both the primary and secondary rings Dual Attachment Station A station with A and B ports for attachment to the primary rin
37. YEL LINK ERROR W sep M Link Error Power PWR LED Figure 5 9 LEDs on the STP Module Using the Hub 5 17 Table 5 10 Interpreting Media Module LEDs LED Color Indicators Meaning Signal Detect Green The signal is detected Off No signal exists Port State Green Port is in active connection state Flashing green off Port is in standby connection state Off Port is in disabled or connecting state Link Error Amber Link confidence test failure link error rate cutoff threshold has been exceeded triggering an alarm Off Port is operating normally In addition to the functional LEDs each module has a power PWR LED which turns green to indicate the module is on Using Miscellaneous Commands Several commands provide diagnostic and connectivity functions Diagnosing Network Problems The commands described in this section provide statistical information that may help solve network problems 5 18 Using the Hub ping Command The ping command sends echo frames to a host and expects to receive a like number of echo frames in return Use the ping command to find out whether or not a host on the network is operational For example type ping 128 45 87 20 where 128 45 87 20 is the host address in Internet dot notation The address can either be a specific station IP address or a broadcast address If the host is operational this reply is displayed 128 45 87 20 is alive If the host is not operat
38. adapters Lifetime LinkBuilder 10BT and 10BTi hubs Three years Other transmission products One year Spare parts and spares kits 90 days Instrumentation 90 days If a product does not operate as warranted during the applicable warranty period 3Com shall at its expense correct any such defect by repairing the defective product or part or at its option by delivering to Customer an equivalent product or part to replace the defective item All products that are replaced will become the property of 3Com Replacement products may be new or reconditioned Any replaced or repaired product or part has a ninety 90 day warranty or the remainder of the initial warranty period whichever is longer 3Com shall not be responsible for any software firmware information or memory data of Customer contained in stored on or integrated with any products returned to 3Com pursuant to any warranty SOFTWARE 3Com warrants that the software programs licensed from it will perform in substantial conformance to the program specifications therefor for a period of ninety 90 days from the date of purchase from 3Com or its Authorized Reseller 3Com warrants the magnetic media containing software against failure during the warranty period No updates are provided 3Com s sole obligation hereunder shall be at 3Com s discretion to refund the purchase price paid by Customer for any defective software products or to replace any defective media with software which substa
39. ating the reset function After you install the management module and one or more media modules one or two empty slots may remain in the base unit Insert a blanking plate into each of these empty slots This keeps objects from falling into the hub and prevents RF emissions from an open slot Removing Modules A To remove modules from the hub follow these steps CAUTION Observe the same precautions outlined above regarding discharge of static electricity and potential loss of data 1 Disconnect all cables connected to the module that you want to remove You do not have to unplug the hub from its power source 2 Enter the disconnect command This disconnects the hub from the ring 3 Remove all jewelry from your hands and wrists b Installing the Hub 2 15 4 Turn the thumb screws on each end of the module counterclockwise to loosen them 5 Holding a thumb screw in each hand slowly pull the module from its slot 6 Place the module on a clean surface or replace the module in its original antistatic bag 7 Place a blanking plate over the empty slot NOTE There must be no empty slots between modules For example if you remove a module from slot 2 and there is a module in slot 3 you must move the module in slot 3 into slot 2 or else replace the removed module with a new module Otherwise an error condition will exist and the hub will not function properly 8 Reset the hub You can either enter the rese
40. ay describes module in slot 2 a 30f3 three modules installed display describes module in slot 3 PMD Class The PMD Physical Layer Medium Dependent protocol defines the medium that provides the physical link between two adjacent FDDI stations Table 5 3 lists and defines the port media types for the PMD Class line in Figure 5 7 Table 5 3 Port Media Types Medium Definition Fiber 62 5 micron multimode fiber STP Shielded twisted pair UTP Unshielded twisted pair LCF Low cost fiber N S Not specified Unknown Unknown connecting medium Sonet Synchronous optical network Using the Hub 5 7 PHY Type The PHY Physical Layer protocol specifies the rules for encoding data for transmission from one FDDI station to another Table 5 4 lists and defines the physical port types for the PHY Type line in Figure 5 7 Table 5 4 Physical Layer Port Types Physical Port Type Definition A The port in a dual attachment station or hub that attaches to the Primary In and the Secondary Out when attaching to the dual ring B The port in a dual attachment station or hub that attaches to the Secondary In and the Primary Out when attaching to the dual ring M A port in a hub that serves as a Master to a connected station or hub S A port in a single attachment station or hub designated as a Slave U Unknown port type Neighbor Neighbor displays the port type when PCM Physical Connection Management State is Active When PCM State is no longer Act
41. cade connectors Dual homing B A 2 Cascade connectors Single S M 1 Cascade connector Null M M None continued Configuring the Hub 3 17 Table 3 5 Configuring Modules continued Attachment Additional Attachment Port Equipment Module Type Configuration Required UTP Dual B A Cross over cable Dual homing B A Cross over cable Single S M Cross over cable Null M M Cross over cable To change the configuration of the attachment ports follow these steps 1 Enter the set attach command Type set attach This selection prompt appears Select one of the following 1 B A 2 S M 3 M M Attachment port configuration Select the attachment port configuration that you want For example type 2 Enter These confirmation lines appear Current configuration B A Initialize attachment as S M When you reset the hub the attachment ports will be configured as S M 3 18 Configuring the Hub Using the STP Cascade Connector By default all ports on an STP media module are physically configured as M ports If you want to configure the module for a B A or S M connection you must use one or two STP cascade connectors to allow the new configuration The STP cascade connector gets its name from its use in connecting a series of rack mounted hubs in which the connecting cascade cables flow from one hub down to the next Figure 3 7 shows two STP cascade connectors installed on an STP module to allow dua
42. ch MAC is required to maintain a Valid Transmission Timer TVX The expiration threshold of the TVX indicates the maximum time allowed between the receipt of valid frames or tokens The factory set default is 2621 40 microseconds You cannot adjust the value of TVX but you can display its value To display the current value of TVX enter the show tvx command A display similar to the following appears TVX Value in use 2 62 milliseconds 4 12 Setting Up the Hub Downloading New Images When you power up the hub it runs a series of self tests and then executes the software image stored in the flash EPROM b Whenever you receive a software upgrade from 3Com you will store the new image in an accessible network server that supports TFTP Trivial File Transfer Protocol You must download the new image from the server into the hub s flash EPROM Using the TFTP option to download new images requires you to enter certain variables individually This downloading method is described below NOTE You cannot load the flash image over the serial link via a modem Downloading from the TFTP Option To download an image from a TFTP server follow these steps 1 Set the server location of the information to be downloaded Type set boot method Enter This selection prompt appears Select one of the following 1 LOCAL 2 oT TP Boot Method Select the TFTP server option Type 2 Enter This display appears co
43. change the alarm value If you enter a cutoff value greater than 15 this message appears Error Cutoff must be in the range 4 to 15 Changes to these parameters take effect immediately The show ports command displays the current values of these parameters Setting Up the Hub 4 11 Displaying SMT Parameters These three SMT parameters which you can display but cannot change provide additional information about ring timer functions m Maximum Token Rotation Time T Max a Negotiated Time T Neg m Valid Transmission Timer TVX Maximum Token Rotation Time T Max The Maximum Token Rotation Time T Max is the maximum length of time allowed for the token to move around the ring The factory set default is 167 77 milliseconds To view the value of the T Max parameter enter the show tmax command A display similar to the following appears T Max 167772 microseconds Negotiated Time T Neg The Negotiated Time T Neg is the ring s operational Target Token Rotation Time that results from the stations bidding process in which the station requesting the fastest token rotation time wins the right to initialize the ring To view the current value of T Neg enter the show tneg command A display similar to the following appears T Neg 83886 microseconds Valid Transmission Timer TVX The Media Access Control MAC protocol is responsible for all frame based functions and controls a station s access to the ring Ea
44. cifications 2 23 setup examples 1 9 fiber media port module 1 12 keys for 2 6 2 9 fiber optic cabling rules 2 20 flash EPROM 1 7 4 12 frame statistics 5 1 G gateway address 4 4 H help command C 17 C 22 HI TEMP LED 5 12 5 14 how to access hub commands 3 8 access the hub 2 16 attach an optional modem 2 18 attach devices to the hub 2 23 attach the hub to the ring 2 24 H continued change the baud rate 2 16 clear the fault log 5 21 configure attachment ports 3 11 4 6 configure modules 3 15 connect a terminal to the hub 2 16 detect the presence of dangerous conditions 5 14 disconnect from the ring 5 22 display port information 5 5 display status of last download 4 14 download new images 4 12 enter primitive console command mode 3 9 find the location of a wrap 5 13 insert and replace the battery 2 7 insert fiber module keys 2 10 install an optical bypass switch 2 26 install modules 2 12 install the STP cascade connector 2 11 interpret download messages A 4 interpret fault log error messages A 6 interpret LER parameters 4 8 interpret system error messages A 1 interpret the LEDs 5 11 monitor module functions 5 16 plan FDDI ring configurations 3 1 plan port connections 2 19 3 11 rack mount the hub 2 2 remove modules 2 14 reset the hub 5 15 select proper cabling 2 20 set IP addresses 4 3 set the password 4 5 understand fault log error codes
45. cking the Modules 3 Installing the Modules 4 Connecting to the Ring 6 Chapter 1 Overview FDDI Technology 1 2 Physical Medium Dependent PMD Protocol 1 4 Fiber Optic 1 4 Shielded Twisted Pair STP 1 4 Unshielded Twisted Pair UTP 1 5 Physical PHY Protocol 1 5 Media Access Control MAC Protocol 1 5 Station Management SMT Protocol 1 6 Features and Functions 1 6 Site Selection 1 8 Typical FDDI Ring Setups 1 9 Management and Media Modules 1 11 Management Module 1 11 Media Modules 1 12 Fiber Media Port Module 1 12 STP Media Port Module 1 14 UTP Media Port Module 1 14 viii Chapter 2 Installing the Hub Unpacking the Hub 2 1 Mounting the Hub in a Rack 2 2 Equipping the Hub 2 5 Basic Contents 2 5 Hub Chassis 2 6 Media Port Modules 2 6 Installing the Battery 2 7 Keys for Fiber Port Modules 2 9 STP Cascade Connector 2 11 Installing Modules 2 12 Removing Modules 2 14 Accessing the Hub 2 16 Changing the Serial Port s Baud Rate 2 16 Installing an Optional Modem 2 18 Using Telnet to Access the Hub 2 19 Planning Connections 2 19 FDDI Cabling Rules 2 20 Fiber Optic Cable 2 20 Shielded Twisted Pair Cable 2 20 Unshielded Twisted Pair Cable 2 21 Data Flow Specifications 2 23 Connecting to the Dual Ring 2 24 Installing an Optical Bypass Switch 2 26 Chapter 3 Configuring the Hub Attachment Options 3 1 Dual Attachment Hub 3 2 Single Attachment Hub 3 4 Null Attachment Hub 3 5 Dual Homing 3 6 Default Configuration 3 7 Accessing Confi
46. ction regardless of the medium being used fiber STP or UTP Station Management SMT Protocol The Station Management protocol is involved in network management and monitoring for all layers of the FDDI stack Every node on an FDDI ring participates in the management of the ring As such all nodes exchange SMT information to control network operation SMT specifies the following Status of links between nodes Error detection and fault isolation algorithms Monitoring of all ring and station activities Ring maintenance Ring initialization control and performance Features and Functions The LinkBuilder FDDI Workgroup Hub performs the following tasks in an FDDI network Connects end stations bridges routers and other FDDI devices as well as additional hubs to the network Isolates segment breaks through an attachment configuration called dual homing and dual attachment Bypasses nodes that have been turned off or are experiencing problems Extends the network s geographical diameter by regenerating all received signals when repeating them onto the network Overview 1 7 The hub provides the following features a Media flexibility You can use any mix of one two or three of these port modules in the hub FDDI media port module supporting 62 5 125 um fiber optic cable per the ANSI FDDI standard STP media port module supporting shielded twisted pair STP type 1 cable and the SDDI de facto standard UTP
47. e LinkBuilder FDDI Workgroup Hub software A modular stand alone device the hub provides four module slots and a passive backplane When installed and equipped with the appropriate modules the hub can be connected to the FDDI backbone ring to other FDDI hubs and to other stations The RS 232 based console interface provides the capability to configure and monitor the media port modules installed in the chassis The hub chassis contains an integrated internal power supply and a fan It requires a single management module and supports one to three media modules for ring and station attachment The hub is an intelligent device with a unique FDDI MAC Media Access Control address implemented with National Semiconductor Corporation s BMAC FDDI Media Access Controller technologies In addition National s BSI FDDI System Interface implements an interface between the BMAC device and the host system providing a multiframe MAC level interface to one or more MAC users The hub s single MAC supports dual single or null attachment and dual homing 1 2 Overview The management module is based on the Motorola 68EC020 processor which provides the following a 256 KB of nonvolatile RAM 1 MB of local RAM a 512 KB of EPROM 1 MB of flash memory a 128 KB of RAM for frame buffer and descriptors This guide is intended for network installers and operators who are familiar with FDDI technology and experienced in installing hub
48. e shipment The repaired or replaced item will be shipped to Customer at 3Com s expense not later than thirty 30 days after receipt by 3Com iii WARRANTIES EXCLUSIVE IF A 3COM PRODUCT DOES NOT OPERATE AS WARRANTED ABOVE CUSTOMER S SOLE REMEDY SHALL BE REPAIR REPLACEMENT OR REFUND OF THE PURCHASE PRICE PAID AT 3COM S OPTION THE FOREGOING WARRANTIES AND REMEDIES ARE EXCLUSIVE AND ARE IN LIEU OF ALL OTHER WARRANTIES EXPRESS OR IMPLIED EITHER IN FACT OR BY OPERATION OF LAW STATUTORY OR OTHERWISE INCLUDING WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 3COM NEITHER ASSUMES NOR AUTHORIZES ANY OTHER PERSON TO ASSUME FOR IT ANY OTHER LIABILITY IN CONNECTION WITH THE SALE INSTALLATION MAINTENANCE OR USE OF ITS PRODUCTS 3COM SHALL NOT BE LIABLE UNDER THIS WARRANTY IF ITS TESTING AND EXAMINATION DISCLOSE THAT THE ALLEGED DEFECT IN THE PRODUCT DOES NOT EXIST OR WAS CAUSED BY CUSTOMER S OR ANY THIRD PERSON S MISUSE NEGLECT IMPROPER INSTALLATION OR TESTING UNAUTHORIZED ATTEMPTS TO REPAIR OR ANY OTHER CAUSE BEYOND THE RANGE OF THE INTENDED USE OR BY ACCIDENT FIRE LIGHTNING OR OTHER HAZARD LIMITATION OF LIABILITY IN NO EVENT WHETHER BASED IN CONTRACT OR TORT INCLUDING NEGLIGENCE SHALL 3COM BE LIABLE FOR INCIDENTAL CONSEQUENTIAL INDIRECT SPECIAL OR PUNITIVE DAMAGES OF ANY KIND OR FOR LOSS OF REVENUE LOSS OF BUSINESS OR OTHER FINANCIAL LOSS ARISING OUT OF OR IN CONNECTION WITH THE SALE INSTALLATI
49. e address format would be 0x12 0x34 0x56 0x78 The Ox indicates that the subsequent digits represent hexadecimal values Netmask The netmask also known as the subnet mask is used when multiple physical networks share the same IP address The bits in the mask determine those bits of the IP address that specify various subnetworks The mask is determined locally Broadcast Address The broadcast address is a special group address It denotes all stations on the network and all the bits are set to one For example if you entered 128 45 255 255 the message would be broadcast to all IP hosts on network 128 45 Default Gateway Address The default gateway address is the Internet address of the gateway used when there are multiple IP networks The default gateway address is administered locally usually by an MIS department To set the default gateway address enter the set gateway command followed by the default address If you omit the address this message appears Usage set gateway address where address is the IP default gateway address g set gateway 128 45 76 10 Setting Up the Hub 4 5 Setting the Password Access to the hub is password protected To display the password prompt when the hub is first powered up press any key The modem init string AT amp F appears briefly You are then prompted for the password The hub is shipped with no password installed At the password prompt press Enter You can set the
50. e effect only when the system is reset To display the current value of the Target Token Rotation Time parameter enter the show treq command This display appears Current T Req 165000 microseconds Initialize T Req as 160000 microseconds Link Error Rate LER The Link Error Monitor LEM examines the Link Error Rate LER per active port as part of its responsibility for keeping link quality at an acceptable level The LEM uses a threshold test to compare the current LER cutoff threshold to the LER alarm threshold NOTE You must always keep the LER_Alarm parameter larger than the value entered for the LER_Cutoff parameter These two thresholds are explained below LER_Alarm This threshold is the LER at which a link connection exceeds the present threshold and will generate an alarm The factory set default is 10 E 08 10 8 This error rate is equivalent to about one error per second Setting Up the Hub 4 9 Set this value higher if the link between stations must handle higher error levels This can be necessary if you are waiting for minor unit or cable repairs but the ring is still operational Set this value lower if you are confident of the quality of the link To change the LER_Alarm parameter follow these steps 1 Enter the set ler alarm command Type set ler alarm Enter You are prompted for the module number and the port number Module Port The current LER values are displayed followed by a prompt
51. e information in the Address Resolution Protocol ARP table of the hub The Address Resolution Protocol maps known IP addresses 32 bits long to MAC addresses 48 bits long To display the contents of the ARP table type arp dump To delete the IP address of the host type arp del XXX XXX XXX XXX where xxx xxx xxx xxx is the IP address of the host in Internet dot notation To add an entry to the ARP table type arp set xxx xxx xxx xxx hh hh hh hh hh hh where XXX XXX XXX XXX is the IP address of the host and hh hh hh hh hh hh is the host 48 bit MAC address in noncanonical format Using the Hub 5 21 show log and clear log Commands The fault log keeps a limited history of recent faults that have occurred in the system a To display the fault log type show log A typical fault log is shown below Fault Log 1 10000001 O 0 2 10000002 O 0 The first column shows the order of all faults since the last clear log command The second column is the code specifying the type of fault Refer to Fault Log Error Code Messages in Appendix A for explanations of the error codes The third column is a time stamp in seconds showing when the fault occurred The timer is restarted after each reset The fourth column is the number of resets since the last recorded reset a To clear the fault log type clear log a To display the fault log in reverse order type show log last This could be helpful when the
52. e learning process Students who pass the test receive a certificate of completion For ordering information and details about other courses in 3Com s data networking technology series turn the page Additional 3Com Data Netw orking Courses 3Com s practical self paced training on the networking industry s prevailing standards and architectures provides a cost effective way for professionals to keep pace with the complex planning and supportdemands ofa multivendor data network Each course contains supplementary technical materials organized for easy future reference These courses come in text format with an interactive testing diskette to guide and reinforce the learning process Students who pass the final test receive a certificate of completion Introduction to Bridging and Routing 3CS 011 Network Architectures Standards and Protocols 3CS 330 Introduction to SNM P 3CS 350 Understanding TCP IP 3CS 340A WAN Technologies for Internetworking 3CS 370 Order through your authorized 3Com reseller or local 3Com office Availability in self study format may vary outside the U S To order directly from 3Com Education Services call 1 800 876 3266 press option 7 then option 3 Callers outside the U S should call 408 492 1790 or contact the 3Com office in their area for local pricing and delivery Bons wants to hear from you To ensure the very best 3Com service and Support take advantage of our One Year Warranty on
53. e mode Refer to Accessing Configuration Commands in Chapter 3 for information on accessing the two console command modes 1 12 Overview By interpreting the LEDs on the management module you can a Monitor network activity Determine chassis environmental factors a Discover ring attachment configuration Refer to Interpreting the LEDs in Chapter 5 for detailed information about the LEDs on all hub modules Media Modules Three media modules are currently available Each module can be placed in any slot but the modules must be installed from the bottom up beginning with slot 1 Do not leave empty slots between modules The two leftmost ports on any module installed in slot 1 are designated as attachment ports The module in slot 1 is given a default configuration of dual attachment B A connection Only the two leftmost ports of modules installed in slot 1 can be configured The three modules are a LinkBuilder FDDI 4 port Optic Module fiber media port module a LinkBuilder FDDI 6 port STP Module STP media port module a LinkBuilder FDDI 8 port UTP Module UTP media port module Fiber Media Port Module The fiber media port module provides four ports as shown in Figure 1 6 When this module is installed in slot 1 you can configure the attachment ports the two leftmost ports as B and A S and M or M and M as necessary to support a given attachment Refer to Chapter 4 for instructions for configuring the
54. e pin assignments for the type DB 9 FDDI shielded twisted pair interface connector are shown in Table 2 1 Installing the Hub 2 21 Table 2 1 DB 9 STP Connector Pin Assignments 5 zZ 5 Function Transmit Not used Not used Not used Receive Transmit Not used Not used Receive OMANMNBWNH Unshielded Twisted Pair Cable a The standard UTP cabling type supported by the LinkBuilder FDDI Workgroup Hub is category 5 screened UTP cross over cable with screened RJ 45 connectors as specified by ANSI X3T9 5 The cross over cable connections and color scheme are shown in Figure 2 7 a The maximum length of this cable from the hub to any potential end station is 100 m 328 ft The cross over cable connects the LinkBuilder FDDI hub and the punchdown block ANSI standards specify the operating distances as shown in Figure 2 8 a The pin assignments for the type RJ 45 FDDI unshielded twisted pair interface connector are shown in Table 2 2 Brown 1 5 Orange Green 2 6 Blue Blue 3 7 Green Orange 4 8 Brown Figure 2 7 Cross over Connections on a UTP Cable 2 22 Installing the Hub Table 2 2 RJ 45 UTP Connector Pin Assignments Pin No Function Transmit Transmit Not used Not used Not used Not used Receive Receive AANADNBEWNRE NOTE To minimize RF emissions the connector shell must be connected to hub ground Also the connector shell must completely surround the cable sh
55. eceived 0 packet loss To stop the transmission of echo frames before the specified number of responses has been achieved press Ctrl D If you request a very large count option and the command has not completed its run the transmission of echo frames will be aborted by a logout or a timeout route Command The route command allows you to add and delete entries in the routing table for the specific host indicated by the destination and gateway addresses You can also display the destination and gateway addresses a To add a destination and gateway to the routing table use this format route add XXX XXX XXX XXX YYY YYY YYY YYY where xxx xxx xxx xxx is the destination IP address and yyy yyy yyy yyy is the gateway IP address 5 20 Using the Hub By including a metric option you can indicate the number of hops number of gateways separating the source and destination to the designated destination network For example to indicate five hops in the above command line type route add 128 87 45 12 128 87 45 33 5 To delete a route from the routing table use the IP address in Internet dot notation For example type route del 128 87 45 12 128 87 45 33 To determine the IP addresses of the destination and gateway enter the route dump command For example type route dump Enter This display appears DESTINATION GATEWAY 128787700 128 87 45 15 arp Command The arp command allows you to display and chang
56. eeded to make the 3Com LinkBuilder FDDI Workgroup Hub operational The list also shows where each step is discussed in this user guide 1 Unpacking the hub and modules Quick Start Chapter 2 Unpacking the Hub Installing Modules Installing the modules Quick Start Chapter 2 Installing Modules Connecting a terminal Chapter 2 Accessing the Hub Determining legal port connections Chapter 2 Planning Connections Chapter 3 Attachment Options Port Connections Attaching the hub to the ring Chapter 2 Connecting to the Dual Ring Attaching other devices to the hub Chapter 2 Data Flow Specifications 2 Quick Start Configuring attachment ports Chapter 3 Configuring Modules Setting up the hub for network operations Chapter 4 Setting Addresses Using Station Management Parameters Downloading New Images Monitoring hub operations Chapter 5 Getting Hub Information Interpreting the LEDs Using Miscellaneous Commands Unpacking the Hub The FDDI Workgroup Hub is shipped separately from the management module and media port modules To unpack the hub follow these steps 1 2 Open the shipping container and carefully remove its contents Return all packing materials to the shipping container and save it If the hub must be returned ship it in its original shipping contai
57. er n Connect the equipment into an outlet on a circuit different from the one which the receiver is connected to n Consult the dealer or an experienced radio TV technician for help The user may find the following booklet prepared by the Federal Communications Commission helpful The Interference Handbook This booklet is available from the U S Government Printing Office Washington D C 20402 Stock No 004 000 00345 4 NOTE In order to maintain compliance with the limits of a Class B digital device 3Com requires that you use quality interface cables when connecting to this device Changes or modifications not expressly approved by 3Com could void the user s authority to operate this equipment Suggested cable types are 0 Thin Ethernet 50 ohm for BNC connections 3C530 xxx or equivalent n Thick Ethernet 50 ohm for AUI connections 3C120 xxx or equivalent n For UTP and STP connections Unshielded twisted pair 100 ohm Level 3 LAN and high speed data cable Example Anixter CM 00424BAG 3 or equivalent Level 4 extended distance LAN cable Example Anixter CM 00424BAG 4 or equivalent Shielded twisted pair 100 ohm Level 5 data grade media cable Example AT amp T type 2061 1061 or equivalent Shielded twisted pair 150 ohm Suggested cable type IBM type 1 specification no 4716748 type CL2 CM or MP or equivalent WARNING This equipment 3C784 has been tested and found to comply with the limits f
58. f 350 700 mV peak to peak a Cable fault detect a DB 9 cable connector specifying M as a male connector and A B and S as female connectors Overview 1 5 Unshielded Twisted Pair UTP The ANSI TP PMD standard provides these services for UTP a Cable requirements for category 5 UTP as defined by EIA TIA 568 a __ Electrical requirements for UTP transceivers E FDDI UTP cable connector Physical PHY Protocol The Physical protocol is responsible for encoding and decoding of data and control information on the FDDI network It specifies the following a 4B 5B nonreturn to zero inverted NRZI encoding scheme for fiber and STP modules a MLT 3 with stream cipher encoding scheme for UTP modules a Clocking rules a Clocking frequency of 125 MHz __ Serial to parallel conversion rules Media Access Control MAC Protocol The Media Access Control protocol controls the flow of data on the FDDI ring The MAC typically exists in every hub and station accessed by the FDDI ring but stations without MACs are allowed This protocol specifies the following a Token passing protocol a Capture and retransmission of token Packet formation and framing of data a Address generation and recognition a 32 bit cyclic redundancy check CRC verification and error detection a Recovery mechanisms 1 6 Overview Le NOTE In contrast to the PMD protocol the PHY and MAC protocols are media independent that is the same protocols fun
59. f frames transmitted fddiMACToken Ct Number of tokens fddiMACError Ct Number of error frames fddiMACLost Ct Number of frames with format errors fddiMACNotCopied Ct Number of frames not copied fddiMACRingOp Ct Number of ring recoveries Show Neighbor Stations To determine the hub s upstream and downstream neighbor station addresses enter the show neigh command Figure 5 5 illustrates the 48 bit addresses of a hub s neighbors gt sh neigh MAC Upstream Neighbor 40 0A 1F B3 CC 24 MAC Downstream Neighbor 40 0D 4F 33 40 AE Figure 5 5 Display of Neighbors Addresses Show Station Identification To discover the station s FDDI identifier and MAC address enter the show sid command Figure 5 6 shows the results of entering this command gt sh sid Station ID 00 00 02 60 8C EA EB EE MAC SMT Addr 02 60 8C EA EB EE noncanonical LLC Addr 40 06 31 57 D7 7 canonical Figure 5 6 Display of Station Identifier Using the Hub 5 5 NOTE The canonical form is a hexadecimal string written from left to right with hyphens separating the individual octets The noncanonical form uses colons instead of hyphens as separators Show Ports Information To view the details of a port module enter the show ports command followed by the slot number of the specified module If you enter this command using the number of an empty slot this message appears That port module slot is empty
60. g only The syntactic representation for a 32 bit integer that consists of four 8 bit numbers written in base 10 with periods dots separating them The normal direction of data flow on a token ring network Also the adjacent station in the transmission ring path A dual ring LAN topology in which two separate fiber or copper cables provide signal paths on which information travels in opposite directions The second ring provides a backup for the first ring in the event of failure of the first primary ring A pair of counter rotating logical rings An FDDI redundant topology This refers to one of two situations in the first a dual MAC station is connected to is homed on both rings at the same time The second situation involves redundant attachments of a dual attached station or concentrator to the ring s with one attachment functioning as a backup link Dual ring of trees FDDI Fiber optic cable Gateway IP ISO Logical ring Glossary 3 One of the FDDI supported topologies in which only one ring is permitted to have multiple trees of any depth consisting of single attached concentrators and stations which are cascaded off the main ring Fiber Distributed Data Interface The local area networking standard that provides high bandwidth for interconnecting computers and peripheral devices using a fiber optic medium in aring configuration The FDDI specification is made up of standards that correspond
61. gement console command mode and the primitive console command mode enable you to set and display the basic parameters needed to configure and operate the hub The commands are grouped into three functional categories that are defined below E Use set commands to institute various functions a Use show commands to display default parameter settings and reflect any changes you make a Use miscellaneous commands to support various diagnostic and troubleshooting functions 4 2 Setting Up the Hub Command Descriptions For a complete listing and detailed description of all the commands refer to Appendix C Commands a Fora list of the set commands with brief definitions type set or set help a Fora list of the show commands with brief definitions type show or show help a To display a list of the miscellaneous commands with brief definitions type help or Display of Command Results You can use the set commands to change various parameters The results of several management console command actions are shown in a two line display as follows Current Initialize Where Current is the present parameter setting and Initialize is the desired parameter setting that will take effect when the hub is reset Setting Up the Hub 4 3 Setting Addresses The hub management module uses the TCP IP network environment for downloading images and managing the hub Refer to the section Downloading New Images
62. gh automated on line systems CardBoard Bulletin Board Service CardBoard is 3Com s menu driven bulletin board service It contains the most current adapter information in downloadable files CardBoard provides Software drivers Technical tips Product information Diagnostic programs Software patches and fixes These files are easy to access through a modem connection Call the CardBoard telephone number nearest you Australia 61 2 955 2073 Up to 2400 baud 8 data bits no parity 1 stop bit France 33 1 69 86 69 54 Up to 9600 baud 8 data bits no parity 1 stop bit Germany 49 89 62732 188 189 Italy Up to 9600 baud 8 data bits no parity 1 stop bit 39 2 27 30 06 80 Up to 9600 baud 8 data bits no parity 1 stop bit D 2 Technical Support U K 44 442 278278 Up to 14400 baud 8 data bits no parity 1 stop bit U S 1 408 980 8204 Up to 19200 baud 8 data bits no parity 1 stop bit For information on international CardBoard access numbers added since this manual was published contact your local 3Com office Refer to the list of international sales offices later in this appendix Automated Fax Service 3Com s interactive fax service provides data sheets technical articles diagrams and troubleshooting instructions on 3Com products 24 hours a day seven days a week To access this service dial 1 408 727 7021 from anywhere in the world using your touch tone telephone Within
63. guration Commands 3 8 Management Console Commands 3 8 Primitive Console Commands 3 9 Accessing the Primitive Console Command Mode 3 9 Returning to the Management Console Command Mode 3 11 Port Connections 3 11 Configuring Modules 3 15 Using the STP Cascade Connector 3 18 Chapter 4 Setting Up the Hub Commands 4 1 Command Descriptions 4 2 Display of Command Results 4 2 Setting Addresses 4 3 IP Address 4 3 Netmask 4 4 Broadcast Address 4 4 Default Gateway Address 4 4 Setting the Password 4 5 Setting Attachment Port Configurations 4 6 Using Station Management Parameters 4 7 Setting SMT Parameters 4 7 Neighbor Notification Timer T Notify 4 7 Target Token Rotation Time T Req 4 8 Link Error Rate LER 4 8 Displaying SMT Parameters 4 11 Maximum Token Rotation Time T Max 4 11 Negotiated Time T Neg 4 11 Valid Transmission Timer TVX 4 11 Downloading New Images 4 12 Downloading from the TFTP Option 4 12 Displaying the Current Download Method 4 14 Chapter 5 Using the Hub Getting Hub Information 5 1 Show Hub Configuration 5 1 Show MAC Frame Statistics 5 1 Show IP Addresses 5 3 Show MIB Counters 5 3 Show Neighbor Stations 5 4 Show Station Identification 5 4 Show Ports Information 5 5 Module Designation 5 6 PMD Class 5 6 PHY Type 5 7 Neighbor 5 7 PCM State 5 7 Connect State 5 9 LER Alarm and LER Cutoff 5 9 LER Estimate 5 9 LEM Rejects 5 10 LEM Count 5 10 Show Ring State 5 10 Interpreting the LEDs 5 11 Management Module LEDs
64. hat is automatically activated when a downstream station detects a fault in the primary ring and the stations on either side of the fault connect the two rings to create a single ring When this occurs the primary and secondary rings have been concatenated Index command C 17 C 22 3Com sales offices D 3 3ComFacts D 2 A A port 2 23 accessing the hub 2 16 via a modem 2 16 2 18 via a PC with terminal emulation 2 16 via a terminal 2 16 via Telnet 2 16 2 19 accessing the primitive console command mode 3 9 Address Resolution Protocol ARP 5 20 addresses broadcast 4 4 default gateway 4 4 IP 4 3 netmask 4 4 American National Standards Institute ANSI 1 3 ANSI protocols 1 3 Media Access Control 1 5 Physical 1 5 Physical Medium Dependent 1 4 Station Management 1 6 ANSI standard UTP cabling distances 2 22 arp command 5 20 C 16 Ask3Com D 2 ATTACH LED 3 16 5 12 attachment options 3 1 dual attachment 3 2 dual homing attachment 3 6 null attachment 3 5 single attachment 3 4 attachment ports 4 6 configuring 3 11 3 12 4 6 displaying configuration of 5 1 B B port 2 23 battery installation 2 7 specifications B 1 baud rate changing 2 16 blanking plates 2 15 boot methods 4 15 broadcast address 4 4 bulletin board information system CardBoard D 1 Cc cabling fiber optic 1 4 2 20 shielded twisted pair 1 4 2 20 unshielded twisted pair 1 5 2 21 cabling rules 2 20
65. he secondary ring dashed line enters through port B as Secondary In SI and exits through port A as Secondary Out SO For both master M and slave S ports the primary ring enters the port as PI and exits as PO The secondary ring never connects to these two ports 2 24 Installing the Hub DAS Figure 2 9 Direction of Data Flow Through a Hub and Stations The acronyms used in Figure 2 9 are defined below and described in Chapter 3 m DAS Dual attachment station a DAC Dual attachment concentrator hub a SAS Single attachment station Connecting to the Dual Ring To attach the hub to an FDDI dual ring follow these steps 1 Install a fiber module in slot 1 on the hub 2 Insert two fiber optic cables from the dual ring into the two leftmost ports B and A of the fiber module The fiber optic cables must terminate in MIC connectors Installing the Hub 2 25 The default configuration of the attachment ports the two leftmost ports on the module installed in slot 1 is B A If the attachment ports have been configured differently as shown by the ATTACH LEDs on the management module you must reconfigure them as detailed below 1 Configure the attachment ports as B and A Type set attach This selection prompt appears Select one of the following 1 B A 2 S M 3 M M Attachment port configuration Select the attachment port configuration that you want For example
66. he communication medium on an FDDI ring in place of optical fiber The Internet standard protocol for remote terminal connection service Telnet lets a user interact with a remote time sharing system at another site as though the user s terminal connected directly to the hub or concentrator Trivial File Transfer Protocol A simplified version of the File Transfer Protocol FTP used to transfer files The condition in which both rings are fully functional The special frame that passes from station to station on an FDDI ring any time the ring can carry data The token is captured by a station that is ready to transmit data and is released back to the ring at the end of the allotted transmission time During token capture time only the station possessing the token can transmit data A physical topology consisting of a hierarchy of master slave connections between a concentrator and other FDDI nodes including subordinate concentrators A connection between tree ports M ports A physical loop topology either open or closed employing two optical fiber signal paths one in each direction forming a sequence of peer connections between FDDI nodes 8 Glossary Upstream UTP Wrap The direction on a token ring network that is contrary to the normal direction of data flow that is downstream Unshielded Twisted Pair A cable consisting of two twisted pair conductors that are not insulated A ring recovery condition t
67. hments to the FDDI network One of them functions as a backup link if the primary link fails This type of attachment is especially useful for connecting to mission critical devices Figure 3 5 illustrates valid connections for a dual homed hub Dual i Primary homed backup i a link link Dual homed hub A B a Server on FDDI Workstation on FDDI Host on FDDI Figure 3 5 Dual Homing Connections Ports A and B are both connected to the primary ring Following the B precedence rule the B port always takes precedence and becomes the primary link If the connection to the B port fails the A port serves as the backup and automatically becomes the primary port The dual homed hub shown in Figure 3 5 is actually a dual attachment hub but only one port is active at a time Default Configuration Configuring the Hub 3 7 Table 3 1 shows the hub s factory default configuration on start up Table 3 1 LinkBuilder FDDI Workgroup Hub Default Configuration Description T Notify TVX T Req LER cutoff LER alarm Attachment IP address IP netmask IP broadcast IP default gateway Boot server IP address Boot method Boot file Password Baud rate This value cannot be changed Factory Set Default 30 seconds 2 6214 milliseconds 165 milliseconds 10 E 07 10 E 08 B A 0 0
68. ield LinkBuilder FDDI hub Cross over cable 3 gt lt 23 ft 7mmaximum Punchdown block lt 295 ft 90 m maximum Wall jack 10ft 3m maximum FDDI end station Figure 2 8 UTP Cabling Distances per ANSI Standards Installing the Hub 2 23 Data Flow Specifications The FDDI standard specifies that data travels on the primary ring in a counterclockwise direction and that data traveling on the secondary ring rotates clockwise Refer to Figure 3 1 As you attach the hub to the ring and network devices to the hub be aware of the data flow direction Table 2 3 shows the four supported port types and the direction of data flow through each port Figure 2 9 illustrates the various port types and the data flow direction allowed by the FDDI standard Table 2 3 FDDI Port Types Port Data Flow Direction Use A Primary In Secondary Out PI SO Connects dual attachment devices to the trunk ring B Primary Out Secondary In Connects dual attachment PO ST devices to the trunk ring M Master PO PI Connects single attachment devices to the hub port uses the primary ring only S Slave PI PO Connects single attachment devices to the hub uses the rimary ring only Table 2 3 and Figure 2 9 show that the primary ring solid line enters the A port as Primary In PI and exits as Primary Out PO through port B T
69. ilable UTP Media Port Module Figure 1 9 shows the front panel of the UTP media port module which provides eight ports configured as M ports by default You can specify any port configuration B A S M or M M for the attachment ports No adapter or special connector is needed for the UTP module If you install three UTP modules in the hub 24 UTP ports are available UTP PORT MODULE Fe or o o o x PWR m oe o o j o oe gt o o Figure 1 9 UTP Media Port Module Front Panel Chapter 2 Installing the Hub This chapter describes installation of the LinkBuilder FDDI Workgroup Hub It includes the following topics Unpacking the hub Rack mounting the hub Equipping the hub Installing and removing modules Accessing the hub Understanding data flow Installing an optional optical bypass switch TA NOTE For a step by step procedure for installing the hub and preparing it for L amp E network operations see the Quick Start chapter at the beginning of this guide Unpacking the Hub To unpack the hub follow these steps 1 2 Open the shipping container and carefully remove its contents Return all packing materials to the shipping container and save it If the hub must be returned ship it in its original shipping container or one providing equivalent protection or the warranty will be voided Verify that you have received all items on the packing list and inspect each ite
70. in slot 1 serve as attachment ports You can configure these ports to be any of the following m B A dual attachment m S M slave master m M M master master The way you configure these ports determines the type of attachment supported by the hub The configurable attachment types are as follows a Dual attachment a Dual homing attachment a Single attachment a Null attachment Table 3 2 shows how to configure the attachment ports for the desired attachment type 3 12 Configuring the Hub Table 3 2 Selecting Port Configurations for Attachment Types Attachment Type Attachment Ports Configuration Dual attachment B A Dual homing attachment B A Single attachment S M Null attachment M M The B A configuration supports both dual attachment and dual homing The B and A ports are used to dual attach the hub to the trunk ring or dual home to other hubs The FDDI connection rules connect the MAC and the attachment ports to the primary ring The secondary ring is used only to complete the primary ring through the hub and wrap the ring if a fault occurs or a station fails on the primary ring If you attach the hub in a dual homed configuration the B port is used as the primary link B precedence rule and the A port becomes the backup link If the primary link fails the backup link is enabled To achieve a dual homed configuration connect the A and B ports to neighbor M ports on one or two other hubs or other devices Config
71. ional this reply is displayed no answer from 128 45 87 20 You can specify two options with the ping command a size This optional argument has a default value of 56 bytes and specifies the number of data bytes in the echo frames a cnt This optional argument count has a default value of one 1 and specifies the number of echo frames to be sent If you type the size option with the ping command the echoing display includes the host address and the number of bytes in the frame which should equal the size data bytes plus eight frame header bytes For example if you type this string in which 64 is the size option variable ping 128 45 87 10 64 this response is displayed PING 128 45 87 10 64 data bytes 128 45 87 10 is alive Using the Hub 5 19 If you type the count option with the ping command the resulting display contains the ping statistics which include the number of packets sent the number of packets received and the percentage of packets lost For example if you type this string in which 64 is the size option variable and 5 is the count option variable ping 128 45 87 10 64 5 this response is displayed PING 128 45 87 10 64 data bytes 72 bytes from 128 45 87 10 icmp_seq 0 72 bytes from 128 45 87 10 icmp_seq 1 72 bytes from 128 45 87 10 icmp_seq 2 72 bytes from 128 45 87 10 icmp_seq 3 72 bytes from 128 45 87 10 icmp_seq 4 128 45 87 10 PING STATISTICS 5 packets transmitted 5 packets r
72. istatic bag Prepare a clean level work area nearby on which to place the module Avoid contact with any of the module s components 4 Insert the module slowly into its slot The printing on the module s front panel indicates its correct horizontal orientation 5 Gently align and push the module s bus connector into its slot in the backplane of the hub 6 When the module is completely seated tighten the captive thumb screws on each end of the module 7 To turn on the hub plug one end of the ac power cord into the back of the hub and the other end into an electrical outlet The PWR LED turns green indicating the hub is on and ready for configuration 2 14 Installing the Hub There is no power switch on the hub Power to the hub is provided by connecting the power cord to the hub and to an ac outlet NOTE The hub allows power on insertion which means that you do not have to unplug the power cord for module insertion or removal When you replace a module reset the hub by pressing the RESET button or entering the reset command Resetting the hub reinitializes the hub and causes the system to run its power on self tests POST CAUTION When the hub is reinitialized any devices connected to the hub are momentarily disconnected This could result in serious data loss unless you take preventative measures before changing installed modules To avoid potential problems enter the disconnect command before activ
73. ive and you enter the show ports command again the Neighbor field displays the last reported port type This is true even if you have physically removed the cable that was previously connected to the port PCM State The PCM Physical Connection Management protocol initializes the connection of neighboring ports and manages the signaling between ports Table 5 5 lists and defines the Physical Connection Management states for the PCM State line in Figure 5 7 5 8 Using the Hub Table 5 5 Physical Connection Management States Physical Connection Management States Active Break Connect Join Next Off Signal Trace Verify Maintenance Maint Definition The port is incorporated into the token ring path A port connection has been broken and a restart process has begun Both ends of the port s requested connection are synchronized This signal ensures that both ends of a connection can enter the active state together The port is exchanging connection information with its neighboring ports The port is in an Off state The port is ready to transmit data The port recognizes a fault condition and is trying to detect its location The port is in the process of entering the Active state The port has moved from the Off state to the Maint state which can be used to determine the status of the neighboring machine Using the Hub 5 9 Connect State The Connect State indicates the state of each po
74. k manager can expect to get about a managed device It defines the access permissions for each data item and the size type and semantics of each data item Media Interface Connector A mated connector pair that provides an attachment between an FDDI node and a fiber optic cable MIC connectors are normally keyed both to prevent accidental reversal of transmit and receive fibers and to ensure connection only to ports of the correct type The agreed upon bit order of transmission Noncanonical addressing is when the most significant bit of the most significant byte is transmitted first The FDDI hub s MAC SMT address appears in noncanonical order when the show sid command is issued A concentrator that can be considered a self contained FDDI network but is not connected to a dual ring backbone It does not contain an A B or S port An optional facility that allows the FDDI optical signal to bypass FDDI nodes when they are powered off A connection between peer ports A B and S ports PHY Ping PMD Port Glossary 5 Physical Layer Protocol The sublayer that describes the medium independent portion of the OSI Physical layer and specifies the rules for encoding digital data for transmission from one FDDI station to another It also provides the link between the PMD and the MAC layer Packet InterNet Groper A program used in the Internet to find out whether or not a host on the network is operational by sending i
75. kaged and shipped separately Two modules the management module and at least one media port module plus the hub constitute the minimum functional setup To unpack the modules follow the steps below CAUTION Each module is packed in an antistatic bag to protect it during AN shipment To avoid damaging any highly static sensitive components on the module or the hub be sure to reduce any static electricity on your person One way to do this is to touch the metal part of the hub You can maintain grounding by wearing a wrist strap attached to the hub 1 Carefully remove each module from its shipping container and set it aside 4 Quick Start 2 Keep all packing and shipping materials If a module must be returned ship it in its original shipping container or one providing equivalent protection or the warranty will be voided 3 One at atime remove each module from its antistatic bag 4 Check the modules for any visible signs of damage If you detect damage immediately notify your network supplier and the carrier that delivered the module 5 Place the modules back in their antistatic bags until you are ready to install them Installing the Modules La NOTE You must install the management module first It can only be installed in slot 0 It will not function in any other slot Install the remaining modules in adjacent slots in numerically ascending order so there are no empty slots between modules When you ins
76. ken Rotation Time for the MAC on the primary ring show tvx Syntax show tvx C 16 Commands Description The show tvx command displays the value of the Valid Transmission Timer fddiMACTvx Value which is the maximum time allowed by the MAC on the primary ring for the receipt of valid frames or tokens Diagnostic and Connectivity Commands arp Syntax arp dump del set Simplified Syntax arp dump arp del host_address arp set host_address hardware_address Description The arp command displays information contained in the Address Resolution Protocol ARP table It also allows you to change information stored in the ARP table a arp dump Displays the current contents of the ARP table a arp del Deletes the IP host address arp Set Adds the host IP address and the host 48 bit FDDI address in noncanonical format tothe ARP table clear Syntax clear log alarm Description The clear log command clears the fault log which contains a limited history of recent faults that have occurred in the system Commands C 17 The clear alarm command clears the HIGH TEMP SEEN alarm that appears on the console when the condition existed previously but is no longer present connect Syntax connect Description The connect command connects the hub to the FDDI ring disconnect Syntax discon disconnect Description The disconnect command disconnects the hub from the FDDI ring It also removes all ports fr
77. l attachment configuration A Figure 3 7 Using Two STP Cascade Connectors to Allow a Dual Attachment Configuration Configuring the Hub 3 19 To use an STP module in a dual attachment configuration for example follow these steps 1 If the attachment ports are not currently configured as B A configure the attachment ports to be B A by invoking the set attach command Reset the hub This step is unnecessary if the attachment ports are already set as B A Install two cascade connectors Insert one cascade connector in each of the two leftmost ports of the STP module in slot 1 Attach the appropriate cables to the two cascade connectors The cable from port number 1 the B port should attach to port A on the device to be dual attached The cable from port number 2 the A port should attach to port B on the device Chapter 4 Setting Up the Hub The LinkBuilder FDDI Workgroup Hub is shipped ready to plug in and use without the need to change any parameters In all probability however you will want to make a number of changes to adapt the hub to your network environment This chapter discusses how to use the management console commands to set up the hub and make any desired parameter changes Topics include a Using commands to Set addresses Set the password Set attachment port configuration Set station management parameters a Downloading new images Commands The commands supported by the mana
78. llowing appears Current configuration is B A Initialize attachment as S M This message means that the hub s current attachment port configuration is B A dual attachment When you reset the hub the attachment ports will be initialized as S M Refer to Chapter 3 Configuring the Hub for descriptions and diagrams of the attachments supported by the LinkBuilder FDDI Workgroup Hub Setting Up the Hub 4 7 Using Station Management Parameters The hub supports a number of station management SMT parameters to help you understand and manage the processes occurring in the FDDI ring You can set and display three of these parameters You can display three other parameters but you cannot set them Setting SMT Parameters Using the console interface you can display and change these SMT parameters a Neighbor Notification Timer T Notify a Target Rotation Time T Req m Link Error Rate LER alarm and cutoff values Neighbor Notification Timer T Notify The T Notify parameter functions as one element of the Neighbor Notification protocol This protocol allows a MAC to determine the address of its logical upstream and downstream neighbors The Neighbor Notification process is performed independently for each MAC in a station The process facilitates the detection of isolation of and recovery from network errors by supplying each MAC with logical fault information The protocol performs these functions by periodically i
79. lot number xx Meaning You entered a slot number for a slot that does not exist Action The LinkBuilder FDDI Workgroup Hub has four slots Slot 0 can only be used for the management module You can insert any of the media modules in slots 1 2 and 3 Network is unreachable Meaning The IP address that you entered does not match your current network Action Reenter the correct network address System Messages A 3 Route already exists Meaning The route you attempted to add with the route command duplicates a route that already exists in the routing table Action Reenter the route command with a different route specification Route does not exist Meaning The route you attempted to delete with the route command does not exist in the routing table Action Reenter the route command with the correct route specification That port module slot is empty Meaning No module is installed in the selected slot Action Examine the hub to determine where each module is installed and enter a correct slot number The path filename is more than xx characters in length Meaning The path filename that you entered is too long Action Reenter the path filename using no more than xx characters The xx exponent must be lt the current alarm exponent Meaning The LER cutoff exponent must be less than the LER alarm exponent Action Set the cutoff exponent to be less than the alarm exponent A 4 System Messages The xx exponent m
80. m for damage If you find any omissions or damage contact your network supplier and the carrier that delivered the package 2 2 Installing the Hub Mounting the Hub in a Rack Mounting the hub in a rack involves installing mounting brackets onto the hub and mounting the hub in the rack To mount the hub in a 19 inch distribution rack follow these instructions 1 Lift the hub from its packing container and place it on a table or other flat surface You should get help lifting the hub it weighs slightly more than 15 pounds 6 8 kg You will also need help when screwing the hub into the rack Determine where you will attach the hub to the rack Align the mounting brackets to the holes in the vertical rails of the rack and mark the holes where you will screw the mounting brackets Attach the two supplied mounting brackets to the hub using the screws that came with the hub See Figure 2 1 Locate the holes on each side of the hub into which you will attach the mounting brackets If you lose one of the screws replace it with a 10 32 x 3 8 inch pan head cross recessed screw with an integral lock washer With the help of at least one other person carefully lift the hub into position in the rack Align the mounting brackets to the holes you designated for mounting Installing the Hub 2 3 While holding the hub in place insert the four mounting screws supplied with the hub into the mounting holes in each bracket two scre
81. ner or equivalent or the warranty will be voided Verify that you have received all items on the packing list and inspect each item for damage The basic package includes the following items a LinkBuilder FDDI Workgroup Hub base unit a LinkBuilder FDDI Workgroup Hub User Guide a LinkBuilder FDDI System Software diskette version 1 0 Standard ac power cord a Two brackets and eight screws for rack mounting Four rubber pads for tabletop placement Quick Start 3 The LinkBuilder FDDI System Software diskette version 1 0 contains a readme file and a backup image for the flash EPROM A 3 volt lithium battery is shipped with the management module The battery is in a small bag inside the management module shipping container If you ordered an STP media port module one cascade connector will be shipped with the module For complete instructions on installing the hub the modules and the battery see Chapter 2 Installing the Hub 4 Place the hub either in an EIA 19 inch rack or on a table or desk a For rack mounting attach the two brackets to the front sides of the hub Then attach the brackets to the front mounting rails of the rack Use the eight screws that are supplied with the hub See Figures 2 1 and 2 2 a For tabletop placement fasten the rubber pads that come with the hub on the four bottom corners of the base unit Unpacking the Modules The management modules and media port modules are pac
82. nfirming your selection and showing that you also need to enter the TFTP server s IP address and the image filename Boot parameters Method gt TFTP Server Filename Setting Up the Hub 4 13 Set the TFTP server s IP address Type set boot server Enter This prompt appears Enter server IP address in dot notation Type the server s IP address For example type 123 44 55 66 Enter This confirmation appears Boot parameters Method TETP Server 123 44 55 66 Filename Set the image filename to be used Type set boot filename The file name prompt appears Enter filename Type the name of the image file after the question mark For example type newimag Enter This display appears showing your entries Boot parameters Method LOCAL Server 123 44 55 66 Filename newimag Optionally if connection to the TFTP server is through a gateway you must enter the gateway address 4 14 Setting Up the Hub 7 Enter the default gateway s IP address For example type set gateway 123 44 66 88 Enter Your local administrator should provide the gateway address you need 8 Reset the hub Press the RESET button The new image is now downloaded and stored in the flash EPROM If no errors are encountered the hub is reset and the new image is executed Displaying the Current Download Method To display the current download method enter the show boot method c
83. nformation until the information is returned to the originating station The ring reconfiguration that takes place when a break occurs in the primary ring and the dual attached hubs and stations on either side of the fault detect and automatically bypass it Single Attachment Concentrator A concentrator that connects a single ring only usually the primary ring to the FDDI network Single Attachment Station A station that offers a single attachment to the FDDI network The connection is to one ring only usually the primary ring and that attachment is made through a concentrator there is no direct attachment to the trunk ring Shielded Twisted Pair Distributed Data Interface FDDI over shielded twisted pair per the SDDI de facto STP standard In the dual counter rotating token ring architecture the ring that is generally used for automatic recovery in the event of a break in the primary ring Station Management The function within an FDDI node responsible for managing maintaining and controlling all the local and remote station functions Station STP Telnet TFTP Thru state Token Tree Tree mode connection Trunk Glossary 7 An addressable node on an FDDI network capable of transmitting repeating and receiving information A station has exactly one SMT at least one MAC at least one PHY and at least one PMD Shielded Twisted Pair Shielded four conductor electrical cable that can be used as t
84. nitiating a request response frame exchange between a MAC and its nearest downstream neighbor The T Notify parameter determines how frequently Neighbor Information Frames NIFs are broadcast to the ring The T Notify parameter is stored in nonvolatile RAM You can set it using the set tnotify command The factory set default for T Notify is 30 seconds but it can be set in the range of 2 to 30 seconds A change to T Notify takes effect immediately To show the current value of T Notify enter the show tnotify command A display similar to the following appears T Notify 20 seconds 4 8 Setting Up the Hub Target Token Rotation Time T Req The FDDI ring is initialized every time a station joins or leaves the ring During the initialization process all stations on the ring agree on a token rotation time This is the maximum amount of time that any station has to wait for a token to arrive and it establishes the minimum level of service on the ring Level of service relates to how often a station requires access to the token The Target Token Rotation Time TTRT is the service level required by an individual station During the initialization process each station makes a request for a level of service that is identical to its local TTRT This service level request is called T Req T Req is stored in nonvolatile RAM and can be set using the set treg command The factory set default is 165 milliseconds Changes to T Req tak
85. ntially conforms to 3Com s applicable published specifications Customer assumes responsibility for the selection of the appropriate applications program and associated reference materials 3Com makes no warranty that its software products will work in combination with any hardware or applications software products provided by third parties that the operation of the software products will be uninterrupted or error free or that all defects in the software products will be corrected For any third party products listed in the 3Com software product documentation or specifications as being compatible 3Com will make reasonable efforts to provide compatibility except where the non compatibility is caused by a bug or defect in the third party s product STANDARD WARRANTY SERVICE Standard warranty service for hardware products may be obtained by delivering the defective product accompanied by a copy of the dated proof of purchase to 3Com s Corporate Service Center or to an Authorized 3Com Service Center during the applicable warranty period Standard warranty service for software products may be obtained by telephoning 3Com s Corporate Service Center or an Authorized 3Com Service Center within the warranty period Products returned to 3Com s Corporate Service Center must be pre authorized by 3Com with a Return Material Authorization RMA number marked on the outside of the package and sent prepaid insured and packaged appropriately for saf
86. ny connection of an A B or S port with an M port is a tree mode connection When the wrap condition involves a port connected in tree mode an M port the WRAP LED remains off 5 14 Using the Hub FAN FAIL LED If the FAN FAIL LED shows amber the fan has failed and must be replaced You must send the hub base unit back to 3Com to replace the fan Contact your 3Com representative for a Return Materials Authorization RMA HI TEMP LED If the HI TEMP LED shows amber it means that the temperature in the hub exceeds 50 C Check to be sure that nothing is blocking air flow around the chassis If the temperature in the wiring closet exceeds 50 C and nothing is blocking the flow of air into the hub you should install a cooling system for the closet LOW BATT LED If the LOW BATT LED is on a low battery condition exists and nonvolatile RAM will not retain data if power is lost You must replace the battery See the instructions in the section Installing the Battery in Chapter 2 Dangerous Environmental Conditions Display If any of the environmental dangers exist Fan Fail Hi Temp or Low Batt the appropriate LED listed in Table 5 8 will show amber In addition an appropriate message appears on a terminal directly or remotely Telnet connected to the hub When one or more of these conditions exist a message is appended to any displayed command string or new line followed by Enter that you type For example if all c
87. odule is installed in the hub the entire hub complies with the limits of a Class A digital device Appendix C Commands This appendix describes the commands in the two command sets used to manage and configure the hub The two command sets are a Management console commands a Primitive console commands The commands in each set are grouped into categories and arranged alphabetically within each category Management Console Commands The management console command set contains three categories of commands Set commands a Display commands a Diagnostic and connectivity commands Set Commands set attach Syntax set attach Description The set attach command allows you to set the configuration of the two leftmost ports on the module in slot 1 C 2 Commands Example When you enter the set attach command you are prompted to select an attachment configuration as shown below Select one of the following 1 B A 2 S M 3 M M Attachment port configuration The possible selections are defined below a B A Sets ports as B and A for dual attachment or dual homing a S M _ Sets ports as S and M for single attachment a M M Sets ports as M ports for null attachment only set baud Syntax set baud Description The set baud command allows you to set the baud rate for the serial console port Examples When you enter the set baud command you are prompted to select a baud rate as shown below Select one of
88. om the ring help Syntax help Description The help or command displays a list of commands with brief command descriptions logout Syntax logout Description The logout command logs the user out of a console session In addition to closing a console session it also closes a Telnet session if access to the console has been through Telnet C 18 Commands ping Syntax ping host_address size cnt Simplified Syntax ping host_address The host address in Internet dot notation ping host_address size Optional Specifies the number of data bytes defaults to 56 bytes ping host_address cnt Optional Specifies the number of echo frames to be sent The default is one 1 Description The ping command sends echo frames composed of random data bits to a host to test the IP stack reset Syntax reset Description The reset function reinitializes the hub and performs the power on self tests POST Before the reset begins you are asked this question Are you sure y n You can enter the reset command on the command line or press the RESET button that is recessed on the management module route Syntax route add delete destination gateway metric route dump Commands C 19 Simplified Syntax route add destination route add destination gateway route add destination gateway metric route delete destination route delete destination gateway route delete destination gateway metric rou
89. ommand This command displays the current download method the IP address of the boot server and the filename of the image as shown below Boot parameters Method TFTP Server 128 34 56 78 Filename newimag To display the status of the last download enter the show boot load command An example of the resulting display is shown below Last download Status TFTP download completed successfully Method 2 TETP Server 2 1283345678 Filename newimag NOTE For a list of the last download status messages that may be displayed refer to the section Download Messages in Appendix A Setting Up the Hub 4 15 Table 4 1 summarizes the available boot methods Table 4 1 Definition of Boot Methods Boot Method Definition LOCAL Runs flash EPROM default TFTP Uses the TFTP protocol and local configuration parameters to load a new image across the network Chapter 5 Using the Hub This chapter discusses how to use the available commands and LED indicators to operate the LinkBuilder FDDI Workgroup Hub This includes m Getting information about hub operation a Interpreting LED behavior a Using miscellaneous commands Getting Hub Information La To get information about data flow on the FDDI ring through the hub enter the show commands described in this section NOTE You can abbreviate the display command show as sh Show Hub Configuration To display the configuration of the attachment ports on the port mod
90. onditions were to exist you would see the following alert message after you entered a command and the terminal displayed the command s response Hardware FAN FAILURE HIGH TEMP LOW BATTERY Only those conditions that exist will be displayed If none exist nothing is displayed Using the Hub 5 15 If a high temperature condition existed but no longer does this message appears Hardware HIGH TEMP SEEN To remove this message enter the clear alarm command as shown below clear alarm Enter This is the only environmental condition that requires you to invoke the clear alarm command The other two danger conditions are cleared only when the condition no longer exists Otherwise the warnings reappear with every subsequent command and new line that you type Reset Function The reset function reinitializes the hub and runs the power on self tests POST You should perform a reset before removing or adding a module to the hub Any devices connected to the hub when a reset is performed are momentarily disconnected until the tests are completed The hub then attempts to reconnect the devices Before the reset begins you are prompted to confirm the reset request This gives you the opportunity to make changes in network connections such as entering the disconnect command which disconnects the hub from the ring This allows you to avoid other problems that could occur with an unexpected interr
91. onnector attached to the first port of an STP module installed in slot 1 Figure 2 6 STP Module Cascade Connector Refer to the section Using the STP Cascade Connector in Chapter 3 for cascade connector configuration instructions Modules NOTE You must install the management module first It can only be installed in slot 0 It will not function in any other slot Install the remaining modules in adjacent slots in numerically ascending order so there are no empty slots between modules Do not insert the management module into the hub until you have installed the battery which is shipped with the module Refer to the section Installing the Battery earlier in this chapter for installation instructions Installing the Hub 2 13 To install the management module and the media modules for the first time follow these steps 1 Remove all jewelry from your hands and wrists 2 If you are installing modules in slots 2 or 3 remove the blanking plates from those slots Keep the removed blanking plates in a safe place for possible future use CAUTION Each module is packed in an antistatic bag to protect it during shipment To avoid damaging any highly static sensitive components on the module or the hub be sure to reduce any static electricity on your person One way to do this is to touch the metal part of the hub You can maintain grounding by wearing a wrist strap attached to the hub 3 Remove the module from its ant
92. or a Class A digital device pursuant to Part 15 of the FCC Rules These limits are designed to provide reasonable protection against harmful interference in a commercial installation This equipment generates uses and can radiate radio frequency energy and if not installed and used in accordance with the instructions may cause harmful interference to radio communications Operation of this equipment in a residential area is likely to cause harmful interference in which case the user will be required to correct the interference at the user s own expense Changes or modifications not expressly approved by 3Com could void the user s authority to operate this equipment vi VDE Class B Compliance 2 Hiermit wird bescheinigt dass die 3C781 3C782 3C783 in Ubereinstimmung mit den Bestimmungen der Vfg 1046 1984 funk entstort sind Der Deutschen Bundespost wurde das Inverkehrbringen dieses G rates angezeigt und die Berechtigung zur Uberpriifung der Serie auf Einhaltung der Bestimmungen einger umt We hereby certify that the 3C781 3C782 3C783 comply with the RFI Suppression Requirements of Vfg 1046 1984 The German Postal Service was notified that the equipment is being marketed The German Postal Service has the right to re test the equipment and to verify that it complies 3Com Corporation 5400 Bayfront Plaza Santa Clara California U S A 95052 8145 Contents Quick Start Road Map to Hub Operations 1 Unpacking the Hub 2 Unpa
93. or supply a server address your response is confirmed as shown in the following example Boot parameters Method LOCAL Server 123 44 55 66 Filename newimag set gateway Syntax set gateway 888 888 888 888 Description The set gateway command allows you to set the IP address ggg gg9 g99 222 for the default gateway set help Syntax set help Description The set help command displays the options available for the set commands set ip Syntax Set IPXXX XXX XXX XXX Lyyy yy yyy YYY ZZZ ZZZ ZZZ ZZZ b Commands C 5 Description The set ip command allows you to set the IP address netmask and broadcast address for IP services set ler Syntax set ler alarm cutoff Simplified Syntax set ler alarm set ler cutoff Description The set ler alarm command sets the link error rate LER alarm threshold fddiPORTLer Alarm The set ler cutoff command sets the link error rate LER cutoff threshold fddiPORTLer Cutoff Example When you enter either command you are prompted for the module number and the port number Module Port The current settings of the LER alarm and LER cutoff are then displayed Current LER Alarm exponent 7 Current LER Cutoff exponent 6 You are then prompted to enter a value for either the LER alarm or the LER cutoff NOTE You must always keep the LER_Alarm parameter larger than the value entered for the LER_Cutoff parameter C 6 Commands set
94. orts of that module The attachment port configuration is stored in nonvolatile RAM Any attachment port configuration changes that you make take effect when the system is reinitialized To reinitialize the hub execute the reset command 3 16 Configuring the Hub All three types of port modules can be installed in slot 1 The type of module you install depends on the medium you are using to connect the hub to the next node Table 3 5 shows how to configure each module for the type of attachment desired and what additional equipment or action is necessary to complete the connection Refer to the section Setting Attachment Port Configurations in Chapter 4 for information about configuring the attachment ports For example if you want to establish either a dual attachment or a dual homed connection configure the module s attachment ports as B A For a single attachment connection configure the module s attachment ports as S M For a null attachment set the attachment ports as M M To discover the configuration of the attachment ports on the module in slot 1 check the ATTACH LED display on the management module or enter the show attach command The ATTACH LED is lit whenever there is a module installed in slot 1 Table 3 5 Configuring Modules Attachment Additional Attachment Port Equipment Module Type Configuration Required Fiber Dual B A None Dual homing B A None Single S M None Null M M None STP Dual B A 2 Cas
95. otocol 1 4 port media types 5 6 STP services 1 4 UTP services 1 5 port connections 2 19 3 11 information display 5 5 media 5 6 types 2 23 5 7 Port State LED 5 17 power requirements B 1 power on insertion 4 2 14 primitive console command mode 3 9 accessing 3 9 leaving 3 11 Index primitive console commands 3 9 C 19 product information service Ask3Com D 2 PWR LED 5 12 R reinitializing 5 16 removing modules 2 14 repair returning products for D 5 reset command 5 15 C 18 C 22 reset function 5 15 check LEDs 5 16 reinitialize the hub 5 16 RESET button 5 15 Return Materials Authorization RMA number D 5 ring connecting to 6 2 24 disconnecting from 5 22 ring of trees 1 10 ring wrap 1 2 RJ 45 UTP connector pin assignments 2 22 RMT primary MAC state 5 10 route command 5 19 C 18 route dump command 5 20 C 19 S S port 2 23 set attach command 4 6 C 1 C 20 set baud command C 2 C 20 set boot command C 3 C 20 set boot filename command 4 13 C 4 set boot method command 4 12 C 3 set boot server command 4 13 C 4 set commands 4 2 C 1 C 20 set defaults command C 20 set gateway command 4 4 4 14 C 4 C 20 set help command C 4 C 20 set ip command 4 3 C 4 C 20 5 6 Index S continued set ler alarm command 4 9 C 5 set ler cutoff command 4 10 C 5 set pwd command 4 5 C 6 C 20 set tnotify command C 6 C 20 set treq command C 6 C 21
96. password using either the management or the primitive console command mode Refer to the section Accessing Configuration Commands in Chapter 3 for information about these two console command modes Once you enter a password it will be required every time you reset the hub To set your own password follow these steps 1 Enter the set pwd command from the terminal that is connected to the management module s serial port You will be prompted for the old password if you are in the management console command mode NOTE In the primitive console command mode you will not be prompted for the old password Skip to step 3 Enter the old password You will be prompted for a new password Enter the new password The password can be one to eight alphanumeric characters Passwords are case sensitive At the next prompt confirm the new password by reentering it If you entered the new password correctly this message appears Password changed If you entered the password incorrectly this message appears Password not changed 4 6 Setting Up the Hub Setting Attachment Port Configurations To configure the attachment ports use the set attach command 1 Type the command set attach This selection prompt appears Select one of the following 1 B A 2 S M 3 M M Attachment port configuration Enter the configuration you want For example type 2 Enter A confirmation message similar to the fo
97. presence or absence of an optical bypass switch Values NOT PRESENT No bypass switch exists on the hub PRESENT A bypass switch is connected to the hub C 12 Commands show ports Syntax show ports Description The show ports command displays information about the ports on the media port module specified by the slot number After entering show ports specify the slot number of the module If you do not specify a slot number you will be prompted for one The information provided is listed below E Number of modules installed on the hub a Number of ports on the module a Port media type fddiPORTPMDClass Fiber 62 5 um multimode fiber STP shielded twisted pair UTP unshielded twisted pair LCF low cost fiber N S not specified Unknown unknown connecting medium Sonet synchronous optical network a Port PHY type fddiPORTMy_Type A PHY A B PHYB M PHYM S PHYS U PHY unknown a Port neighbor type fddiPORTNeighborType A PHY A B PHYB M PHYM S PHYS U PHY unknown Commands C 13 m Port PCM state fddiPORTPCMState Active Break Connect Join Next Off Signal Trace Verify Maintenance abbreviated as Maint m Port status fddiPORTConnectState Active Connecting abbreviated as Connect Disabled abbreviated as Disable Standby m LER Alarm m LER Cutoff n LER Estimate
98. protocols operating in the hub Indicate invalid data length Contain incorrect contents Indicate the termination of the operation which may be caused by lack of memory Reinitialize the hub Inform the management station that the local MAC is stuck at beacon indicating a serious ring failure Using the Hub 5 3 Show IP Addresses To display the current IP address IP netmask and the Internet broadcast address of the hub enter the show JP command An example of the resulting display is shown in Figure 5 3 gt sh ip IP address 128 56 87 25 Netmask 250 ZO OO Broadcast 128 56 255 255 Figure 5 3 Display Produced by show IP Command Show MIB Counters The show mib counters command illustrates one type of command used by the optional SNMP management application An example of the display produced by the show mib counters command is shown in Figure 5 4 gt sh mib counters Primary MAC fddiMACCounters Grp fddiMACFrame Ct 6417 fddiMACError Ct 0 fddiMACCopied Ct 765 fddiMACLost Ct 0 fddiMACTransmit Ct 732 fddiMACNotCopied Ct 0 fddiMACToken Ct 45202063 fddiMACRingOp Ct 0 Figure 5 4 Display Produced by show MIB counters Command 5 4 Using the Hub The MIB counters shown in Figure 5 4 are defined in Table 5 2 Table 5 2 Definition of MIB Counters MIB Counter Definition fddiMACFrame Ct Number of frames received fddiMACCopied Ct Number of frames copied fddiMACTransmit Ct Total number o
99. pwd Syntax set pwd Description The set pwd command allows you to set and change the password You are prompted for the old password a You are then prompted for a new password a You are prompted for the new password again Passwords can be one to eight alphanumeric characters and are case sensitive Null passwords are allowed set tnotify Syntax set tnotify val Description The set tnotify command sets T Notify fddisMTT Notify to the decimal value specified by val This value is used in the Neighbor Notification protocol T Notify must be in the range of 2 to 30 seconds The default is 30 seconds set treq Syntax set treq val Description The set treq command sets the Target Token Rotation Time fddiMACT Req for the MAC on the primary ring The time is set to the decimal value specified by val The default is 165000 microseconds 165 milliseconds Commands C 7 Show Commands show attach Syntax show attach Description The show attach command displays the configuration of the attachment ports the two leftmost ports on the module in slot 1 The configuration is not restricted regardless of the slot 1 module type If the module type physically creates an illegal connection a warning is displayed The possible attachment port configurations are a B A Band A for dual attachment or dual homing a S M_ SandM for single attachment a M M M ports for null attachment only show baud Syntax show baud
100. re are a large number of faults in the log and you want to see the last one first 5 22 Using the Hub Using Connectivity Commands Three connectivity commands deal with connecting the hub to the FDDI ring disconnecting the hub from the ring and logging out of a console session connect and disconnect Commands Once you have installed the hub and attached it to the ring and to other network devices you have established a connect condition You do not have to enter the connect command to effect the connection to the ring When you enter the disconnect discon command you disable the ports on the installed modules and disconnect the hub from the ring The TOKEN LED on the management module turns off to indicate the hub is no longer receiving tokens on the ring CAUTION To avoid the possible loss of data on devices connected to the hub invoke the disconnect command before removing or adding a module When the connect or disconnect function has been completed this notification appears Done logout Command When you want to close a session from the console enter the logout command This command also closes a Telnet session if access to the console was through Telnet Appendix A System Messages This appendix lists the error and information messages that may be displayed on the terminal attached to the hub The messages are listed alphabetically Each message includes a brief explanation and suggested action Error Mes
101. retation of the management module LEDs is shown in Table 5 8 5 12 Using the Hub Table 5 8 Interpreting Management Module LEDs LED PWR ATTACH B A S M M M STATUS TOKEN WRAP FAN FAIL HI TEMP LOW BATT Color Indicators Green Green Green Green Amber Flashing amber green Flashing amber off Flashing green off Green Green Off Amber Amber Amber Amber Meaning Hub is on Only one attachment exists at any one time Configuration refers only to module in slot 1 Port 1 B port 2 A other ports M Port 1 S other ports M All ports M From 0 to 20 seconds after reset power on self test POST is in progress 20 seconds after reset hardware failure has occurred in management module backplane or critical parts of port modules Access to the primitive command mode is available now If a reset occurs during this limited period you are instructed to press Ctrl P to enter primitive console mode Failure has occurred during download operation TFTP download is in progress Normal operation The token is circulating and the ring is operational A ring operation is occurring The ring is wrapped A fan failure has occurred A high temperature condition exists above 50 C inside the chassis A low battery voltage condition exists Using the Hub 5 13 Additional information about the last four LEDs in Table 5 8 is provided below WRAP LED If the WRAP LED
102. rned off Connect the modem to the hub s serial port The serial port requires a female DB 9 connector The modem requires a male DB 25 connector Power on the modem Within 2 minutes the modem will be programmed to auto answer within two rings The modem is ready to respond to the hub when the AA LED comes on Installing the Hub 2 19 Using Telnet to Access the Hub To use the Telnet protocol to access the hub the hub must be connected to the network and must be running You must also have the Telnet protocol running on some device on your network Follow these steps 1 Enter the telnet command followed by the hub s IP address For example type telnet 123 45 67 89 Enter When the connection is completed the hub prompt appears You now have access to the management console commands You cannot access primitive console commands via a Telnet connection 2 When finished exit Telnet by typing logout Enter 3 Press any key and enter the password at the prompt Planning Connections As you plan the network layout of the FDDI ring with its connections to one or more hubs and various other devices you must be aware of the following a FDDI cabling rules a FDDI data flow specifications Port attachment rules and connection restrictions This section discusses FDDI cabling rules and data flow specifications Chapter 3 contains detailed information about port connections and port attachment rules 2 20 In
103. rs can verify hardware failures and advise you when it is more cost effective to replace rather than repair a product Technical Support D 5 Returning Products for Repair A product sent directly to 3Com for repair must first be assigned a Return Materials Authorization number RMA A product sent to 3Com without an RMA number will be returned to the sender unopened at the sender s expense When you call for an RMA number be prepared to provide the product name serial number and diagnostic error messages Payment shipping instructions and turnaround time will be confirmed when the RMA number is assigned To obtain an RMA number call or fax Europe Phone 44 0 442 231000 Fax 44 0 442 236824 U S Phone 800 876 3266 press option 2 Fax 408 764 7290 NOTE RMA forms except Europe are available on CardFacts Dial 408 727 7021 Outside Europe and the U S Phone 408 492 1790 Fax 408 764 7290 Glossary Attachment Beacon Broadcast Bypass Canonical order CDDI The capability of a station or concentrator or FDDI hub for connection into an FDDI network Stations and concentrators are classified as dual attachment single attachment or null attachment A special type of frame transmitted when a station detects a logical problem on the ring It is automatically transmitted during the ring initialization sequence when the claim token process does not finish in the time allotted for it
104. rt module a LinkBuilder FDDI 8 port UTP port module Installing the Hub 2 7 Installing the Battery A lithium battery which powers the nonvolatile memory bank is supplied with the management module The hub s nonvolatile memory preserves the following Boot parameters a Last download status Set command parameters a Fault log entries The lithium battery is a 3 volt 550 mA hr battery in a 2450 blister pack It can last up to 10 years before it must be replaced However its actual lifetime depends on the number and duration of power outages that may occur It has enough capacity to last up to 5500 hours after power is lost Replace the battery when the LOW BAT LED lights You can purchase replacements in most computer and electronic retail stores Ask for a type 2450 battery Be sure to replace the battery with one made by the same manufacturer CAUTION The battery may explode if it is replaced incorrectly Replace the battery only with the same or equivalent type as described above Used lithium batteries can be considered other household waste and disposed of accordingly Do not incinerate disassemble or deform batteries Do not attempt to recharge the battery Do not heat the battery over 100 C Failure to follow these handling instructions may result in battery failure including seal breakdown leakage internal shorting fire and potential explosion ACHTUNG Diese Batterie kann explodieren wenn sie falsch in
105. rts connection Table 5 6 lists the values and defines the connect states for the Connect State line in Figure 5 7 Table 5 6 Connect States Connect State Value Definition Active The port is incorporated into the token ring path Connect Both ends of the port s requested connection are in the process of being synchronized Disabled The port is nonoperational Standby The port is waiting for initialization to finish before completing the requested connection In the case of a dual homing configuration the A port is held in Standby while the B port is Active LER Alarm and LER Cutoff The LER alarm value is the Link Error Rate LER at which a link connection exceeds the present threshold and generates an alarm The LER cutoff is the link error rate at which a faulty or poor link connection will be broken For a complete description of these two link error rate parameters and their values refer to the section Setting SMT Parameters in Chapter 4 LER Estimate This parameter provides a long term average Link Error Rate estimate LER Estimate ranges from 104 to 10 15 5 10 Using the Hub LEM Rejects This parameter lists the number of times a link is removed because the error rate has exceeded the threshold test as determined by the link error monitor LEM LEM Count This parameter provides the aggregate link error count which is set to zero only on station initialization The aggregate link error count
106. s The next section contains a brief summary of FDDI technology it is intended as an overview only For detailed information about FDDI architecture and its functionality 3Com recommends that you secure the FDDI self paced study course Understanding FDDI 3CS 360 available through 3Com Education Services FDDI Technology FDDI technology is an American National Standards Institute ANSD standard that supports data transfer rates of 100 million bits per second 100 Mbps Advancements in fiber technology allow modulated beams of light to be carried in dual counter rotating token rings made of glass fiber optic cable The FDDI standard now includes the definition of other types of cabling media including shielded twisted pair STP and unshielded twisted pair UTP FDDI provides for up to 500 nodes operating over tens of kilometers The maximum network length is 100 km FDDI s dual ring architecture provides a high level of reliability and fault tolerance Under normal operation one of the rings called the primary ring or the trunk ring carries data traffic The other ring called the secondary ring is generally used for automatic recovery in the event of a break in the primary ring If a fault occurs as shown in Figure 1 1 the dual attached stations on either side of the fault detect and automatically bypass it This ring reconfiguration is known as a ring wrap Overview 1 3 Break in ring or station failure x 3 4 Ring
107. s a typical ring setup in which m Two dual attachment stations DAS are connected to the trunk ring m Two dual attachment hubs DAC are connected to the trunk ring m Two single attachment stations SAS are connected to each of the hubs NOTE 3Com uses the standard acronym DAC for dual attachment concentrator shown above but calls the concentrator a hub rather than a concentrator DAS 1 DAS 2 CA co p E g Sz co SAS 1 SAS 2 SAS 3 SAS 4 Figure 1 3 Physical Topology for Typical FDDI Ring 1 10 Overview The most common FDDI to the desktop configuration is the ring of trees topology shown in Figure 1 4 This figure illustrates the connecting of stations using a hub to form a tree like structure that branches off the main trunk ring ys DAC 7 SAS SAS SAS SAS Figure 1 4 FDDI Ring of Trees Overvie
108. sages Bad route command Meaning You entered a route command with incorrect syntax Action Follow this syntax for the route command route add destination gateway metric route delete destination l gateway metric route dump Baud rate must be 1200 2400 4800 or 9600 Meaning You entered an invalid baud rate for the serial port Action Enter the set baud command again using one of the valid baud rates Change failed with error xx Meaning The change you were attempting to make failed because of the error specified by xx Action Take care of error xx first then attempt to make the change again A 2 System Messages Invalid IP address xxxxxx Meaning You entered an IP address using an incorrect format Action Reenter the address using the dotted decimal notation format xxx xxx xxx xxx where xxx xxx xxx xxx is the syntactic representation for a 32 bit integer consisting of four 8 bit numbers written in base 10 with dots separating them Invalid port number xx Meaning You entered a port number for a port that does not exist Action Check the module you are using to determine the number of ports it has The fiber module has four ports The STP module has six ports The UTP module has eight ports Invalid response xxxxxxx Meaning You entered an invalid choice in response to a menu prompt Action Display the menu again Read the displayed instructions carefully In most cases you should enter a number Invalid s
109. sceiver If you decide to change the configuration of a fiber module attachment port you must change the key in the transceiver receptacle To remove a key from the receptacle follow these steps 1 Remove the attached cable from the transceiver 2 Remove the module from the hub Refer to the section Removing Modules later in this chapter 3 Place the tip of a small flat screwdriver in the slot at the back of the key and exert gentle but firm pressure on the screwdriver 4 Remove the key Replace the removed key in its plastic bag for possible future use 5 Insert the appropriate key into the transceiver Reinsert the module into the hub and insert the different cable into the rekeyed transceiver STP Cascade Connector By default all ports on the STP module are physically configured as M ports If you want to configure the STP module s attachment ports differently you must use an STP cascade connector to allow the use of these ports as B A or S port types NOTE A module s attachment ports are the two leftmost ports when a module is installed in slot 1 Whenever a module is installed in a slot other than shot 1 the two leftmost ports are no longer designated attachment ports 2 12 Installing the Hub Installing La One cascade connector is supplied with each STP media port module You can purchase additional cascade connectors by contacting your 3Com sales representative Figure 2 6 shows a cascade c
110. stalliert wird Verwenden Sie nur den gleichen oder entsprechenden vom Hersteller empfohlenen Typ Verbrauchte Batterien sind nach den Angaben des Herstellers zu entsorgen 2 8 Installing the Hub You must insert the battery on the management module before installing the module in the hub To install the battery in the management module follow these steps 1 Remove the battery from its container Each management module is shipped with its battery in a small bag inside the shipping container 2 Remove the management module from its antistatic bag 3 Locate the circular battery holder on the module Figure 2 3 shows where to insert the battery Figure 2 3 Battery Location on the Management Module Installing the Hub 2 9 4 Carefully slide the battery into its circular holder Ensure that the sign on the battery faces up and makes contact with the positive clip that holds the battery in place The management module is now ready to be installed in slot 0 Follow the instructions given in the section Installing Modules later in this chapter To remove the battery for replacement reverse the procedure above Keys for Fiber Port Modules Four sets of media port module keys packaged in small plastic bags are included with each fiber port module Use the keys to specify the port configuration of each fiber optic transceiver The keys are identified as A B S or M port types as shown in Figure 2 4 Kage
111. stalling the Hub FDDI Cabling Rules The type of cabling you use depends on the media modules that you ordered When installing the hub and the modules observe these FDDI cabling rules Fiber Optic Cable All cabling media must conform to the American National Standard FDDI Physical Layer Medium Dependent PMD Standard ISO 166 1990 American National Standards Institute The standard FDDI cabling type supported by the LinkBuilder FDDI Workgroup Hub is multimode 62 5 125 um The maximum length of this cable from the hub to any potential end station is approximately 2 km 1 25 mi per the ANSI X3T9 5 specification Attenuation must not exceed 11 dBm on any link between nodes regardless of distance NOTE When you insert the fiber optic cable s media interface connector MIC into a fiber module port the MIC must click twice to ensure a complete connection Shielded Twisted Pair Cable The standard STP cabling type supported by the LinkBuilder FDDI Workgroup Hub is category 1 STP cable with DB 9 connectors No cross over wiring is required The maximum length of this cable from the hub to any potential end station is 100 m 328 ft per the SDDI de facto STP standard The STP cable connectors must conform to IBM token ring standards or their equivalent The specifications for this standard are contained in AMP document number 6609 revision 11 01 88 Contact AMP Inc Harrisburg PA 17105 for a copy of this document Th
112. t command or press the RESET button that is recessed on the management module 2 16 Installing the Hub Accessing the Hub To monitor hub activity and optionally configure the hub to suit your particular network environment you must set up an interface with the hub You can access the hub in several ways Connect a terminal such as a VT100 or similar dumb terminal to the RS 232 serial port on the management module using a null modem connector to the terminal a Connect a PC running terminal emulation software to the RS 232 serial port on the management module using a null modem connector to the PC a Attach a modem to the serial port on the management module Refer to the section Installing an Optional Modem later in this chapter a Access the hub across the network using the TCP Telnet protocol Refer to the section Using Telnet to Access the Hub later in this chapter Once one of these connection is made you can use the console commands to monitor and configure the hub Two console command sets are available the management console command mode and the primitive console command mode These command modes are discussed in Chapter 3 The commands in these command sets are listed and described in Appendix C Commands Instructions for using the commands are provided in Chapter 4 Setting Up the Hub Changing the Serial Port s Baud Rate When you connect a terminal or modem to the hub you may need
113. t echo frames and waiting to receive the same number of frames in return Physical Layer Medium Dependent The sublayer in the FDDI architecture that specifies the optical fiber hardware components that create the physical link between two adjacent FDDI stations A point of access where a physical connection is made between a device and cabling to another device network etc The FDDI standard defines four port types A B M and S Port type A Primary IN Secondary OUT allows attachment to the incoming primary ring and to the outgoing secondary ring Port type B Secondary IN Primary OUT allows attachment to the outgoing primary ring and to the incoming secondary ring Port type M Master allows attachment between a concentrator and a single attach station Uses the primary ring only See SAS Port type S Slave allows attachment between an SAS or SAC and a concentrator Uses the primary ring only 6 Glossary Primary path Primary ring Ring Ring wrap SAC SAS SDDI Secondary ring SMT The segment s of the primary ring that pass through a station Conditions may exist in parts of the network that may cause the path to be in a different ring that is secondary instead of primary In the dual counter rotating token ring architecture the ring that carries data traffic A set of stations through which information is passed sequentially between stations each station in turn examining or copying the i
114. tall the management module for the first time be sure that power to the hub is off There is no power switch on the hub Power to the hub is provided by connecting the power cord to the hub and to an ac outlet NOTE The hub allows power on insertion which means that you do not have to unplug the power cord for module insertion or removal After removing or inserting a module press the RESET button which is recessed on the management module or enter the reset command on the command line This reinitializes the ring and causes the system to run its power on self tests POST Quick Start 5 To install the modules follow these steps 1 2 Remove all jewelry from your hands and wrists If necessary remove blanking plates from the module slots Keep the removed blanking plates in a safe place for possible future use Remove the module from its antistatic bag Prepare a clean level work area nearby on which to place the module Avoid contact with any of the module s components Insert the module slowly into its slot Gently align and push the module s bus connector into its slot in the backplane of the hub When the module is completely seated tighten the captive thumb screws on each end of the module To turn on the hub plug one end of the ac power cord into the back of the hub and the other end into an electrical socket The green PWR LED lights indicating the hub is on and ready for configuration After
115. te dump Description The route command adds or deletes a path to a particular device or hub where a destination is the destination IP address a gateway is the gateway IP address a metric is the number of hops number of gateways separating the source and destination to the network Optional The route dump command displays the current IP addresses of the destination and gateway Primitive Console Commands The primitive console command set contains three categories of commands E Set commands a Display commands n Miscellaneous commands NOTE The primitive console commands are a subset of the management console commands The command descriptions are therefore abbreviated For complete command descriptions refer to the section Management Console Commands earlier in this appendix C 20 Commands Set Commands set attach Sets the configuration of the first two ports of the module in slot 1 set baud Sets the console serial port baud rate set boot Sets the boot method filename of the software image or server IP address set defaults Sets the factory defaults set gateway Sets the IP address for the default gateway set help Lists the set commands and gives information about them set ip Sets the IP address IP netmask and the Internet broadcast address set pwd Sets the new password In primitive command mode you will not be prompted for your old password set tnotify Se
116. the following 1 1200 2 2400 3 4800 4 9600 Baudrate Commands C 3 You can also enter the baud rate on the same line with the set baud command as shown below set baud 4800 Enter set boot Syntax set boot method filename server Simplified Syntax set boot method set boot filename set boot server Description The set boot method command allows you to select the method to use when downloading an image to the flash EPROM The available options are LOCAL Loads and runs the flash EPROM code default TFTP Uses TFTP and local configuration parameters to load a new image over the network The set boot filename command allows you to set the filename of the software image to be loaded when using TFTP The set boot server command allows you to set the IP address of the boot server Examples An example of each option is shown below a When you enter the set boot method command you are prompted to select the server location of the information to be downloaded as shown below Select one of the following 1 LOCAL 2 TFTP Boot Method C 4 Commands a When you enter the set boot filename command you are prompted to enter a filename for the software image as shown below Enter filename a When you enter the set boot server command you are prompted to select a boot server as shown below Enter Servers IP address in dot notation a When you select a boot method enter a boot filename
117. tion Rules 3 14 Definitions for the Port Connection Rules 3 15 Configuring Modules 3 16 Definition of Boot Methods 4 15 Components Polled by the show fstats Command 5 2 Definition of MIB Counters 5 4 Port Media Types 5 6 Physical Layer Port Types 5 7 Physical Connection Management States 5 8 Connect States 5 9 Ring Management States 5 11 Interpreting Management Module LEDs 5 12 CFM State Values Displayed by the show cfm Command 5 13 Interpreting Media Module LEDs 5 17 3Com s FDDI Training and Reference M anual Understanding FDDI 3CS 360 is a pragmatic independent study course and reference manual written for professionals involved in the design implementation or support of multivendor FDDI networks Chapters 1 through 5 contain core information about FDDI These chapters explore critical elements of an FDDI environment including attachment stations MAC interfaces concentrators and optical bypass switches Port keying and configuration internetworking ring startup operation fault isolation and ring recovery light properties fiber media and optics are also covered Chapters 6 through 12 constitute a 250 page technical reference that takes you down to the engineering level Here 3Com interprets the FDDI standards to provide tangible and accessible information on all four FDDI protocol layers and the SMT Management Information Base This text based course comes with a testing diskette to guide and reinforce th
118. to the IEEE OSI model layers on the physical and data link levels These standards specify the physical interfaces functions and operations needed to support interoperability between devices A fiber optic cable consists of a glass center cladding a buffer layer strength members and a cable sheath The glass center supports the transmission of light signals A special purpose dedicated computer that attaches to two or more networks and routes packets from one to another Internet protocol which defines the Internet datagram as the unit of information passed across the Internet and provides the basis for the Internet connectionless best effort packet delivery service International Standards Organization The international agency that develops information exchange standards implementation A set of MACs serially connected to form a single ring A fault free FDDI network provides two logical rings 4 Glossary MAC MIB MIC Noncanonical order Null attachment concentrator Optical bypass Peer mode connection Media Access Control MAC the OSI access layer specifies the access mechanism used by FDDI nodes for transmitting and receiving data on the ring The MAC is responsible for receiving frames and transmitting frames according to the rules of a timed token rotation protocol a dynamic protocol unique to FDDI Management Information Base A set of FDDI managed objects The MIB defines the data that a networ
119. ts the T Notify value used in the Neighbor Notification protocol Commands C 21 set treq Sets the Target Token Rotation Time T Req Display Commands show attach Displays the configuration of the attachment ports on the module in slot 1 of the hub show baud Displays the baud rate setting for the serial port show boot Displays the boot method filename of the software image and boot server IP address show gateway Displays the default gateway address show help Lists the show commands and gives information about them show ip Displays the current IP address netmask and broadcast address show log Displays the contents of the fault log C 22 Commands show obs Detects the presence or absence of an optical bypass switch show rev Displays the revision number of the EPROM and software show sid Displays the 64 bit station ID and the 48 bit MAC address show tnotify Displays the value of T Notify show treq Displays the value of T Req show tvx Displays the value of TVX Miscellaneous Commands clear Clears the fault log help Lists the miscellaneous commands and gives information about them reset Reinitializes the hub and runs the power on self tests POST Appendix D Technical Support This appendix explains how to obtain worldwide support for 3Com products On line Product Support 3Com offers worldwide product support 24 hours a day seven days a week throu
120. ule in slot 1 enter the show attach command An example of the resulting display is shown in Figure 5 1 gt sh attach Current configuration is B A Initialize attachment as B A Figure 5 1 Display of Attachment Port Configuration Show MAC Frame Statistics To display the raw frame statistics for the hub s MAC enter the show fstats command An example of the resulting display is shown in Figure 5 2 5 2 Using the Hub gt sh fstats Raw frame statistics To To To To To To To To To Received resets tal tal tal tal tal tal transmit received transmit received transmit received for primary MAC frames frames SMT frames SMT frames LLC frames LLC frames tal tal received received short frames invalid frames tal aborts Directed beacons entered Directed beacons sent Figure 5 2 Display of MAC Frame Statistics 632 1561 550 1513 83 48 OOS OO Table 5 1 defines the elements for which MAC statistics were collected and displayed in Figure 5 2 Table 5 1 Components Polled by the show fstats Command MAC Statistical Components SMT station management frames LLC logical link control frames Short frames Invalid frames Aborts Resets Directed beacons Functions of Listed Components Provide network statistics detect network faults and tune configuration and operational parameters Provide an interface between the MAC and the higher level
121. up Hub See hub lithium battery 2 5 installation 2 7 logout command 5 22 C 17 LOW BATT LED 5 12 5 14 M M port 2 23 MAC frame statistics 5 1 functions 1 5 Media Access Control protocol 1 5 management console commands 3 8 C 1 management module battery 2 5 functions 1 11 installing 4 2 12 LEDs 5 12 removing 2 14 RESET button 1 11 5 15 Maximum Token Rotation Time T Max 4 11 media modules configuring 3 15 fiber 1 12 keys 2 9 installing 4 2 12 LEDs 5 16 removing 2 14 STP 1 14 unpacking 3 UTP 1 14 Media Access Control MAC protocol 1 3 metric option 5 20 C 18 MIB counters 5 3 miscellaneous command display 4 2 modem installing 2 18 N Negotiated Time T Neg 4 11 neighbor defined 3 13 neighbor station addresses 5 4 Neighbor Notification protocol 4 7 netmask 4 4 null attachment hub NAC 3 5 O on line technical services D 1 D 2 optical bypass switch OBS 2 26 cabling 2 27 P password setting 4 5 PCM neighbor fields 5 7 state 5 8 peer mode connection 5 13 PHY layer functions 1 5 port types 5 7 protocol 1 5 physical specifications B 1 Physical Connection Management PCM 5 7 states 5 8 Physical Medium Dependent PMD protocol 1 3 Physical PHY layer protocol 1 3 pin assignments DB 9 STP connector 2 21 RJ 45 UTP connector 2 22 ping command 5 18 C 18 PMD layer fiber optic services 1 4 optical bypass switch 1 4 pr
122. uption of service You can perform the reset function in one of two ways n Enter the reset command on the command line m Press the RESET button on the management module The RESET button on the management module is recessed behind the faceplate To access the RESET button insert a small pointed object such as the tip of a sharp pencil or end of a bent paper clip into the hole below the RESET label Pressing the RESET button performs the two functions described below 5 16 Using the Hub Reinitialize If you press the RESET button only briefly the hub reinitializes and performs the power on self tests POST The tests take several seconds to complete LED Check If you hold down the RESET button all functioning LEDs on all installed modules light This allows you to determine whether any LEDs are not functioning When you release the RESET button the reinitialize function begins Media Module LEDs Each port connector on each module is equipped with three LEDs The Signal Detect LED indicates whether or not a received signal is present The Port State LED indicates the port s connection state The Link Error LED indicates the existence of a link error or a marginal connection Figure 5 9 shows the location of the LEDs on the STP module The LED locations are the same on the other media port modules Table 5 10 interprets the meaning of the LED colors LED legend Signal Detect GRN SIGNAL DETECT GRN PORT STATE S
123. uring the Hub 3 13 The concept of neighbor is shown in Figure 3 6 Upstream Downstream neighbor neighbor from B from B Direction of data flow A to B to C Figure 3 6 Upstream and Downstream Neighbors To display the addresses of the hub s upstream and downstream neighbors enter the show neigh command A single attachment to the ring occurs when you use the S M attachment port configuration Because the S port restricts the hub to single attachment the S port is never attached directly to the primary trunk ring and cannot participate in wrap configuration The M M attachment port configuration restricts the hub to a null attachment type Tables 3 3 and 3 4 define and summarize the port connection rules supported by the FDDI specification Configuring the Hub Table 3 3 Port Connection Rules Attachment Neighbor Ports Ports A B A V U T V B V V U T M V W vV W S V U W V U W M S V P W V U W V P W V U W X V V V Table 3 4 Definitions for the Port Connection Rules Condition Port Connection Indicator Condition P Prevents thru state U Undesirable connection V Valid connection X Illegal connection Definition of Port Condition Exists when both rings are not fully functional Thru state is the normal condition of an FDDI station Exists because the connection creates undesirable hub configurations such as a twisted ring not prevented by the connection
124. ust be gt the current cutoff exponent Meaning The LER alarm exponent must be greater than the LER cutoff exponent Action Set the alarm exponent to be greater than the cutoff value There are no ports in the management module slot Meaning You entered the slot number 0 zero in the show ports command Action Examine the hub to see where the media modules are installed and enter a correct slot number xx must be in the range xx to xx Meaning An exponent must fall within the given range of values For example the LER Cutoff parameter must be set to a value between 4 to 15 Action Change the value of the exponent to be within the range shown Download Messages Download image requested has invalid format Meaning You have requested and received the wrong filename The image that was downloaded is not an executable image for this filename You no longer have an executable image in flash memory Action Reissue the download request System Messages A 5 Download image unusable corrupted Meaning A serious error occurred during download You no longer have an executable image in flash memory Action Reissue the download request Download image unusable not executable Meaning A serious error occurred during download or you may have requested the wrong filename You no longer have an executable image in flash memory Action Reissue the download request No response from TFTP server Meaning The TFT
125. w 1 11 Management and Media Modules The hub chassis provides slots for one management module required and three media modules which can be mixed or matched This section briefly describes each of these modules For information about the operation of the management and media modules see Chapter 5 Using the Hub Management Module The LinkBuilder FDDI Management Module hereafter called the management module must be inserted in slot 0 the bottom slot of the hub Its main purpose is to run the Station Management SMT 7 3 software that is required for FDDI operations The management module provides management and configuration functions through a console interface Access to this interface is either by a 9 pin RS 232C console serial port for a terminal or modem connection or via a TCP Telnet protocol connection over the network Figure 1 5 shows the front panel of the management module which provides a 6 pin mini DIN receptacle for the connection to an optical bypass switch OBS opto esis o artaci MANAGEMENT MODULE BYPASS BA oT FAN HI LOW RESET gt O Eo s STATUS TOKEN WRAP FAIL TEMP BATT e oe oe oe eo oe eu Figure 1 5 Management Module Front Panel The management module contains a recessed RESET button for reinitializing the hub s software running the power on self tests POST and running the flash EPROM You can also use the RESET button to access the primitive consol
126. ware Clause at 48 C F R 52 227 7013 3Com Corporation 5400 Bayfront Plaza Santa Clara California 95052 8145 For civilian agencies Restricted Rights Legend Use reproduction or disclosure is subject to restrictions set forth in subparagraph a through d of the Commercial Computer Software Restricted Rights clause at 48 C F R 52 227 19 and the limitations set forth in 3Com s standard commercial agreement for the Software Unpublished rights reserved under the copyright laws of the United States Portions of this manual are reproduced in whole or in part with permission from as appropriate 3Com and LinkBuilder are registered trademarks of 3Com Corporation CardFacts NetFacts Ask3Com 3ComFacts and CardBoard are service marks of 3Com Corporation Motorola is a registered trademark of Motorola Corporation National Semiconductor is a registered trademark of National Semiconductor Corporation CompuServe is a service mark of CompuServe Incorporated Manual written by John Jeter Edited by Nancy Kurahashi Technical illustrations and production by Tim Buckreus LIMITED WARRANTY HARDWARE 3Com warrants its hardware products to be free from defects in workmanship and materials under normal use and service for the following lengths of time from the date of purchase from 3Com or its Authorized Reseller Bridge gateway and other internetworking products One year Server products One year Station products One year Network
127. ware diskette 2 5 T T Max 4 11 T Neg 4 11 T Notify 4 7 T Req 4 8 Target Token Rotation Time TTRT 4 8 technical specifications B 1 technical support services D 1 Telnet protocol 2 16 2 19 terminal connections 2 16 TFTP download option 4 12 TOKEN LED 5 12 5 22 tree mode connection 5 13 TVX 4 11 twisted ring 3 14 U unshielded twisted pair See UTP UTP cabling rules 2 21 media port module 1 14 pin assignments 2 22 V Valid Transmission Timer TVX 4 11 WwW WRAP LED 5 12 5 13 wrap state 3 15 5 13 Index 7
128. wrap Ring wrap Primary ring Secondary ring Figure 1 1 Ring Wrap The FDDI standard developed by the American National Standards Institute ANSI defines four protocols a Physical Medium Dependent PMD m Physical PHY m Media Access Control MAC m Station Management SMT Each of these protocols is briefly defined below 1 4 Overview Physical Medium Dependent PMD Protocol The Physical Medium Dependent protocol provides all of the services necessary to exchange data across the cable medium PMD also specifies an optional optical bypass facility that enhances reliability This bypass capability is invoked when an FDDI station is powered off For information on the optical bypass switch see Chapter 2 Installing the Hub The PMD services included for each type of media supported by the LinkBuilder FDDI Workgroup Hub are listed below Fiber Optic The PMD standard provides these services for fiber media a Optical power and cable requirements for 62 5 125 um fiber optic cables a Power requirements for optical bypass switches and fiber optic transceivers a FDDI cable connector the Media Interface Connector MIC mating requirements and keying a Light wavelength of 1300 nm nanometers Shielded Twisted Pair STP The PMD standard uses the SDDI de facto standard and provides these services for STP a Transmit signal amplitude o
129. ws per bracket 5 Fasten the brackets to the rails by screwing in the screws 6 Tighten each screw e ENSA eR S C P P P P o Ps hg S Ga Figure 2 1 Attaching Mounting Brackets to the Hub The hub is now installed in the distribution rack as shown in Figure 2 2 2 4 Installing the Hub ee 20 QB B Q Figure 2 2 LinkBuilder FDDI Workgroup Hub Installed in a Distribution Rack Installing the Hub 2 5 Equipping the Hub This section discusses the following hub equipment Hub chassis Management module Lithium battery Media port modules Fiber port keys optional Cascade connector optional Basic Contents The basic package includes the following items LinkBuilder FDDI Workgroup Hub base unit LinkBuilder FDDI Workgroup Hub User Guide LinkBuilder FDDI System Software diskette version 1 0 Standard ac power cord Two brackets and eight screws for rack mounting Four rubber pads for tabletop placement The LinkBuilder FDDI System Software diskette version 1 0 contains a readme file and a backup image for the flash EPROM One LinkBuilder Management Module which is shipped separately is required for each hub A 3 volt lithium battery is shipped with the management module The battery is in a small bag inside the management module shipping container For battery functions and installation instructions see the section Installing the Batter
130. y later in this chapter 2 6 Installing the Hub If you ordered a fiber media module four small packets of fiber port module keys will be included with the module For information on installing these keys see the section Keys for Fiber Port Modules later in this chapter If you ordered an STP media port module one cascade connector will be shipped with the module For information about the cascade connector refer to the section STP Cascade Connector later in this chapter NOTE Remember to fill out the Product Registration Card at the back of this manual and return it to 3Com or call 1 800 NET 3Com for immediate registration Hub Chassis The LinkBuilder FDDI hub is shipped with no modules installed the modules you ordered are shipped separately and packaged individually The hub is shipped with two blanking plates attached over slots 2 and 3 Install the management module in slot 0 Install one of the media port modules in slot 1 To install additional modules remove the blanking plates and insert the modules Retain the blanking plates for possible future use when modules are removed Refer to the section Installing Modules later in this chapter for complete information about mounting the modules in the hub Media Port Modules Depending on your order you should also have received one or more of the following modules a LinkBuilder FDDI 4 port fiber port module a LinkBuilder FDDI 6 port STP po
131. y Description The show gateway command displays the IP address of the default gateway C 10 Commands show help Syntax show help Description The show help or show command displays the options available for the show commands show ip Syntax show ip Description The show ip command displays the current IP address IP netmask and the Internet broadcast address show log Syntax show log last Description The show log command displays the contents of the fault log The show log last command displays the fault log entries in reverse order show mib counters Syntax show mib counters Description The show mib counters command displays the number of the entities counted by the fddiMAC CounterGrp as shown below Commands C 11 m Total number of frames received fddiMACFrame Ct a Number of frames copied fddiMACCopied Ct m Number of frames transmitted fddiMACTransmit Ct m Number of tokens fddiMACToken Ct m Number of error frames fddiMACError Ct m Number of frames with format errors fddiMACLost Ct a Number of frames not copied fddiMACNotCopied Ct a Number of ring recoveries fddiMACRingOp Ct show neigh Syntax show neigh Description The show neigh command displays the 48 bit address of the upstream fddiMACUpstreamNbr and downstream fddiMACDownstreamNbr neighbor stations in noncanonical format show obs Syntax show obs Description The show obs command displays the

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LinkBuilder® FDDI Workgroup Hub User Guide