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3Com 3800 User Manual

Manual is about: 3COM Switch User Guide

Summary of 3800

  • Page 1

    ® http://www.3com.Com/ superstack ® ii switch 3800 user guide part no. Dua1691-0aaa01 100004-00 rev. 01 published april 1998 sw3800.Bk page i tuesday, may 5, 1998 5:20 pm.

  • Page 2

    Ii 3com corporation 5400 bayfront plaza santa clara, california 95052-8145 copyright © 3com corporation, 1998. All rights reserved. No part of this documentation may be reproduced in any form or by any means or used to make any derivative work (such as translation, transformation, or adaptation) wit...

  • Page 3

    Iii vcci statement information to the user if this equipment does cause 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: ■ reorient the recei...

  • Page 4

    Iv sw3800.Bk page iv tuesday, may 5, 1998 5:20 pm.

  • Page 5: Ontents

    V c ontents a bout t his g uide introduction 1 terminology 1 finding information in this guide 2 conventions 3 command syntax symbols 4 line-editing commands 5 related publications 5 1 s witch 3800 o verview about the switch 3800 1-1 summary of features 1-1 port connections 1-3 full-duplex 1-3 port ...

  • Page 6

    Vi 2 i nstallation and s etup following safety information 2-1 determining the switch 3800 location 2-1 configuration rules for ethernet 2-2 installing the switch 3800 2-2 rack mounting 2-2 free-standing 2-3 stacking the switch and other devices 2-4 connecting equipment to the console port 2-4 power...

  • Page 7

    Vii configuring snmp settings 3-10 displaying snmp settings 3-12 resetting and disabling snmp 3-12 checking basic connectivity 3-12 ping 3-12 traceroute 3-13 configuring ports 3-13 enabling and disabling ports 3-13 configuring autonegotiation 3-14 10/100 port settings 3-14 gigabit port settings 3-14...

  • Page 8: Lan

    Viii port commands 4-12 pace commands 4-13 stp commands 4-14 basic ip commands 4-16 ip arp commands 4-17 ip route table commands 4-18 icmp commands 4-18 rip commands 4-20 logging commands 4-22 configuration and image commands 4-23 5 v irtual lan s (vlan s ) overview of virtual lans 5-1 benefits 5-1 ...

  • Page 9: (Stp)

    Ix configuring fdb entries 6-3 fdb configuration example 6-3 displaying fdb entries 6-3 removing fdb entries 6-4 7 s panning t ree p rotocol (stp) overview of the spanning tree protocol 7-1 how stp works 7-3 initialization 7-3 stabilization 7-4 reconfiguration 7-4 spanning tree domains 7-4 defaults ...

  • Page 10

    X 9 s tatus m onitoring and s tatistics status monitoring 9-1 port statistics 9-4 port errors 9-6 switch logging 9-7 local logging 9-8 real-time display 9-8 remote logging 9-9 logging commands 9-10 rmon 9-11 about rmon 9-11 about the rmon groups 9-12 statistics 9-12 history 9-12 alarms 9-13 events 9...

  • Page 11

    Xi fiber optic ports a-3 lithium battery a-4 l’information de sécurité importante a-4 power a-5 cordon électrique a-6 fuse a-6 ports pour fibres optiques a-7 batterie au lithium a-7 wichtige sicherheitsinformationen a-8 power a-8 power cord a-9 fuse a-9 faseroptikanschlüsse - optische sicherheit a-1...

  • Page 12

    Xii g lossary i ndex 3c om c orporation l imited w arranty sw3800.Bk page xii tuesday, may 5, 1998 5:20 pm.

  • Page 13: Bout

    A bout t his g uide about this guide provides an overview of this guide, describes guide conventions, tells you where to look for specific information and lists other publications that may be useful. Introduction this guide provides the required information to install and configure the superstack ® ...

  • Page 14

    2 a bout t his g uide finding information in this guide this table shows where to find specific information in this guide. Task location learning concepts chapter 1, “switch 3800 overview” installing the switch 3800 chapter 2, “installation and setup” appendix a, “safety information” setting up user...

  • Page 15

    Conventions 3 conventions table 1 and table 2 list conventions that are used throughout this guide. Table 1 notice icons icon notice type alerts you to... Note important features or instructions caution risk of personal injury, system damage, or loss of data warning risk of severe personal injury ta...

  • Page 16

    4 a bout t his g uide command syntax symbols you may see a variety of symbols shown as part of the command syntax. These symbols explain how to enter the command, and you do not type them as part of the command itself. Table 3 summarizes command syntax symbols. Table 3 command syntax symbols symbol ...

  • Page 17

    Line-editing commands 5 line-editing commands table 4 describes the line-editing commands available using the command-line interface. The command syntax is explained in chapter 4. Related publications the switch 3800 documentation set includes the following: ■ superstack ii switch 3800 quick referen...

  • Page 18

    6 a bout t his g uide sw3800.Bk page 6 tuesday, may 5, 1998 5:20 pm.

  • Page 19: Witch

    1 s witch 3800 o verview this chapter describes the following: ■ switch 3800 features ■ how to use the switch 3800 in your network configuration ■ switch 3800 front view ■ switch 3800 rear view ■ factory default settings about the switch 3800 network managers are currently faced with the challenge o...

  • Page 20

    1-2 c hapter 1: s witch 3800 o verview ■ virtual lans (vlans) ■ support for 64 vlans on a single switch 3800 ■ support for ieee 802.1q tagging ■ controls traffic (including broadcasts) ■ provides extra security ■ protocol-sensitive filtering for vlans ■ recognition of the priority access control ena...

  • Page 21

    Summary of features 1-3 port connections the switch 3800 has 24 autosensing 10base-t/100base-tx ports with standard rj-45 connectors, and supports one gigabit ethernet port, and one redundant gigabit ethernet port with standard gigabit interface connectors (gbics). You must have a 3com-approved gbic...

  • Page 22

    1-4 c hapter 1: s witch 3800 o verview in the event that the active main port fails or loses link status, the standby port is automatically activated. When the main port resumes operation, the standby port becomes inactive. This feature can be disabled. Load sharing load sharing with switch 3800 swi...

  • Page 23

    Network configuration example 1-5 priority access control enabled (pace) the switch recognizes the pace bit set by 3com etherlink ® adapters and other devices supporting pace. When enabled, traffic with these bits receives priority service from the switch. Spanning tree protocol (stp) the switch 380...

  • Page 24

    1-6 c hapter 1: s witch 3800 o verview figure 1-2 switch 3800 used in a backbone configuration the switch 1100 on each floor has a 100mbps full-duplex link to the switch 3800. A switch 3300 is connected to a group of servers on one floor of the building. The switch 3800 routes ip traffic between the...

  • Page 25

    Switch 3800 front view 1-7 in addition to providing a fast backbone between ethernet lans, gigabit ethernet equipped file servers and services may be directly attached to the switch 3800 providing improved performance to the ethernet desktop. Switch 3800 front view figure 1-3 shows the switch 3800 f...

  • Page 26

    1-8 c hapter 1: s witch 3800 o verview for more information on 1000base-sx and 1000base-lx characteristics refer to ieee draft p802.3z/d4.2 tables 38-2 and 38-6. Leds table 1-2 describes the led behavior on the switch 3800. Table 1-1 media types and distances standard media type mhz/km rating maximu...

  • Page 27

    Switch 3800 rear view 1-9 switch 3800 rear view figure 1-4 shows the switch 3800 rear view. Figure 1-4 switch 3800 rear view the rear panel has the following features: power socket the switch 3800 automatically adjusts to the supply voltage. The power supply operates down to 90 v. The fuse is suitab...

  • Page 28

    1-10 c hapter 1: s witch 3800 o verview mac address this label shows the unique ethernet mac address assigned to this device. Console port the console port (9-pin, “d” type connector) is used to connect a terminal and to carry out local out-of-band management. Factory defaults table 1-3 shows the fa...

  • Page 29: Nstallation

    2 i nstallation and s etup this chapter describes the following: ■ how to decide where to install the switch 3800 ■ ethernet configuration rules ■ how to install the switch in a rack or free-standing ■ how to connect equipment to the console port ■ how to check the installation using the power on se...

  • Page 30

    2-2 c hapter 2: i nstallation and s etup ■ water or moisture cannot enter the case of the unit. ■ temperature must be within the range of 0 to 40 degrees celsius. ■ air-flow around the unit and through the vents in the side of the case is not restricted. You should provide a minimum of 25mm (1-inch)...

  • Page 31

    Installing the switch 3800 2-3 figure 2-1 fitting the mounting bracket 5 repeat the three previous steps for the other side of the switch. 6 refer to the instructions that shipped with your rack, runners, shelf or tray to complete the installation of the switch into the mounting rack. Caution: when ...

  • Page 32

    2-4 c hapter 2: i nstallation and s etup stacking the switch and other devices up to four units can be placed on top of one another. If mixing switch 3800, switch 3000 fx, switch 1000, switch 1200, and other superstack ® ii hubs, the smaller units must be positioned at the top using rubber pads. Thi...

  • Page 33

    Connecting equipment to the console port 2-5 figure 2-2 shows the pin-outs for a 9-pin to rs-232 25-pin null modem cable. Figure 2-2 null modem cable pin-outs figure 2-3 shows the pin-outs for a 9-pin to 9-pin pc-at serial null modem cable. Figure 2-3 pc-at serial cable pin-outs screen txd rxd groun...

  • Page 34

    2-6 c hapter 2: i nstallation and s etup powering-up the switch to power-up the switch, follow these steps: 1 connect the power cable to the switch. 2 connect the power cable to the wall outlet. 3 if necessary, turn the on/off switch to the on position. Checking the installation after turning on pow...

  • Page 35

    Logging on for the first time 2-7 5 assign an ip address and subnetwork mask for vlan default. The example below assigns an ip address of 123.45.67.8 and a subnetwork mask of 255.255.255.0. Config vlan default ipaddress 123.45.67.8 255.255.255.0 your changes take effect immediately. 6 save your conf...

  • Page 36

    2-8 c hapter 2: i nstallation and s etup sw3800.Bk page 8 tuesday, may 5, 1998 5:20 pm.

  • Page 37: Ccessing

    3 a ccessing t he s witch this chapter describes the following information that you can use to begin managing the switch 3800: ■ security access level overview ■ configuring the switch for management ■ switch management methods ■ configuring snmp caution: for configuration changes to be retained thr...

  • Page 38

    3-2 c hapter 3: a ccessing t he s witch administrator access level an administrator-level account can view and change all switch parameters, add and delete users, and change the password associated with any account name. The administrator can disconnect a telnet management session. If this happens, ...

  • Page 39

    Security access levels 3-3 4 enter the new password at the prompt. 5 re-enter the new password at the prompt. 6 save your changes by typing save creating a management account the switch can have a total of three management accounts. You can use the default names (admin and user), or you can create n...

  • Page 40

    3-4 c hapter 3: a ccessing t he s witch 3 enter the new password at the prompt. 4 re-enter the new password at the prompt. 5 save your changes by typing save if you forget your password contact your local technical support representative, who will advise on your next course of action. Viewing switch...

  • Page 41

    Using telnet 3-5 using the console interface the command-line interface built into the switch is accessible by way of the 9-pin, rs-232 console port located on the rear of the unit. For more information on the console port pin-outs, refer to chapter 2. Once the connection is established, you will se...

  • Page 43

    Using telnet 3-7 4 at the password prompt, enter the password and press [return]. When you have successfully logged on to the switch, the command-line prompt displays the name of the switch in its prompt. 5 assign an ip address and subnetwork mask for the default vlan by using the following command ...

  • Page 44

    3-8 c hapter 3: a ccessing t he s witch sample output from the show session command is as follows: 3c16910:2 # sh sess # login time user type location ============================================================ 0 tue mar 10 11:10:53 1998 admin console serial 4 tue mar 10 13:11:13 1998 user telnet 1...

  • Page 45

    Using snmp 3-9 accessing switch agents in order to have access to the snmp agent residing in the switch, at least one vlan on the switch must have an ip address assigned to it. For more information on assigning an ip address, refer to “manually configuring the ip settings,” on page 3-6. Saving confi...

  • Page 46

    3-10 c hapter 3: a ccessing t he s witch configuring snmp settings the following snmp parameters can be configured on the switch: ■ authorized trap receivers — an authorized trap receiver can be one or more network management stations on your network. The switch sends snmp traps to the trap receiver...

  • Page 47

    Using snmp 3-11 table 3-4 describes snmp configuration commands. Table 3-4 snmp configuration commands command description config vlan ipaddress {} configures an ip address for the vlan. This is required in order to use an snmp manager. Enable snmp access allows you to turn on snmp support for the s...

  • Page 48

    3-12 c hapter 3: a ccessing t he s witch displaying snmp settings to display the snmp settings configured on the switch 3800, use the following command: show management this command displays the following information: ■ enable/disable state for telnet, snmp, and web access ■ snmp community strings ■...

  • Page 49

    Configuring ports 3-13 options for the ping command are described in table 3-6. Traceroute the traceroute command allows you to trace the routed path between the switch and a destination endstation. The traceroute command syntax is as follows: traceroute where ip_address is the ip address of the des...

  • Page 50

    3-14 c hapter 3: a ccessing t he s witch configuring autonegotiation by default, the switch 3800 is configured to use autonegotiation for all ports. Autonegotiation on 10/100 mbps ports is used to automatically determine speed and duplex settings. You can select to manually configure the duplex and ...

  • Page 51

    Load sharing 3-15 load sharing load sharing with the switch 3800 allows you to increase bandwidth and resilience by using a group of ports to carry traffic in parallel between switches. The sharing algorithm allows the switch to use multiple ports as a single logical port. For example, vlans see the...

  • Page 52

    3-16 c hapter 3: a ccessing t he s witch when you define a load-sharing group, you assign a group of ports to a single, logical port number. To enable or disable a load-sharing group, use the following commands: enable sharing grouping disable sharing the following example defines a load-sharing gro...

  • Page 53

    Smartredundancy 3-17 smartredundancy smartredundancy for the switch 3800 refers to fail-over behavior of the main and standby gigabit ethernet ports. Smartredundancy allows the switch to always use the main link if it is available. For example, if only the standby link is available it will be used, ...

  • Page 54

    3-18 c hapter 3: a ccessing t he s witch disable smartredundancy allows you to disable the smartredundancy feature. If the feature is disabled, the switch changes the active link only when the current active link becomes inoperable. Show port config displays state, link status, speed, and autonegoti...

  • Page 55: Ommands

    4 c ommands this chapter contains a description of each command-line interface command for the switch 3800. It also provides the following information related to switch 3800 commands: ■ command syntax ■ line-editing commands ■ command history substitution if an asterisk (*) appears in front of the c...

  • Page 56

    4-2 c hapter 4: c ommands if the command does not include a parameter, skip to step 3. If the command requires more information, or if you want to include optional parameters, continue to step 2a. A if the command has additional parameters include them after the command name. B if the command includ...

  • Page 57

    Understanding the command syntax 4-3 config vlan engineering add port 1-3,6 could use the following shortcut: config engineering add port 1-3, 6 numerical ranges commands that require you to enter one or more port numbers use the parameter, , in the syntax. A portlist can be a range of numbers, for ...

  • Page 59

    Command history substitution 4-5 command history substitution the switch 3800 “remembers” the last 50 commands you enter. You can display a list of these commands by typing history common commands table 4-3 describes common commands used to manage the switch. Commands specific to a particular featur...

  • Page 60

    4-6 c hapter 4: c ommands switch 3800 commands the tables in this section list all of the commands used on the switch 3800. The commands are organized by the following categories: ■ general switch commands ■ user account commands ■ switch management commands ■ vlan commands ■ protocol commands ■ fdb...

  • Page 61

    Switch 3800 commands 4-7 general switch commands table 4-4 describes general switch commands. Table 4-4 general switch commands command description show switch displays the current switch information, including: ■ sysname, syslocation, syscontact ■ mac address ■ current date and time, and system upt...

  • Page 63

    Switch 3800 commands 4-9 switch management commands table 4-6 describes switch management commands table 4-6 switch management commands command description show management displays network management configuration and statistics including enable/disable states for telnet and snmp, snmp community str...

  • Page 64

    4-10 c hapter 4: c ommands vlan commands table 4-7 describes vlan commands. Config snmp syscontact allows you to configure the name of the system contact. A maximum of 32 characters is allowed. Config snmp sysname allows you to configure the name of the switch. The sysname appears in the command lin...

  • Page 66

    4-12 c hapter 4: c ommands port commands table 4-10 describes port commands. Create fdbentry vlan allows you to create a permanent fdb entry. Specify the following: ■ mac_address — device mac address, using colon separated bytes. ■ name — vlan associated with mac address. ■ portlist — port number as...

  • Page 69

    Switch 3800 commands 4-15 config stpd port cost allows you to specify the path cost of the port in this stpd. The range is 1–65,535. The switch automatically assigns a default path cost of 1. Config stpd port priority allows you to specify the priority of the port in this stpd. By changing the prior...

  • Page 73

    Switch 3800 commands 4-19 enable icmp useredirects allows you to enable the modification of route table information when an icmp redirect message is received. The default setting is disabled. Disable icmp useredirects allows you to disable the changing of routing table information when an icmp redir...

  • Page 75

    Switch 3800 commands 4-21 enable rip exportstatic allows you to enable the advertisement of static routes using rip. The default setting is enabled. Disable rip exportstatic allows you to disable the filtering of static routes. Config rip updatetime {} allows you to change the periodic rip update ti...

  • Page 76

    4-22 c hapter 4: c ommands logging commands table 4-18 describes switch logging commands. Table 4-18 logging commands command description show log config displays the log configuration, including the syslog host ip address, the priority level of messages being logged locally, and the priority level ...

  • Page 77

    Switch 3800 commands 4-23 configuration and image commands table 4-19 describes configuration and image commands. Config syslog {} {} allows you to configure the syslog host address and filter messages sent to the syslog host. Options include: ■ ipaddress — the ip address of the syslog host. ■ facil...

  • Page 79: Irtual

    5 v irtual lan s (vlan s ) setting up virtual local area networks (vlans) on the switch 3800 eases many time-consuming tasks of network administration while increasing efficiency in network operations. This chapter describes the vlan concepts and explains how to implement vlans on the switch 3800. O...

  • Page 80

    5-2 c hapter 5: v irtual lan s (vlan s ) ■ it helps to control traffic. With traditional networks, congestion can be caused by broadcast traffic that is directed to all network devices, regardless of whether they require it. Vlans increase the efficiency of your network because each vlan can be set ...

  • Page 81

    Overview of virtual lans 5-3 for example, in figure 5-1, the vlans are configured as followings: ■ ports 3, 6, and 17 are part of vlan marketing ■ ports 13, 16, and 20 are part of vlan sales ■ ports 21 and 24 are part of vlan finance figure 5-1 example of a port-based vlan even though they are physi...

  • Page 82

    5-4 c hapter 5: v irtual lan s (vlan s ) expanding port-based vlans across switches to create a port-based vlan that spans two switches you must do two things: ■ assign the port on each switch to the vlan. ■ cable the two switches together using one port on each switch per vlan. Figure 5-2 illustrat...

  • Page 83

    Overview of virtual lans 5-5 figure 5-3 illustrates two vlans spanning two switches. On switch 1, ports 1–16 are part of vlan accounting; ports 17–24 are part of vlan engineering. On switch 2, ports 1–16 are part of vlan accounting; ports 17–24 are part of vlan engineering. Vlan accounting spans swi...

  • Page 84

    5-6 c hapter 5: v irtual lan s (vlan s ) tagged vlans the switch 3800 uses the ieee 802.1q d4 draft standard for rules associated with vlan tagging. Tagging is a process that inserts a marker (called a tag) into the ethernet frame. The tag contains the identification number of a specific vlan, calle...

  • Page 85

    Overview of virtual lans 5-7 figure 5-4 illustrates the physical view of a network that uses tagged and untagged traffic. Figure 5-4 physical diagram of tagged and untagged traffic figure 5-5 shows a logical diagram of the same network. Figure 5-5 logical view of tagged and untagged traffic switch 1...

  • Page 86

    5-8 c hapter 5: v irtual lan s (vlan s ) in figure 5-4 and figure 5-5: ■ the trunk port on each switch carries traffic for both vlan marketing and vlan sales. ■ the trunk port on each switch is tagged. ■ the server connected to port 1 on switch 1 has a nic that supports 802.1q tagging. ■ the server ...

  • Page 87

    Overview of virtual lans 5-9 the ip traffic has been divided into two ip subnets, 192.207.35.0 and 192.207.36.0. The subnets are internally routed by the switch 3800. The subnets are assigned different vlan names, finance and personnel, respectively. The remainder of the traffic belongs to the vlan ...

  • Page 88

    5-10 c hapter 5: v irtual lan s (vlan s ) defining protocol filters if necessary, you can define a customized protocol filter based on ethertype, llc, and/or snap. Up to six filters may be part of a protocol filter. To define a protocol filter, do the following: ■ create a protocol using the followi...

  • Page 89

    Configuring vlans on the switch 3800 5-11 the default vlan the switch 3800 ships with one default vlan that has the following properties: ■ the vlan name is default. ■ it contains all the ports on a new or initialized switch. ■ the default vlan is untagged, and has no vlanid or protocol filter assig...

  • Page 90

    5-12 c hapter 5: v irtual lan s (vlan s ) table 5-1 describes the commands used to configure a vlan. Vlan configuration examples the following example creates a port-based vlan named accounting, assigns the ip address 132.15.121.1, and assigns ports 1, 2, 3, and 6 to it: create vlan accounting confi...

  • Page 91

    Displaying vlan settings 5-13 the following example creates a tag-based vlan named video. It assigns the vlanid 1000. Ports 4–8 are added as tagged ports to the vlan. Create vlan video config video tag 1000 config video add port 4-8 tagged the following example creates a vlan named sales , with the ...

  • Page 92

    5-14 c hapter 5: v irtual lan s (vlan s ) ■ status for each port ■ enabled/disabled ■ tagged/untagged ■ protocol information ■ ip address ■ stpd information sample output from this command is as follows: 3c16910:7 # sh vlan all vlan "default" created by user tagging: 802.1q tag 1 ip: 192.207.37.214/...

  • Page 93

    Deleting and resetting vlans 5-15 sample output from this command is as follows: show protocol all protocol name type value ----------------- ---- ----- ip etype 0x0806 etype 0x0800 ipx etype 0x8137 netbios 11c 0xf0f0 decnet etype 0x6004 etype 0x6003 this show command displays protocol information, ...

  • Page 94

    5-16 c hapter 5: v irtual lan s (vlan s ) sw3800.Bk page 16 tuesday, may 5, 1998 5:20 pm.

  • Page 95: Witch

    6 s witch f orwarding d atabase (fdb) this chapter describes the contents of the switch forwarding database (fdb), how the fdb works, and how to configure the fdb. Overview of the fdb the switch 3800 maintains a database of all addresses received on all of its ports. It uses the information in this ...

  • Page 96

    6-2 c hapter 6: s witch f orwarding d atabase (fdb) ■ permanent entries — permanent entries are retained in the database if the switch is reset or a power off/on cycle occurs. The system administrator must make entries permanent. A permanent entry can either be a unicast or multicast mac address. Al...

  • Page 97

    Configuring fdb entries 6-3 configuring fdb entries to configure entries in the fdb, use the commands listed in table 6-1. Fdb configuration example this example adds a permanent entry to the fdb: create fdbentry 02:60:8c:12:34:56 vlan marketing port 4 the permanent entry has the following character...

  • Page 98

    6-4 c hapter 6: s witch f orwarding d atabase (fdb) ■ portlist — displays the entries for one or more ports ■ permanent — displays all permanent entries the following sample output shows the information displayed when you request output for all fdb entries: show fdb hash num mac vlan flags ptag port...

  • Page 99: Panning

    7 s panning t ree p rotocol (stp) using the spanning tree protocol (stp) functionality of the switch 3800 makes your network more fault tolerant. The following sections describe stp concepts, and how stp features are supported by the switch. Stp is a part of the 802.1d bridge specification defined b...

  • Page 100

    Switch 3800 commands 4-13 pace commands table 4-11 describes pace commands. Config port auto off {speed [10

  • Page 101

    Overview of the spanning tree protocol 7-3 if the link through bridge c fails, as shown in figure 7-3, the stp system reconfigures the network so that traffic from segment 2 flows through bridge b. Figure 7-3 traffic flowing through bridge b how stp works stp has the following three stages of operat...

  • Page 102

    7-4 c hapter 7: s panning t ree p rotocol (stp) the root bridge generates bpdus on all ports at a regular interval known as the hello time. All other bridges in the network have a root port. This is the port that costs the least in getting to the root bridge, and it is used for receiving the bpdus i...

  • Page 103

    Spanning tree domains 7-5 ■ within any given stpd, all vlans belonging to it use the same spanning tree. Care must be taken to ensure that stpd instances within a single switch do not see each other in the same broadcast domain. This could happen if, for example, another external bridge is used to c...

  • Page 104

    7-6 c hapter 7: s panning t ree p rotocol (stp) stp configurations when you assign vlans to an stpd, pay careful attention to the stp configuration and its effect on the forwarding of vlan traffic. Figure 7-4 illustrates a network that uses vlan tagging for trunk connections. The following four vlan...

  • Page 105

    Stp configurations 7-7 when the switches in this configuration start up, stp configures each stp domain such that there are no active loops in the topology. Stp could configure the topology in a number of ways to make it loop-free. In figure 7-4, the connection between switch a and switch b is put i...

  • Page 106

    7-8 c hapter 7: s panning t ree p rotocol (stp) stp configurations to avoid within a single stpd, you must be careful when configuring your vlans. The following figures illustrate networks that have been incorrectly set up so that the stp configuration disables the ability of the switches to forward...

  • Page 107

    Creating stp domains 7-9 figure 7-6 shows a similar configuration in which the vlans are all port-based. The trunk connections between the switches require one trunk port per switch for each vlan. Figure 7-6 port-based stp configuration to remove all the bridging loops, stp may block traffic on the ...

  • Page 110

    7-12 c hapter 7: s panning t ree p rotocol (stp) configuration example the following example creates and enables an stpd named backbone_st. It assigns the manufacturing vlan to the stpd. It disables stp on ports 1 through 3, and port 4. Create stpd backbone_st config stpd backbone_st add vlan manufa...

  • Page 111

    Displaying stp settings 7-13 sample output from the command is as follows: 3c16910:28 # sh stpd s0 po 5-8 stpd: s0 port: 8 portid: 8008 stp: enabled path cost: 4 port state: forwarding topology change ack: false port priority: 128 designated root: 80:00:08:00:4e:2c:13:00 designated cost: 0 designate...

  • Page 112

    7-14 c hapter 7: s panning t ree p rotocol (stp) disabling and resetting stp to disable stp or return stp settings to their defaults, use the commands listed in table 7-2. Caution: if you ignore warnings and delete an stpd without removing all of its vlan members first, those vlans will also be dele...

  • Page 113: Ip U

    8 ip u nicast r outing this chapter describes how to configure ip routing on the switch 3800. It assumes that you are already familiar with ip unicast routing. If not, refer to the following publications for additional information: rfc 1058 — routing information protocol rfc 1256 — icmp router disco...

  • Page 114

    8-2 c hapter 8: ip u nicast r outing in figure 8-1, a switch 3800 is shown with two vlans defined: finance and personnel. Ports 1 and 3 are assigned to finance; ports 2 and 4 are assigned to personnel. Finance belongs to the ip network 192.207.35.0; the router interface for finance is assigned the i...

  • Page 115

    Overview of ip unicast routing 8-3 dynamic routes dynamic routes are typically learned by way of rip. Routers using rip exchange information in their routing tables in the form of rip advertisements. Using dynamic routes, the routing table contains only networks that are reachable. Dynamic routes ar...

  • Page 116

    8-4 c hapter 8: ip u nicast r outing configuring ip unicast routing this section describes the commands associated with configuring ip unicast routing on the switch 3800. Configuring routing involves the following steps: ■ verify the switch operating mode is set to “iprouting” by using the following...

  • Page 117

    Verifying the ip unicast routing configuration 8-5 verifying the ip unicast routing configuration use the “show iproute” command to display the current configuration of ip unicast routing for the switch, and for each vlan. The “show iproute” command displays the currently configured routes, includin...

  • Page 120

    8-8 c hapter 8: ip u nicast r outing enable rip splithorizon enables the split horizon algorithm for rip. Default setting is enabled. Enable rip triggerupdate enables triggered updates. Triggered updates are a mechanism for immediately notifying a router’s neighbors when the router adds or deletes r...

  • Page 121

    Configuring dhcp/bootp relay 8-9 table 8-4 describes the commands used to configure the icmp protocol. Disable rip splithorizon disables split horizon. Disable rip poisonreverse disables poison reverse. Disable rip triggerupdate disables triggered updates disable rip exportstatic disables the filter...

  • Page 122

    8-10 c hapter 8: ip u nicast r outing routing configuration example figure 8-2 illustrates a switch that has three vlans defined as follows: ■ finance ■ protocol-sensitive vlan using the ip protocol ■ ports 1 and 3 have been assigned ■ ip address 192.207.35.1 ■ personnel ■ protocol-sensitive vlan us...

  • Page 123

    Routing configuration example 8-11 figure 8-2 unicast routing configuration example in this configuration, all ip traffic from stations connected to ports 1 and 3 have access to the router by way of the vlan finance. Ports 2 and 4 reach the router by way of the vlan personnel. All other traffic (net...

  • Page 127: Tatus

    9 s tatus m onitoring and s tatistics this chapter describes how to view the current operating status of the switch, how to display information in the switch log, and how to take advantage of the rmon capabilities available in the switch. Viewing statistics on a regular basis allows you to: ■ monito...

  • Page 129

    Status monitoring 9-3 show port collisions displays collision statistics for each port. Show port config displays state, link status, speed, and autonegotiation setting for each port. Show port errors displays error information for one or more ports. Show port packet displays a histogram of packet s...

  • Page 130

    9-4 c hapter 9: s tatus m onitoring and s tatistics port statistics the switch 3800 provides a facility for viewing port statistic information. The summary information lists values for the current counter against every port on the switch and it is refreshed approximately every 2 seconds. Values are ...

  • Page 131

    Port statistics 9-5 the following port statistic information is collected by the switch: link status —the current status of the link. Options are: ■ ready — the port is ready to accept a link. ■ active — the link is present at this port. Transmit packet count (tx pkt count) —the number of packets th...

  • Page 132

    9-6 c hapter 9: s tatus m onitoring and s tatistics port errors the switch 3800 keeps track of errors for each port. To view port error, type show port errors the following port error information is collected by the switch: link status — the current status of the link. Options are: ■ ready — the por...

  • Page 133

    Switch logging 9-7 receive jabber frames (rx jab) — the total number of frames received by the port that were of longer than the support maximum length and had a cyclic redundancy check (crc) error. Receive alignment errors (rx align) — the total number of frames received by the port that occurs if ...

  • Page 134

    9-8 c hapter 9: s tatus m onitoring and s tatistics ■ message — the message contains the log information with text that is specific to the problem. Local logging the switch maintains up to 1,000 messages in its internal log. You can display a snapshot of the log at any given point in time by using t...

  • Page 135

    Switch logging 9-9 if priority is not specified, only messages of critical priority are displayed. If the subsystem is not specified, all subsystems are displayed. If you enable the log display on a terminal connected to the console port, your settings will remain in effect even after your console s...

  • Page 136

    9-10 c hapter 9: s tatus m onitoring and s tatistics logging commands the commands described in table 9-4 allow you to do the following: ■ configure logging options ■ reset logging options ■ display the log ■ clear the log table 9-4 logging commands command description config log display {} {} allow...

  • Page 137

    Rmon 9-11 rmon using the remote monitoring (rmon) capabilities of the switch allows network administrators to make decisions about improving switch efficiency and reducing the load on the network. The following sections explain more about rmon concepts and the rmon features supported by the switch 3...

  • Page 138

    9-12 c hapter 9: s tatus m onitoring and s tatistics a typical rmon setup consists of the following two components: ■ the rmon probe — an intelligent, remotely controlled device or software agent that continually collects statistics about a lan segment or vlan. The probe transfers the information to...

  • Page 139

    Rmon 9-13 alarms the alarms group provides a versatile, general mechanism for setting threshold and sampling intervals to generate events on any mib variable. Alarms inform you of a network performance problem and they can trigger automated action responses through the events group. Events effective...

  • Page 140

    9-14 c hapter 9: s tatus m onitoring and s tatistics an rmon probe, however, autonomously looks at the network on behalf of the management workstation without affecting the characteristics and performance of the network. The probe reports by exception, which means that it only informs the management...

  • Page 141

    Rmon 9-15 when using the rmon features of the switch, you should note the following: ■ after the default sessions are created, they have no special status. You can delete or change them as required. ■ the greater the number of rmon sessions, the greater the burden on the management resources of the ...

  • Page 142

    9-16 c hapter 9: s tatus m onitoring and s tatistics sw3800.Bk page 16 tuesday, may 5, 1998 5:20 pm.

  • Page 143: Oftware

    10 s oftware u pgrade and b oot o ptions this chapter describes the procedure for upgrading the switch software image. It also covers how to save and load a primary and secondary configuration file on the switch. Upgrading the software the image file contains the executable code that runs on the swi...

  • Page 145

    Boot option commands 10-3 returning to factory defaults to return the switch configuration to factory defaults, use the following command: unconfig switch this command resets the entire configuration, with the exception of user accounts and passwords that have been configured. To reset all parameter...

  • Page 146

    10-4 c hapter 10: s oftware u pgrade and b oot o ptions sw3800.Bk page 4 tuesday, may 5, 1998 5:20 pm.

  • Page 147: Afety

    A s afety i nformation you must read the following safety information before carrying out any installation or removal of components, or any maintenance procedures on the switch 3800. Important safety information warning: warnings contain directions that you must follow for your personal safety. Foll...

  • Page 148

    A-2 a ppendix a: s afety i nformation ■ this unit operates under selv (safety extra low voltage) conditions according to iec 950. The conditions are only maintained if the equipment to which it is connected also operates under selv conditions. ■ the appliance coupler (the connector to the unit and n...

  • Page 149

    Important safety information a-3 ■ if the power cord plug is unsuitable and must be replaced, you may find other codings for the respective connections. Connect the power supply wires for the unit according to the following scheme: ■ brown wire to the live (line) plug terminal which may be marked wi...

  • Page 150

    A-4 a ppendix a: s afety i nformation lithium battery ■ replace the lithium battery with the same or equivalent type, as recommended by the manufacturer. Warning: there is a danger of explosion if the battery is incorrectly replaced. ■ dispose of used batteries according to the manufacturers instruc...

  • Page 151

    L’information de sécurité importante a-5 ■ pour réduire les risques d'incendie ou de choc électrique, installez ce groupe sous abri dans une zone dont la température et l'humidité sont régulées et qui ne contient pas de produits contaminateurs conductifs. Power ■ pour garantir le respect des normes ...

  • Page 152

    A-6 a ppendix a: s afety i nformation cordon électrique ■ il doit être agréé dans le pays d'utilisation : ■ si la prise mâle du cordon électrique est défectueuse, vous devez la remplacer en identifiant d'autres codages pour assurer les différentes connexions nécessaires. Branchez les fils d'alimenta...

  • Page 153

    L’information de sécurité importante a-7 porte-fusibles. Pour ce groupe, vous devez uniquement utiliser des fusibles réalisés par le même constructeur et offrant le même pouvoir de coupure et respectant le même type que le fusible d'origine. Refermez le porte-fusibles. ■ pour respecter les normes eu...

  • Page 154

    A-8 a ppendix a: s afety i nformation ■ les batteries au lithium ne figurent pas sur la liste epa des déchets dangereux. Par conséquent, vous pouvez en général vous en débarrasser comme s'il s'agissait d'un déchet normal. ■ si vous souhaitez vous débarrasser de quantités importantes, contactez un se...

  • Page 155

    Wichtige sicherheitsinformationen a-9 ■ das gerät muß an eine geerdete steckdose angeschlossen werden, die die europäischen sicherheitsnormen erfüllt. ■ das gerät nicht an eine wechselstromsteckdose anschließen, die nicht geerdet ist. ■ die netzsteckdose muß in der nähe des geräts und leicht zugängl...

  • Page 156

    A-10 a ppendix a: s afety i nformation ■ zur erfüllung europäischer sicherheitsnormen darf keine ersatzsicherung am geräteeingang angebracht werden. Es dürfen nur sicherungen vom gleichen hersteller, der gleichen marke und art mit dem gerät verwendet werden. Faseroptikanschlüsse - optische sicherhei...

  • Page 157

    Wichtige sicherheitsinformationen a-11 lithiumbatterie ■ die lithiumbatterie nach den empfehlungen des herstellers durch eine batterie des gleichen oder eines gleichwertigen typs ersetzen. Warnhinweis: wird die batterie falsch ersetzt, besteht explosionsgefahr. ■ verbrauchte batterien nach den angab...

  • Page 158

    A-12 a ppendix a: s afety i nformation sw3800.Bk page 12 tuesday, may 5, 1998 5:20 pm.

  • Page 159: Echnical

    B t echnical s pecifications physical dimensions height: 3.5 inches x width: 17.32 inches x depth: 17.32 inches weight: 22 pounds environmental requirements operating temperature 0 to 40˚ c storage temperature -10 to 70 ˚ c operating humidity 10% to 95% relative humidity, noncondensing standards en6...

  • Page 160

    B-2 a ppendix b: t echnical s pecifications standards supported ethernet iso 8802-3 ieee 802.3z/d3 iso 10038:1993 (ieee 802.1d) ieee 802.1q/d10 snmp snmp protocol (rfc 1157) mib-ii (rfc 1213) bridge mib (rfc 1493) vlan mib (rfc 1573) rmon mib (rfc 1757) terminal emulation telnet (rfc 854) protocols ...

  • Page 161: Roubleshooting

    C t roubleshooting if you encounter problems when using the switch, this appendix may be helpful. If you have a problem which is not listed here or in the release notes, please contact your local technical support representative. Leds power led does not light: check that the power cable is firmly co...

  • Page 162

    C-2 a ppendix c: t roubleshooting both sides of the link must have the same setting for autonegotiation. It the two are different, typically the side with autonegotiation disabled will have the link led lit, and the side with autonegotiation enabled will not be lit. The default configuration for a p...

  • Page 163

    Using the command-line interface c-3 traps are not received by the snmp network manager: check that the snmp network manager's ip address and community string are correctly configured and that the ip address of the trap receiver is configured properly on the switch. The snmp network manager or telne...

  • Page 164

    C-4 a ppendix c: t roubleshooting you forget your password and cannot log on: if you are not an administrator, another user having administrator access level can log on, delete your user name, and create a new user name for you, with a new password. Alternatively, another user having administrator a...

  • Page 165

    Using the command-line interface c-5 vlan names: there are restrictions on vlan names. They cannot contain white spaces and cannot start with a numeric value unless you use quotation marks around the name. If a name contains white spaces or starts with a numeric, you must use quotation marks wheneve...

  • Page 166

    C-6 a ppendix c: t roubleshooting the switch keeps aging out endstation entries in the switch forwarding database (fdb): reduce the number of topology changes by disabling stp on those switches that do not use redundant paths. Specify that the endstation entries are static or permanent. Routing the ...

  • Page 167: Echnical

    D t echnical s upport 3com provides easy access to technical support information through a variety of services. This appendix describes these services. Information contained in this appendix is correct at time of publication. For the very latest, we recommend that you access 3com corporation’s world...

  • Page 168

    D-2 a ppendix d: t echnical s upport access by digital modem isdn users can dial in to 3combbs using a digital modem for fast access up to 56 kbps. To access 3combbs using isdn, use the following number: 408 654 2703 3comfacts sm automated fax service 3com corporation’s interactive fax service, 3com...

  • Page 169

    Support from your network supplier d-3 3comforum on compuserve ® online service 3comforum is a compuserve-based service containing patches, software, drivers, and technical articles about all 3com products, as well as a messaging section for peer support. To use 3comforum, you need a compuserve acco...

  • Page 170

    D-4 a ppendix d: t echnical s upport support from 3com if you are unable to receive support from your network supplier, technical support contracts are available from 3com. Contact your local 3com sales office to find your authorized service provider using one of these numbers: regional sales office...

  • Page 171

    Returning products for repair d-5 returning products for repair before you send a product directly to 3com for repair, you must first be obtain a return materials authorization (rma) number. Products sent to 3com without rma numbers will be returned to the sender unopened, at the sender’s expense. T...

  • Page 172

    D-6 a ppendix d: t echnical s upport sw3800.Bk page 6 tuesday, may 5, 1998 5:20 pm.

  • Page 173: Lossary

    G lossary ageing the automatic removal of dynamic entries from the switch database that have timed-out and are no longer valid. Arp address resolution protocol. The protocol used to dynamically bind high-level ip addresses to low-level hardware addresses. Arp is used only across a single physical ne...

  • Page 174

    2 g lossary csma/cd carrier sense multiple access/collision detection that is a channel access method used by ethernet and ieee 802.3 standards in which devices transmit only after finding the data channel clear for some period of time. When two devices transmit simultaneously, a collision occurs an...

  • Page 175

    3 lan local area network that consists of connected computing resources (such as pcs, printers, and servers) covering a relatively small geographic area (usually not larger than a floor or building). Characterized by high data rates and low error rates. Latency the delay between the time a device re...

  • Page 176

    4 g lossary on a wide range of computers and networking equipment and may be used to manage many aspects of network and endstation operation. Spanning tree protocol (stp) a bridge-based mechanism for providing fault tolerance on networks. Stp works by allowing the implementation of parallel paths fo...

  • Page 177: Ndex

    I ndex 1 i ndex numerics 3com bulletin board service (3combbs) d-1 3com sales offices d-4 3com url d-1 3comfacts d-2 3comforum d-3 a accounts, creating 3-3 alarms 9-15 alarms (rmon group) 9-13, 9-14 b bootp 3-5 bridge identifier 7-3 bridge priority, configuring 4-14, 7-11 bulletin board service d-1 ...

  • Page 178

    2 i ndex router interfaces 8-1 router show commands (table) 8-12 routing table configuration commands (table) 8-7 dynamic routes 8-3 populating 8-2 static routes 8-3 settings, displaying 8-12 l leds 1-8 load sharing 3-15 configuring 3-15 log display 9-8 logging and telnet 9-9 commands 9-10 fault lev...

  • Page 179

    I ndex 3 forward delay 4-14, 7-11 hello time configuring 4-14, 7-11 description 7-4 max age configuring 4-14, 7-11 overview 7-1 path costs 4-15, 7-11 port priority 4-15, 7-11 switch 3800 configuration examples 1-5 dimensions b-1 factory defaults 1-10 free-standing installation 2-3 front view 1-7 gig...

  • Page 180

    4 i ndex sw3800.Bk page 4 tuesday, may 5, 1998 5:20 pm.

  • Page 181

    3com corporation l imited w arranty h ardware 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: if a product does not operate as war...

  • Page 182

    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 modify, or any other caus...