IBM 8275-416 User manual

8275 Model 416 High Performance Ethernet
Workgroup Switch
User’s Guide
Release 1.2
GC30-4026-02
IBM

8275 Model 416 High Performance Ethernet
Workgroup Switch
User’s Guide
Release 1.2
GC30-4026-02
IBM

Note
Before using this information and the product it supports, be sure to read “Appendix A. Safety Information” on page 93 and
“Appendix B. Notices” on page 103.
Third Edition (December 1999)
This edition applies to Release 1.2 of the IBM 8275 Model 416 High Performance Ethernet Workgroup Switch.
Order publications through your IBM representative or the IBM branch office serving your locality. Publications are
not stocked at the address given below.
A form for readers’ comments appears at the back of this publication. If the form has been removed, address your
comments to:
Department CGF
Design & Information Development
IBM Corporation
PO Box 12195
Research Triangle Park NC 27709
U.S.A.
When you send information to IBM, you grant IBM a nonexclusive right to use or distribute the information in any
way it believes appropriate without incurring any obligation to you.
© Copyright International Business Machines Corporation 1999. All rights reserved.
US Government Users Restricted Rights – Use, duplication or disclosure restricted by GSA ADP Schedule Contract
with IBM Corp.

Contents
Figures ...........................vii
Tables ............................ix
About this guide ........................xi
Who should use this guide .....................xi
How this guide is organized ....................xi
Accessing the softcopy library....................xi
Online support .........................xii
Obtaining service ........................xii
Summary of Changes .....................xiii
Chapter 1. Introduction......................1
Product overview ........................1
Switch functions .........................1
Layer 2 switching .......................1
Virtual local area networks (VLANs).................2
Self Learning IP ........................2
Link aggregation (trunking) ....................4
Fast spanning tree mode ....................4
Management and user interfaces..................5
Security ...........................6
Reliability and serviceability....................6
Performance .........................6
Year 2000 (Y2K) Compliance ...................6
Hardware ...........................7
Cabling requirements ......................7
Front panel..........................8
Switch LED status.......................10
Single-digit display ......................11
Base ports LEDs .......................12
Feature module LEDs .....................13
Physical characteristics.....................17
Chapter 2. Accessing the switch .................19
Types of Connectivity ......................19
Out-of-band connection.....................19
In-band connection – Telnet, Web, SNMP ..............21
Chapter 3. Configuring your switch ................25
Configuring IP information .....................25
Remote configuration using DHCP or BootP .............25
Manual configuration using the terminal interface ...........25
Configuration Changes ......................27
Making configuration changes using the terminal interface ........27
Making configuration changes using the Web interface .........29
Making configuration changes using SNMP .............30
Managing the configuration file ...................30
Chapter 4. Using the Terminal Interface ...............31
Login panel ..........................31
The Main Menu.........................32
© Copyright IBM Corp. 1999 iii

System information .......................32
Inventory information......................33
System description ......................33
Management..........................35
Configuring network connection for the switch ............35
Configuring serial port .....................36
Configuring for DHCP or BootP..................37
Configuring the SNMP community .................38
Configuring traps .......................41
Configuring Telnet.......................44
Ping ............................45
ARP cache .........................46
Device configuration .......................47
Configuring the switch .....................47
Configuring ports .......................48
Configuring port monitoring ...................50
Configuring spanning tree protocol (STP) ..............52
VLAN management ......................53
Trunk management menu ....................58
Statistics ...........................61
Port summary statistics .....................61
Port detailed statistics .....................62
Switch summary statistics ....................64
Switch detailed statistics ....................64
Forwarding database information .................66
Self Learning IP router table menu ................66
Self Learning IP host address menu ................67
User account management ....................70
Defining user accounts .....................70
Managing login sessions ....................71
System utilities .........................72
Saving applied changes ....................72
Logging out .........................72
Handling files ........................73
Reset utility .........................77
System reset menu ......................77
Resetting configuration data to factory default values ..........78
Resetting passwords to factory default values ............79
Chapter 5. Using the Web Interface ................81
Configuring for Web Access ....................81
Web Page Layout........................81
Starting the Web Interface.....................82
Commands .........................82
Chapter 6. Using the SNMP Interface ................85
MIBs supported ........................85
MIB II (RFC 1213) ......................85
Definitions of managed objects for bridges (RFC 1493) .........86
IEEE 802.3 Ethernet MIB (RFC 1643) ...............86
Remote monitoring (RMON) MIB (RFC 1757) ............87
IBM 8275-416 switch enterprise MIB ................87
Port ifIndex values .......................87
Chapter 7. Troubleshooting and Obtaining Service ..........89
Diagnosing Problems ......................89
iv 8275-416 User’s Guide

Obtaining Software .......................89
Troubleshooting in a Network ...................89
Start of Troubleshooting Process ..................89
Choosing a Troubleshooting Procedure ................90
Procedure A .........................90
Procedure B .........................90
Procedure C.........................91
Procedure D.........................91
Procedure E .........................92
Obtaining Service ........................92
Appendix A. Safety Information ..................93
Reference to Safety Booklet ....................93
Safety Notice .........................97
Appendix B. Notices ......................103
Electronic Emission Notices....................104
Federal Communications Commission (FCC) Statement ........104
Industry Canada Class A Emission Compliance Statement .......104
Avis de conformité aux normes d’Industrie Canada ..........104
European Norm (EN) Statement .................104
Japanese Voluntary Control Council for Interference (VCCI) Statement 105
Korean Communications Statement................105
Power line harmonics compliance ................106
Taiwanese Class A Warning Statement ..............106
Class 1 Laser Statement.....................106
Class 1 LED Statement .....................106
Trademarks..........................107
Appendix C. Cable Pinout Diagrams................109
Straight-Through 10BASE-T/100BASE-TX Cables ...........109
Straight-Through 10BASE-T/100BASE-TX Cables for STP ........109
Crossover 10BASE-T/100BASE-TX Cables ..............110
Crossover 10BASE-T/100BASE-TX Cables for STP ...........110
EIA-232 Port .........................111
Null-Modem Cables.......................112
Appendix D. Interface Conventions for the Console..........113
Appendix E. Introduction to Virtual LANs (VLANs) ..........117
Virtual LANs .........................117
Benefits of VLANs ......................117
How VLANs ease change and movement..............117
How VLANs control broadcast traffic ...............117
How VLANs provide extra security ................117
VLANs and the switch .....................118
Priority and traffic classes ...................118
Overview of IEEE 820.1Q VLAN support ..............119
Configuration examples ....................120
Using unique MAC addresses ..................123
Duplicate VLAN configurations and oversubscription of switch resources 123
Index ............................125
Glossary ..........................133
Contents v

Readers’ Comments — We’d Like to Hear from You .........137
vi 8275-416 User’s Guide

Figures
1. Self-Learning IP in the network ..........................3
2. Front panel of the switch. ............................8
3. LEDs for the switch...............................10
4. LEDs for the base 10/100BASE-TX ports on the switch ................12
5. LEDs for the 8-port 10/100BASE-TX feature module. .................13
6. LEDs for the 8-port 100BASE-FX feature module....................14
7. LEDs for the 4-port 100BASE-FX feature module....................15
8. LEDs for the 2-port 1000BASE-SX feature module. ..................16
9. Out-of-band connectivity - locally attached terminal ..................20
10. Out-of-band connectivity - remotely attached terminal .................20
11. In-band connection ..............................22
12. Configuring BootP/static DHCP and network connection (IP information). ..........26
13. Login panel for terminal interface .........................31
14. Main menu for terminal interface .........................32
15. System information menu............................33
16. Inventory information menu ...........................33
17. System description menu............................34
18. Management menu ..............................35
19. Network connection configuration.........................35
20. Serial port configuration ............................37
21. SNMP community configuration .........................39
22. SNMP trap receiver configuration.........................41
23. Trap flags configuration ............................42
24.Traplog..................................43
25. Trap log status ...............................44
26. Telnet configuration ..............................44
27. Ping ...................................45
28. ARP cache .................................46
29. Device configuration .............................47
30. Switch configuration..............................47
31. Port configuration ..............................49
32. Port monitoring ...............................51
33. Spanning tree switch configuration/status ......................52
34. Spanning tree port configuration/status.......................53
35. VLAN management menu ...........................54
36. VLAN summary and configuration ........................54
37. VLAN Configuration Menu ...........................55
38. GARP configuration..............................56
39. 802.1Q port configuration............................57
40. VLAN reset .................................58
41. Trunk status menu ..............................59
42. Configure trunk menu .............................60
43. Statistics Menu ...............................61
44. Port summary statistics ............................62
45. Port detailed statistics (Page 1 of 4)........................62
46. Port detailed statistics (Page 2 of 4)........................63
47. Port detailed statistics (Page 3 of 4)........................63
48. Port detailed statistics (Page 4 of 4)........................64
49. Switch summary statistics ...........................64
50. Switch detailed statistics ............................65
51. Self Learning IP statistics............................65
52. Forwarding database information .........................66
53. Self Learning IP router table menu ........................67
© Copyright IBM Corp. 1999 vii

54. Self Learning IP host address menu........................68
55. User account management ...........................70
56. Login session management ...........................71
57. Save applied changes .............................72
58. Logout utility ................................73
59. Downloading a file to the switch .........................75
60. Uploading a file from the switch .........................76
61. System Reset menu .............................77
62. System reset menu ..............................78
63. Reset configuration data to factory defaults .....................78
64. Reset passwords to factory defaults........................79
65. Web interface panel–example ..........................82
66. Straight-Through UTP Cable (RJ-45 to RJ-45), T568A ................109
67. Straight-Through UTP Cable (RJ-45 to RJ-45), T568B ................109
68. Straight-Through STP Cable (RJ-45 to IBM Data Connector) ..............109
69. Crossover UTP Cable (RJ-45 to RJ-45), T568A ...................110
70. Crossover UTP Cable (RJ-45 to RJ-45), T568B ...................110
71. Crossover STP Cable (RJ-45 to IBM Data Connector Crossover) ............110
72. Pinout of the EIA-232 Port ...........................111
73. EIA-232 Null Modem Cable for Terminal with 25-Pin Connector .............112
74. EIA-232 Null Modem Cable for Terminal with 9-Pin Connector..............112
75. An Example of VLANs ............................118
76. Untagged device to untagged device configuration ..................120
77. 802.1Q-compliant device (tagging and GVRP) to 802.1Q-compliant device (tagging and GVRP)
configuration ................................121
78. Untagged device to 802.1Q compliant device (tagging and GVRP) configuration .......122
79. Untagged device to 802.1Q-compliant device (tagging only) configuration .........123
viii 8275-416 User’s Guide

Tables
1. Ethernet cable requirements ...........................7
2. LED status for the switch. ...........................10
3. Problem indications on the single-digit display when the Fault LED is ON...........11
4. Status of LEDs for 16 base 10/100BASE-TX ports ..................12
5. Status of LEDs for 8-port 10/100BASE-TX feature module ...............13
6. Status of LEDs for 8-port 100BASE-FX feature module.................14
7. Status of LEDs for 4-port 100BASE-FX feature module.................15
8. Status of LEDs for 2-port 1000BASE-SX feature module ................16
9. Summary of physical characteristics for the switch ..................17
10. Connection methods and available user interfaces ..................19
11. Messages - while downloading files ........................73
12. Messages - while uploading files .........................74
13. MIBs Supported by the Switch. .........................85
14. Troubleshooting Symptoms and Actions ......................90
15. Special Keys and Commands Used with the Terminal Interface .............113
16. Acceptable VLAN configurations with no feature modules ...............124
© Copyright IBM Corp. 1999 ix

x8275-416 User’s Guide

About this guide
This guide briefly describes the features and capabilities of the 8275 Model 416
High Performance Ethernet Workgroup Switch. However, its primary purpose is to
describe how to use the capabilities offered by the switch to configure, obtain status
information, and monitor performance of the switch in your network.
Who should use this guide
This guide is intended for the network administrator or person responsible for
integrating, maintaining and monitoring the switch in your network. The person
responsible for coordinating installation and service for the switch will also find this
manual useful.
How this guide is organized
This guide contains the following chapters and appendixes:
v“Chapter 1. Introduction” on page 1 describes the functions and capabilities of the
switch.
v“Chapter 2. Accessing the switch” on page 19 describes the various physical
methods of accessing the switch.
v“Chapter 3. Configuring your switch” on page 25 describes initial configuration of
IP information.
v“Chapter 4. Using the Terminal Interface” on page 31 describes the using
functions of the terminal interface.
v“Chapter 6. Using the SNMP Interface” on page 85 contains information about
using SNMP to manage the switch.
v“Chapter 5. Using the Web Interface” on page 81 introduces the Web interface.
v“Chapter 7. Troubleshooting and Obtaining Service” on page 89 gives
suggestions for solving problems obtaining service.
v“Appendix A. Safety Information” on page 93 contains translated safety
instructions to observe when performing troubleshooting procedures.
v“Appendix B. Notices” on page 103 lists important notices about the use of this
product.
v“Appendix C. Cable Pinout Diagrams” on page 109 describes and illustrates
pinout diagrams for Ethernet and null-modem cable connectors.
v“Appendix D. Interface Conventions for the Console” on page 113 describes the
definitions and functions of special keys and commands that are used by the
terminal interface.
v“Appendix E. Introduction to Virtual LANs (VLANs)” on page 117 briefly introduces
concepts and terminology about virtual local area Networks (VLANs).
Accessing the softcopy library
Softcopy versions of 8275-416 product documentation are available from either the
Documentation CD-ROM (shipped with the product) or the IBM Networking
Products Web site. To access product documentation shipped on the CD-ROM,
follow the instructions in the booklet that accompanies the CD-ROM. Visit the
following Web site to access the 8275-416 documentation at:
http://www.ibm.com/networking/support/docs.nsf/8275docs?OpenView
© Copyright IBM Corp. 1999 xi

Online support
To obtain support information, including technical tips, current product information,
and code updates and fixes for the switch, visit the IBM Networking Tech Support
page at:
http://www.ibm.com/networking/support
You may also subscribe to receive e-mail notifications about code updates, tips, and
FAQs for your switch.
Obtaining service
If you need assistance in troubleshooting or you need service for your 8275-416,
call IBM at:
v1-800-772-2227 in the United States
v1-800-426-7378 (1-800-IBM-SERV) in Canada.
vIn other locations, contact your place of purchase.
Refer to your IBM Warranty for information concerning service for the product.
xii 8275-416 User’s Guide

Summary of Changes
Changes in this revision are indicated with revision bars in the left margin and
reflect:
vThe addition of the 2-Port 1000BASE-SX Gigabit Feature Module
vThe addition of these functions:
– Trunking
– Self-learning IP
– Port-based and fast spanning tree
– Enable/disable Web mode configuration from SNMP
– Enable/disable broadcast storm suppression trap
vNew terminal interface panels in Chapter 4 to reflect new function for Release
1.2.
vGeneral editorial changes
© Copyright IBM Corp. 1999 xiii

xiv 8275-416 User’s Guide

Chapter 1. Introduction
This chapter briefly describes the functions, capabilities, and benefits of the 8275
Model 416 High Performance Ethernet Workgroup Switch. This information helps
you to plan for and use the switch in your network.
Product overview
Fast Ethernet switching continues to evolve from high-end backbone applications to
desktop-switching applications. The switch provides a low-cost and powerful Layer
2 switch solution. It is an attractive base switch offering with the following key
functions:
vHigh-performance, Layer 2, managed switch
v16 base ports (10/100BASE-TX), expandable from 18 to 32 ports, depending on
the combination of the following optional feature modules:
– 8-Port 10/100BASE-TX
– 8-Port 100BASE-FX
– 4-Port 100BASE-FX
– 2-Port 1000BASE-SX
vRobust management support; VT100 terminal interface, Web interface, SNMP
vBackplane performance 10 gigabits per second Ethernet switching
vDesktop and segment switching infrastructure
vAffordable migration to higher-performance networks
As a network administrator, you have a choice of three easy-to-use management
methods: VT100 terminal interface, Web-based, and Simple Network Management
Protocol (SNMP). These management methods enable you to configure, manage,
and control the switch locally or from anywhere on the network.
The Spanning Tree Protocol (STP) provides fault tolerance on the network.
Switch functions
This section describes the functional support included in the switch:
vLayer 2 switching
vVirtual local area networks (VLANs)
vManagement and user interface
vSelf-learning IP
vLink aggregation (trunking)
vFast spanning tree mode
vSecurity
vReliability and serviceability
vPerformance
vFlow Control
vYear 2000 (Y2K) compliance
Layer 2 switching
The 8275-416 is a Layer 2 Ethernet switch in which frame forwarding is based on
MAC addresses and VLAN membership. The switch supports the IEEE 802.1D
(1998) and 802.1Q standards.
© Copyright IBM Corp. 1999 1

802.3x flow control
The switch supports 802.3x flow control, which, when enabled, allows the
transmission of data frames to be inhibited for a specified period of time. The
default for 802.3x flow control is
Disabled . 802.3x flow control is valid only when the
port is in full-duplex mode.
Broadcast storm recovery
The switch detects broadcast storms and automatically blocks broadcast traffic to
minimize the impact of the broadcast storm on the rest of the network. You can
enable or disable this function at a switch level. For all broadcast frames received
by the switch, the broadcast storm recovery operation depends on port speed and
is described as follows:
1. If the Broadcast Storm Recovery Mode is
Enable , and if the broadcast traffic on
a 10 Mbps Ethernet port exceeds 20% of the link speed, then the switch blocks
the broadcast traffic on the port until the broadcast traffic is returned to 10% or
below.
2. If the Broadcast Storm Recovery Mode is
Enable , and if the broadcast traffic on
a 100 Mbps Ethernet port exceeds 5% of the link speed, then the switch blocks
the broadcast traffic on the port until the broadcast traffic is returned to 2.5% or
below.
3. Broadcast Storm Recovery is not supported on 1000 Mbps Ethernet ports.
4. If Broadcast Storm Recovery Mode is
Disable , the switch does not block the
broadcast traffic on the Ethernet port.
5. The switch issues a trap message when traffic exceeds a port’s broadcast
threshold and when it returns to or below the port’s recovery threshold.
Forwarding database
The switch port MAC addresses are stored in the forwarding database. An address
learned by the switch is removed from the forwarding database after a period of
time if no frames have been received from that address. The default value for the
aging period is 300 seconds (5 minutes), but it can be configured by the user. The
time values range from 10 seconds to 600 seconds.
The switch forwarding database stores 12 000 entries. When the database is full,
no new entries are learned until an existing entry ages out. All frames with unknown
destination addresses are multicast to all ports in the appropriate VLAN.
Virtual local area networks (VLANs)
The switch supports VLANs. “Appendix E. Introduction to Virtual LANs (VLANs)” on
page 117 provides an introduction to VLANs. It describes concepts and terminology,
as well as, the benefits of using VLANs. The switch is manageable only through the
ports which are members of the Default VLAN (VLAN 1).
Figure 36 on page 54 and Figure 37 on page 55 show examples of the panels and
descriptions of the parameters used to configure VLANs.
Self Learning IP
Self Learning IP is a configurable function of the switch that learns where IP
addresses are in the network so that packets normally sent from one host to
another through a router can bypass the router and be sent directly to the
destination host address. Self Learning IP is most effective when the switch is used
to “front” the router (the switch is positioned logically between the router and the
networks to which it belongs). Because of this strategic vantage point in the network
(Figure 1 on page 3), the switch has visibility to all packets flowing to and from the
28275-416 User’s Guide

router, as well as between any two switch ports. The switch monitors the traffic to
determine if a Layer 2 shortcut can be used instead of subjecting the packet to
Layer 3 router processing which can be relatively lengthy.
The Self Learning IP function essentially:
vLearns the network structure, classifying attached devices as routers or hosts.
vMaintains knowledge of network structure, aging out unused devices over time.
vExpedites packet flow through the network by circumventing the router whenever
possible.
Device learning and classification is accomplished by watching ARP replies that
flow naturally through the switch with the addition of active probing to determining
whether a device is a router or a host. When an IP packet enters the switch, the
Self Learning IP function compares the destination MAC address against the list of
known routers, then checks if the destination IP address is a known host. If both
tests pass, the packet is automatically re-addressed to the destination IP host
device and is sent out the appropriate switch port.
A Router Table and Host Table are used to manage information learned about
router and host devices, respectively. To keep this network information current, the
Router Table entries are refreshed every 5 minutes while Host Table entries are
checked every 3 minutes. Devices which are no longer active are dropped from
their table; devices may be relearned at a later time as conditions change.
To use the Self Learning IP function, the switch must be configured with the
following:
vIP information (see Network Connectivity Configuration Menu in Chapter 4).
Note: For the Self Learning IP function to work, the IP information must include
a default gateway for the network.
vEnable the Self Learning IP function (see the Switch Configuration Menu in
Chapter 4).
Router
Switch
2.2.2.x
Subnet
1.1.1.x
Subnet
Server
Host A
1.1.1.10
* Host = clients or servers
Host B
2.2.2.20
Figure 1. Self-Learning IP in the network
Chapter 1. Introduction 3

Once Self Learning IP is enabled, the following information is available:
vSelf Learning IP statistics for the switch (see Switch Detailed Statistics Menu in
Chapter 4).
vIP and MAC addresses of routers learned (see Self Learning IP Router Table
Menu in Chapter 4).
vHost IP statistics (see Self Learning IP Host Address Menu in Chapter 4).
Note that the Packets Switched count included in the Switch Detailed Statistics
Menu may not reflect the absolute latest value. The information used for updating
this count is obtained as individual Host Table entries are refreshed, so while this
value can change over time, it does not necessarily update at the same frequency
as other statistics on the menu.
While intended as an autonomous feature, Self Learning IP is affected by certain
changes in switch configuration. If Self Learning IP is enabled and the switch IP
address is reset, the Self Learning IP function is automatically disabled. The Self
Learning IP Router and Host Tables are cleared whenever there is a link
aggregation configuration change (see Link aggregation (trunking) in this chapter),
forcing router and host devices to be relearned.
Link aggregation (trunking)
Link aggregation, also called trunking allows 802.3 MAC interfaces to be grouped
together logically to appear as one super-link. The super-link or Link Aggregation
Group (LAG) has access to the combined bandwidth of all links.
The Sun Trunking
™
1.0 specification is supported for the 10/100BASE-TX and
100BASE-FX ports. All members of the trunk must support Sun Trunking
™
1.0. For
information about configuring trunks, see “Trunk management menu” on page 58.
Up to 8 trunks can be configured.
Advantages of trunking are:
vFault tolerance: Failure of one or more of the links in the LAG are handled
gracefully. If a link of the LAG fails, the flows mapped to that link are dynamically
reassigned to the remaining links of the LAG.
vRedundancy: Link aggregation also provides automatic, point-to-point redundancy
between two devices (switch-to-switch).
Fast spanning tree mode
The IEEE 802.1D spanning tree protocol (STP) is designed to prevent loops in
Ethernet networks. To achieve this objective the STP does not allow switches to
forward data frames on a link immediately after the link is activated. The STP first
listens for spanning tree BPDUs from other switches, then determines whether to
put the link into forwarding state. When a default IEEE spanning tree timer value of
15 seconds is used for the forward delay timer, a link can start forwarding traffic 30
seconds after it becomes active on the network.
In networks with shared media hubs, there is a trend to attach network stations (or
hosts) directly to multi-port bridges (otherwise known as switches). Unfortunately,
the 802.1D spanning tree protocol has not been changed to accommodate this
trend. So, when a network station is ready to send data, the switch does not allow
the network station to communicate on the network until STP puts the port in
forwarding state. The 30 second delay forces the network station users to wait
48275-416 User’s Guide