3Com 1100 User Manual

SuperStack® II Switch

Management Guide

For units in the SuperStack II Switch 1100/3300 and 610/630 Family Management Software Version 2.50

http://www.3com.com/

Part No. DUA1695-0BAA04 Published May 2000

3Com Corporation 5400 Bayfront Plaza Santa Clara, California 95052-8145

Copyright © 2000, 3Com Technologies. 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) without written permission from 3Com Technologies.

3Com Technologies reserves the right to revise this documentation and to make changes in content from time to time without obligation on the part of 3Com Technologies to provide notification of such revision or change.

3Com Technologies provides this documentation without warranty, term, or condition of any kind, either implied or expressed, including, but not limited to, the implied warranties, terms or conditions of merchantability, satisfactory quality, and fitness for a particular purpose. 3Com may make improvements or changes in the product(s) and/or the program(s) described in this documentation at any time.

If there is any software on removable media described in this documentation, it is furnished under a license agreement included with the product as a separate document, in the hard copy documentation, or on the removable media in a directory file named LICENSE.TXT or !LICENSE.TXT. If you are unable to locate a copy, please contact 3Com and a copy will be provided to you.

UNITED STATES GOVERNMENT LEGEND

If you are a United States government agency, then this documentation and the software described herein are provided to you subject to the following:

All technical data and computer software are commercial in nature and developed solely at private expense. Software is delivered as “Commercial Computer Software” as defined in DFARS 252.227-7014 (June 1995) or as a “commercial item” as defined in FAR 2.101(a) and as such is provided with only such rights as are provided in 3Com’s standard commercial license for the Software. Technical data is provided with limited rights only as provided in DFAR 252.227-7015 (Nov 1995) or FAR 52.227-14 (June 1987), whichever is applicable. You agree not to remove or deface any portion of any legend provided on any licensed program or documentation contained in, or delivered to you in conjunction with, this User Guide.

Unless otherwise indicated, 3Com registered trademarks are registered in the United States and may or may not be registered in other countries.

3Com, the 3Com logo, Net Age, SmartAgent, SuperStack and Transcend are registered trademarks of 3Com Corporation. CoreBuilder and PACE are trademarks of 3Com Corporation. 3ComFacts is a service mark of 3Com Corporation.

All other company and product names may be trademarks of the respective companies with which they are associated.

ENVIRONMENTAL STATEMENTS

It is the policy of 3Com Corporation to be environmentally- friendly in all operations. To uphold our policy, we are committed to:

• Establishing environmental performance standards that comply with national legislation and regulations.

• Conserving energy, materials and natural resources in all operations.

• Reducing the waste generated by all operations. Ensuring that all waste conforms to recognized environmental standards. Maximizing the recyclable and reusable content of all products.

• Ensuring that all products can be recycled, reused and disposed of safely.

• Ensuring that all products are labelled according to recognized environmental standards.

• Improving our environmental record on a continual basis.

End Of Life Statement

3Com processes allow for the recovery, reclamation and safe disposal of all end- of- life electronic components.

Regulated Materials Statement

3Com products do not contain any hazardous or ozone- depleting material.

Environmental Statement about the Documentation

The documentation for this product is printed on paper that comes from sustainable, managed forests; it is fully biodegradable and recyclable, and is completely chlorine- free.

The varnish is environmentally-friendly, and the inks are vegetable-based with a low heavy-metal content.

ONTENTS

BOUT THIS GUIDE

Conventions 13 Related Documentation 15 Year 2000 Compliance 15 Documentation Comments 16 Product Registration 16

I Getting Started with Management

UPERSTACK

What is Management Software? 20 Summary of Software Features 20 Software Features Explained 21

Stack Management 21 Forwarding Modes 21 Duplex Modes 22 Flow Control 23 Traffic Prioritization 23 PACE 24 Security 24 Resilient Links 25 Port Trunks 25 Broadcast Storm Control 26 Virtual LANs 26 FastIP 26 Multicast Filtering 27 Spanning Tree Protocol 27 RMON 27 Roving Analysis 28 Management 28

Default Settings 29

WITCH MANAGEMENT SOFTWARE

II S

ETTING UP FOR MANAGEMENT

Methods of Managing a Switch 32 Setting Up Web Interface Management 33

Setting Up Through the Console Port 33 Setting Up Over the Network 34 Installing Online Help and Documentation 34 Choosing a Browser 35 Configuring the Browser 35

Setting Up Command Line Interface Management 36

Setting Up Through the Console Port 36

Setting Up Over the Network 37 Setting Up SNMP Management 37 Managing a Switch Over the Network 38

IP Addresses 38

Obtaining a Registered IP Address 38

Subnets and Using a Subnet Mask 39 Logging in as a Default User 39

II The Management Interfaces

ORKING WITH THE WEB INTERFACE

Accessing the Web Interface 44

Exiting the Web Interface 45 The Getting Started Pages 46 The Main Web Interface 48

The External Link Icons 49

The Management Icons 50

The Page Area 50

Navigating the Page Area 52 Making Changes in the Page Area 53

Configuring the Current Switch 54

Displaying the Status of the Ports 54

Displaying the Color Codes Used by the Switch Graphic 54 Displaying the Speed and Duplex Mode of Ports 55 Refreshing the Switch Graphic 55

Displaying Administration Details 56

Setting Up IP Information 58 Configuring a Port 59 Configuring the Console Port 66

Changing the Management Settings for the Stack 67

Specifying a Descriptive Name 67 Changing Your Password 68 Specifying a Physical Location 69 Accessing the Getting Started Pages 69 Specifying the Location of the Online Help and Documentation 70 Specifying Contact Details 71

Configuring the Stack 71

Configuring the Switch Database 72

What is the Switch Database? 72 Displaying the Switch Database 73 Inserting Permanent Entries 74

Deleting Entries 75 Configuring the Advanced Stack Settings 76 Setting Up Resilient Links 79

What are Resilient Links? 79

Displaying Resilient Link Pairs 80

Creating a Resilient Link Pair 80

Deleting a Resilient Link Pair 81

Swapping the Active Port of a Resilient Link Pair 81 Setting Up Port Trunks 81

What are Port Trunks? 82

Displaying the Ports that Belong to Each Port Trunk 82

Placing Ports in a Port Trunk 82 Configuring VLANs 83

What are VLANs? 84

Defining VLAN Information 84

Editing VLAN Information 84

Deleting VLAN Information 85

Displaying the Ports that Belong to Each VLAN 85

Placing Ports in Single VLANs 85

Placing Ports in Multiple VLANs Using VLT Tagging 85

Placing Ports in Multiple VLANs Using 802.1Q Tagging 85 Setting Up Roving Analysis Ports 86

What is Roving Analysis? 87

Defining Monitor Ports and Analysis Ports 87 Enabling the Roving Analysis System 88

Resetting All the Units in the Stack 88

What Happens During a Reset? 88

Initializing All the Units in the Stack 88

What Happens During an Initialization? 88

Upgrading Management Software 89

Displaying Statistics for the Current Switch 91

Displaying Unit Statistics 91

Interpreting the Statistics 92

Displaying Port Statistics 92

Interpreting the Statistics 94

ORKING WITH THE COMMAND LINE INTERFACE

Accessing the Interface 96

Exiting the Interface 96 How Many Users Can Access the Interface? 97

About the Interface Menus 97

Entering Commands 99 Displaying Menus 100

Obtaining Help 100 A Quick Guide to the Commands 101 Displaying and Changing Bridging/VLANs Information 105

Setting the Bridge Address Aging Time 105

Displaying Bridge Information 105

Enabling and Disabling IGMP Snooping 107

Enabling and Disabling Router Port Auto-Discovery 108

Manually Identifying a Router Port 108

Displaying all Router Ports 108

Removing a Router Port 109

Adding a Statically Configured Address to a Switch Database 110

Finding a MAC Address 110

Displaying MAC Addresses for a Port 111

Removing MAC Addresses from a Port 111

Displaying Port Information 111

Setting the Spanning Tree Path Cost 112

Enabling and Disabling Spanning Tree Fast Start 112

Displaying Port Summary Information 113 Enabling and Disabling VLT Tagging on a Port 114 Setting the Bridge Spanning Tree Forward Delay 114 Setting the Bridge Spanning Tree Hello Timer 115 Setting the Bridge Spanning Tree Maximum Age 115 Setting the Spanning Tree Bridge Priority 115 Enabling and Disabling Spanning Tree on a Bridge 116 Adding a Port to a VLAN 116 Creating a VLAN 116 Deleting a VLAN 117 Displaying Detailed VLAN Information 117 Modifying a VLAN 118 Removing a Port from a VLAN 119 Displaying Summary VLAN Information 119

Displaying and Changing Port Information 120

Enabling and Disabling Ports 120 Specifying the Speed and Duplex Mode 121 Enabling and Disabling Auto-negotiation 121 Enabling and Disabling Flow Control 123 Displaying Port Statistics 123

Packet Size Analysis 126

Displaying Port Summary Information 126

Displaying and Changing System Feature Information 127

Setting up a Roving Analysis Port 127 Displaying the Roving Analysis Port Information 127 Removing a Roving Analysis Port 128 Starting Data Monitoring 128 Stopping Data Monitoring 129 Enabling and Disabling Broadcast Storm Control 129 Setting Up a Resilient Link 130 Displaying Resilient Link Information 130 Removing a Resilient Link 131 Swapping over Active Links 131 Adding a Port to a Trunk 131 Displaying Detailed Trunk Information 132 Removing a Port from a Trunk 132 Displaying Summary Trunk Information 133

Displaying and Changing IP-related Information 133

Specifying IP and SLIP Information 133

Displaying IP and SLIP Information 135

Enabling and Disabling BOOTP 135

Pinging Other Devices 136

Resetting the IP Configuration 136 Displaying and Changing SNMP-related Information 137

Specifying SNMP Community Strings 137

Specifying Trap Destination Details 137

Displaying Trap Destination Details 138

Modifying Trap Destination Details 138

Removing Trap Destination Details 139

Performing an SNMP GET Command 139

Performing an SNMP GETNEXT Command 139

Performing an SNMP SET Command 140 Displaying and Changing Stack Information 141

Moving the Focus of the Command Line Interface 141

Returning the Focus to the Previous Switch Unit 142 Specifying Stack Administration Details 142 Displaying Switch Administration Details 143 Displaying Stack Summary Information 144 Configuring Intelligent Modules 146

Setting Module Configuration 146

Displaying Module Configuration 146

Enabling and Disabling the Module Interface 146 Changing Your Password 147 Specifying User Details 147 Displaying User Details 148 Modifying User Details 148 Removing User Details 149 Displaying Access Rights 149 Modifying Access Rights 150 Enabling and Disabling Remote Access 150 Resetting All the Units in the Stack 151

What Happens During a Reset? 151 Initializing All the Units in the Stack 152

What Happens During an Initialization? 152 Upgrading Management Software 153

III Management Reference

ORT TRUNKS

What are Port Trunks? 158 Port Trunks and Your Switch 158 Placing Ports in a Port Trunk 159 Port Trunk Example 160

IRTUAL

What are VLANs? 164 Benefits of VLANs 164 VLANs and Your Switch 165

VLAN Configuration for Beginners 171

VLAN Configuration - Advanced Examples 177

LANS (VLANS)

The Default VLAN 165 Defining New VLANs 166 Untagged and Tagged VLANs 166 Placing a Port in a Single VLAN 166 Placing a Port in Multiple VLANs 166

802.1Q Tagging 166

VLT Tagging 167 Using IEEE 802.1Q Learning 167 Forwarding Traffic Containing Unknown 802.1Q Tags 168 Connecting VLANs to Other VLANs 170 Connecting to VLANs on Legacy Switch Units 170

Simple Example: Using Untagged Connections 171 Simple Example: Untagged Connections with Hubs 172 Simple Example: 802.1Q Tagged Connections 174

Using 802.1Q Tagged Connections and 802.1Q Learning 177 Connecting to a Legacy Network 178

AST

What is FastIP? 182 How FastIP Works 182 An Example 183 FastIP and the Switch Database 186 Enabling FastIP 187

ULTICAST FILTERING

What is a Multicast? 190 What is Multicast Filtering? 190 Multicast Filtering and Your Switch 191

IEEE 802.1p Multicast Filtering 191

Enabling 802.1p Multicast Learning 191

IGMP Multicast Filtering 192

Enabling IGMP Multicast Learning 192

Manual Filtering 192

PANNING TREE PROTOCOL

What is STP? 194 How STP Works 196

STP Requirements 196 STP Calculation 197 STP Configuration 197 STP Reconfiguration 197 An Example 198

STP Configurations 199 Using STP on a Network with Multiple VLANs 201 Connecting to STP Systems on Legacy Switch Units 202 Enabling STP 202

RMON

What is RMON? 204

The RMON Groups 204

Statistics 204 History 204 Alarms 204 Hosts 205 Hosts Top N 205 Matrix 205

Events 205 Benefits of RMON 206 RMON and Your Switch 207

The Alarm Events 208 The Default Alarm Settings 208 The Audit Log 209

IV Problem Solving

ROBLEM SOLVING

Solving Web Interface Problems 214 Solving Command Line Interface Problems 216 Solving SNMP Management Software Problems 218 Solving Serial Web Utility Problems 219 Solving Management Software Upgrade Utility Problems 220 Solving Other Problems 221

V Appendices and Index

ERIAL WEB UTILITY

Introduction 227 Installing the Serial Web Utility 227 Using the Serial Web Utility 229

ANAGEMENT SOFTWARE UPGRADE UTILITY

Using the Upgrade Utility 231

LOSSARY

NDEX

BOUT

HIS

UIDE

Conventions

This guide provides all the information you need to manage units in the SuperStack software version 2.50.

The guide is intended for use by network administrators who are responsible for installing and setting up network equipment; consequently, it assumes a basic working knowledge of LANs (Local Area Networks).

Throughout this guide, the term stack refers to a number of Switch units that are managed as a single unit. However, a stack can contain a single Switch. In the case of the 610/630 family, stackability is not supported.

If the information in the release notes that are shipped with your product differs from the information in this guide, follow the instructions in the release notes.

Ta bl e 1 and Tabl e 2 list conventions that are used throughout this guide.

Tab le 1

Icon Notice Type Description

II Switch 1100/3300 and 610/630 family with management

Notice Icons

Information note Information that describes important features or

instructions

Caution Information that alerts you to potential loss of data or

Warning Information that alerts you to potential personal injury

potential damage to an application, system, or device

14 A

BOUT THIS GUIDE

Tab le 2

Text Conventions

Convention Description

Screen displays

This typeface represents information as it appears on the screen.

Syntax

The word “syntax” means that you must evaluate the syntax provided and then supply the appropriate values for the placeholders that appear in angle brackets. Example:

To change your password, use the following syntax:

system password <password>

In this example, you must supply a password for

Commands

The word “command” means that you must enter the command exactly as shown and then press Return or Enter. Commands appear in bold. Example:

To display port information, enter the following command:

bridge port detail

The words “enter” and “type”

When you see the word “enter” in this guide, you must type something, and then press Return or Enter. Do not press Return or Enter when an instruction simply says “type.”

Keyboard key names If you must press two or more keys simultaneously, the key

names are linked with a plus sign (+). Example:

Press Ctrl+Alt+Del

Words in italics Italics are used to:

■

Emphasize a point.

■

Denote a new term at the place where it is defined in the text.

■

Identify menu names, menu commands, and software button names. Examples:

From the Help menu, select Contents. Click OK.

Year 2000 Compliance

In addition, there are other publications you may find useful:

■

Documentation accompanying the Expansion Modules.

■

Documentation accompanying the Transceiver Modules.

■

Documentation accompanying the Advanced Redundant Power System.

For information on Year 2000 compliance and 3Com products, visit the 3Com Year 2000 Web page:

http://www.3com.com/products/yr2000.html

16 A

BOUT THIS GUIDE

Documentation Comments

Product Registration

Your suggestions are very important to us. They will help make our documentation more useful to you. Please e-mail comments about this document to 3Com at:

pddtechpubs_comments@3com.com

Please include the following information when commenting:

■

Document title

■

Document part number (on the title page)

■

Page number (if appropriate)

Example:

■

SuperStack II Switch Management Guide

■

Part Number DUA1695-0BAA04

■

Page 21

You can now register your SuperStack II Switch on the 3Com web site to receive up-to-date information on your product:

http://www.3com.com/productreg/pdd

ETTING

ANAGEMENT

Chapter 1 SuperStack II Switch Management Software

Chapter 2 Setting Up for Management

TARTED WITH

UPERSTACK

II S

WITCH

ANAGEMENT

This chapter contains introductory information about the SuperStack® II Switch management software and how it can be used in your network. It covers the following topics:

■

What is Management Software?

■

Summary of Software Features

■

Software Features Explained

■

Default Settings

OFTWARE

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What is Management Software?

Summary of Software Features

Your Switch contains software that allows you to change and monitor the way it works. This

management

software is not required to get the Switch working, but if you do use it, you may improve the efficiency of the Switch and therefore improve the overall performance of your network.

Ta bl e 3 describes the software features that are supported by units in the

Switch 1100/3300 and 610/630 family.

Tab le 3

Feature Switch 1100/610 Family Switch 3300 /630 Family No. of MAC

Addresses Supported

Stack Management

Forwarding Modes

Duplex Modes

Flow Control Tra ffic

Prioritization PACE Security Resilient Links Port Trunking

Broadcast Storm Control

Virtual LANs (VLANs)

FastIP Multicast Filtering

Software features

Up to 6,000 Up to 12,000

Supported for up to four Switch units (stackability not supported on 610/630 units)

Store and Forward, Fast Forward, Fragment Free, Intelligent

Half and full duplex on all ports

Supported on all ports Supported on all ports Supported Supported

Supported on all ports Supported on all ports Supported on all ports Supported on all ports Supported Supported Support for two Port Trunks a

unit Supported Supported

Support for up to 16 VLANs using the IEEE 802.1Q standard

Supported Supported IEEE 802.1p and IGMP

filtering supported

Supported for up to four Switch units (stackability not supported on 610/630 units)

Store and forward

Half and full duplex on all ports

Support for two Port Trunks a unit

Support for up to 16 VLANs using the IEEE 802.1Q standard

IEEE 802.1p and IGMP filtering supported

Software Features Explained 21

Software Features Explained

Stack Management

Tab le 3

Feature Switch 1100/610 Family Switch 3300 /630 Family Spanning Tree

Protocol RMON

Roving Analysis Management

Software features

Supported Supported

Seven groups supported: Statistics, History, Alarms, Hosts, Hosts Top N, Matrix, Events

Supported Supported Web interface, command line

interface, and SNMP supported

Seven groups supported: Statistics, History, Alarms, Hosts, Hosts Top N, Matrix, Events

Web interface, command line interface, and SNMP supported

Units in the Switch 1100/3300 family can be interconnected so that they form a stack, that is, a group of devices that are managed as a single device.

Stackability is not supported by the Switch 610/630 units.

Forwarding Modes

You can interconnect these Switch units together in two ways:

■

The matrix port on the rear of each Switch allows you to connect two Switch units back-to-back. For this you need a Matrix Cable (part number 3C16965).

■

The Expansion Module slot at the rear of each Switch allows you to install a Matrix Module (part number 3C16960). The Matrix Module provides four ports and allows you to interconnect up to four units using Matrix Cables.

For information about stacking Switch units, refer to Chapter 2 of the relevant Switch User Guide.

Units in the Switch 3300/630 family support Store and Forward packet forwarding mode. In this mode, received packets are buffered entirely before they are forwarded, which ensures that only good packets are forwarded to their destination.

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Units in the Switch 1100/610 family support three forwarding modes in addition to Store and Forward:

■

Fast Forward

— Packets are forwarded as soon as the destination address is received and processed. With Fast Forward, packets take less time to be forwarded, but all error packets are propagated onto the network because no time is allowed for checking.

■

Fragment Free

— Packets are forwarded when at least 512 bits of the packet is received, which ensures that collision fragments are not propagated through the network. With Fragment Free, packets take less time to be forwarded, but all error packets except fragments are propagated.

■

Intelligent

— The Switch monitors the amount of error traffic on the network and changes the forwarding mode accordingly. If the Switch detects less than 20 errors a second, the forwarding mode is set to Fast Forward. If the Switch detects 20 or more errors a second, the forwarding mode is set to Store and Forward until the number of errors a second returns to zero.

For information about setting the forwarding mode for units in the Switch 1100/610 family, see on

page 76

“Configuring the Advanced Stack Settings”

Duplex Modes

All the ports on your Switch can be set to one of two duplex modes:

■

Half duplex

— Allows packets to be transmitted and received, but not

simultaneously. This is the default Ethernet duplex mode.

■

Full duplex

— Allows packets to be transmitted and received simultaneously and, in effect, doubles the potential throughput of a link. In addition, full duplex supports 100BASE-FX cable runs of up to 2km (6562ft).

To communicate effectively, both ends of a link must use the same duplex mode. If the link uses an auto-negotiating connection, this is done automatically. If the link uses a connection that is not auto-negotiating, both ends must be set to half duplex or full duplex manually.

For more information about setting the duplex mode of a port, see

“Configuring a Port”

page 59

Software Features Explained 23

Flow Control

Traffic Prioritization

All the ports on your Switch support flow control, which is a congestion control mechanism. Congestion is caused by one or more devices sending traffic to an already overloaded port on the Switch. Flow control prevents packet loss and inhibits the devices from generating more packets until the period of congestion ends.

Flow control is implemented in two ways:

■

IEEE 802.3x standard for ports operating in full duplex.

■

Intelligent Flow Management (IFM), a 3Com proprietary method of flow control, for ports operating in half duplex. IFM should only be enabled if the port is connected to another switch, or an endstation. If the port is connected to a repeated segment with local traffic, IFM should be disabled.

For information about enabling flow control on a port, see

a Port”

page 59

“Configuring

Your Switch supports IEEE 802.1p traffic prioritization, which allows data that has been assigned a high priority to be forwarded through the Switch without being obstructed by other data. The system works by using the multiple traffic queues that are present in the hardware of the Switch — high priority traffic is forwarded on a different queue from other traffic, and it is always given preference over the other traffic.

Traffic prioritization can be useful for critical applications that require a high Class of Service (CoS) from the network. This could include:

■

Financial applications

— Accounts departments that need immediate access to large files and spreadsheets at the end of the month.

■

CAD/CAM design applications

— Design departments that need priority connections to server farms and other devices for transferring large files.

■

Converged network applications

— Organizations with a converged network (that is, a network that uses the same infrastructure for voice data and traditional data) that require high quality voice data transmission at all times.

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If you use IEEE 802.1p traffic prioritization, we recommend that all relevant ports on your Switch are placed in one or more Virtual LANs (VLANs) using 802.1Q tagging. For a brief explanation of VLANs, see

“Virtual LANs”

page 26

802.1Q tagging, see

. For a detailed explanation of VLANs and

“Virtual LANs (VLANs)”

page 163

PACE

Security

Your Switch supports PACE (Priority Access Control Enabled) which is a 3Com proprietary feature that allows multimedia traffic to move across a network effectively.

PACE provides two main features:

■

Implicit Class of Service

— This feature gives priority to traffic from

multimedia applications, and provides the same functionality as IEEE

802.1p traffic prioritization (see “Traffic Prioritization”

■

Interactive Access

— When two-way multimedia traffic passes over

on page 23).

an Ethernet or Fast Ethernet network, interference can occur because access to the bandwidth is unequally allocated to traffic in one direction. The Interactive Access feature allocates the available bandwidth equally in both directions, therefore increasing the quality of the multimedia traffic.

For information about enabling PACE on an individual port, see

“Configuring a Port”

page 59

on a whole Switch or stack, see

Settings”

page 76

. For information about enabling PACE

“Configuring the Advanced Stack

Each port on your Switch can use a security feature that guards against unauthorized users connecting devices to your network. When security is enabled on a port, it enters Single Address Learning Mode. In this mode, the Switch:

■

Removes all the MAC (Ethernet) addresses stored for the port in the Switch Database. For more information about the Switch Database, see “What is the Switch Database?”

■

Learns the address of the first packet it receives on the port.

■

Defines the address as a permanent entry.

on page 72.

Once the first address is learned:

■

The port is disabled if a different address is seen on the port.

Software Features Explained 25

■

No other address can be learned until security is disabled or the address is manually removed from the database.

■

The address cannot be learned on another port until security is disabled or the address is manually removed from the database.

Resilient Links

Port Trunks

For more information about enabling security on a port, see

a Port”

page 59

“Configuring

The resilient link feature of the Switch enables you to protect critical links and prevent network downtime should those links fail. Setting up resilience ensures that if a main communication link fails, a standby duplicate link immediately and automatically takes over the task of the main link. Each main and standby link pair is referred to as a resilient link pair.

Resilient links are a simple method of creating redundancy that provides you with an instant reaction to link failure. Resilient links are quick to set up, you have full control over their configuration, and the port at the other end of the resilient link does not have to support any resilience feature.

For more information about resilient links, see

Links”

page 79

“Setting Up Resilient

Your Switch supports port trunks — connections that allow devices to communicate using up to four links in parallel. Port trunks provide two benefits:

■

They can potentially double, triple or quadruple the bandwidth of a connection.

■

They can provide redundancy — if one link is broken, the other links share the traffic for that link.

For more information about port trunks, see

“Port Trunks”

page 157

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Broadcast Storm

Control

Virtual LANs

Your Switch supports Broadcast Storm Control, a system that automatically creates an alarm for each port to monitor the level of broadcast traffic on that port.

frames per

broadcast

second, the broadcast traffic on the port is blocked until the

traffic level drops to 1488 frames per second.

If the broadcast traffic level rises to 2976

This system prevents the overwhelming broadcast traffic that can result from network equipment which is faulty or configured incorrectly.

For more information about enabling Broadcast Storm Control, see

“Configuring the Advanced Stack Settings”

page 76

Your Switch provides supports for up to 16 Virtual LANs (VLANs). A VLAN is a flexible group of devices that can be located anywhere in a network, but they communicate as if they are on the same physical segment. With VLANs, you can segment your network without being restricted by physical connections — a drawback of traditional network design. As an example, with VLANs you can segment your network according to:

■

Departmental groups

— For example, you can have one VLAN for the Marketing department, another for the Finance department, and another for the Development department.

■

Hierarchical groups

— For example, you can have one VLAN for

directors, another for managers, and another for general staff.

FastIP

■

Usage groups

— For example, you can have one VLAN for users of

e-mail, and another for users of multimedia.

For more information, see

“Virtual LANs (VLANs)”

page 163

Your Switch supports FastIP, a system that reduces the load on routing devices when VLANs are implemented on your network.

Devices within different VLANs can only communicate using a routing device; if there is a large amount of inter-VLAN traffic, the router can become overloaded and network performance can be affected. FastIP allows your endstations and Switch units to find secure short-cuts for inter-VLAN traffic that bypass the routing device altogether.

For more information about FastIP, see

“FastIP”

page 181

Software Features Explained 27

Multicast Filtering

Spanning Tree

Protocol

Your Switch supports two multicast filtering systems:

■

IEEE 802.1p, which uses the GARP Multicast Registration Protocol (GMRP)

■

IGMP (Internet Group Management Protocol)

These systems allow the Switch to forward multicast traffic to the endstations that are interested rather than broadcasting the traffic to the whole network.

For more information, see

“Multicast Filtering”

page 189

Your Switch supports the Spanning Tree Protocol (STP), a bridge-based system that makes your network more resilient to link failure and also provides a protection from loops — one of the major causes of broadcast storms.

STP allows you to implement parallel paths for network traffic and uses a loop-detection process to:

■

Discover the efficiency of each path.

■

Enable the most efficient path (that is, the one that has the highest bandwidth).

■

Disable the less efficient paths.

RMON

■

Enable one of the less efficient paths if the most efficient path fails.

For information about STP, see

“Spanning Tree Protocol”

For information about enabling STP, see

Stack Settings”

page 76

“Configuring the Advanced

page 193

Your Switch supports RMON (Remote Monitoring), a system that allows you to monitor LANs remotely. The Switch contains RMON probe software that continually collects statistics about the LAN segments connected to the Switch. If you have a management workstation with an RMON management application, the Switch can transfer these statistics to your workstation on request or when a pre-defined threshold is crossed.

For more information, see

“RMON”

page 203

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Roving Analysis

Management

Your Switch supports roving analysis, a system that allows you to attach a network analyzer to one port and use it to monitor the traffic of other ports on the Switch. The system works by enabling you to define an analysis port (the port that is connected to the analyzer), and a monitor port (the port that is to be monitored). Once the pair are defined, and you enable the system, the Switch takes all the traffic going in and out of the monitor port and copies it to the analysis port.

Roving analysis is used when you need the functions of a network analyzer, but do not want to change the physical characteristics of the monitored segment by attaching an analyzer to that segment.

For information about setting up roving analysis ports, see

Roving Analysis Ports”

page 86

“Setting Up

Your Switch can be managed using three methods:

■

Web interface management

— The Switch has an internal set of web pages that allow you to manage it using any Java-enabled Web browser. You can access the web interface using:

A management workstation connected over the network

■

A management workstation connected to the console port of the

■

Switch, running the Serial Line Internet Protocol (SLIP)

■

Command line interface management

— The Switch has a command line interface that allows you to perform limited management. You can access the command line interface using:

A terminal or terminal emulator connected over the network

■

using Telnet A terminal or terminal emulator connected to the console port of

■

the Switch

■

SNMP management

— You can manage the Switch using any network management application running the Simple Network Management Protocol (SNMP), such 3Com Transcend

Enterprise

Manager software.

For information about setting up your Switch for management, see

“Setting Up for Management”

page 31

Default Settings 29

Default Settings

Ta bl e 4 shows the default settings of units in the Switch 1100/3300 and

610/630 family. If you initialize one of these Switch units, it is returned to these defaults.

Tab le 4

Port Status Port Speed

Forwarding Mode

Duplex Mode

Flow Control

PACE Security Broadcast

Storm Control BOOTP Virtual LANs

(VLANs)

FastIP Multicast

Filtering Spanning Tree

Protocol RMON Alarm

(broadcast bandwidth used)

Default Settings

Switch 1100/610 Family Switch 3300/630 Family

Enabled Enabled 10BASE-T/

100BASE-TX ports are auto-negotiated.

Intelligent Store-and-forward

All fixed 10BASE-T and 10BASE-T/100BASE-TX ports are auto-negotiated.

Enabled in half duplex, auto-negotiated in full duplex

Disabled Disabled Disabled Disabled Enabled Enabled

Enabled Enabled All ports belong to the

untagged Default VLAN (VLAN 1) only; 802.1Q learning is disabled

Disabled Disabled

802.1p and IGMP filtering are both disabled

Disabled Disabled

Enabled: High threshold: 2976 broadcast frames per second — Notify and filter Low threshold: 1488 broadcast frames per second — Notify and unfilter

10BASE-T/100BASE-TX ports are auto-negotiated; 1000BASE-T and 1000BASE-SX ports are permanently fixed at 1000Mbps

All fixed 10BASE-T/100BASE-TX ports are auto-negotiated; all fixed 100BASE-FX ports are half duplex; all 1000BASE-T and !000BASE-SX ports are permanently set to full duplex.

Enabled in half duplex, auto-negotiated in full duplex

All ports belong to the untagged Default VLAN (VLAN 1) only; 802.1Q learning is disabled

802.1p and IGMP filtering are both disabled

Enabled: High threshold: 2976 broadcast frames per second — Notify and filter Low threshold: 1488 broadcast frames per second — Notify and unfilter

30 C

HAPTER

1: S

UPERSTACK

II S

WITCH MANAGEMENT SOFTWARE

Tab le 4

Default Settings

RMON Alarm (errors over 1min)

Switch 1100/610 Family Switch 3300/630 Family

Enabled: High threshold: 20 errors per second — Notify Low threshold: 1 error per second — No action

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