Allied Telesyn International Corp AT-8026FC User`s guide

Management
Software
®
AT-S39
◆
User’s Guide
AT-8016F, AT-8024, AT-8024M, AT-8024GB, AND
AT-8026FC FAST ETHERNET SWITCHES
VERSION 3.0
PN 613-50245-00 Rev G
Copyright  2002 Allied Telesyn, Inc.
960 Stewart Drive Suite B, Sunnyvale, CA 94085 USA
All rights reserved. No part of this publication may be reproduced without prior written permission from Allied Telesyn, Inc.
Microsoft is a registered trademark of Microsoft Corporation, Netscape Navigator is a registered trademark of Netscape
Communications Corporation. All other product names, company names, logos or other designations mentioned herein are
trademarks or registered trademarks of their respective owners.
Allied Telesyn, Inc. reserves the right to make changes in specifications and other information contained in this document without
prior written notice. The information provided herein is subject to change without notice. In no event shall Allied Telesyn, Inc. be liable
for any incidental, special, indirect, or consequential damages whatsoever, including but not limited to lost profits, arising out of or
related to this manual or the information contained herein, even if Allied Telesyn, Inc. has been advised of, known, or should have
known, the possibility of such damages.
Table of Contents
List of Figures ........................................................................................................................................................................................................ 8
Preface ....................................................................................................................................................................................................................11
How This Guide is Organized ...........................................................................................................................................................................11
Document Conventions ....................................................................................................................................................................................13
Where to Find Web-based Guides .................................................................................................................................................................14
Contacting Allied Telesyn .................................................................................................................................................................................15
Sales or Corporate Information ..............................................................................................................................................................15
Management Software Updates ....................................................................................................................................................................16
Section I
Overview
.......................................................................................................................................................... 17
Chapter 1
Overview ................................................................................................................................................................................................................18
Local Management Session ..............................................................................................................................................................................20
Telnet Management Session ............................................................................................................................................................................21
Web Browser Management Session ..............................................................................................................................................................22
SNMP Management Session ............................................................................................................................................................................23
Management Access Levels .............................................................................................................................................................................24
Section II
Local and Telnet Management .................................................................................................. 25
Chapter 2
Starting a Local or Telnet Management Session ................................................................................................................................26
Local Management Session ..............................................................................................................................................................................27
Starting a Local Management Session................................................................................................................................................. 28
Enhanced Stacking ..................................................................................................................................................................................... 31
Quitting from a Local Session ................................................................................................................................................................. 31
Telnet Management Session ............................................................................................................................................................................32
Starting a Telnet Management Session .............................................................................................................................................. 32
Quitting from a Telnet Management Session................................................................................................................................... 33
3
Table of Contents
Chapter 3
Basic Switch Parameters ................................................................................................................................................................................ 34
When Does a Switch Need an IP Address? ................................................................................................................................................. 35
How Do You Assign an IP Address?...................................................................................................................................................... 36
Configuring an IP Address and Switch Name ........................................................................................................................................... 37
Activating the BOOTP and DHCP Services ................................................................................................................................................. 40
Configuring SNMP Community Strings and Trap IP Addresses ......................................................................................................... 42
Resetting a Switch ............................................................................................................................................................................................... 44
Configuring the AT-S39 Software Security Features .............................................................................................................................. 45
Configuring the Management Passwords......................................................................................................................................... 46
Configuring Management Access ........................................................................................................................................................ 47
Viewing the AT-S39 Version Number and Switch MAC Address ........................................................................................................ 48
Pinging a Remote System ................................................................................................................................................................................ 49
Returning the AT-S39 Software to the Factory Default Values ........................................................................................................... 50
Configuring the Console Startup Mode ...................................................................................................................................................... 51
Chapter 4
Enhanced Stacking ........................................................................................................................................................................................... 52
Enhanced Stacking Overview ......................................................................................................................................................................... 53
Guidelines...................................................................................................................................................................................................... 53
Example.......................................................................................................................................................................................................... 55
Setting a Switch’s Enhanced Stacking Status ............................................................................................................................................ 56
Selecting a Switch in an Enhanced Stack ................................................................................................................................................... 58
Returning to the Master Switch............................................................................................................................................................. 59
Chapter 5
Port Parameters ................................................................................................................................................................................................. 60
Displaying Port Status ........................................................................................................................................................................................ 61
Configuring Port Parameters .......................................................................................................................................................................... 64
Displaying Uplink Information ....................................................................................................................................................................... 68
Chapter 6
Port Security ........................................................................................................................................................................................................ 70
Port Security Overview ...................................................................................................................................................................................... 71
Configuring Port Security ................................................................................................................................................................................. 73
Configuring the Limited Security Mode ...................................................................................................................................................... 75
Chapter 7
Port Trunking ...................................................................................................................................................................................................... 77
Port Trunking Overview .................................................................................................................................................................................... 78
Load Distribution Methods ..................................................................................................................................................................... 79
Creating a Port Trunk ......................................................................................................................................................................................... 84
Deleting a Port Trunk ......................................................................................................................................................................................... 86
Chapter 8
Port Mirroring ..................................................................................................................................................................................................... 87
Port Mirroring Overview ................................................................................................................................................................................... 88
Creating a Port Mirror ........................................................................................................................................................................................ 89
Deleting a Port Mirror ........................................................................................................................................................................................ 90
Chapter 9
STP and RSTP ....................................................................................................................................................................................................... 91
STP and RSTP Overview ..................................................................................................................................................................................... 92
Bridge Priority and the Root Bridge ..................................................................................................................................................... 93
Mixed STP and RSTP Networks .............................................................................................................................................................. 99
Spanning Tree and VLANs ....................................................................................................................................................................... 99
4
Enabling or Disabling STP or RSTP .............................................................................................................................................................. 100
Configuring STP ................................................................................................................................................................................................. 101
Configuring a Bridge’s STP Settings .................................................................................................................................................. 101
Configuring a Port’s STP Settings ....................................................................................................................................................... 103
Configuring RSTP .............................................................................................................................................................................................. 105
Configuring a Bridge’s RSTP Settings................................................................................................................................................ 105
Configuring a Port’s RSTP Settings .................................................................................................................................................... 107
Chapter 10
Virtual LANs ....................................................................................................................................................................................................... 110
VLAN Overview .................................................................................................................................................................................................. 111
Port-based VLAN Overview ........................................................................................................................................................................... 113
General Rules to Creating a Port-based VLAN ............................................................................................................................... 115
Drawbacks to Port-based VLANs ........................................................................................................................................................ 116
Port-based Example 1............................................................................................................................................................................. 117
Port-based Example 2............................................................................................................................................................................. 118
Tagged VLAN Overview .................................................................................................................................................................................. 120
General Rules to Creating a Tagged VLAN...................................................................................................................................... 122
Tagged VLAN Example ........................................................................................................................................................................... 123
Basic VLAN Mode Overview .......................................................................................................................................................................... 125
Creating a Port-based or Tagged VLAN .................................................................................................................................................... 126
Example of Creating a Port-based VLAN .................................................................................................................................................. 130
Example of Creating a Tagged VLAN ......................................................................................................................................................... 131
Modifying a VLAN ............................................................................................................................................................................................. 132
Displaying VLAN Information ....................................................................................................................................................................... 135
Deleting a VLAN ................................................................................................................................................................................................. 136
Deleting All VLANs ............................................................................................................................................................................................ 138
Changing a PVID Value ................................................................................................................................................................................... 139
Displaying PVIDs and Port Priorities ........................................................................................................................................................... 141
Setting a Switch’s VLAN Mode ..................................................................................................................................................................... 142
Enabling or Disabling All VLANs .................................................................................................................................................................. 143
Enabling or Disabling Ingress Filtering ..................................................................................................................................................... 145
Specifying a Management VLAN ................................................................................................................................................................. 147
Chapter 11
MAC Address Table ........................................................................................................................................................................................ 149
MAC Address Overview .................................................................................................................................................................................. 150
Displaying MAC Addresses ............................................................................................................................................................................ 152
Viewing MAC Addresses by Port ................................................................................................................................................................. 155
Identifying a Port Number by MAC Address ........................................................................................................................................... 156
Viewing the MAC Addresses of a VLAN ..................................................................................................................................................... 157
Deleting All Dynamic MAC Addresses ....................................................................................................................................................... 158
Adding Static and Multicast MAC Addresses .......................................................................................................................................... 159
Deleting MAC Addresses ................................................................................................................................................................................ 160
Changing the Aging Time .............................................................................................................................................................................. 161
Chapter 12
Class of Service ................................................................................................................................................................................................ 162
Class of Service Overview ............................................................................................................................................................................... 163
Configuring CoS ................................................................................................................................................................................................ 164
Chapter 13
IGMP Snooping ................................................................................................................................................................................................ 165
IGMP Snooping Overview .............................................................................................................................................................................. 166
Activating IGMP Snooping ............................................................................................................................................................................ 168
Displaying a List of Host Nodes ................................................................................................................................................................... 171
Displaying a List of Multicast Routers ........................................................................................................................................................ 172
5
Table of Contents
Chapter 14
Broadcast Frame Control ............................................................................................................................................................................173
Broadcast Frame Control Overview ............................................................................................................................................................174
Configuring the Interval Timer .....................................................................................................................................................................176
Configuring the Maximum Broadcast Frame Count ............................................................................................................................178
Chapter 15
TACACS+ and RADIUS Protocols .............................................................................................................................................................179
TACACS+ and RADIUS Overview .................................................................................................................................................................180
Configuring an Authorization Protocol .....................................................................................................................................................183
Chapter 16
Ethernet Statistics ...........................................................................................................................................................................................188
Displaying Port Statistics ................................................................................................................................................................................189
Displaying Switch Statistics ...........................................................................................................................................................................191
Chapter 17
File Downloads and Uploads .....................................................................................................................................................................193
Obtaining Software Updates .........................................................................................................................................................................195
Transferring Files from a Local Management Session ..........................................................................................................................196
Downloading Files Switch to Switch ..........................................................................................................................................................201
Uploading Files ...................................................................................................................................................................................................203
Downloading and Uploading Files using TFTP from a Management Workstation ...................................................................205
Downloading Files.................................................................................................................................................................................... 205
Uploading a Configuration File ........................................................................................................................................................... 206
Section III
Web Browser Management ........................................................................................................ 207
Chapter 18
Starting a Web Browser Management Session ................................................................................................................................208
Starting a Web Browser Management Session .......................................................................................................................................209
Browser Tools............................................................................................................................................................................................. 211
Quitting from a Web Browser Management Session .................................................................................................................. 211
Chapter 19
Basic Switch Parameters ..............................................................................................................................................................................212
Configuring an IP Address and Switch Name .........................................................................................................................................213
Activating the BOOTP and DHCP Services ...............................................................................................................................................217
Viewing System Information .........................................................................................................................................................................218
Configuring the SNMP Parameters and Trap IP Addresses ................................................................................................................220
Resetting a Switch .............................................................................................................................................................................................222
Pinging a Remote System ..............................................................................................................................................................................223
Returning the AT-S39 Software to the Factory Default Values .........................................................................................................224
Chapter 20
Enhanced Stacking .........................................................................................................................................................................................225
Setting a Switch’s Enhanced Stacking Status ..........................................................................................................................................226
Selecting a Switch in an Enhanced Stack .................................................................................................................................................228
Returning to the Master Switch........................................................................................................................................................... 229
Chapter 21
Port Parameters ...............................................................................................................................................................................................230
Configuring Port Parameters ........................................................................................................................................................................231
Displaying Port Status and Statistics ..........................................................................................................................................................234
6
Chapter 22
Port Security ...................................................................................................................................................................................................... 239
Displaying the Port Security Level .............................................................................................................................................................. 240
Chapter 23
Port Trunks ........................................................................................................................................................................................................ 241
Creating or Deleting a Port Trunk ............................................................................................................................................................... 242
Chapter 24
Port Mirroring ................................................................................................................................................................................................... 244
Creating or Deleting a Port Mirror .............................................................................................................................................................. 245
Chapter 25
STP and RSTP .................................................................................................................................................................................................... 247
Enabling or Disabling STP or RSTP .............................................................................................................................................................. 248
Configuring STP ................................................................................................................................................................................................. 249
Configuring RSTP .............................................................................................................................................................................................. 253
Displaying STP or RSTP Settings .................................................................................................................................................................. 257
Chapter 26
Virtual LANs ....................................................................................................................................................................................................... 259
Creating a VLAN ................................................................................................................................................................................................. 260
Modifying a VLAN ............................................................................................................................................................................................. 263
Deleting VLANs .................................................................................................................................................................................................. 264
Displaying VLANs .............................................................................................................................................................................................. 265
Setting the Switch’s VLAN Mode ................................................................................................................................................................. 266
Enabling or Disabling VLANs ........................................................................................................................................................................ 267
Changing a PVID ................................................................................................................................................................................................ 268
Chapter 27
MAC Address Table ........................................................................................................................................................................................ 270
Viewing the MAC Address Table ................................................................................................................................................................. 271
Adding Static and Multicast MAC Addresses .......................................................................................................................................... 274
Deleting MAC Addresses ................................................................................................................................................................................ 275
Changing the Aging Time .............................................................................................................................................................................. 276
Chapter 28
Class of Service ................................................................................................................................................................................................ 277
Configuring CoS ................................................................................................................................................................................................ 278
Chapter 29
IGMP Snooping ................................................................................................................................................................................................ 279
Configuring IGMP Snooping ......................................................................................................................................................................... 280
Displaying a List of Host Nodes and Multicast Routers ....................................................................................................................... 283
Chapter 30
Broadcast Frame Control ............................................................................................................................................................................ 285
Configuring the Interval Timer ..................................................................................................................................................................... 286
Setting the Maximum Number of Broadcast Frames ........................................................................................................................... 287
Chapter 31
TACACS+ and RADIUS Protocols ............................................................................................................................................................. 288
Configuring TACACS+ and RADIUS ............................................................................................................................................................ 289
Appendix A
AT-S39 Default Settings .............................................................................................................................................................................. 293
Index ......................................................................................................................................................................... 296
7
List of Figures
Figure 1: Connecting a Terminal or PC to the RS232 Terminal Port ................................................................................................. 28
Figure 2: Main Menu .......................................................................................................................................................................................... 30
Figure 3: Administration Menu ...................................................................................................................................................................... 37
Figure 4: System Configuration Menu ......................................................................................................................................................... 42
Figure 5: Advanced Configuration Window .............................................................................................................................................. 42
Figure 6: SNMP Configuration Window ...................................................................................................................................................... 43
Figure 7: Passwords Menu ............................................................................................................................................................................... 46
Figure 8: Diagnostics Window ........................................................................................................................................................................ 48
Figure 9: Enhanced Stacking Example ........................................................................................................................................................ 55
Figure 10: Enhanced Stacking Window ...................................................................................................................................................... 56
Figure 11: Stacking Services Window .......................................................................................................................................................... 58
Figure 12: Port Menu ......................................................................................................................................................................................... 61
Figure 13: Port Status Window ....................................................................................................................................................................... 62
Figure 14: Port Configuration Window ....................................................................................................................................................... 64
Figure 15: Uplink Information Window ....................................................................................................................................................... 68
Figure 16: GBIC Information Window .......................................................................................................................................................... 69
Figure 17: Port Security Menu ........................................................................................................................................................................ 73
Figure 18: Limited Security Mode Menu ..................................................................................................................................................... 75
Figure 19: Port Trunk Example ....................................................................................................................................................................... 78
Figure 20: Load Distribution Method .......................................................................................................................................................... 80
Figure 21: Port Trunking Menu ...................................................................................................................................................................... 84
Figure 22: Port Trunking Menu ...................................................................................................................................................................... 89
Figure 23: Point-to-Point Ports ....................................................................................................................................................................... 97
Figure 24: Edge Port ........................................................................................................................................................................................... 98
Figure 25: Point-to-Point and Edge Point .................................................................................................................................................. 98
Figure 26: VLAN Fragmentation .................................................................................................................................................................... 99
Figure 27: Spanning Tree Menu .................................................................................................................................................................. 100
Figure 28: STP Menu ........................................................................................................................................................................................ 101
Figure 29: Config STP Port Settings Window ......................................................................................................................................... 103
Figure 30: RSTP Menu ..................................................................................................................................................................................... 105
Figure 31: RSTP Port Parameters ................................................................................................................................................................ 107
Figure 32: Configure RSTP Port Settings Menu ..................................................................................................................................... 108
Figure 33: Port-based VLAN - Example 1 ................................................................................................................................................. 117
Figure 34: Port-based VLAN - Example 2 ................................................................................................................................................. 118
Figure 35: Example of a Tagged VLAN ..................................................................................................................................................... 123
Figure 36: VLAN Menu .................................................................................................................................................................................... 126
Figure 37: Virtual LAN Definitions Menu ................................................................................................................................................. 126
8
Figure 38: Create a VLAN Window .............................................................................................................................................................
Figure 39: Modifying a VLAN Menu ...........................................................................................................................................................
Figure 40: Show All VLANs Window ..........................................................................................................................................................
Figure 41: Delete a VLAN Menu ..................................................................................................................................................................
Figure 42: Configure Port VLANs and Priorities Window ...................................................................................................................
Figure 43: Port VLANs and Priorities Window ........................................................................................................................................
Figure 44: Show Port VLANs and Priorities Window ...........................................................................................................................
Figure 45: Virtual LAN Support Menu .......................................................................................................................................................
Figure 46: VLAN Support Window .............................................................................................................................................................
Figure 47: Ingress Filtering Window ..........................................................................................................................................................
Figure 48: MAC Address Table Menu ........................................................................................................................................................
Figure 49: Show All MAC Addresses Window ........................................................................................................................................
Figure 50: IGMP Snooping Configuration Window .............................................................................................................................
Figure 51: View Multicast Hosts List Window ........................................................................................................................................
Figure 52: View Multicast Routers List Window ....................................................................................................................................
Figure 53: Broadcast Storm Control Window ........................................................................................................................................
Figure 54: Authentication Menu .................................................................................................................................................................
Figure 55: Authentication Menu (TACACS+) ..........................................................................................................................................
Figure 56: RADIUS Client Configuration ..................................................................................................................................................
Figure 57: RADIUS Server Configuration .................................................................................................................................................
Figure 58: Ethernet Statistics Menu ...........................................................................................................................................................
Figure 59: Display Module Statistics Window ........................................................................................................................................
Figure 60: Downloads & Uploads Menu ..................................................................................................................................................
Figure 61: Local Management Window ...................................................................................................................................................
Figure 62: Send File Window .......................................................................................................................................................................
Figure 63: XModem File Send Window ....................................................................................................................................................
Figure 64: Entering a Switch’s IP Address in the URL Field ...............................................................................................................
Figure 65: Home Page ....................................................................................................................................................................................
Figure 66: General Tab Window - Configuration ..................................................................................................................................
Figure 67: General Tab Window - Monitoring .......................................................................................................................................
Figure 68: SNMP Tab .......................................................................................................................................................................................
Figure 69: Ping Client Window ....................................................................................................................................................................
Figure 70: Factory Default Tab ....................................................................................................................................................................
Figure 71: Enhanced Stacking Tab .............................................................................................................................................................
Figure 72: Stacking Switches Window ......................................................................................................................................................
Figure 73: Port Setting Configuration Tab ..............................................................................................................................................
Figure 74: Settings for Port Window .........................................................................................................................................................
Figure 75: Port Monitoring Page ................................................................................................................................................................
Figure 76: Port Status Window ....................................................................................................................................................................
Figure 77: Port Statistics Window ..............................................................................................................................................................
Figure 78: Port Security Menu .....................................................................................................................................................................
Figure 79: Port Trunking Window ..............................................................................................................................................................
Figure 80: Port Mirroring Window .............................................................................................................................................................
Figure 81: Spanning Tree Tab ......................................................................................................................................................................
Figure 82: STP Bridge Configuration Window .......................................................................................................................................
Figure 83: STP Port Configuration Window ............................................................................................................................................
Figure 84: RSTP Bridge Configuration Window ....................................................................................................................................
Figure 85: RSTP Port Configuration Window .........................................................................................................................................
Figure 86: Spanning Tree Tab - Monitoring ............................................................................................................................................
Figure 87: Rapid Spanning Tree Window - Monitoring ......................................................................................................................
Figure 88: VLAN Window ...............................................................................................................................................................................
Figure 89: Add VLAN Window .....................................................................................................................................................................
Figure 90: VLAN Monitoring Window .......................................................................................................................................................
Figure 91: CoS Setting Window ..................................................................................................................................................................
Figure 92: Forwarding Database Tab ........................................................................................................................................................
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9
List of Figures
Figure 93: Add Static MAC Address window .......................................................................................................................................... 274
Figure 94: IGMP Window - Configuration ................................................................................................................................................ 280
Figure 95: IGMP Window - Monitoring ..................................................................................................................................................... 283
Figure 96: Server-based Authentication Tab .......................................................................................................................................... 289
Figure 97: TACACS+ Configuration Window .......................................................................................................................................... 290
Figure 98: RADIUS Configuration ............................................................................................................................................................... 291
10
Preface
This guide contains instructions on how to configure an AT-8000 Series
Fast Ethernet Switch using the AT-S39 management software.
The AT-8000 Series consists of the following Fast Ethernet switches:
❑ AT-8016F
❑ AT-8024
❑ AT-8024M
❑ AT-8024GB
❑ AT-8026FC
How This Guide is Organized
This manual is divided into three sections.
Section I: Overview
This section contains just one chapter. It reviews the different ways that
you can access the AT-S39 management software on a switch.
Section II: Local and Telnet Management
The chapters in this section explain how to manage a switch from a local
management session or a Telnet management session.
A local management session is established by connecting a terminal or
PC to the RS-232 Terminal Port on the front panel of the switch.
11
AT-S39 User’s Guide
A Telnet management session is established using the Telnet application
protocol. This type of management session can be performed from any
workstation on your network that has the application protocol.
Section III: Web Browser Management
The chapters in this section explain how to manage a switch using a web
browser, such as Microsoft® Internet Explorer or Netscape® Navigator,
from a workstation on your network.
12
Section II: Local and Telnet Management
Document Conventions
This document uses the following conventions:
Note
Notes provide additional information.
Warning
Warnings inform you that performing or omitting a specific action
may result in bodily injury.
Caution
Cautions inform you that performing or omitting a specific action
may result in equipment damage or loss of data.
13
AT-S39 User’s Guide
Where to Find Web-based Guides
The installation and user guides for all Allied Telesyn products are
available in Portable Document Format (PDF) from on our web site at
www.alliedtelesyn.com. You can view the documents on-line or
download them onto a local workstation or server.
14
Section II: Local and Telnet Management
Contacting Allied Telesyn
To contact Technical Support by phone, find your country or region in
the table below.
United States, Canada, Mexico, Central
America, South America
Tel: 1 800 428 4835 (option 4)
Germany, Switzerland, Austria, Eastern
Europe
Tel: (+49) 30-435-900-126
United Kingdom, Denmark, Norway,
Sweden, Finland
(+44) 1-235-442560
France, Belgium, Luxembourg, The
Netherlands, Middle East, Africa
(+33) 1-60-92-15-25
Singapore, Taiwan, Thailand, Malaysia,
Australia
Indonesia, Korea, Philippines, China, India, Tel:1 (800) 000-880
Hong Kong
Tel: (+65) 3815-612
Italy, Spain, Portugal, Greece, Turkey, Israel
Tel: (+39) 02-41-30-41
Japan
Tel: (+81) 3-3443-5640
You can also contact Technical Support on-line at
http://kb.alliedtelesyn.com.
Sales or
Corporate
Information
Allied Telesyn, Inc.
19800 North Creek Parkway,
Suite 200
Bothell, WA 98011
Tel:1 (425) 487-8880
Fax:1 (425) 489-9191
15
AT-S39 User’s Guide
Management Software Updates
New releases of management software for our managed products are
available from our web site at www.alliedtelesyn.com and our FTP server
at ftp.alliedtelesyn.com. To use the FTP server, enter ‘anonymous’ for the
user name when you log in and your e-mail address for the password.
16
Section I
Overview
The chapter in this section provides a brief overview of the AT-S39
management software. It explains some of the functions that you can
perform with the management software and reviews the different
methods for accessing the AT-S39 software on an AT-8000 Series Fast
Ethernet Switch.
17
Chapter 1
Overview
The AT-S39 management software is intended for the AT-8000 Series
Fast Ethernet Switches. The software is used to monitor and adjust a
switch’s operating parameters. Functions that you can perform with the
software include:
❑ Enable and disable ports
❑ Configure port parameters, such as port speed and duplex mode
❑ Create virtual LANs (VLANs)
❑ Create port trunks and port mirrors
❑ Assign an Internet Protocol (IP) address and subnet mask
❑ Activate and configure the Spanning Tree Protocol (STP)
❑ Configure port security
The AT-S39 management software comes pre-installed on the switch
with default settings for all operating parameters. If the default settings
are adequate for your network, you can use the switch as an unmanaged
switch simply by connecting the unit to your network, as explained in
the hardware installation guide, and powering ON the device.
Note
The default settings for the management software can be found in
Appendix A, AT-S39 Default Settings on page 293.
To actively manage a switch, such as to change or adjust the operating
parameters, you must access the switch’s AT-S39 management software.
The AT-S39 software has a menu interface that makes it very easy to use,
and a special interface for managing a switch with a web browser.
18
Section I: Overview
There are four different ways that you can access the management
software on an AT-8000 Series switch. The methods are referred to as
management sessions in this guide. They are:
❑ Local Management Session
❑ Telnet Management Session
❑ Web Browser Management Session
❑ SNMP Management Session
The following sections in this chapter briefly describe each type of
management session.
19
AT-S39 User’s Guide
Local Management Session
You establish a local management session with an AT-8000 Series switch
by connecting a terminal or a PC with a terminal emulator program to
the RS232 Terminal port on the front panel of the switch, using a
straight-through RS-232 cable. This type of management session is
referred to as “local” because you must be physically close to the switch,
such as in the wiring closet where the switch is located.
Once the session is started, you will see a menu from which you can
make selections to configure and monitor the switch. You can configure
all of a switch’s operating parameters from a local management session.
Note
For instructions on starting a local management session, refer to
Starting a Local Management Session on page 28.
20
Section I: Overview
Telnet Management Session
Any management workstation on your network that has the Telnet
application protocol can be used to manage an AT-8000 Series switch.
This type of management session is referred to in this guide as a remote
management session because you do not have to be in the wiring closet
where the switch you want to manage is located. You can manage the
switch from any workstation on the network that has the application
protocol.
To establish a Telnet management session with a switch, there must be
at least one AT-8000 Series switch on the subnet that has been assigned
an Internet Protocol (IP) address. Only one switch in a subnet needs to
have an IP address. Once you have established a Telnet management
session with the switch that has an IP address, you can use the enhanced
stacking feature of the AT-S39 software to access all other AT-8000
Series switches in the same subnet.
Note
For further information on enhanced stacking, refer to Enhanced
Stacking Overview on page 53.
Note
For instructions on how to start a Telnet management session, refer
to Starting a Telnet Management Session on page 32.
A Telnet management session gives you complete access to all of a
switch’s operating parameters. You can perform nearly all the same
functions from a Telnet management session as you can from a local
management session.
21
AT-S39 User’s Guide
Web Browser Management Session
You can also use a web browser to manage a switch. This too is referred
to as remote management, just like a Telnet management session. You
can manage a switch from any workstation on your network that has a
web browser.
Note
For instructions on starting this type of management session, refer
to Starting a Web Browser Management Session on page 209.
22
Section I: Overview
SNMP Management Session
Another way to remotely manage the switch is with an SNMP
management program. A familiarity with Management Information Base
(MIB) objects is necessary for this type of management.
The AT-S39 software supports the following MIBs:
❑ SNMP MIB-II (RFC 1213)
❑ Bridge MIB (RFC 1493)
❑ Interface Group MIB (RFC 1573)
❑ Ethernet MIB (RFC 1643)
❑ Remote Network MIB (RFC 1757)
❑ Allied Telesyn managed switch MIB
You must download the Allied Telesyn managed switch MIB file from the
Allied Telesyn web site and compile the file with your SNMP program.
For instructions, refer to your SNMP management documentation.
Note
SNMP management does not utilize the enhanced stacking feature.
Consequently, you must assign an IP address to each switch to be
managed with an SNMP program.
23
AT-S39 User’s Guide
Management Access Levels
There are two levels of management access on an AT-8000 Series switch:
Manager and Operator. When you log in as a Manager, you can view and
configure all of a switch’s operating parameters. When you log in as an
Operator, you can only view the operating parameters; you cannot
change any values.
You log in as a Manager or an Operator by entering the appropriate
password when you start an AT-S39 management session. The default
password for Manager access is “admin”. The default password for
Operator access is “friend”. The password is case-sensitive.
24
Section II
Local and Telnet Management
The chapters in this section explain how to manage an AT-8000 Series
switch from a local or Telnet management session. The chapters include:
❑ Chapter 2: Starting a Local or Telnet Management Session on
page 26
❑ Chapter 3: Basic Switch Parameters on page 34
❑ Chapter 4: Enhanced Stacking on page 52
❑ Chapter 5: Port Parameters on page 60
❑ Chapter 6: Port Security on page 70
❑ Chapter 7: Port Trunking on page 77
❑ Chapter 8: Port Mirroring on page 87
❑ Chapter 9: STP and RSTP on page 91
❑ Chapter 10: Virtual LANs on page 110
❑ Chapter 11: MAC Address Table on page 149
❑ Chapter 12: Class of Service on page 162
❑ Chapter 13: IGMP Snooping on page 165
❑ Chapter 14: Broadcast Frame Control on page 173
❑ Chapter 15: TACACS+ and RADIUS Protocols on page 179
❑ Chapter 16: Ethernet Statistics on page 188
❑ Chapter 17: File Downloads and Uploads on page 193
25
Chapter 2
Starting a Local or Telnet
Management Session
This chapter contains the procedure for starting a local or Telnet
management session on an AT-8000 Series switch. The sections in the
chapter are:
❑ Local Management Session on page 27
❑ Telnet Management Session on page 32
26
Section II: Local or Telnet Management
Local Management Session
On the front panel of the switch is a port labelled RS232 Terminal Port.
You use this port to establish a local management session with the
switch’s AT-S39 management software.
A local management session is so named because you must be close to
the switch, usually within a few meters, to start this type of management
session. This typically means that you must be in the wiring closet where
the switch is located.
A switch does not need an IP address to be managed from a local
management session. You can start a local management session at any
time on any AT-8000 Series switch in your network. Running a local
management session does not interfere with the flow of Ethernet traffic
through the unit.
Starting a local management session on a switch that has been
configured as a Master switch of an enhanced stack allows you to
manage all the switches in the subnet from the same local management
session. You do not have to start a separate local management session
for each switch. This can simplify network management.
Starting a local management session on a switch that is not part of an
enhanced stack or that is a slave switch in an enhanced stack allows you
to manage just that switch.
Note
For information on enhanced stacking, refer to Enhanced Stacking
Overview on page 53.
27
AT-S39 User’s Guide
Starting a Local
Management
Session
To start a local management session, perform the following procedure:
1. Connect one end of a straight-through RS232 cable with a DB-9
connector to the RS232 Terminal Port on the switch.
POR
TB
RS-
DE
232
LINK
MOD
E
TER
MIN
AL P
ORT
FAU
LT
MAS
TER
PWR
Figure 1 Connecting a Terminal or PC to the RS232 Terminal Port
2. Connect the other end of the cable to an RS-232 port on a terminal or
PC with a terminal emulator program.
3. Configure the terminal or terminal emulator program as follows:
❑ Baud rate: 1200 bps to 115200 bps (default 9600; see Note below)
❑ Data bits: 8
❑ Parity: None
❑ Stop bits: 1
❑ Flow control: None
28
Section II: Local or Telnet Management
Note
The switch has an auto-detect feature that automatically
determines the speed of the terminal. You use this feature by
pressing any key on your keyboard within five seconds after
powering on or resetting the switch. The switch responds by
determining the speed of the terminal and automatically
configuring the speed of the RS232 Terminal Port accordingly.
Otherwise, the switch uses a default baud rate of 9600 bits per
second (bps). The switch maintains the terminal port speed until the
system is again powered on or reset. The range of the port’s baud
rate is 1200 to 115200 bps.
Note
The port settings are for a DEC VT100 or ANSI terminal, or an
equivalent terminal emulator program.
Note
During boot up, the switch displays the following prompt: Press
any key to stop image loading and go to Boot
Prompt. This message is intended for manufacturing purposes
only. (If you inadvertently display the boot prompt (=>), type boot
and press Return to start the switch.)
4. Press the Return key twice.
If prompted for a password, enter the password for the management
software. The default password for manager access is “admin”.
The default password for operator access is “friend”. The
passwords are case-sensitive. For information on the two access
levels, refer to Management Access Levels on page 24. (For
instructions on how to change a password, refer to Configuring
the Management Passwords on page 46.)
29
AT-S39 User’s Guide
The Main Menu is displayed.
Allied Telesyn Ethernet Switch AT-8024GB
Login Session: Manager
Main Menu
1
2
3
4
5
6
7
8
9
C
-
Port Menu
VLAN Menu
Spanning Tree Menu
Administration Menu
System Config Menu
MAC Address Tables
Ethernet Statistics
Diagnostics
Enhanced Stacking
Command Line Interface
Q - Quit
Enter your selection?
Figure 2 Main Menu
To select a menu item, type the corresponding letter or number.
Pressing the Esc key or typing the letter R in a submenu or window
returns you to the previous menu.
Please note the following:
❑ The Command Line Interface selection in the Main Menu is not
described in this manual. For instructions on this option, refer to
the AT-S39 Command Line Interface User’s Guide.
❑ If a dollar sign ($) is displayed instead of the Main Menu, the
console interface has been configured for a command line
interface management session. To display the Main Menu, type
menu and press Return.
❑ During boot up, the switch displays the following message:
Press any key to stop image loading and go to
Boot Prompt. This message is for manufacturing purposes only.
If you do inadvertently display the boot prompt (=>), type boot
and press Return to start the switch’s software.
30
Section II: Local or Telnet Management
Enhanced
Stacking
When you start a local management session on a switch that has been
designated as the Master switch of an enhanced stack, you can manage
all the switches in the same subnet from the same management session.
This can save you the time and trouble of having to start a separate local
management session each time you want to manage a switch in your
network. It can also save you from having to go to the different wiring
closets where the switches are located.
For information on enhanced stacking and how to manage different
switches from the same management session, refer to Chapter 4,
Enhanced Stacking on page 52.
Quitting from a
Local Session
To quit a local session, return to the Main Menu and type Q for Quit.
You should always exit from a management session when you are
finished managing a switch. This can prevent unauthorized individuals
from making changes to a switch’s configuration should you leave your
management station unattended.
Note
You cannot operate both a local management session and a Telnet
management session on the same switch simultaneously. Failure to
properly exit from a local or Telnet management session may block
future management sessions.
31
AT-S39 User’s Guide
Telnet Management Session
You can use the Telnet application protocol from a workstation on your
network to manage an AT-8000 Series switch. This type of management
is referred to as remote management because you do not have to be
physically close to the switch to start the session, such as with a local
management session. Any workstation on your network that has the
application protocol can be used to manage the switch.
In terms of functionally, there are almost no differences between
managing a switch locally through the RS232 Terminal Port and
remotely with the Telnet application protocol. You see the same menu
selections and have nearly the same management capabilities.
Starting a Telnet management session requires that there be at least one
AT-8000 Series switch on your network that has an IP address. The switch
with the IP address is referred to as the master switch. Once you have
started a Telnet management session on the master switch, you will
have management access to all the other AT-8000 Series switches that
reside in the same subnet.
Note
For background information on enhanced stacking, refer to
Enhanced Stacking Overview on page 53.
Starting a Telnet
Management
Session
To start a Telnet management session, specify the IP address of the
master switch of the enhanced stack in the Telnet application protocol
and enter the management software password when prompted. The
default password for manager access is “admin”. The default password
for operator access is “friend”. The passwords are case-sensitive. For
information on the two access levels, refer to Management Access
Levels on page 24. (For instructions on how to change a password, refer
to Configuring the Management Passwords on page 46.)
The Main Menu of a Telnet management session is the same menu that
you see in a local management session, shown in Figure 2 on page 30.
Nearly all the functions from a local management session are available to
you from a Telnet management session.
The menus also function the same. To make a selection, type its
corresponding number of letter. To return to a previous menu, type R or
press ESC twice.
32
Section II: Local or Telnet Management
Note
You can run only one Telnet management session on a switch at a
time. Additionally, you cannot run both a Telnet management
session and a local management session on the same switch at the
same time.
Quitting from a
Telnet
Management
Session
To end a Telnet management session, return to the Main Menu and type
Q for Quit.
33
Chapter 3
Basic Switch Parameters
This chapter contains a variety of information and procedures. There is a
discussion on when to assign an IP address to a switch and the different
ways that you can go about it. There are also procedures for resetting
the switch, activating the original switch default settings, and more.
Sections in the chapter include:
❑ When Does a Switch Need an IP Address? on page 35
❑ Configuring an IP Address and Switch Name on page 37
❑ Activating the BOOTP and DHCP Services on page 40
❑ Configuring SNMP Community Strings and Trap IP Addresses
on page 42
❑ Resetting a Switch on page 44
❑ Configuring the AT-S39 Software Security Features on page
45
❑ Viewing the AT-S39 Version Number and Switch MAC Address
on page 48
❑ Pinging a Remote System on page 49
❑ Returning the AT-S39 Software to the Factory Default Values
on page 50
❑ Configuring the Console Startup Mode on page 51
34
Section II: Local and Telnet Management
When Does a Switch Need an IP Address?
One of the tasks to building or expanding a network is deciding which of
the managed switches need to be assigned unique IP addresses. The
rule used to be that a managed switch needed an IP address if you
wanted to manage it remotely, such as with the Telnet application
protocol. However, if a network contained a lot of managed switches,
having to assign each one an IP address was often cumbersome and
time consuming. It was also often difficult keeping track of all the IP
addresses.
The enhanced stacking feature of the AT-8000 Series switch simplifies all
this. With enhanced stacking, you need assign an IP address to only one
AT-8000 Series switch in each subnet in your network. The switch with
the IP address is referred to as the Master switch of the subnetwork. All
switches in the same subnet share the IP address.
Starting a local or remote management session on the Master switch
automatically gives you complete management access to all the other
switches in the same subnet.
This feature has two primary benefits. First, it helps reduce the number
of IP addresses you have to assign to your network devices. Second, it
allows you to configure multiple switches through the same local or
remote management session.
If your network consists of multiple subnets, you must assign a unique IP
address to at least one switch in each subnet. The switch with the IP
address will be the Master switch of that subnet.
When you assign a switch an IP address, you must also assign it a subnet
mask. The switch uses the subnet mask to determine which portion of an
IP address represents the network address and which the node address.
You must also assign the switch a gateway address if there is a router
between the switch and the remote management workstation. This
gateway address is the IP address of the router through which the switch
and management station will communicate.
Note
For further information on enhanced stacking, refer to Enhanced
Stacking Overview on page 53.
If you do not plan to remotely manage any of the AT-8000 Series
switches in your network, then you do not need to assign any of them an
IP address. The switches will operate fine without an IP address and you
will still be able to manage them completely using local management
sessions.
35
AT-S39 User’s Guide
How Do You
Assign an IP
Address?
Once you have decided which, if any, switches on your network need an
IP address, you have to access the AT-S39 software on the switches and
assign the addresses. There are actually two ways in which a switch can
obtain an IP address.
The first method is for you to assign the IP configuration information
manually. The procedure for this is explained in the next procedure.
Initially assigning an IP address to a switch can only be done through a
local management session.
The second method is for you to activate the BOOTP and DHCP services
on the switch and have the switch automatically download its IP
configuration information from a BOOTP or DHCP server on your
network. This procedure is explained in Activating the BOOTP and
DHCP Services on page 40.
36
Section II: Local and Telnet Management
Configuring an IP Address and Switch Name
The procedure in this section explains how to manually assign an IP
address, subnet mask, and gateway address to the switch from a local or
Telnet management session. (If you want the switch to obtain its IP
configuration from a DHCP or BOOTP server on your network, go to the
procedure Activating the BOOTP and DHCP Services on page 40.)
This procedure also explains how to assign a name to the switch, along
with other optional information, such as the name of the administrator
responsible for maintaining the unit and the location of the switch.
To manually set a switch’s IP address, perform the following procedure:
1. From the Main Menu, type 4 to select Administration Menu.
The Administration Menu in Figure 3 is displayed.
Allied Telesyn Ethernet Switch AT-8024
Login Session: Manager
Administration Menu
1
2
3
4
5
6
7
8
-
IP Address .........
Subnet Mask ........
Default Gateway ....
System Name ........
Administrator ......
Comments ...........
Set Password .......
BOOTP/DHCP .........
0.0.0.0
255.255.0.0
0.0.0.0
9
A
D
P
-
Reset Switch
Server-based Authentication
Downloads & Uploads
Ping a remote system
Disabled
S - Save Configuration Changes
R - Return to Previous Menu
Enter your selection?
Figure 3 Administration Menu
37
AT-S39 User’s Guide
2. Change the parameters as desired.
The parameters in the IP Parameters window are described below:
1 - IP Address
This parameter specifies the IP address of the switch. You must
specify an IP address if you intend to remotely manage the switch
using a web browser, a Telnet utility, or an SNMP management
program, or if you want a switch to function as the Master switch
of an enhanced stack.
2 - Subnet Mask
This parameter specifies the subnet mask for the switch. You must
specify a subnet mask if you assigned an IP address to the switch.
3 - Default Gateway
This parameter specifies the default router’s IP address. This
address is required if you intend to remotely manage the switch
from a management station that is separated from the switch by
a router.
4 - System Name
This parameter specifies a name for the switch (for example, Sales
Ethernet switch). This parameter is optional.
Note
It is advisable that you assign each switch a name. The names can
help you identify the various switches when you manage them and
avoid performing a configuration procedure on the wrong switch.
5 - Administrator
This parameter specifies the name of the network administrator
responsible for managing the switch. This parameter is optional.
6 - Comments
This parameter specifies additional information about the Fast
Ethernet switch, such as its location (for example, 4th Floor wiring closet 402B). This parameter is optional.
7 - Set Password
This parameter is used to change the Manager and Operator’s
login passwords. For instructions, refer to Configuring the
Management Passwords on page 46.
8 - BOOTP/DHCP
This selection activates and deactivates the BOOTP and DHCP
services on the switch. For information on this selection, refer to
Activating the BOOTP and DHCP Services on page 40.
38
Section II: Local and Telnet Management
9 - Reset Switch
This selection resets the switch.
A - Server-based Authentication
This selection is used to configure the TACACS+ and RADIUS
authentication protocols on the switch. For information on this
feature, refer to Chapter 15, TACACS+ and RADIUS Protocols
on page 179.
X - Xmodem Downloads and Uploads
For information on this selection, refer to Chapter 17, File
Downloads and Uploads on page 193.
R - Ping a Remote System
For information on this selection, refer to Pinging a Remote
System on page 49.
3. After you have set the parameters, type S to select Save Configuration
Changes.
Note
A change to any of the parameters in this menu, including the IP
address, subnet mask, or gateway address, are immediately
activated on a switch.
39
AT-S39 User’s Guide
Activating the BOOTP and DHCP Services
The BOOTP and DHCP application protocols were developed to simplify
network management. They are used to automatically assign IP
configuration information to the devices on your network, such as an IP
address, subnet mask, and a default gateway address.
An AT-8000 Series switch supports these protocols and can obtain its IP
configuration information from a BOOTP or DHCP server on your
network. If you activate this feature, the switch will seek its IP address
and other IP configuration information from a BOOTP or DHCP server on
your network whenever you reset or power ON the device.
Naturally, for this to work there must be a BOOTP or DHCP server
residing on your network and you must configure the service by
entering in the switch’s MAC address.
BOOTP and DHCP services typically allow you to specify how the IP
address is to be assigned to the switch. Choices are static and dynamic. If
you choose static, the server will always assign the same IP address to
the switch when the switch is reset or powered ON. This is the preferred
configuration. Since the BOOTP and DHCP services always assigns the
same IP address to a switch, you will always know which IP address to
use when you need to remotely manage a particular switch.
If you choose dynamic, the server will assign any unused IP address that
it has not already assigned to another device. This means that a switch
might have a different IP address each time you reset or power cycle the
device, making it difficult for you to remotely manage the unit.
Note
The BOOTP and DHCP option is disabled by default on the switch.
To activate or deactivate the BOOTP and DHCP protocols on the switch,
perform the following procedure:
1. From the Main Menu, type 4 to select Administration Menu.
The Administration in Figure 3 on page 37 is displayed.
2. Type 8 to select BOOTP/DHCP.
The following prompt is displayed:
BOOTP/DHCP (E-Enabled, D-Disabled):
3. Type E to enable BOOTP and DHCP services on the switch or D to
disable the services and press Return. The default is disabled.
4. Type S to select Save Configuration Changes.
40
Section II: Local and Telnet Management
Note
If you activated BOOTP/DHCP, the switch immediately begins to
query the network for a BOOTP or DHCP server. The switch will
continue to query the network for its IP configuration until it
receives a response.
41
AT-S39 User’s Guide
Configuring SNMP Community Strings and Trap IP Addresses
To configure the SNMP community strings for the switch and to assign
up to four IP addresses of management stations to receive traps from
the switch, perform the following procedure:
1. From the Main Menu, type 5 to select System Config Menu.
The System Configuration Menu in Figure 4 is displayed.
Allied Telesyn AT-8024 Ethernet Switch
Login Session: Manager
System Config Menu
1
2
3
4
5
6
7
8
-
MAC Aging Time ...................
Switch Mode ......................
Console Discount Timer Interval ..
Web Server Status ................
SNMP Access ......................
TFTP Server Status ...............
Console Setup Mode ...............
Reset to Factory Defaults
300 seconds
Tagged
10 minute(s)
Enabled
Enabled
Enabled
Menu
A - Advanced Configuration
S - Save Configuration Changes
R - Return to Previous Menu
Enter your selection:
Figure 4 System Configuration Menu
2. From the System Configuration Menu, type A to select Advanced
Configuration.
The Advanced Configuration window in Figure 5 is displayed.
Allied Telesyn AT-8024 Ethernet Switch
Login Session: Manager
Advanced Configuration Menu
1 - IGMP Snooping Configuration
2 - Broadcast Timers Setup
3 - SNMP Configuration
R - Return to Previous Menu
Enter your selection:
Figure 5 Advanced Configuration Window
42
Section II: Local and Telnet Management
3. From the Advanced Configuration window, type 3 to select SNMP
Configuration. The SNMP Configuration window in Figure 6 is
displayed.
Allied Telesyn AT-8024 Ethernet Switch
Login Session: Manager
SNMP Configuration
1 - GET Community .............. public
2 - SET Community .............. private
3 - Trap Community ............. public
4
5
6
7
-
Trap
Trap
Trap
Trap
Receiver
Receiver
Receiver
Receiver
1
2
3
4
............
............
............
............
0.0.0.0
0.0.0.0
0.0.0.0
0.0.0.0
S - Save Configuration Changes
R - Return to Previous Menu
Enter your selection:
Figure 6 SNMP Configuration Window
4. Adjust the parameters as desired. To change a value, type its
corresponding number and, when prompted, enter the new value.
The parameters are described below.
1 - GET Community
2 - SET Community
3- Trap Community
Use these parameters to set a switch’s SNMP community strings.
4 - Trap Receiver 1
5 - Trap Receiver 2
6 - Trap Receiver 3
7 - Trap Receiver 4
Use these selections to specify the IP addresses of up to four
management workstations on your network to receive traps from
the switch.
5. After making your changes, type S to select Save Configuration
Changes.
Changes to the SNMP parameters are immediately activated on
the switch.
43
AT-S39 User’s Guide
Resetting a Switch
To reset a switch, perform the following procedure:
1. From the Main Menu, type 4 to select Administrator Menu.
2. From the Administrator Menu, type 9 to select Reset Switch.
The following prompt is displayed:
Do you want to proceed with the switch reboot?
[Yes/No] ->
3. Type Y to reset the switch or N to cancel this procedure.
The following prompt is displayed:
Please press <ENTER> key TWICE to proceed with the
Switch Reset...
4. Press the Return key twice.
The switch reloads its operating system, a task requiring
approximately 20 seconds to complete.
Caution
The switch will not forward traffic during the brief period required to
reload its operating software. Some data traffic may be lost.
44
Section II: Local and Telnet Management
Configuring the AT-S39 Software Security Features
The AT-S39 software has several security features that can help prevent
unauthorized individuals from changing the parameter settings of an
AT-8000 Series switch. The security features are:
❑ Manager and Operator Passwords - The management software
has two standard, management login accounts: Manager and
Operator. The Manager acount allows you to configure all switch
parameters, while the Operator account only allows you to view
the parameter settings. The default login password for Manager
access is “admin”. The default password for Operator access is
“friend”. The passwords are case-sensitive. For instructions on
how to change a password, refer to Configuring the
Management Passwords on page 46. (You can create additional
management login accounts for the switch if your network
contains a TACACS+ or RADIUS authentication protocol server.
For instructions, refer to Chapter 15, TACACS+ and RADIUS
Protocols on page 179.)
❑ Console Timeout - This parameter causes the management
software to automatically end a management session if it does
not detect any activity from the local or remote management
station after the specified period of time. This security feature can
prevent unauthorized individuals from using your management
station should you step away from your system while configuring
a switch. The default for the console timeout value is 10 minutes.
For instructions on how to set this security feature, refer to
Configuring Management Access on page 47.
❑ Web Access - You can disable the web browser management
feature on the switch, and so prevent individuals from managing
the switch remotely using a web browser. For instructions on how
to set this security feature, refer to Configuring Management
Access on page 47.
❑ SNMP Access - You can also disable the SNMP management
feature on the switch, and so prevent individuals from managing
the switch remotely using a SNMP management program. For
instructions on how to set this security feature, refer to
Configuring Management Access on page 47.
❑ TFTP Server Access - Disabling TFTP server access prevents
anyone from downloading management software switch to
switch. For instructions on how to set this security feature, refer to
Configuring Management Access on page 47.
45
AT-S39 User’s Guide
Configuring the
Management
Passwords
There are two levels of management access on an AT-8000 Series switch:
Manager and Operator. When you log in as a Manager, you can view and
configure all of a switch’s operating parameters. When you log in as an
Operator, you can only view the operating parameters; you cannot
change any values.
You log in as a Manager or an Operator by entering the appropriate
password when you start an AT-S39 management session. The default
password for Manager access is “admin”. The default password for
Operator access is “friend”. The passwords are case-sensitive.
To change the Manager or Operator password, perform the following
procedure:
1. From the Main Menu, type 4 to select Administrator Menu.
2. From the Administrator Menu, type 7 to select Set Password. The
Passwords Menu in Figure 7 is displayed.
Allied Telesyn Ethernet Switch AT-8024
Login Session: Manager
Passwords Menu
1 - Set Manager Password
2 - Set Operator Password
R - Return to Previous Menu
Enter your selection?
Figure 7 Passwords Menu
3. To change the Manager password, type 1. To change the Operator
password, type 2. Follow the prompts. The password can be from 0 to
20 alphanumeric characters. The passwords are case-sensitive.
Caution
You should not use spaces or special characters, such as asterisks (*)
and exclamation points (!), in a password if you will be managing the
switch from a web browser. Many web browsers cannot handle
special characters in passwords.
Note
The two passwords should be the different. If both passwords are
the same, the management software will always assume that you
want to log in as Manager.
4. You are prompted to enter the new password again.
46
Section II: Local and Telnet Management
Configuring
Management
Access
To configure the console timer, web access, SNMP access, and TFTP
server security features of the AT-S39 management software, perform
the following procedure:
1. From the Main Menu, type 5 to select System Config Menu.
The System Configuration Menu Figure 4 on page 42 is displayed.
2. To configure the console timer, type 3 to select Console Disconnect
Timer Interval and, when prompted, enter a value of from 1 to 60
minutes. The default is ten minutes.
For example, if you specify 2 minutes, the AT-S39 management
software automatically ends a management session if it does not
detect any activity from the local or remote management station
after 2 minutes.
3. To configure web browser access, type 4 to select Web Server Access
and, when prompted, type E to enable web access or D to disable
web access.
For example, if you disable web access, no one will be able to
manage the switch remotely using a web browser.
4. To configure SNMP access, type 5 to select SNMP Access and, when
prompted, type E to enable SNMP management access or D to
disable it.
For example, if you disable SNMP access, no one will be able to
manage the switch remotely using an SNMP management
program.
5. To configure TFTP access, type 6 to select TFTP Server Status and,
when prompted, type E to enable TFTP access or D to disable it.
If you disable TFTP server access, you cannot download
management software images switch to switch.
6. After you have made the desired changes, type S to select Save
Configuration Changes.
Your changes are immediately activated on the switch.
47
AT-S39 User’s Guide
Viewing the AT-S39 Version Number and Switch MAC Address
The procedure in this section displays the following switch information:
❑ AT-S39 version number
❑ Bootloader version number
❑ Serial number
❑ MAC Address
To display the information, type 8 to select Diagnostics from the Main
Menu. The Diagnostics window in Figure 8 is displayed.
Allied Telesyn Ethernet Switch AT-8024
Login Session: Manager
Diagnostics
1
2
3
4
5
6
7
-
Application Software Version .... AT-S39 v3.0
Application Software Build Date . Oct 2002
Bootloader Version ...............ATS39_LOADER v2.0.1
Bootloader Build Date ........... Jul 2002
Serial Number ................... 5456411
MAC Address ..................... 00.A0.D2.17.32.00
Uplink Information
R - Return to Previous Menu
Enter your selection?
Figure 8 Diagnostics Window
The information displayed in selections 1 through 6 in this window
cannot be changed. For information on option 7, refer to Displaying
Uplink Information on page 68.
48
Section II: Local and Telnet Management
Pinging a Remote System
You can instruct the switch to ping a remote device on your network.
This procedure is useful in determining whether a valid link exists
between the switch and another device.
To ping a network device, perform the following procedure:
1. From the Main Menu, type 4 to select Administration Menu.
2. From the Administration Menu, type P to select Ping a Remote
System.
The following prompt is displayed:
Please enter an IP address ->
3. Enter the IP address of the end node you want the switch to ping and
press Return.
The results of the ping command are displayed on the screen. To
stop the ping, press any key.
49
AT-S39 User’s Guide
Returning the AT-S39 Software to the Factory Default Values
The procedure in this section returns all AT-S39 software parameters to
their default values. This procedure also deletes any VLANs that you
have created on the switch.
Note
The AT-S39 software default values can be found in Appendix A,
AT-S39 Default Settings on page 293.
To return the AT-S39 management software to its default settings,
perform the following procedure:
1. From the Main Menu, type 5 to select System Config Menu.
2. From the System Configuration Menu, type 8 to select Reset to
Factory Defaults.
The following prompt is displayed:
Are you sure you want to reset to Factory Defaults?
[Yes/No] ->
3. Type Y for yes or N for no.
The following prompt is displayed:
Do you want to reset IP, Subnet and Gateway as well?
[Yes/No] ->
4. If you type Y for yes, all switch parameters including the IP address,
subnet mask, and gateway address are changed to their default
values. If you type N for no, all switch parameters excluding the IP
address, subnet mask, and gateway address are changed to their
default values.
The following prompt is displayed:
The Factory Defaults take effect only after the
Switch reboots.
Do you want to Reboot the Switch now? [Yes/No] ->
5. Type Y to reset the switch.
The operating parameters are returned to their default values and
the switch is reset.
Caution
The switch will not forward traffic during the brief period required to
reload its operating software. Some data traffic may be lost.
50
Section II: Local and Telnet Management
Configuring the Console Startup Mode
You can configure the AT-S39 software to display either the Main Menu
or the command line interface prompt ($) whenever you start a local
management session. The default is the Main Menu.
To change the console startup mode, perform the following procedure:
1. From the Main Menu, type 5 to select System Config Menu.
2. From the System Configuration Menu, type 7 to select Console
Startup Mode.
The following prompt is displayed:
Enter Console Mode (M-Menu, C-CLI):
3. Type M if you want a local management session to always start with
the Main Menu, or C if you want it to display the command line
interface prompt.
A change to the console startup mode takes effect the next time
you start a local management session.
51
Chapter 4
Enhanced Stacking
This chapter explains the enhanced stacking feature. The sections in this
chapter include:
❑ Enhanced Stacking Overview on page 53
❑ Setting a Switch’s Enhanced Stacking Status on page 56
❑ Selecting a Switch in an Enhanced Stack on page 58
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Section II: Local and Telnet Management
Enhanced Stacking Overview
The enhanced stacking feature can make it easier for you to manage the
AT-8000 Series switches in your network. It offers the following benefits:
❑ You can manage up to 24 switches from one local or remote
management session. This eliminates the need of having to
initiate a separate management session for each switch in your
network.
❑ The switches can share the same IP address. This reduces the
number of IP addresses that you need to assign to your network
devices for remote management.
❑ Remotely managing a new switch in your network is simplified.
You simply connect it to your network. Once connected to the
network, you can begin to manage it immediately from any
workstation in your network.
Guidelines
There are a few guidelines to keep in mind when implementing
enhanced stacking for your network:
❑ Each subnet in your network constitutes an enhanced stack. You
cannot have multiple enhanced stacks in a subnet.
❑ Each subnet must have at least one master switch.
❑ You must assign the master switch an IP address and subnet mask.
❑ You must change the master switch’s stacking status to Master.
There are three basic steps to implementing this feature on your
network:
1. You must select a switch in your network to function as the master
switch of the stack.
You can select any AT-8000 Series switch to act as the master
switch of an enhanced stack. For networks that consist of more
than one subnet, there must be at least one master switch in each
subnet.
It is recommended that each subnet have two master switches.
That way, should you remove one of the master switches from the
network, such as for maintenance, you all still be able to remotely
manage the switches in the subnet using the other master switch.
53
AT-S39 User’s Guide
2. You must assign the master switch an IP address and subnet mask.
A master switch must have an IP address and subnet mask. The
other switches in an enhanced stack, referred to as slave switches,
do not.
If an enhanced stack will have more than one master switch, you
must assign each master switch a unique IP address.
Note
You can set the IP address manually or activate the BOOTP and
DHCP services on a master switch and have the master switch
obtain its IP information from a BOOTP or DHCP server on your
network. Initially assigning an IP address or activating the BOOTP
and DHCP services can only be performed through a local
management session.
For instructions on how to set the IP address manually, refer to
Configuring an IP Address and Switch Name on page 37. For
instructions on activating the BOOTP and DHCP services, refer to
Activating the BOOTP and DHCP Services on page 40.
3. You must change the enhanced stacking status of the master switch
to Master.
This is explained in the procedure Setting a Switch’s Enhanced
Stacking Status on page 56.
54
Section II: Local and Telnet Management
Example
Figure 9 is an example of the enhanced stacking feature.
Master 1
IP Address
149.32.11.22
Master 2
IP Address
Subnet A
149.32.11.16
Router
TROP LANIMRET 232-SR
TLUAF
RETSAM
RWP
Subnet B
Master 1
IP Address
149.32.09.18
Master 2
IP Address
149.32.09.24
Figure 9 Enhanced Stacking Example
The example consists of a network of two subnets interconnected with a
router. Two switches in each subnet have been selected as the master
switches of their respective subnets, and each has been assigned a
unique IP address.
To manage the switches of a subnet, you could start a local management
session or a remote Telnet management session with one of the master
switches in the subnet. You would then have management access to all
the AT-8000 Series switches in the same subnet.
55
AT-S39 User’s Guide
Setting a Switch’s Enhanced Stacking Status
The enhanced stacking status of the switch can be master switch, slave
switch, or unavailable. Each status is described below:
❑ Master switch - A master switch of a stack can be used to manage
all the other AT-8000 Series switches in a subnet. Once you have
established a local or remote management session with the
Master switch, you can access and manage all the switches in the
subnet.
A master switch must have a unique IP address. You can
manually assign a master switch an IP address or activate the
BOOTP and DHCP services on the switch.
❑ Slave switch - A slave switch can be remotely managed through a
master switch. It does not need an IP address or subnet mask.
❑ Unavailable - A switch with an unavailable stacking status cannot
be remotely managed through a master switch. A switch with this
designation can be managed locally. To be managed remotely, a
switch with an unavailable stacking status must be assigned a
unique IP address.
Note
The default setting for a switch is Slave.
To adjust a switch’s enhanced stacking status, perform the following
procedure:
1. From the Main Menu, type 9 to select Enhanced Stacking.
The Enhanced Stacking window in Figure 10 is displayed.
Allied Telesyn Ethernet Switch AT-8024
Login Session: Manager
Enhanced Stacking
1 - Switch State-(M)aster/(S)lave/(U)navailable.... Master
2 - Stacking Services
S - Save Configuration Changes
R - Return to Previous Menu
Enter your selection?
Figure 10 Enhanced Stacking Window
56
Section II: Local and Telnet Management
The window displays the current status of the switch at the end of
selection “1 - Switch State.” For example, the switch’s current
status in the figure above is Master.
Note
The “2 - Stacking Services” selection in the window is available only
on master switches.
2. To change a switch’s stacking status, type 1 to select Switch State.
The following prompt is displayed.
Enter new setup (M/S/U) ->
3. Type M to change the switch to a master switch, S to make it a slave
switch, or U to make the switch unavailable. Press Return.
4. Type S to select Save Configuration Changes.
A change to the status is immediately activated on the switch.
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AT-S39 User’s Guide
Selecting a Switch in an Enhanced Stack
The first thing that you should do before performing any procedure on a
switch in an enhanced stack is check to be sure that you are performing
it on the correct switch. If you assigned system names to your switches,
this should be easy. The name of the switch being managed is always
displayed at the top of every management window.
When you start a management session on the Master switch of a subnet,
you are by default addressing that particular switch. The management
tasks that you perform effect only the master switch.
To manage a slave switch or another Master switch in the subnet, you
need to select it from the management software.
To select a switch to manage in an enhanced stack, perform the
following procedure:
1. From the Main Menu, type 9 to select Enhanced Stacking.
2. From the Enhanced Stacking window, type 2 to select Stacking
Services.
The window in Figure 11 is displayed.
Allied Telesyn Ethernet Switch AT-8024GB
Sales Switch
Login Session: Manager
Stacking Services
Switch
Software
Switch
Num MAC Address
Name
Mode
Version
Model
------------------------------------------------------------G
S
A
I
C
B
R
-
Get/Refresh List of Switches
Sort Switches in New Order
Access Switch
Image Download to Remote Switches
Config Download to Remote Switches
Boot Loader Download to Remote Switches
Return to Previous Menu
Enter your selection?
Figure 11 Stacking Services Window
58
Section II: Local and Telnet Management
3. Type G to select Get/Refresh List of Switches.
The Master switch polls the network for all slave and Master
switches in the subnet and displays a list of the switches in the
Stacking Services window.
Note
The Master switch on which you started the management session is
not included in the list, nor are any switches with an enhanced
stacking status of Unavailable.
Note
The selections I, C, and B for downloading image and bootloader
files are explained in Chapter 17, File Downloads and Uploads on
page 193.
By default, the switches are sorted in the window by MAC address.
You can sort the switches by name as well. This is accomplished
with the selection S - Sort Switches in New Order.
4. To manage a different switch in an enhanced stack, type A to select
Access Switch.
A prompt similar to the following is displayed:
Enter the switch number -> [1 to 24}
5. Type the number of the switch in the list you want to manage.
A prompt is displayed if the switch has been assigned a password.
6. Enter the switch’s password and press Return.
The default password for manager access is “admin”. The default
password for operator access is “friend”. The passwords are casesensitive.
The Main Menu of the selected switch is displayed. You now can
manage the switch. Any management tasks you perform effect
only the selected switch.
Returning to
the Master
Switch
When you have finished managing a slave switch and want to manage
another switch in the subnet, return to the Main Menu of the slave
switch and type Q for Quit. This returns you to the Stacking Services
window. Once you see that window, you are again addressing the
Master switch from which you started the management session.
You can either select another switch in the list to manage or, if you want
to manage the Master switch, return to the master switch’s Main Menu
by typing R twice.
59
Chapter 5
Port Parameters
The chapter contains procedures for viewing and changing the
parameter settings for the individual ports on a switch.
This chapter contains the following procedures:
❑ Displaying Port Status on page 61
❑ Configuring Port Parameters on page 64
❑ Displaying Uplink Information on page 68
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Section II: Local and Telnet Management
Displaying Port Status
To display the status of the ports on the switch, perform the following
procedure:
1. From the Main Menu, type 1 to select Port Menu.
The Port Menu in Figure 12 is displayed.
Allied Telesyn Ethernet Switch AT-8024
Login Session: Manager
Port Menu
1
2
3
4
5
-
Port
Port
Port
Port
Port
Configuration
Mirroring
Trunking
Status
Security
S - Save Configuration Changes
R - Return to Previous Menu
Enter your selection?
Figure 12 Port Menu
2. From the Port Menu, type 4 to select Port Status.
61
AT-S39 User’s Guide
The Port Status window is displayed. Figure 13 is an example of
the window.
Allied Telesyn Ethernet Switch AT-8024
Login Session: Manager
Port Status
Prt Link Neg
MDIO Spd Dplx PVID
VlanID Flow
State
--------------------------------------------------------------------001 Up
Auto
MDI 10
Half 00001 00001 Disabled Forwarding
002 Up
Auto
MDI 100 Full 00001 00001 Disabled Forwarding
003 Up
Auto
MDI 100 Full 00001 00001 Disabled Forwarding
004 Up
Auto
MDI 100 Full 00001 00001 Disabled Forwarding
005 Up
Auto
MDI 10
Half 00001 00001 Disabled Forwarding
006 Up
Auto
MDI 100 Full 00001 00001 Disabled Forwarding
007 Up
Auto
MDI 100 Full 00001 00001 Disabled Forwarding
008 Up
Auto
MDI 10
Half 00001 00001 Disabled Forwarding
N - Next Page
U - Update Display
R - Return to Previous Menu
Enter your selection?
Figure 13 Port Status Window
The information in this window is for viewing purposes only. The
columns in the window are described below:
Prt
The port number.
Link
The status of the link between the port and the end node
connected to the port. Possible values are:
Up - indicates that a valid link exists between the port and the end
node.
Down - indicates that the port and the end node have not
established a valid link.
Neg
The status of Auto-Negotiation on the port. Possible values are:
Auto - Indicates that the port is using Auto-Negotiation to set
operating speed and duplex mode.
Manual - Indicates that the operating speed and duplex mode
have been set manually.
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Section II: Local and Telnet Management
MDIO
The operating configuration of the port. Possible values are Auto,
MDI, MDI-X. The status Auto indicates that the port is
automatically determining the appropriate MDI or MDI-X setting.
Spd
The operating speed of the port. Possible values are:
10 - 10 Mbps
100 - 100 Mbps
1000 - 1000 Mbps (AT-8024GB switch only)
Dplx
The duplex mode of the port. Possible values are half-duplex and
full-duplex.
PVID
The port VLAN identifier currently assigned to the port.
VlanID
The VLAN identifier of the VLAN in which the port is an untagged
member. This column will not include the VIDs of the VLANs
where the port is a tagged member.
Flow
The flow control setting for the port. Possible values are:
None - No flow control on the port.
Transmit - Flow control only as packets are being transmitted out
the port.
Receive - Flow control only on as packets are being received on
the port.
Both - Flow control for both packets entering and leaving the port.
State
The current operating status of the port. Possible values are:
Forwarding - The port is sending and receiving Ethernet frames.
Disabled - The port has been manually disabled.
63
AT-S39 User’s Guide
Configuring Port Parameters
To configure the parameter settings for a port on the switch, perform the
following procedure:
1. From the Main Menu, type 1 to select Port Menu.
2. From the Port Menu, type 1 to select Port Configuration.
The following prompt is displayed:
Starting Port to Configure [1 to 24] ->
3. Enter the number of the port you want to configure and press Return.
To configure a range of ports, enter the first port of the range.
The following prompt is displayed:
Ending Port to Configure [1 to 24] ->
4. To configure only one port, enter the same port number here as you
entered in Step 3 and press Return. To configure a range of ports,
enter the last port number in the range.
The Port Configuration window in Figure 14 is displayed.
Allied Telesyn Ethernet Switch AT-8024
Login Session: Manager
Port Configuration
Configuring Ports 4 to 4
0
1
4
5
6
7
8
M
B
-
Status ..............
Negotiation .........
Flow Control ........
Advertise 10FDX .....
Advertise 10HDX .....
Advertise 100FDX ....
Advertise 100HDX ....
MDI/MDIX Mode .......
Broadcast Control ...
Forwarding
Auto
None
Yes
Yes
Yes
Yes
AUTO
0 - No Broadcast Control
S
F
X
R
-
Save Configuration Changes
Force Renegotiation
Reset Port
Return to Previous Menu
Enter your selection?
Figure 14 Port Configuration Window
64
Section II: Local and Telnet Management
Note
The example Port Configuration window in the figure above is for a
10/100 Mbps twisted pair port. The window for a fiber optic port, a
GBIC module, or a stacking module will contain a subset of the
parameters.
5. Adjust the port parameters as desired. You adjust a parameter by
typing its number. This toggles the parameter through its possible
settings. The parameters are described below.
0 - Status
You use this selection to enable or disable a port. When disabled,
a port will not receive or transmit frames.
You might want to disable a port and prevent packets from being
forwarded if a problem occurs with the node or cable connected
to the port. Once the problem has been fixed, you can enable the
port again to resume normal operation. You can also disable an
unused port to secure it from unauthorized connections.
Possible settings are:
Forwarding - The port will receive and forward packets. This is the
default setting.
Disabled - The port will not receive or forward packets.
1 - Negotiation
You use this selection to configure a port for Auto-Negotiation or
to manually set a port’s speed and duplex mode.
If you select Auto for Auto-Negotiation, which is the default, the
switch will set both speed and duplex mode for the port
automatically.
If you select Manual, two additional selections are displayed in the
window:
2 - Speed .............. 0100
3 - Duplex ..............Full-Duplex
You use these two selections to set the port’s speed and duplex
mode. The possible settings for the 2 - Speed selection are:
0010 - 10 Mbps
0100 - 100 Mbps
1000 - 1000 Mbps (AT-8024GB switch only)
The possible settings for 3 - Duplex are Full-duplex and Halfduplex.
65
AT-S39 User’s Guide
Flow Control
Flow control applies only to ports operating in full-duplex mode.
The switch uses a special pause packet to stop the end node from
sending frames. The pause packet notifies the end node to stop
transmitting for a specified period of time.
Possible settings are:
None - No flow control on the port.
Transmit - Flow control only as packets are being transmitted out
the port.
Receive - Flow control only on as packets are being received on
the port.
Both - Flow control for both packets entering and leaving the port.
5 - Advertise 10FDX
6 - Advertise 10HDX
7 - Advertise 100FDX
8 - Advertise 100HDX
These selections are used for ports configured for AutoNegotiation. During Auto-Negotiation, a switch port determines
the appropriate speed and duplex mode by advertising its
capabilities to the end node connected to it.
By default, a switch port will advertise its full capabilities, which in
the case of a port on an AT-8000 Series switch are 10 or 100 Mbps
speed and half- or full-duplex mode.
You can use these four selections to limit the capabilities a switch
port will advertise during Auto-Negotiation. For example, if you
set the selection 8 - Advertise 100HDX to No, the switch port will
not advertise that it is capable of 100 Mbps, half-duplex operation.
Note
In most network environments you should leave all AutoNegotiation advertisements activated, which is the default setting.
M - MDI/MDIX Mode
Use this selection to set the wiring configuration of the port. If you
set this to Auto, which is the default setting, the port will configure
itself automatically according to the end node connected to it.
If desired, you can set the wiring configuration manually by
selecting either MDI or MDIX.
Note
The Auto setting is not available if you set a port’s speed and duplex
mode manually.
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Section II: Local and Telnet Management
B - Broadcast Control
For background information on this selection and instructions on
how to set the option, refer to Broadcast Frame Control
Overview on page 174 and Configuring the Maximum
Broadcast Frame Count on page 178.
6. Once you have set the port parameters, type S to select Save
Configuration Changes.
Configuration changes are immediately activated on a port.
The Port configuration window features a Reset Port selection. You can
use this option to reset the selected port. This can prove useful in
situations where a port is experiencing a problem establishing a valid
connection to the end node.
The window also has a Force Renegotiation selection, which, when
selected, prompts the port to Auto-Negotiate with the end node. This
can be helpful if you believe that a port and end node are not operating
at the same speed and duplex mode.
Note
You can configure Ports 25 and 26 in an AT-8026FC switch even if no
GBIC modules are installed. This allows you to configure the
expansion slots so that they will be fully function from the moment
you install a GBIC module.
67
AT-S39 User’s Guide
Displaying Uplink Information
The AT-S39 management software can display basic manufacturer
information about a GBIC module in an AT-8024GB switch or the fiber
optic ports in an AT-8026FC switch.
To display uplink information, perform the following procedure:
1. From the Main Menu, type 8 to select Diagnostics.
2. From the Diagnostics window, type 7 to select Uplink Information.
The GBIC Information window in Figure 15 is displayed.
Allied Telesyn Ethernet Switch AT-8024
Login Session: Manager
Uplink Information Menu
1 - Uplink Information
R - Return to Previous Menu
Enter your selection?
Figure 15 Uplink Information Window
3. Type 1 to select Uplink Information.
The following prompt is displayed:
Enter Uplink Port number -> [25 to 26]
4. Type either 25 or 26; these are the port numbers for GBIC modules in
an AT-8024GB switch. Press Return.
68
Section II: Local and Telnet Management
The management software displays a window containing basic
information about the GBIC module. Figure 16 is an example of
the window.
Allied Telesyn AT-8024GB Ethernet Switch
GBIC Information Menu
Port Number ......................
Type of Serial Interface .........
Extended Serial Transceiver ......
Connector Type ...................
Elect/Opt Transceiver ............
Shortwave laser w/o OFC
M5 M6 100 MBytes/sec
Serial Encoding ..................
Length 9/125 mm Fib. (k) .........
Length 9/125 um Fib. (100m) ......
Length 50/125 um Fib. (10m) ......
Length 62.5/125 um Fib. (10k) ....
25
GBIC
Module Not Defined
FC SC connector
1000Base-SX
8B10B
0
0
50
22
N - Next Page
R - Return to Previous Menu
Enter your selection:
Figure 16 GBIC Information Window
The information in the window is for viewing purposes only. You
cannot change this information.
69
Chapter 6
Port Security
This chapter contains the procedures for setting port security. The
sections in this chapter include:
❑ Port Security Overview on page 71
❑ Configuring Port Security on page 73
❑ Configuring the Limited Security Mode on page 75
Note
Port security does not apply to ports on GBIC modules in an
AT-8024GB switch.
Note
Port security can only be set through a local management session,
You cannot set port security from a Telnet management session.
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Section II: Local and Telnet Management
Port Security Overview
The port security feature can enhance the security of your network. You
can use the feature to control the number of MAC addresses learned on
the ports, and so control the number of network devices that can
forward frames through the switch.
There are four levels of port security. Only one security level can be
active on a switch at a time.
Automatic
This operating mode disables port security. The switch learns and adds
addresses to its dynamic MAC address table as it receives frames on the
ports. The switch continues to learn MAC addresses so long as there is
space in the MAC address table and deletes inactive MAC addresses.
Note
The Automatic security mode is the default security level for the
switch.
Limited
You can use this security level to manually specify a maximum number
of dynamic MAC addresses each port on the switch can learn. Once a
port has learned its maximum limit, it discards frames that ingress the
port with source MAC addresses not already stored in the MAC address
table.
Once this mode is activated, the switch deletes all MAC addresses in the
dynamic MAC address table and immediately begins learning new
addresses, adding them to the dynamic MAC address table for each port
until it reaches the port’s maximum limit.
The MAC aging time is disabled under this security level. Once a dynamic
MAC address has been learned on a port and added to the MAC address
table, it remains in the table and is never purged, even when the end
node is inactive.
Note
Static MAC addresses are retained by the switch and are not
included in the count of maximum addresses that can be learned by
a port. You can continue to add static MAC addresses to a port even
if the port has already learned its maximum number of dynamic
MAC addresses.
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AT-S39 User’s Guide
Secure
This security level instructs the switch to forward frames based solely on
static MAC addresses. When this security level is activated, the switch
deletes all dynamic MAC addresses and disables the MAC address table
so that no new addresses can be learned.
The switch also deletes any addresses in the static MAC address table.
Once you have activated this security level, you must enter the static
MAC addresses of the nodes whose frames the switch should forward.
The switch will forward frames only from those nodes whose MAC
addresses you enter in the static MAC address table. Any node whose
MAC address is not in the static MAC address table will not be able to
send frames through the switch.
Lock All Ports
This security level causes the switch to immediately stop learning new
dynamic MAC addresses. The switch forwards frames based on the
dynamic MAC addresses that it has already learned and any static MAC
addresses that the network administrator has entered.
The MAC aging time is disabled in this security level; no dynamic MAC
addresses are deleted from the MAC address table, even those
belonging to inactive end nodes.
Note
For background information on MAC addresses and aging time,
refer to MAC Address Overview on page 150.
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Section II: Local and Telnet Management
Configuring Port Security
Note
Port security can only be set through a local management session.
You cannot set port security from a Telnet management session or
from a web browser management session.
To set a switch’s port security level, perform the following procedure:
1. From the Main Menu, type 1 to select Port Menu.
2. From the Port Menu, type 5 to select Port Security.
The Port Security menu in Figure 17 is displayed.
Allied Telesyn Ethernet Switch AT-8024
Login Session: Manager
Port Security
The current mode is mode.
1 - Configure Port Security Mode ... AUTOMATIC
2 - Configure Limited Mode Parameters
R - Return to Previous Menu
Enter your selection?
Figure 17 Port Security Menu
3. Type 1 to select Configure Port Security Mode.
The following prompt is displayed:
Enter new mode (A-Automatic, L-Limited, S-Secured, KlocKed) :
4. Select the desired security level by typing the corresponding letter:
❑ To disable port security on the switch, type A to select Automatic
mode. A switch operating in Automatic mode does not restrict the
number of MAC addresses learned by the ports. The switch
continues to learn addresses so long as there is available space in
the MAC address table. This is the default setting.
❑ To specify a maximum number of MAC addresses each port can
learn, type L to select Limited mode. To specify the limits, perform
the procedure in Configuring the Limited Security Mode on
page 75.
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AT-S39 User’s Guide
❑ To forward frames based solely on static MAC addresses, type S to
select the Secured mode. After activating this security mode, you
must enter the static MAC addresses of the nodes with frames the
switch is to forward. For instructions on how to add static MAC
addresses, refer to Adding Static and Multicast MAC Addresses
on page 159.
❑ To stop the switch from learning new dynamic MAC addresses
and have it forward frames based only on static MAC addresses
and on those dynamic addresses that it has already learned, type
K to select Lock all the ports now.
Note
Only one security level can be active on a switch at a time.
A change to the security level is immediately activated on the
switch.
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Section II: Local and Telnet Management
Configuring the Limited Security Mode
The Limited security mode lets you set a maximum number of dynamic
MAC addresses each port on a switch can learn. When you activate this
security level, the switch deletes all MAC addresses in the dynamic MAC
address table and immediately begins to learn new addresses as frames
are received on the ports. Once the maximum number of MAC addresses
have been learned by a port, frames with new source MAC addresses are
discarded and are not forwarded.
You can assign the same limit to all ports or different limits to different
ports.
Static MAC addresses are not deleted from the static MAC address table.
Static MAC addresses are not included in the count of the maximum
MAC addresses a port can learn. You can continue to add static MAC
addresses even after a port has learned its maximum number of dynamic
MAC addresses.
To configure Limited security mode, perform the following procedure:
1. From the Main Menu, type 1 to select Port Menu.
2. From the Port Menu, type 5 to select Port Security.
The Port Security menu in Figure 17 on page 73 is displayed.
3. From the Port Security menu, type 2 to select Configure Limited
Mode Parameters.
The Limited Security Mode menu in Figure 18 is displayed.
Allied Telesyn Ethernet Switch AT-8024
Login Session: Manager
Port security limited-mode menu
1 - Display MAC Limits
2 - Configure Limited Mode Parameters
R - Return to Previous Menu
Enter your selection?
Figure 18 Limited Security Mode Menu
75
AT-S39 User’s Guide
4. Type 2 to select Configure Limited Mode Parameters.
The following prompt is displayed:
Enter ports list:
5. Enter the port(s) where you want to specify a new MAC address limit.
You can specify the ports individually (e.g., 1,4), as a range (e.g., 4-7),
or both (e.g., 2-7,11,15).
The following prompt is displayed:
Enter new MAC limit ->
[1 to 150] ->
6. Enter the maximum number of dynamic MAC addresses you want the
port to be able to learn and press Return. The range is 1 to 150
addresses. The default is 100.
7. Repeat this procedure starting with Step 4 to specify MAC address
limits on other ports.
8. Type S to select Save Configuration Changes.
9. Type 1 to select Display MAC Limits.
The current MAC address limits for all ports are displayed.
10. Examine the MAC limits. Check to be sure that they are correct. If you
assigned different values to different ports, be sure that the different
values apply to the correct ports. If necessary, repeat this procedure
to change any MAC address limits.
76
Chapter 7
Port Trunking
This chapter contains the procedures for creating and deleting port
trunks. Sections in the chapter include:
❑ Port Trunking Overview on page 78
❑ Creating a Port Trunk on page 84
❑ Deleting a Port Trunk on page 86
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AT-S39 User’s Guide
Port Trunking Overview
Port trunking is an economical way for you to increase the bandwidth
between two Ethernet switches. A port trunk is 2, 3, or 4 ports that have
been grouped together to function as one logical path. A port trunk
increases the bandwidth between switches and is useful in situations
where a single physical data link between switches is insufficient to
handle the traffic load.
A port trunk always sends packets from a particular source to a particular
destination over the same link within the trunk. A single link is
designated for flooding broadcasts and packets of unknown destination.
The example in Figure 19 consists of a port trunk of four data links
between two AT-8024 switches.
AT-8024
RS-232 TERMINAL PORT
10Base-T / 100Base-TX Fast Ethernet Switch
MODE
Link
COL
Mode
Link
100
Mode
ACT
FAULT
MASTER
FULL
PWR
AT-8024
RS-232 TERMINAL PORT
10Base-T / 100Base-TX Fast Ethernet Switch
MODE
Link
COL
Mode
Link
100
Mode
ACT
FULL
FAULT
MASTER
PWR
Figure 19 Port Trunk Example
Observe the following guidelines when creating a port trunk:
❑ An AT-8000 Series switch can support only one port trunk at a
time.
❑ A port trunk can consist of 2, 3, or 4 ports.
❑ The ports of a port trunk must be of the same medium type. For
example, they can be all twisted pair ports or all fiber optic ports.
❑ The speed, duplex mode, and flow control settings must be the
same for all the ports in a trunk.
❑ The ports of a port trunk must be members of the same VLAN. A
port trunk cannot consist of ports from different VLANs.
78
❑ When cabling a trunk, the order of the connections should be
maintained on both nodes. The lowest numbered port in a trunk
on the switch should be connected to the lowest numbered port
of the trunk on the other device, the next lowest numbered port
on the switch should be connected to the next lowest numbered
port on the other device, and so on.
For example, assume that you are connecting a trunk between
two AT-8024 switches. On the first AT-8024 switch you had
chosen ports 12, 13, 14, 15 for the trunk. On the second AT8024 switch you had chosen ports 21, 22, 23, and 24. To
maintain the order of the port connections, you would
connect port 12 on the first AT-8024 switch to port 21 on the
second AT-8024, port 13 to port 22, and so on.
❑ You can create a port trunk of optional GBIC modules installed in
Port 25 and Port 26 of an AT-8024GB switch.
❑ You can create a port trunk of the fiber optic ports in an
AT-8026FC switch.
❑ You can create a port trunk of the ports in two expansion modules
in an AT-8016F switch, providing that the ports are of the same
medium type and have the same operating specifications.
Load
Distribution
Methods
There are two steps to creating a port trunk. The first is to identify the
ports on the switch that are to function as the port trunk. The second is
to select a load distribution method. This second step is important
because unless you select the correct distribution method for your
configuration, the switch might not evenly distribute the load across all
the links of a trunk. Naturally, this could greatly diminish the value and
purpose of the port trunk.
The AT-S39 management software offers two load distribution methods.
They are:
❑ Source Address (SA) Trunking
❑ Source Address / Destination Address (SA/DA) Trunking
Let’s first take a look at the SA method. When a switch receives a packet
from a network node, it examines the destination address to determine
on which switch port, if any, the packet should be transmitted. If the
packet is destined for a port trunk, the switch then examines the source
address of the packet. If this is the first packet from the source node to
be transmitted over a port trunk, the switch assigns the source address
to one of the trunk links. All subsequent packets from the source node
are sent out the assigned data link of the trunk.
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AT-S39 User’s Guide
The switch assigns source addresses so as to evenly distribute the
addresses, or at least as much as possible, across all the ports of the
trunk. The intent is to try and ensure that all links in the trunk are utilized.
Here is an example. Figure 20 shows two AT-8000 Series Switches, an AT8024 (Switch #1) and an AT-8024GB (Switch #2) interconnected with a
port trunk of three data links. The trunk on Switch #1 consists of Ports 13
to 15 and on Switch #2 of Ports 1 to 3. The 10Base and 100Base
workstations are directing traffic to a server connected to Switch #2. The
server is connected to Switch #2 with a fiber optic Gigabit Ethernet data
link provided by a 1000Base fiber optic GBIC module in the AT-8024GB
switch.
Workstation
C
Workstation
B
Workstation
D
Workstation
A
AT-8024
RS-232 TERMINAL PORT
10Base-T / 100Base-TX Fast Ethernet Switch
Switch #1
MODE
Link
COL
Mode
Link
100
Mode
ACT
FAULT
MASTER
FULL
PWR
AT-8026FC
RS-232 TERMINAL PORT
CLASS 1
LASER PRODUCT
DO NOT STARE
INTO BEAM
10Base-T / 100Base-TX Fast Ethernet Switch
25
MODE
Link
COL
Mode
Link
100
Mode
ACT
26
FAULT
LINK
LINK
FULL
TX
RX
MODE
TX
RX
MODE
MASTER
Switch #2
PWR
Figure 20 Load Distribution Method
80
Now assume that you configured the port trunk on Switch #1 for SA load
distribution. The switch might distribute the load as follow:
Table 1 Switch #1 Load Distribution
Source Workstation
Source MAC
Address
Trunk Port
A
00A0EE 2313A3
13
B
00A134 1A9032
14
C
00A301 9083B2
15
D
001B21 87C6D6
14
For example, when Workstation B sends a packet to the server, Switch #1
will use Port 14 of the trunk to transmit it to Switch #2.
An assignment of a source MAC address to a port trunk remains active as
long as the source node remains active. If the MAC address times out,
the assignment is dropped. Should the source node become active
again and need to transmit a packet over the trunk, a new assignment is
made, either to the same port or to a different port in the trunk.
It should be noted that packets sent back from the destination node to
the original source node may travel the same or a different data link in
the trunk.
As a general rule, the SA load distribution method is useful in situations
where the number of source nodes equals or is greater than the number
of data links in the trunk.
So when would the SA method be inappropriate? Let’s look back again
at the example in Figure 20. Let’s assume that you configured Switch #2
also for SA load distribution. The result would be that the switch would
use only one data link in the trunk to send packets back to Switch #1,
because there is only one source, a Gigabit Ethernet server, connected to
Switch #2. Since there is only one source, only one data link is used. So
obviously the SA method is not appropriate when there are fewer source
nodes than data links.
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AT-S39 User’s Guide
So now let’s look at the SA/DA method. A switch using the SA/DA
method creates a matrix of the source and destination MAC addresses
and then uses the matrix to determine which port in the trunk a frame is
to be transmitted. With this method, packets from a particular source
node might be sent over different data links in a trunk when sent to
different destination addresses.
So let’s take a look at how this might look in practice. Assume that you
configured Switch #2 in our example for SA/DA. The result might be
something similar to that shown in Table 2.
Table 2 Trunk Port Assignments in an SA/DA Matrix
Destinations MAC Addresses
Source MAC Address
Server
00B012 DA0231
Workstation
Workstation
Workstation
Workstation
A
B
C
D
00A0EE 2313A3 00A134 1A9032 00A301 9083B2 001B21 87C6D6
2
1
3
1
Even though there is only one source, all the data links in the trunk are
used. For instance, if the server needed to send a packet to Workstation
C, by referring to the matrix Switch #2 would use Port 3 of the trunk to
transmit the packet from that particular source MAC address to Switch
#1.
As you can see, the SA/DA method is useful when a port trunk needs to
send packets from one source node to many destination nodes,
something that the SA method is not suited for. Additionally, the SA/DA
method is also valid when sending from many source nodes to one
destination node, or from many sources to many destinations.
The table below shows a possible matrix for a port trunk of three data
links using the SA/DA method, handling traffic from four sources to four
destinations.
82
Table 3 Trunk Port Assignments in an SA/DA Matrix
Destinations Addresses
Source Addresses
00A0EE 2313A3 00A134 1A9032 00A301 9083B2 001B21 87C6D6
00B012 DA0231
1
2
3
1
001230 DA2943
2
3
1
2
0042AA D45A21
3
1
2
3
00456A C23521
1
2
3
1
The bottom line is that the SA/DA method is more flexible than the SA
method. A general rule to follow is if you are not sure which load
distribution to choose, you should probably go with SA/DA.
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AT-S39 User’s Guide
Creating a Port Trunk
This section contains the procedure for creating a port trunk on the
switch. Be sure to review the guidelines in Port Trunking Overview on
page 78 before performing the procedure.
Caution
Do not connect the cables to the trunk ports on the switches until
after you have configured the trunk with the management
software. Connecting the cables before configuring the software
will create a loop in your network topology. Data loops can result in
broadcast storms and poor network performance.
Note
Before creating a port trunk, examine the parameter settings of the
ports that will make up the trunk. Check to be sure that the settings,
such as speed and duplex mode, are the same for all the ports of the
trunk. You should also check to be sure that the ports are members
of the same VLAN.
To create a port trunk, perform the following procedure:
1. From the Main Menu, type 1 to select Port Menu.
2. From the Port Menu, type 3 to select Port Trunking.
The Port Trunking menu in Figure 21 is displayed.
Allied Telesyn Ethernet Switch AT-8024
Login Session: Manager
Port Trunking
1 - Trunk Ports ..... None
S - Save Configuration Changes
R - Return to Previous Menu
Enter your selection?
Figure 21 Port Trunking Menu
84
3. Type 1 to select Trunk Ports.
The following prompt is displayed.
Enter Trunk Port(s) ->
4. Enter the ports that will constitute the port trunk and press Return.
You can specify the ports individually (e.g., 1,2,3,4) or as a range
(e.g., 7-10).
Once you have specified the ports of the trunk, the following
menu selection appears in the window:
2 - Trunk Method ....... SA/DA trunking
You can use this selection to specify the load distribution method.
The default is SA/DA.
5. To change the load distribution method, type 2 to toggle the
selection through its possible settings of SA/DA and SA only trunking.
6. Type S to select Save Configuration Changes.
7. Configure the ports on the remote switch for port trunking.
8. Connect the cables to the ports of the trunk on the switch.
The port trunk is ready for network operation.
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AT-S39 User’s Guide
Deleting a Port Trunk
Caution
Disconnect the cables from the port trunk on the switch before
performing the following procedure. Deleting a port trunk without
first disconnecting the cables can create loops in your network
topology. Data loops can result in broadcast storms and poor
network performance.
To delete a port trunk from the switch, perform the following procedure:
1. From the Main Menu, type 1 to select Port Menu.
2. From the Port Menu, type 3 to select Port Trunking.
The Port Trunking menu in Figure 21 on page 84 is displayed.
3. Type D to select Delete trunk.
A confirmation prompt is displayed.
4. Type Y for yes to delete the port trunk or N for no to cancel this
procedure.
5. Type S to select Save Configuration Changes.
The port trunk is deleted from the switch.
86
Chapter 8
Port Mirroring
This chapter contains the procedures for creating and deleting a port
mirror. Sections in the chapter include:
❑ Port Mirroring Overview on page 88
❑ Creating a Port Mirror on page 89
❑ Deleting a Port Mirror on page 90
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AT-S39 User’s Guide
Port Mirroring Overview
The port mirroring feature allows you to unobtrusively monitor the
traffic being received and transmitted on one or more ports on a switch
by having the traffic copied to another switch port. You can connect a
network analyzer to the port where the traffic is being copied and
monitor the traffic on the other ports without impacting network
performance or speed.
Observe the following guidelines when creating a port mirror:
❑ You can mirror from one to 23 ports on a switch at a time.
However, the more ports you mirror, the less likely the mirroring
port will be able to handle all the traffic. For example, if you mirror
the traffic of six heavily active ports, the mirror port is likely to
drop packets, meaning that it will not provide an accurate mirror
of the traffic of the other six ports.
❑ The ports to be mirrored and the mirroring port must be located
on the same switch.
❑ The ports to be mirrored and the mirroring port must be
operating at the same speed. For example, you cannot use a
10/100 Mbps port to mirror traffic on a 1000 Mbps GBIC port.
88
Creating a Port Mirror
To create a port mirror, perform the following procedure:
1. From the Main Menu, type 1 to select Port Menu.
2. From the Port Menu, type 2 to select Port Mirroring.
The Port Mirroring menu in Figure 22 is displayed.
Allied Telesyn Ethernet Switch AT-8024
Login Session: Manager
Port Mirroring
1 - Mirror (Destination) Port ....... None
2 - Mirroring (Source) Port(s) ...... None
S - Save Configuration Changes
R - Return to Previous Menu
Enter your selection?
Figure 22 Port Trunking Menu
3. Type 1 to select Mirror (Destination) Port.
The following prompt is displayed.
Enter Mirror port (0=None) [0 to 24] ->
4. Enter the number of the port to function as the mirror port (that is, the
port to where the traffic will be copied). Press Return.
You can specify only one mirror port.
5. Type 2 to select Mirroring (Source) Port.
The following prompt is displayed.
Enter Mirroring Ports (0=None):
6. Enter the number of the port whose traffic is to be mirrored. To mirror
the traffic of more than one port, enter the ports individually (e.g.,
1,4,6) or as a range (e.g., 11-14). Press Return.
7. Type S to select Save Configuration Changes.
The port mirror is now functional.
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AT-S39 User’s Guide
Deleting a Port Mirror
To delete a port mirror, perform the following procedure:
1. From the Main Menu, type 1 to select Port Menu.
2. From the Port Menu, type 2 to select Port Mirroring.
The Port Mirroring menu in Figure 22 on page 89 is displayed.
3. Type 1 to select Mirror (Destination) Port.
The following prompt is displayed.
Enter mirror port (0=None) [0 to 24] ->
4. Enter 0 and press Return.
5. Type S to select Save Configuration Changes.
The port mirror on the switch is deleted. The port that was
functioning as the port mirror is now available for normal network
operations.
90
Chapter 9
STP and RSTP
This chapter provides background information on the Spanning Tree
Protocol (STP) and Rapid Spanning Tree Protocol (RSTP). The chapter
also contains procedures on how to adjust the STP and RSTP bridge and
port parameters. The sections in this chapter include:
❑ STP and RSTP Overview on page 92
❑ Enabling or Disabling STP or RSTP on page 100
❑ Configuring STP on page 101
❑ Configuring RSTP on page 105
Note
For detailed information on the Spanning Tree Protocol, refer to IEEE
Std 802.1d. For detailed information on the Rapid Spanning Tree
Protocol, refer to IEEE Std 802.1w.
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AT-S39 User’s Guide
STP and RSTP Overview
A significant danger to Ethernet network performance is the existence of
a data loop in a network topology. A data loop exists when two or more
nodes on a network can transmit data to each other over more than one
data link. The problem that data loops pose is that data packets can
become caught in repeating cycles, referred to as broadcast storms, that
needlessly consume network bandwidth and significantly reduce
network performance.
STP and RSTP prevent data loops from forming by ensuring that only
one path exists between the end nodes in your network. Where multiple
paths exist, these protocols place the extra paths in a standby or
blocking mode, leaving only one main active path.
STP and RSTP can also activate a redundant path if the main path goes
down. So not only do these protocols guard against multiple links
between segments and the risk of broadcast storms, but they can also
maintain network connectivity by activating a backup redundant path in
case a main link fails.
Where the two protocols differ is in the time each takes to complete the
process commonly referred to as convergence. When a change is made
to the network topology, such as the addition of a new bridge, a
spanning tree protocol must determine whether there are redundant
paths that must be blocked to prevent data loops, or activated to
maintain intercommunications between the various network segments.
This process is referred to as convergence.
With STP, convergence can take minutes to complete in a large network.
This can result in lost data packets and the loss of intercommunication
between various parts of the network during the convergence process.
RSTP is much faster. Rather than taking minutes, RSTP can complete a
convergence in seconds, and so greatly diminish the possible impact the
process can have on your network.
Note
RSTP is activated by default on the switch.
The STP implementation on the AT-8000 Series Switch complies with the
IEEE 802.1d standard. The RSTP implementation complies with the IEEE
802.1w standard. The following subsections provide a basic overview on
how STP and RSTP operate and define the different parameters that you
can adjust.
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Section II: Local and Telnet Management
Bridge Priority
and the Root
Bridge
The first task that bridges perform when a spanning tree protocol is
activated on a network is the selection of a root bridge. A root bridge
distributes network topology information to the other network bridges
and is used by the other bridges to determine if there are redundant
paths in the network.
A root bridge is selected by a combination of a bridge priority number,
also referred to as the bridge identifier, and sometimes the bridge’s MAC
address. The bridge with the lowest bridge priority number in the
network is selected as the root bridge. If two or more bridges have the
same bridge priority number, of those bridges the one with the lowest
MAC address is designated as the root bridge.
The bridge priority number can be changed on an AT-8000 Series switch.
You can designate which switch on your network you want as the root
bridge by giving it the lowest bridge priority number. You might also
consider which bridge should function as the backup root bridge in the
event you need to take the primary root bridge off-line, and assign that
bridge the second lowest bridge identifier number.
With STP, the bridge priority has a range of from 0 to 65535. You can
select any value within that range.
With RSTP, the range is slightly less, from 0 to 61440. Furthermore, you
can only select a value that is a multiple of 4096. To make this easier for
you, the management software divides the range into increments. You
specify the increment that represents the desired bridge priority value.
The range is divided into sixteen increments, as shown in the following
table.
Table 4 RSTP Bridge Priority Value Increments
Increment
Bridge
Priority
Increment
Bridge
Priority
0
0
8
32768
1
4096
9
36864
2
8192
10
40960
3
12288
11
45056
4
16384
12
49152
5
20480
13
53248
6
24576
14
57344
7
28672
15
61440
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AT-S39 User’s Guide
Path Costs and Port Costs
Once the Root Bridge has been selected, the bridges must determine if
the network contains redundant paths and, if one is found, they must
select a preferred path while placing the redundant paths in a backup or
blocking state.
Where there is only one path between a bridge and the root bridge, the
bridge is referred to as the designated bridge and the port through which
the bridge is communicating with the root bridge is referred to as the
root port.
If redundant paths exist, the bridges that are a part of the paths must
determine which path will be the primary, active path, and which path(s)
will be placed in the standby, blocking mode. This is accomplished by an
determination of path costs. The path offering the lowest cost to the root
bridge becomes the primary path and all other redundant paths are
placed into blocking state.
Path cost is determined through an evaluation of port costs. Every port
on a bridge participating in STP has a cost associated with it. The cost of
a port on a bridge is typically based on port speed. The faster the port,
the lower the port cost. The exception to this is the ports on the root
bridge, where all ports have a port cost of 0.
Path cost is simply the cumulation of the port costs between a bridge
and the root bridge.
The port costs of the ports on an AT-8000 Series switch are adjustable
through the management software, but the range is different
depending on whether you are using STP or RSTP.
For STP, the range is 1 to 65535. You can assign a port a port cost of any
value within the range. Below are the default values.
Table 5 STP Default Port Costs
Port Speed
Port Cost
10 Mbps
10
100 Mbps
10
1000 Mbps
4
In RSTP, the range is much greater: 0 to 20 000 000. This greater range
allows you to have more control over path costs.
94
Section II: Local and Telnet Management
RSTP port cost also features an Auto-Detect feature. This features allows
RSTP to automatically set the port cost according to the speed of the
port, assigning a lower value for higher speeds. Auto-Detect is the
default setting on the ports when the switch is operating in RSTP. Table
6 lists the ports cost with Auto-Detect.
Table 6 RSTP Auto-Detect Port Costs
Port Speed
Port Cost
10 Mbps
2 000 000
100 Mbps
200 000
1000 Mbps
20 000
You can override Auto-Detect and set the port cost manually.
Port Priority
If two paths have the same port cost, the bridges must select a preferred
path. In some instances this can involve the use of the port priority
parameter. This parameter can be used as a tie-breaker when two paths
have the same cost.
In STP, the range for port priority is 0 to 255.
In RSTP, the range is 0 to 240. As with RSTP Bridge Priority, this range is
broken into increments, in this case multiples of 16. When you specify a
port priority for a port, you enter the increment of the desired value.
Table 7 RSTP Port Priority Value Increments
Increment
Bridge
Priority
Increment
Bridge
Priority
0
0
8
128
1
16
9
144
2
32
10
160
3
48
11
176
4
64
12
192
5
80
13
208
6
96
14
224
7
112
15
240
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AT-S39 User’s Guide
Forwarding Delay and Topology Changes
If there is a change in the network topology due to a failure, removal, or
addition of any active components, the active topology also changes.
This may trigger a change in the state of some blocked ports. However, a
change in a port state is not activated immediately.
It might take time for the root bridge to notify all bridges that a topology
change has occurred, especially if it is a large network. If a topology
change is made before all bridges have been notified, a temporary data
loop could occur, and that could adversely impact network
performance.
To forestall the formation of temporarily data loops during topology
changes, a port designated to change from blocking to forwarding
passes through two additional states, listening and learning, before it
begins to forward frames. The amount of time a port spends in these
states is set by the forwarding delay value. This value states the amount
of time that a port spends in the listening and learning states prior to
changing to the forwarding state.
The forwarding delay value is adjustable on the AT-8000 Series switch
through the management software. The appropriate value for this
parameter will depend on a number of variables, with the size of your
network being a primary factor. For large networks, you should specify a
value large enough to allow the root bridge sufficient time to propagate
a topology change throughout the entire network. For small networks,
you should not specify a value so large that a topology change is
unnecessarily delayed, which could result in the delay or loss of some
data packets.
Note
The forwarding delay parameter applies only to STP.
Hello Time and Bridge Packet Data Units (BPDU)
The bridges that are part of a spanning tree domain communicate with
each other using a bridge broadcast frame that contains a special
section devoted to carrying STP or RSTP information. This portion of the
frame is referred to as the Bridge Packet Data Unit (BPDU). When a
bridge is brought on-line, it will issue a BPDU in order to determine
whether a root bridge has already been selected on the network. and if
not, whether it has the lowest bridge priority number of all the bridges
and should therefore become the root bridge.
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Section II: Local and Telnet Management
The root bridge will periodically transmit a BPDU to determine whether
there have been any changes to the network topology and to inform
other bridges of topology changes. The frequency with which the root
bridge sends out a BPDU is called the Hello Time. This is a value that you
can set on the AT-8000 Series switch. The interval is measured in seconds
and the default is 2 seconds. Consequently, if an AT-8000 Series switch is
selected as the Root Bridge of a spanning tree domain, it will transmit a
BPDU every two seconds.
Point-to-Point Ports and Edge Ports
Note
This section applies only to RSTP.
Part of the task of configuring RSTP is defining the port types on the
bridge. This relates to the device(s) connected to the port. With port type
defined, RSTP can reconfigure a network much quicker than STP when a
change in network topology is detected.
There are two possible selections:
❑ Point-to-point
❑ Edge port
If a bridge port is operating in full-duplex mode, than the port is
functioning as point-to-point. Figure 23 illustrates two AT-8024 switches
that have been interconnected with one data link. With the link
operating in full-duplex, the ports are said to be point-to-point ports.
AT-8024
RS-232 TERMINAL PORT
10Base-T / 100Base-TX Fast Ethernet Switch
MODE
Link
COL
Mode
Link
100
Mode
ACT
FAULT
MASTER
FULL
PWR
Point-to-Point Ports
(Full-duplex Mode)
AT-8024
RS-232 TERMINAL PORT
10Base-T / 100Base-TX Fast Ethernet Switch
MODE
Link
COL
Mode
Link
100
Mode
ACT
FULL
FAULT
MASTER
PWR
Figure 23 Point-to-Point Ports
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AT-S39 User’s Guide
If a port is operating in half-duplex mode and is not connected to any
further bridges participating in STP or RSTP, then the port is an edge
port. Figure 24 illustrates an edge port on an AT-8024 switch. The port is
connected to an Ethernet hub, which in turn is connected to a series of
Ethernet workstations. This is an edge port because it is connected to a
device operating at half-duplex mode and there are no participating STP
or RSTP devices connected to it.
AT-8024
RS-232 TERMINAL PORT
10Base-T / 100Base-TX Fast Ethernet Switch
MODE
Link
COL
Mode
Link
100
Mode
ACT
FAULT
MASTER
FULL
PWR
Edge Port
8
7
6
5
4
3
2
1
Figure 24 Edge Port
A port can be both point-to-point and edge at the same time. It would
operate in full-duplex and have no STP or RSTP devices connected to it.
Figure 25 illustrates a port functioning both as point-to-point and edge.
AT-8024
RS-232 TERMINAL PORT
10Base-T / 100Base-TX Fast Ethernet Switch
MODE
Link
COL
Mode
Link
100
Mode
ACT
FULL
FAULT
MASTER
PWR
Point-to-Point and Edge Port
Workstation
(Full-duplex Mode)
Figure 25 Point-to-Point and Edge Point
Determining whether a bridge port is point-to-point, edge, or both, can
be a bit confusing. For that reason it might be best not to change the
default values for this RSTP feature unless in have a good grasp of the
concept. In most cases, the default values will work fine.
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Section II: Local and Telnet Management
Mixed STP and
RSTP Networks
RSTP IEEE 802.1w is fully compliant with STP IEEE 802.1d. Your network
can consist of bridges running both protocols. STP and RSTP in the same
network should be able to operate together to create a single spanning
tree domain.
There is no reason not to activate RSTP on an AT-8000 Series switch even
when all other switches are running STP. The AT-8000 Series switch can
combine its RSTP with the STP of the other switches. An AT-8000 Series
switch will monitor the traffic on each port for BPDU packets. Ports that
receive RSTP BPDU packets will operate in RSTP while ports receiving
STP BPDU packets will operate in STP.
Spanning Tree
and VLANs
The spanning tree implementation on an AT-8000 Series switch is a
single-instance spanning tree. The switch supports just one spanning
tree. You cannot define multiple spanning trees.
The single spanning tree encompasses all ports on the switch. If the
ports are divided into different VLANs, the spanning tree crosses the
VLAN boundaries. This point can pose a problem in networks containing
multiple VLANs that span different switches and are connected with
untagged ports. What can happen is that STP will block a data link
because it detects a data loop. This can cause fragmentation of your
VLANs.
This issue is illustrated in Figure 26. Two VLANs, Sales and Production,
span two AT-8024GB switches. Two links consisting of untagged ports
interconnect the separate parts of each VLAN. If STP is activated on the
switches, one of the links would be disabled. This problem can be
avoided by not activating spanning tree or by connecting VLANs using
tagged instead of untagged ports. (For information on tagged and
untagged ports, refer to Chapter 10, Virtual LANs on page 110.
Sales
VLAN
Production
VLAN
AT-8024
RS-232 TERMINAL PORT
10Base-T / 100Base-TX Fast Ethernet Switch
MODE
Link
COL
Mode
Link
100
Mode
ACT
FAULT
MASTER
FULL
PWR
AT-8024
RS-232 TERMINAL PORT
10Base-T / 100Base-TX Fast Ethernet Switch
MODE
Link
COL
Mode
Link
100
Mode
ACT
FULL
FAULT
MASTER
PWR
Sales
VLAN
Production
VLAN
Figure 26 VLAN Fragmentation
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AT-S39 User’s Guide
Enabling or Disabling STP or RSTP
To select and activate a spanning tree protocol, or to disable spanning
tree, perform the following procedure:
1. From the Main Menu, type 3 to select Spanning Tree Menu.
The Spanning Tree Menu in Figure 27 is displayed.
Allied Telesyn Ethernet Switch AT-8024
Login Session: Manager
Spanning Tree Menu
1
2
3
4
-
Spanning Tree Status ...... Enabled
Active Protocol Version ... RSTP
STP Configuration
RSTP Configuration
S - Save Configuration Changes
R - Return to Previous Menu
Enter your selection?
Figure 27 Spanning Tree Menu
2. To enable or disable spanning tree, type 1 to select Spanning Tree
Status.
3. Type E to enable spanning tree or D to disable it. The default is
enabled.
4. To change the version of spanning tree protocol running on the
switch, type 2 to select Active Protocol Version.
Note
Changing the spanning tree version will reboot the switch.
The following prompt is displayed:
The switch will be rebooted for changing the
protocol version.
Do you want to continue? [Yes/No]
5. Type Y for yes to change the current version of spanning tree and
reboot the switch, or N to cancel this procedure.
6. If you deactivate spanning tree, type S to save your changes and
return to the Main Menu. If you activated spanning tree and you
selected STP, go to Configuring STP on page 101 for further
instructions. If you selected RSTP, go to Configuring RSTP on page
105
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Section II: Local and Telnet Management
Configuring STP
This section contains the following procedures:
❑ Configuring a Bridge’s STP Settings on page 101
❑ Configuring a Port’s STP Settings on page 103
Configuring a
Bridge’s STP
Settings
This section contains the procedure for configuring a bridge’s STP
settings.
Caution
The default STP parameters are adequate for most networks.
Changing them without prior experience and an understanding of
how STP works might have a negative effect on your network. You
should consult the IEEE 802.1d standard before changing any of the
STP parameters.
1. From the Spanning Tree Menu, type 3 to select STP Configuration.
The STP Menu in Figure 28 is displayed.
Allied Telesyn AT-8024 Ethernet Switch
Login Session: Manager
STP Menu
The current protocol version is STP.
1
2
3
4
-
Bridge
Bridge
Bridge
Bridge
Priority .....
Hello Time ...
Forwarding ...
Max Age ......
65535
2
15
20
6 - Config STP Port Settings
7 - Display STP Port Settings
8 - Reset STP to Defaults
R - Return to Previous Menu
Enter your selection?
Figure 28 STP Menu
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AT-S39 User’s Guide
2. Adjust the bridge STP settings as needed. The parameters are
described below.
1 - Bridge Priority
The priority number for the bridge. This number is used in
determining the root bridge for STP. The bridge with the lowest
priority number is selected as the root bridge. If two or more
bridges have the same priority value, the bridge with the
numerically lowest MAC address becomes the root bridge. When
a root bridge goes off-line, the bridge with the next priority
number automatically takes over as the root bridge. This
parameter can be from 0 (zero) to 65,535, with 0 being the highest
priority.
2 - Bridge Hello Time
The time interval between generating and sending configuration
messages by the bridge. This parameter can be from 1 to 10
seconds. The default is 2 seconds.
3 - Bridge Forwarding
The waiting period before a bridge changes to a new state, for
example, becomes the new root bridge after the topology
changes. If the bridge transitions too soon, not all links may have
yet adapted to the change, resulting in network loops. The default
is 15 seconds.
4 - Bridge Max Age
The length of time after which stored bridge protocol data units
(BPDUs) are deleted by the bridge. All bridges in a bridged LAN
use this aging time to test the age of stored configuration
messages called bridge protocol data units (BPDUs). For example,
if you use the default 20, all bridges delete current configuration
messages after 20 seconds. This parameter can be from 6 to 40
seconds. The default is 20 seconds.
In selecting a value for maximum age, the following must be
observed:
MaxAge must be less then (2 x (HelloTime + 1)).
MaxAge must be less then (2 x (ForwardingDelay - 1)).
Note
The aging time for BPDUs is different from the aging time used by
the MAC address table.
3. After you have made the desired changes, type S to select Save
Configuration Changes.
4. To change STP port settings, go to the next procedure.
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Section II: Local and Telnet Management
Configuring a
Port’s STP
Settings
To adjust a port’s STP parameters, perform the following procedure:
1. From the Spanning Tree Menu, type 3 to select STP Configuration.
2. From the STP Configuration menu, type 6 to select Config STP port
settings.
The following prompt is displayed:
Starting Port to Configure [1 to 24] ->
3. Enter the number of the port you want to configure. To configure a
range of ports, enter the first port of the range.
The following prompt is displayed:
Ending Port to Configure [1 to 24] ->
4. To configure just one port, enter the same port number here as you
entered in the previous step. To configure a range of ports, enter the
last port of the range.
The STP Port Configuration window in Figure 29 is displayed.
Allied Telesyn AT-8024 Ethernet Switch
Login Session: Manager
Config STP Port Settings
Configuring Ports 4 to 4
1
2
3
4
5
6
-
Participating ......
Fast Mode ..........
Path Cost ..........
Port Priority ......
Port State .........
Root Bridge ........
Yes
No
10
128
Forwarding
00:A8:22:34:C1:2D
R - Return to Previous Menu
Enter your selection?
Figure 29 Config STP Port Settings Window
5. Adjust the settings as desired. The parameters are described below.
1 - Participating
This selection activates and deactivates STP on the port. If set to
Yes, which is the default, the port will participate in the spanning
tree. If you select No, the port will continue to receive and transmit
Ethernet frames, but it will not participate in spanning tree.
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AT-S39 User’s Guide
Note
A port on which STP is disabled is immediately placed in the
forwarding state. It should be noted that a port where STP has been
disabled cannot be placed in the blocking state by STP should there
be a loop in the network topology. Consequently, it is incumbent on
the network administrator to insure that no loop will develop
should STP be disabled on a port.
2 - Fast Mode
The port will skip the Listening and Learning stages of STP. This
setting is appropriate for ports connected to edge nodes that are
not running STP.
3 - Path Cost
The spanning tree algorithm uses the cost parameter to decide
which port provides the lowest cost path to the root bridge for
that LAN. The default value for this parameter for all ports and
speeds is 100. The range is 1 to 65535.
4 - Priority
This parameter is used as a tie breaker when two or more ports are
determined to have equal costs to the root bridge. The default
value for priority is 128. The range is 0-255.
5 - Port State
The current STP status of the port. The status can be Forwarding,
Listening, Learning, or Blocking. This value cannot be changed.
6 - Root Bridge
The MAC address of the bridge functioning as the root bridge in
the spanning tree domain. This value is for display purposes only
and cannot be changed.
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Section II: Local and Telnet Management
Configuring RSTP
This section contains the following procedures:
❑ Configuring a Bridge’s RSTP Settings on page 105
❑ Configuring a Port’s RSTP Settings on page 107
Configuring a
Bridge’s RSTP
Settings
This section contains the procedure for configuring a bridge’s RSTP
settings.
Caution
The default RSTP parameters are adequate for most networks.
Changing them without prior experience and an understanding of
how RSTP works might have a negative effect on your network. You
should consult the IEEE 802.1w standard before changing any of the
RSTP parameters.
1. From the Spanning Tree Menu, type 4 to select RSTP Configuration.
The RSTP Menu in Figure 30 is displayed.
Allied Telesyn Ethernet Switch AT-8024
Login Session: Manager
RSTP Menu
The current protocol version is RSTP.
1
2
3
4
5
6
7
8
-
Force Version ....... RSTP
Bridge Priority ..... 32768
Bridge Hello Time ... 2
Bridge Forwarding ... 15
Bridge Max Age ...... 20
Bridge Identifier ... 00:30:84:52:11:11
Root Bridge ......... 00:30:84:52:11:11
Root Priority ......... 32768
P - RSTP Port Parameters
R - Return to Previous Menu
Enter your selection?
Figure 30 RSTP Menu
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AT-S39 User’s Guide
2. Adjust the parameters as needed. The parameters are defined below.
1 - Force Version
This selection determines whether the bridge will operate with
RSTP or in an STP-compatible mode. If you select RSPT, the bridge
will operate all ports in RSTP, except for those ports that receive
STP BPDU packets. If you select Force STP Compatible, the bridge
will operate in RSTP, using the RSTP parameter settings, but it will
send only STP BPDU packets out the ports.
2 - Bridge Priority
The priority number for the bridge. This number is used in
determining the root bridge for STP. The bridge with the lowest
priority number is selected as the root bridge. If two or more
bridges have the same priority value, the bridge with the
numerically lowest MAC address becomes the root bridge. When
a root bridge goes off-line, the bridge with the next priority
number automatically takes over as the root bridge. This
parameter can be from 0 (zero) to 61,440 in increments of 4096,
with 0 being the highest priority. For a list of the increments, refer
to Table 4, RSTP Bridge Priority Value Increments on page 93
3 - Bridge Hello Time
The time interval between generating and sending configuration
messages by the bridge. This parameter can be from 1 to 10
seconds. The default is 2 seconds.
4 - Bridge Forwarding
The waiting period before a bridge changes to a new state, for
example, becomes the new root bridge after the topology
changes. If the bridge transitions too soon, not all links may have
yet adapted to the change, possibly resulting in a network loop.
The range is 4 to 30 seconds. The default is 15 seconds. This
setting applies only to ports running in the STP-compatible mode.
5 - Bridge Max Age
The length of time after which stored bridge protocol data units
(BPDUs) are deleted by the bridge. All bridges in a bridged LAN
use this aging time to test the age of stored configuration
messages called bridge protocol data units (BPDUs). For example,
if you use the default 20, all bridges delete current configuration
messages after 20 seconds. This parameter can be from 6 to 40
seconds. The default is 20 seconds.
In selecting a value for maximum age, the following must be
observed:
MaxAge must be less then (2 x (HelloTime + 1)).
MaxAge must be less then (2 x (ForwardingDelay - 1))
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Section II: Local and Telnet Management
6 - Bridge Identifier
The MAC address of the bridge. The bridge identifier is used as a
tie breaker in the selection of the root bridge when two or more
bridges have the same bridge priority value. This value cannot be
changed.
7 - Root Bridge
The MAC address of the bridge functioning as the root bridge in
the spanning tree domain. This value is for display purposes only
and cannot be changed.
8 - Root Priority
The priority number of the root bridge.
3. After adjusting the parameters, type S to select Save Configuration
Changes.
Configuring a
Port’s RSTP
Settings
To adjust a port’s RSTP parameters, perform the following procedure:
1. From the Spanning Tree Menu, type 4 to select RSTP Configuration.
2. From the RSTP Configuration menu, type P to select RSTP Port
Parameters.
The following menu is displayed:
Allied Telesyn Ethernet Switch AT-8024
Login Session: Manager
RSTP Port Parameters
The current protocol version is RSTP.
1 - Configure RSTP Port Settings
2 - Display RSTP Port Configuration
3 - Display RSTP Port State
R - Return to Previous Menu
Enter your selection?
Figure 31 RSTP Port Parameters
3. Type 1 to select Configure RSTP Port Settings.
The following prompt is displayed:
Starting Port to Configure [1 to 24] ->
4. Enter the number of the port you want to configure. To configure a
range of ports, enter the first port of the range.
The following prompt is displayed:
Ending Port to Configure [1 to 24] ->
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AT-S39 User’s Guide
5. To configure just one port, enter the same port number here as you
entered in the previous step. To configure a range of ports, enter the
last port of the range.
The RSTP Port Configuration menu in Figure 32 is displayed.
Allied Telesyn Ethernet Switch AT-8024
Login Session: Manager
Configure RSTP Port Settings
Configuring Ports 4 to 4
1
2
3
4
-
Port Priority ......
Path Cost ..........
Point-to-Point .....
Edge Port ..........
128
Auto Update
Auto Detect
Yes
M - MCHECK (Check Migration to RSTP on Selected Ports)
S - Save Configuration Changes
R - Return to Previous Menu
Enter your selection?
Figure 32 Configure RSTP Port Settings Menu
6. Adjust the settings as needed. The parameters are explained below.
1 - Port Priority
This parameter is used as a tie breaker when two or more ports are
determined to have equal costs to the root bridge. The range is 0
to 240 in increments of 16. The default value is 8 (priority value
128). For a list of the increments, refer to Table 7, RSTP Port
Priority Value Increments on page 95.
2 - Port Cost
The spanning tree algorithm uses the cost parameter to decide
which port provides the lowest cost path to the root bridge for
that LAN. The range is 0 to 20 000 000. The default setting is Autodetect, which sets port cost depending on the speed of the port.
Default values are 2 000 000 for 10 Mbps ports, 200 000 for a 100
Mbps ports, and 20 000 for one gigabit ports.
3 - Point-to-Point
This parameter defines whether the port is functioning as a pointto-point port. For an explanation of this parameter, refer to Pointto-Point Ports and Edge Ports on page 97.
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Section II: Local and Telnet Management
4 - Edge Port
This parameter defines whether the port is functioning as an edge
port. For an explanation of this parameter, refer to Point-to-Point
Ports and Edge Ports on page 97.
M - MCHECK
This option instructs the bridge to send out RSTP BPDU packets
for several seconds from the selected port. The purpose is to
determine if there are any RSTP or STP bridges connected to the
port. If the port receives STP BPDU packets in response, the port
changes to STP compatible mode. If the port receives RSTP BPDU
packets, it operates in RSTP.
7. After making your changes, type S to select Save Configuration
Changes.
109
Chapter 10
Virtual LANs
This chapter contains basic information about virtual LANs (VLANs). It
also contains the procedures for creating, modifying, and deleting
VLANs from a local or Telnet management session. This chapter also
describes the Basic VLAN mode and how you can change a switch’s
VLAN operating mode.
This chapter contains the following sections:
❑ VLAN Overview on page 111
❑ Port-based VLAN Overview on page 113
❑ Tagged VLAN Overview on page 120
❑ Basic VLAN Mode Overview on page 125
❑ Creating a Port-based or Tagged VLAN on page 126
❑ Example of Creating a Port-based VLAN on page 130
❑ Modifying a VLAN on page 132
❑ Displaying VLAN Information on page 135
❑ Deleting a VLAN on page 136
❑ Deleting All VLANs on page 138
❑ Changing a PVID Value on page 139
❑ Setting a Switch’s VLAN Mode on page 142
❑ Enabling or Disabling All VLANs on page 143
❑ Enabling or Disabling Ingress Filtering on page 145
❑ Specifying a Management VLAN on page 147
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Section II: Local and Telnet Management
VLAN Overview
A VLAN is a group of ports on an Ethernet switch that form a logical
Ethernet segment. The ports of a VLAN form an independent broadcast
domain where the traffic generated by the nodes of a VLAN remains
within the VLAN.
With VLANs, you can segment your network through the switch’s
management software and so be able to group nodes with related
functions into their own separate, logical LAN segments. These VLAN
groupings can be based on similar data needs or security requirements.
For example, you could create separate VLANs for the different
departments in your company, such as one for Sales and another for
Accounting.
VLANs offer several important benefits:
❑ Improved network performance
Network performance often suffers as networks grow in size and
as data traffic increases. The more nodes on each LAN segment
vying for bandwidth, the greater the likelihood overall network
performance will decrease.
VLANs improve network perform because VLAN data traffic stays
within the VLAN. The nodes of a VLAN receive traffic only from
nodes of the same VLAN. This reduces the need for nodes to
handle traffic not destined for them. It also frees up bandwidth
within all the logical workgroups.
Additionally, since each VLAN constitutes a separate broadcast
domain, broadcast traffic remains within the VLAN. This too can
improve overall network performance.
❑ Increased security
Since data traffic generated by a node in a VLAN is restricted only
to the other nodes of the same VLAN, VLANs can be used to
control the flow of data in your network and prevent data from
flowing to unauthorized end nodes.
❑ Simplified network management
VLANs can also simplify network management. Before the advent
of VLANs, physical changes to the network often had to been
made at the switches in the wiring closets. For example, if an
employee changed departments, changing the employee’s LAN
segment assignment might require a change to the wiring at the
switches.
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AT-S39 User’s Guide
But with VLANS, you can change the LAN segment assignment of
an end node connected to the switch through the switch’s AT-S39
management software. VLAN memberships can be changed any
time through the management software without moving the
workstations physically, or having to change group memberships
by moving cables from one switch port to another.
Additionally, a virtual LAN can span more than one switch. This
means that the end nodes of a VLAN do not need to be connected
to the same switch and so are not restricted to being in the same
physical location.
The AT-8000 Series switch supports the following types of VLANs:
❑ Port-based VLANs
❑ Tagged VLANs
These VLANs are described in the following sections.
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Section II: Local and Telnet Management
Port-based VLAN Overview
As explained in the VLAN Overview section earlier in this chapter, a
VLAN consists of a group of ports on one or more Ethernet switches that
form an independent broadcast domain. Traffic generated by the end
nodes of a VLAN remains within the VLAN and does not cross over to the
end nodes of other VLANs unless there is an interconnection device,
such as a router or Layer 3 switch.
A port-based VLAN is a group of ports on a Fast Ethernet Switch that
form a logical Ethernet segment. Each port of a port-based VLAN can
belong to only one VLAN at a time.
A port-based VLAN can have as many or as few ports as needed. The
VLAN can consist of all the ports on an Ethernet switch, or just a few
ports. A port-based VLAN also can span switches and consist of ports
from multiple Ethernet switches.
Note
The AT-8000 Series switch is pre-configured with one port-based
VLAN. All ports on the switch are members of this VLAN, called the
Default VLAN.
The parts that make up a port-based VLAN are:
❑ VLAN name
❑ VLAN Identifier
❑ Untagged ports
❑ Port VLAN Identifier
VLAN Name
To create a port-based VLAN, you must give it a name. The name should
reflect the function of the network devices that are be members of the
VLAN. Examples include Sales, Production, and Engineering.
VLAN Identifier
Each VLAN in a network must have a unique number assigned to it. This
number is called the VLAN identifier (VID). This number uniquely
identifies a VLAN in the switch and the network.
If a VLAN consists only of ports located on one physical switch in your
network, you would assign it a VID unique from all other VLANs in your
network.
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AT-S39 User’s Guide
If a VLAN spans multiple switches, then the VID for the VLAN on the
different switches must be the same. In this manner, the switches are
able to recognize and forward frames belonging to the same VLAN even
though the VLAN spans multiple switches.
For example, if you had a port-based VLAN titled Marketing that
spanned three AT-8024 switches, you would assign the Marketing VLAN
on each switch the same VID.
You can assign this number manually or allow the management
software to do it automatically. If you allow the management software to
do it automatically, it will simply select the next available VID. This is
acceptable when you are creating a new, unique VLAN.
If you are creating a VLAN on a switch that will be part of a larger VLAN
that spans several switch, then you will need to assign the number
yourself so that the VLAN has the same VID on all switches.
Untagged Ports
Naturally, you need to specify which ports on the switch are to be
members of a port-based VLAN. Ports in a port-based VLAN are referred
to as untagged ports and the frames received on the ports as untagged
frames. The names derive from the fact that the frames received on a
port will not contain any information that indicates VLAN membership,
and that VLAN membership will be determined solely by the port’s PVID.
(There is another type of VLAN where VLAN membership is determined
by information within the frames themselves, rather than by a port’s
PVID. This type of VLAN is explained in Tagged VLAN Overview on page
120.)
A port on a switch can be an untagged member of only one port-based
VLAN at a time. An untagged port cannot be assigned to two port-based
VLANs simultaneously.
Port VLAN Identifier
Each port in a port-based VLAN must have a port VLAN identifier (PVID).
The switch associates a frame to a port-based VLAN by the PVID
assigned to the port on which the frame is received, and forwards the
frame only to those ports with the same PVID. Consequently, all ports of
a port-based VLAN must have the same PVID. Additionally, the PVID of
the ports in a VLAN must match the VLAN’s VID.
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Section II: Local and Telnet Management
For example, assume that you were creating a port-based VLAN on a
switch and you had assigned the VLAN the VID 5. Consequently, the
PVID for each port in the VLAN would need to be assigned the value 5.
Some switches and switch management programs require that you
assign the PVID value for each port manually. However, the AT-S39
management software performs this task automatically. The software
automatically assigns a PVID to a port, making it identical to the VID of
the VLAN to which the port is a member.
General Rules
to Creating a
Port-based
VLAN
Below is a summary of the general rules to observe when creating a portbased VLAN.
❑ Each port-based VLAN must be assigned a unique VID. If a
particular VLAN spans multiples switches, each part of the VLAN
on the different switches must be assigned the same VID.
❑ A port can be an untagged member of only one port-based VLAN
at a time.
❑ Each port must be assigned a PVID. This value must be the same
for all ports in a port-based VLAN and it must match the VLAN’s
VID. This value is assigned automatically by the AT-S39
management software.
❑ A port-based VLAN that spans multiple switches requires a port
on each switch where the VLAN is located to function as an
interconnection between the switches where the various parts of
the VLAN reside.
❑ If there are end nodes in different VLANs that need to
communicate with each other, a router or Layer 3 switch is
required to interconnect the VLANs.
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AT-S39 User’s Guide
Drawbacks to
Port-based
VLANs
There are several drawbacks to port-based VLANs:
❑ It is not easy to share network resources, such as servers and
printers, across multiple VLANs. A router or Layer 3 switch must be
added to the network to provide a means for interconnecting the
port-based VLANs.
❑ The introduction of a router into your network could create
security issues from unauthorized access to your network.
❑ A VLAN that spans several switches will require a port on each
switch for the interconnection of the various parts of the VLAN.
For example, a VLAN that spans three switches would require one
port on each switch to interconnect the various sections of the
VLAN. In network configurations where there are many individual
VLANs that span switches, many ports can end up being used
ineffectively just to interconnect the various VLANs.
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Section II: Local and Telnet Management
Port-based
Example 1
Figure 33 illustrates an example of one AT-8024 Fast Ethernet Switch
with three port-based VLANs. (For purposes of the following examples,
the Default VLAN is not shown.)
Engineering VLAN
(VID 3)
Sales VLAN
(VID 2)
Production VLAN
(VID 4)
AT-8024 Ethernet Switch
AT-8024
RS-232 TERMINAL PORT
10Base-T / 100Base-TX Fast Ethernet Switch
MODE
Link
COL
Mode
Link
100
Mode
ACT
FAULT
MASTER
FULL
PWR
Port 4
Port 12
Port 22
WAN
Router
Figure 33 Port-based VLAN - Example 1
The table below lists the port assignments for the Sales, Engineering,
and Production VLANs on the switch.
AT-8024 Switch (top)
Sales VLAN
(VID 2)
Engineering VLAN
(VID 3)
Production VLAN
(VID 4)
Ports 1 - 4 (PVID 2)
Ports 9, 11 - 13 (PVID 3)
Ports 21 - 24 (PVID 4)
Each VLAN has been assigned a unique VID. You assign this number
when you create a VLAN.
The ports have been assigned PVID values. A port’s PVID is assigned
automatically by the management software when you create the VLAN.
A PVID is the same as the VID to which the port is an untagged member.
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AT-S39 User’s Guide
In the example, each VLAN has one port connected to the router. The
router interconnects the various VLANs and functions as a gateway to
the WAN.
Port-based
Example 2
Figure 34 illustrates more port-based VLANs. In this example, two VLANs
span more than one Ethernet switch.
Engineering VLAN
(VID 3)
Production VLAN
(VID 4)
Sales VLAN
(VID 2)
AT-8024 Ethernet Switch
AT-8024
RS-232 TERMINAL PORT
10Base-T / 100Base-TX Fast Ethernet Switch
MODE
Link
COL
Mode
Link
100
Mode
ACT
FAULT
MASTER
FULL
PWR
WAN
AT-8024 Ethernet Switch
AT-8024
RS-232 TERMINAL PORT
10Base-T / 100Base-TX Fast Ethernet Switch
MODE
Link
COL
Mode
Link
100
Mode
ACT
FULL
FAULT
MASTER
PWR
Sales VLAN
(VID 2)
Engineering VLAN
(VID 3)
Figure 34 Port-based VLAN - Example 2
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The table below lists the port assignments for the Sales, Engineering,
and Production VLANs on the switches:
Sales VLAN
(VID 2)
Engineering VLAN
(VID 3)
Production VLAN
(VID 4)
AT-8024 Switch (top)
Ports 1 - 6, 18 (PVID 2)
Ports 9 - 11, 14, 20
(PVID 3)
Ports 21 - 24 (PVID 4)
AT-8024 Switch (bottom)
Ports 1 - 6 (PVID 2)
Ports 13, 19-24 (PVID 3)
none
❑ Sales VLAN - This VLAN spans both switches. It has a VID value of
2 and consists of seven untagged ports on the top switch and six
untagged ports on the bottom switch.
The two parts of the VLAN are interconnected by a direct link from
Port 6 on the top switch to Port 5 on the bottom switch. This direct
link allows the two parts of the Sales VLAN to function as one
logical LAN segment.
Port 18 on the top switch connects to the router. This port allows
the Sales VLAN to exchanged Ethernet frames with the other
VLANs and to access the WAN.
❑ Engineering VLAN - This port-based VLAN uses Ports 9 to 11 on
the top switch and Ports 19 to 24 on the bottom switch as
connections to the workstations of the VLAN.
Since this VLAN spans multiple switches, it needs a direct
connection between its various parts to provide a
communications path. This is provided in the example with a
direct connection from Port 14 on the top switch and Port 13 on
the bottom switch.
This VLAN uses Port 20 on the top switch as a connection to the
router and the WAN.
❑ Production VLAN - This is the final VLAN in the example. It has the
VLAN of 4 and its ports have been assigned the PVID also of 4.
The nodes of this VLAN are connected to only the top switch. So
this VLAN does not require a direct connection to the bottom
VLAN. However, it uses Port 22 as a connection to the router.
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Tagged VLAN Overview
The second type of VLAN supported by the AT-8000 Series switch is the
tagged VLAN. VLAN membership in a tagged VLAN is determined by
information within the frames that are received on a port. This contrasts
to a port-based VLAN, where the PVIDs assigned to the ports determine
VLAN membership.
The VLAN information within an Ethernet frame is referred to as a tag or
tagged header. A tag, which follows the source and destination
addresses in a frame, contains the VID of the VLAN to which the frame
belongs (IEEE 802.3ac standard). As explained earlier in this chapter in
VLAN Identifier on page 113, this number uniquely identifies each
VLAN in a network.
When a switch receives a frame with a VLAN tag, referred to as a tagged
frame, the switch forwards the frame only to those ports that share the
same VID.
A port to receive or transmit tagged frames is referred to as a tagged
port. Any network device connected to a tagged port must be IEEE
802.1Q-compliant. This is the standard that outlines the requirements
and standards for tagging. The device must be able to process the
tagged information on received frames and add tagged information to
transmitted frames.
The benefit of a tagged VLAN is that the tagged ports within the VLAN
can belong to more than one VLAN at one time. This can greatly simplify
the task of adding shared devices to the network. For example, a server
can be configured to accept and return packets from many different
VLANs simultaneously.
Tagged VLANs are also useful where multiple VLANs span across
switches. You can use one port per switch for connecting all VLANs on
the switch to another switch.
The IEEE 802.1Q standard deals with how this tagging information is
used to forward the traffic throughout the switch. The handling of
frames tagged with VIDs coming into a port is straightforward. If the
incoming frame’s VID tag matches one of the VIDs of a VLAN that the
port is a tagged member of, the frame will be accepted and forwarded to
the appropriate ports. If the frame’s VID does not match any of the
VLANs that the port is a member of, the frame will be discarded.
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The parts of a tagged VLAN are much the same as those for a port-based
VLAN. They are:
❑ VLAN Name
❑ VLAN Identifier
❑ Tagged and Untagged Ports
❑ Port VLAN Identifier
Note
For explanations of VLAN name and VLAN identifier, refer back to
VLAN Name and VLAN Identifier on page 113.
Tagged and Untagged Ports
You need to specify which ports will be members of the VLAN. In the
case of a tagged VLAN, it will usually be a combination of both untagged
ports and tagged ports. You specify which ports will be tagged and
which untagged when you create the VLAN.
An untagged port, whether a member of a port-based VLAN or a tagged
VLAN, can be in only one VLAN at a time. However, a tagged port can be
a member of more than one VLAN. A port can also be an untagged
member of one VLAN and a tagged member of different VLANs,
simultaneously.
Port VLAN Identifier
As explained earlier in the discussion on port-based VLANs, the
management software automatically assigns a PVID to each port when a
port is made a member of a VLAN. The PVID is always identical to the
VLAN’s VID, and that in a port-based VLAN packets are forwarded based
on the PVID.
Since a tagged port determines VLAN membership by examining the
tagged header within the frames that it receives, there would seem to be
no need for a PVID. But actually there is. The PVID is used if a tagged port
receives an untagged frame (that is, a frame without any tagged
information). The port will forward the frame based on the port’s PVID.
But this is only in cases where untagged frames arrive on tagged ports.
Otherwise, the PVID of a port is ignored on a tagged port.
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General Rules
to Creating a
Tagged VLAN
Below is a summary of the rules to observe when creating a tagged
VLAN.
❑ Each tagged VLAN must be assigned a unique VID. If a particular
VLAN spans multiple switches or stacks, each part of the VLAN on
the different switches or stacks must be assigned the same VID.
❑ A tagged port can be a member of multiple VLANs.
❑ An untagged port can be an untagged member of only one VLAN
at a time.
❑ The AT-8000 Series switch can support up to 32 tagged VLANS.
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Section II: Local and Telnet Management
Tagged VLAN
Example
Figure 35 illustrates how tagged ports can be used to interconnect IEEE
802.1Q-based products.
Engineering VLAN
(VID 3)
Legacy Server
Production VLAN
(VID 4)
Sales VLAN
(VID 2)
AT-8024 Ethernet Switch
AT-8024
RS-232 TERMINAL PORT
10Base-T / 100Base-TX Fast Ethernet Switch
MODE
Link
COL
Mode
Link
100
Mode
ACT
FAULT
MASTER
FULL
PWR
WAN
IEEE 802.1Q
Compliant Server
AT-8024 Ethernet Switch
AT-8024
RS-232 TERMINAL PORT
10Base-T / 100Base-TX Fast Ethernet Switch
MODE
Link
COL
Mode
Link
100
Mode
ACT
FULL
FAULT
MASTER
PWR
Sales VLAN
(VID 2)
Engineering VLAN
(VID 3)
Figure 35 Example of a Tagged VLAN
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AT-S39 User’s Guide
The port assignments for the VLANs are as follows:
Sales VLAN (VID 2)
Engineering VLAN (VID 3)
Production VLAN (VID 4)
Untagged Ports Tagged Ports
Untagged Ports Tagged Ports
Untagged Ports Tagged Ports
AT-8024
Switch
(top)
1 to 5, 18
(PVID 2)
8, 16
9 to 11, 20
(PVID 3)
8, 16
21 to 24 (PVID 4) 8
AT-8024
Switch
(bottom)
1 to 5 (PVID 2)
15
19 to 24
(PVID 3)
15
none
none
This example is nearly identical to the Port-based Example 2 on page
118. Tagged ports have been added to simplify network implementation
and management.
One of the tagged ports is Port 8 on the top switch. This port has been
made a tagged member of the three VLANs. It is connected to an IEEE
802.1Q-compliant server, meaning the server can handle frames from
multiple VLANs. Now all three VLANs can access the server without
having to go through a router or other interconnection device.
It is important to note that even though the server is accepting frames
from and transmitting frames to more than one VLAN, data separation
and security remain.
Two other tagged ports are used to simplify network design in the
example. They are Port 16 on the top switch and Port 15 on the bottom
switch. These ports have been made tagged members of the Sales and
Engineering VLANs. They provide a connection between the different
parts of these two VLANs.
In the Port-based Example 2 on page 118, each VLAN had to have its
own data link between the switches to connect the different parts of the
VLANs. But with tagged ports, you can use one data link to carry data
traffic from several VLANs, while still maintaining data separation and
security. The tagged frames, when received by the switch, are delivered
only to those ports that belong to the VLAN from which the tagged
frame originated.
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Basic VLAN Mode Overview
The Fast Ethernet Switches support a special VLAN configuration
referred to as Basic VLAN Mode. When the Basic VLAN Mode is activated,
frames are forwarded based solely on MAC addresses. All VLAN
information, including PVIDs assigned to ports and VLAN tags in tagged
frames, is ignored. Tagged frames are analyzed only for priority level.
Packets are passed through the switch unchanged. Tagged and
untagged frames exit the switch the same as they entered, either tagged
or untagged, regardless of the type of ports on which the frames are
received and transmitted.
You should be aware of the following before you activate the Basic VLAN
mode:
❑ You cannot create or modify port-based or tagged VLANs when
the Basic VLAN Mode is activated.
❑ Any pre-existing port-based or tagged VLANs are retained in the
event you later disabled Basic VLAN Mode, but the VLANs are not
used.
Note
For instructions on how to activate the Basic VLAN mode, refer to
Setting a Switch’s VLAN Mode on page 142.
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AT-S39 User’s Guide
Creating a Port-based or Tagged VLAN
To create a new port-based or tagged VLAN, perform the following
procedure:
1. From the Main Menu, type 2 to select VLAN Menu.
The VLAN Menu in Figure 36 is displayed.
Allied Telesyn Ethernet Switch AT-8024
Login Session: Manager
VLAN Menu
1 - Virtual LAN Support
2 - Virtual LAN Definitions
3 - Configure Port VLANs & Priorities
R - Return to Previous Menu
Enter your selection?
Figure 36 VLAN Menu
2. From the VLAN Menu, type 2 to select Virtual LAN Definitions.
The Virtual LAN Definitions menu in Figure 37 is displayed.
Allied Telesyn Ethernet Switch AT-8024
Login Session: Manager
Virtual LAN Definitions
1
2
3
4
5
6
-
Create VLAN
Modify VLAN
Delete VLAN
Show All VLANs
Clear All VLANs
Management VLAN ....... 1 (Default_VLAN)
S - Save Configuration Changes
R - Return to Previous Menu
Enter your selection?
Figure 37 Virtual LAN Definitions Menu
3. From the Virtual LAN Definitions menu, type 1 to select Create a
VLAN.
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The Create a VLAN window in Figure 38 is displayed.
Allied Telesyn Ethernet Switch AT-8024
Login Session: Manager
Create a VLAN
1
2
3
4
5
-
VLAN Name ............
VLAN ID (VID) ........ 2
Tagged Ports .........
Untagged Ports .......
Mirroring Port ....... None
C - Create VLAN
R - Return to Previous Menu
Enter your selection?
Figure 38 Create a VLAN Window
4. Type 1 to select VLAN Name and enter a name for the new VLAN.
The name can be from one to fifteen characters in length. The name
should reflect the function of the nodes that will be a part of the VLAN
(for example, Sales or Accounting). The name can contain spaces, but
not special characters, such as asterisks (*) or exclamation points (!).
If the VLAN will be unique in your network, then the name should be
unique as well. If the VLAN will be part of a larger VLAN that spans
multiple switches, then the name for the VLAN should be the same on
each switch where nodes of the VLAN are connected.
Note
A VLAN must be assigned a name.
5. Type 2 to select VLAN ID (VID) and enter a VID value for the new VLAN.
The permitted range of the VID value is 2 to 4094.
The management software will use the next available VID number on
the switch as the default value. If this VLAN will be unique in your
network, then its VID must also be unique. If this VLAN will be part of
a larger VLAN that spans multiple switches, than the VID value for the
VLAN should be the same on each switch. For example, if you are
creating a VLAN called Sales that will span three switches, you must
assign the Sales VLAN on each switch the same VID value.
Note
A VLAN must have a VID.
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6. If the VLAN will contain tagged ports, type 3 to select Tagged Ports
and specify the ports. If this VLAN will not contain any tagged ports,
leave this field empty.
You can specify the ports individually (e.g., 2,3,5), as a range (e.g., 7-9),
or both (e.g., 2,5,7-9).
7. Type 4 to select Untagged Ports and specify the ports on the switch
to function as untagged ports in the VLAN. If this VLAN will not
contain any untagged ports, leave this field empty.
You can specify the ports individually (e.g., 2,3,5), as a range (e.g., 7-9),
or both (e.g., 2,5,7-9).
8. If you want all received traffic on the ports of the VLAN to be mirrored
to another port on the switch, type 5 to select Mirroring Port and
enter a port number when prompted.
This feature is useful when troubleshooting a VLAN. By placing a
packet sniffer on the mirroring port, you can analyze the VLAN traffic.
Note
In most cases, this parameter should be left with its default value of
0. A value of 0 means that the VLAN traffic will not be mirrored. For
more information on port mirroring, refer to Port Mirroring
Overview on page 88.
9. Type C to select Create VLAN.
If the switch is successful in creating the new VLAN, you will see the
following message:
SUCCESS - Press any key to continue.
10. Press any key.
The Virtual LAN Definitions menu in Figure 37 is displayed.
11. Type S to select Save Configuration Changes.
12. To verify that the VLAN was created correctly, type 4 to select Show
All VLANs.
13. Check to see that the VLAN was created correctly and that it contains
the appropriate ports.
14. Press Esc or type R to return to the Virtual LAN Definitions menu.
You can repeat this procedure to create additional VLANs.
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Note
When you create a new VLAN, ports designated as untagged ports
of the new VLAN are automatically removed from their current
untagged VLAN assignment. For example, if you are creating a new
VLAN on a switch that contains only the Default_VLAN, the ports
that you specify as untagged ports of the new VLAN are
automatically removed from the Default_VLAN.
Tagged ports are not removed from any current VLAN assignments
because tagged ports can belong to more than one VLAN at a time.
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Example of Creating a Port-based VLAN
The following procedure creates the Sales VLAN illustrated in Portbased Example 1 on page 117. This VLAN will be assigned a VID of 2 and
will consist of four untagged ports, Ports 1 to 4. The VLAN will not
contain any tagged ports. The VLAN traffic will not be mirrored on
another port, nor will it be sent to the switch’s CPU.
To create the example Sales VLAN, perform the following procedure:
1. From the Main Menu, type 2 to select VLAN Menu.
2. From the VLAN Menu, type 2 to select Virtual LAN Definitions.
3. From the Virtual LAN Definitions menu, type 1 to select Create a
VLAN.
4. Type 1 to select VLAN Name and enter “Sales”. Press Return.
5. Type 2 to select VLAN ID (VID) and enter “2”. This is the VID value for
the new VLAN. Press Return.
6. Type 4 to select Untagged Ports and enter “1-4”. These are the
untagged ports of the VLAN. Press Return.
7. Type C to select Create VLAN.
8. After the switch displays the prompt notifying you that it created the
VLAN, press any key.
9. Type S to select Save Configuration Changes.
The new Sales VLAN has now been created.
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Example of Creating a Tagged VLAN
The following procedure creates the Engineering VLAN in the top switch
illustrated in Tagged VLAN Example on page 123. This VLAN will be
assigned a VID of 3. It will consist of four untagged ports, Ports 9, 10, 11,
and 20, and two untagged ports, Ports 8 and 16. The VLAN traffic will not
be mirrored on another port, nor will it be sent to the switch’s CPU.
To create the example Engineering VLAN, perform the following
procedure:
1. From the Main Menu, type 2 to select VLAN Menu.
2. From the VLAN Menu, type 2 to select Virtual LAN Definitions.
3. From the Virtual LAN Definitions menu, type 1 to select Create a
VLAN.
4. Type 1 to select VLAN Name and enter “Engineering”. Press Return.
5. Type 2 to select VLAN ID (VID) and enter “3”. This is the VID value for
the new VLAN. Press Return.
6. Type 3 to select Tagged Ports and enter “8,16”. These are the tagged
ports of the VLAN. Press Return.
7. Type 4 to select Untagged Ports and enter “9,10,11, 20”. These are the
untagged ports of the VLAN. Press Return.
8. Type C to select Create VLAN.
9. After the switch displays the prompt notifying you that it created the
VLAN, press any key.
10. Type S to select Save Configuration Changes.
The new Engineering VLAN has now been created.
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Modifying a VLAN
Note
You need to know the VID of the VLAN you want to modify in order
to perform this procedure. To view the VLAN VIDs, refer to the
procedure Displaying VLAN Information on page 135.
To modify a VLAN, perform the following procedure:
1. From the Main Menu, type 2 to select VLAN Menu.
2. From the VLAN Menu, type 2 to select Virtual LAN Definitions.
3. From the Virtual LAN Definitions menu, type 2 to select Modify a
VLAN.
The Modify a VLAN window in Figure 41 is displayed.
Allied Telesyn Ethernet Switch AT-8024
Login Session: Manager
Modify VLAN
1 - VLAN ID (VID) ........
S - Save Configuration Changes
R - Return to Previous Menu
Enter your selection?
Figure 39 Modifying a VLAN Menu
4. Type 1 to select VLAN ID (VID).
The following prompt is displayed:
Enter new value -> [1 to 4096] ->
5. Enter the VID of the VLAN you want to modify. Press Return.
The Modify a VLAN window for the selected VLAN is displayed. This
window contains all relevant information about the VLAN.
6. Change the VLAN’s information as desired.
The menu selections in the window are described below:
1 - VLAN Name
Use this selection to change a VLANs name. The name can be from
one to fifteen characters in length. The name should reflect the
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function of the nodes that will be a part of the VLAN (for example,
Sales or Accounting). The name can contain spaces, but not special
characters, such as asterisks (*) or exclamation points (!).
When changing a VLAN’s name, observe the following guidelines:
❑ A VLAN’s new name cannot be the same as the name of another
VLAN on the same switch. For example, if the switch already
contains a VLAN called Sales, you cannot change an existing
VLAN’s name to Sales.
❑ You cannot change the name of the Default_VLAN.
Note
A VLAN must be assigned a name.
2 - VLAN ID (VID)
This is the VLAN’s VID value. You cannot change this value.
3 - Tagged Ports
Use this selection to add or remove tagged ports from the VLAN. You
can specify the ports individually (e.g., 2,3,5), as a range (e.g., 7-9), or
both (e.g., 2,5,7-9).
When adding or removing tagged ports, observe the following
guidelines:
❑ To add or remove tagged ports, enter the new list of tagged ports
for the VLAN. For example, if the VLAN currently contains tagged
port 4 and you wanted to add port 7, you would enter “4,7”.
❑ If the VLAN will not contain any tagged ports, leave this field
empty.
❑ If the VLAN contains tagged ports and you want to remove them
all, enter a 0 (zero) for this value.
4 - Untagged Ports
Use this selection to add or remove untagged ports from the VLAN.
You can specify the ports individually (e.g., 2,3,5), as a range (e.g., 7-9),
or both (e.g., 2,5,7-9).
When adding or removing untagged ports, observe the following
guidelines:
❑ To add or remove untagged ports, enter the new list of untagged
ports for the VLAN. For example, if the VLAN currently contains
untagged ports 15 through 19 and you want to add ports 4
through 9, you would enter “4-9,15-19”.
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AT-S39 User’s Guide
❑ If the VLAN will not contain any untagged ports, leave this field
empty.
❑ If you want to remove all untagged ports from the VLAN, enter a 0
(zero) for this value.
❑ You cannot remove untagged ports directly from the Default
VLAN. Instead, you remove an untagged port from the Default
VLAN by assigning the port as an untagged port to another VLAN.
An untagged port removed from a VLAN is automatically returned to
the Default VLAN as an untagged port.
5 - Mirroring Port
Use this option to direct all received traffic on the ports of the VLAN
to a mirror port on the switch. This feature is useful when
troubleshooting a VLAN. By placing a packet sniffer on the mirroring
port, you can analyze the VLAN traffic.
Note
In most cases, this parameter should be left with its default value of
0. A value of 0 means that the VLAN traffic will not be mirrored. For
more information on port mirroring, refer to Port Mirroring
Overview on page 88.
7. After making the desired changes, type M to select Modify VLAN.
A confirmation prompt is displayed.
8. Press any key.
9. Type S to select Save Configuration Changes.
The VLAN has been modified.
10. Repeat this procedure starting with Step 4 to modify other VLANs.
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Displaying VLAN Information
To view the name, VID number, and member ports of all the VLANs on a
switch, perform the following procedure:
1. From the Main Menu, type 2 to select VLAN Menu.
2. From the VLAN Menu, type 2 to select Virtual LAN Definitions.
3. From the Virtual LAN Definitions menu, type 4 to select Show All
VLANs.
The Show All VLANs window is displayed. An example of the window
is shown in Figure 40.
Allied Telesyn Ethernet Switch AT-8024
Show All VLANs
Login Session: Manager
VID
VLAN Name
Mirror Untagged (U) / Tagged (T)
---------------------------------------------------------------1
Default VLAN
2
Sales
3
Production
U:
T:
U:
T:
U:
T:
20-24
7,9
1-7
9
8-19
7
N - Next Page
U - Update Display
R - Return to Previous Menu
Enter your selection?
Figure 40 Show All VLANs Window
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Deleting a VLAN
Note
You need to know the VID of the VLAN you want to delete to
perform this procedure. To obtain a VLAN’s VID, refer to the
procedure Displaying VLAN Information on page 135.
To delete a VLAN, perform the following procedure:
1. From the Main Menu, type 2 to select VLAN Menu.
2. From the VLAN Menu, type 2 to select Virtual LAN Definitions.
3. From the Virtual LAN Definitions menu, type 3 to select Delete a
VLAN.
The Delete a VLAN menu in Figure 41 is displayed.
Allied Telesyn Ethernet Switch AT-8024
Login Session: Manager
Delete a VLAN
1 - VLAN ID (VID) ........
R - Return to Previous Menu
Enter your selection?
Figure 41 Delete a VLAN Menu
4. Type 1 to select VLAN ID (VID).
The following prompt is displayed:
Enter new value -> [2 to 4096] ->
5. Enter the VID of the VLAN you want to delete and press Return.
Note
You cannot delete the Default_VLAN, which has a VID of 1.
The specifications of the selected VLAN are displayed. Use this
window to confirm that you are deleting the correct VLAN.
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6. Type D to delete the VLAN or R to cancel the procedure.
The following confirmation prompt is displayed:
Are you sure you want to delete this VLAN [Yes/No] ->
7. Type Y to delete the VLAN or N to cancel the procedure. Press Return.
A following prompt is displayed:
This operation deletes ALL user created VLANs!
Do you want to continue [Yes/No] ->
8. Press any key.
9. Type S to select Save Configuration Changes.
The VLAN has been deleted. All untagged ports in the deleted VLAN
are returned to the Default_VLAN as untagged ports.
10. Repeat this procedure starting with Step 4 to delete other VLANs.
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Deleting All VLANs
This section contains the procedure for deleting all VLANs, except the
Default VLAN, on a switch. To delete selected VLANs, perform the
procedure Deleting a VLAN on page 136.
To delete all VLANs on a switch, perform the following procedure:
1. From the Main Menu, type 2 to select VLAN Menu.
2. From the VLAN Menu, type 2 to select Virtual LAN Definitions.
3. From the Virtual LAN Definitions menu, type 5 to select Clear All
VLANs.
A confirmation message is displayed.
4. Type Y to delete all VLANs or N to cancel the procedure. Press Return.
A confirmation message is displayed.
5. Press any key.
6. Type S to select Save Configuration Changes.
All VLANs are deleted and their tagged and untagged ports are
returned to the Default VLAN as untagged ports.
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Changing a PVID Value
The procedure in this section explains how to change a PVID value for a
port. As explained in Port-based VLAN Overview on page 113, a port
receives a PVID when it is assigned as an untagged port to a VLAN. A
port’s PVID will be the same as the VLAN’s VID to which it has been
assigned. For example, if you assign Port 4 on the switch as an untagged
port to a VLAN with a VID of 7, then the port will be assigned a PVID also
of 7.
The assignment of PVIDs is performed automatically by the AT-S39
software when you create a VLAN. There should be little need or reason
for you to manually change a PVID yourself. But the AT-S39 software
does allow you to adjust the value if you deem it necessary.
To change a PVID for a port, perform the following procedure:
1. From the Main Menu, type 2 to select VLAN Menu.
2. From the VLAN Menu, type 3 to select Configure Port VLANS &
Priorities.
The Port VLANS & Priorities window in Figure 42 is displayed.
Allied Telesyn Ethernet Switch AT-8024
Login Session: Manager
Configure Port VLANs & Priorities
1 - Configure Port VLANs & Priorities
2 - Show Port VLANs & Priorities
S - Save Configuration Changes
R - Return to Previous Menu
Enter your selection?
Figure 42 Configure Port VLANs and Priorities Window
3. Type 1 to select Configure Port VLANs and Priorities.
The following prompt is displayed:
Enter port number -> [1 to 24] ->
4. Enter the number of the port on the switch whose PVID you want to
change. Press Return.
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AT-S39 User’s Guide
The Configure Port VLANS & Priorities window in Figure 43 is
displayed.
Allied Telesyn Ethernet Switch AT-8024
Login Session: Manager
Configure Port VLANs & Priorities
1
2
3
4
-
Port Number ...................
Port VLAN ID ..................
Priority (0-7) 0=Low 7=High ...
Override Priority (Y/N) .......
1
1
0
N
C - Configure Port VLANs and Priorities
S - Save Configuration Changes
R - Return to Previous Menu
Enter your selection?
Figure 43 Port VLANs and Priorities Window
5. Type 2 to select Port VLAN ID.
The following prompt is displayed:
Enter new value -> [1 to 4096] ->
6. Specify the new PVID value for the port. Press Return.
Note
You cannot assign a PVID to a port for a VLAN that does not exist. For
example, if you want to assign a port a PVID of 7, there must be a
VLAN on the switch with a VID of 7.
7. Type C to select Configure Port VLANs and Priorities.
The switch displays the following prompt:
SUCCESS - Press any key to continue.
8. Type S to select Save Configuration Changes.
The port now has a new PVID. You can repeat this procedure to assign
new PVIDs to other ports on the switch.
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Displaying PVIDs and Port Priorities
The following procedure displays a window that lists the PVIDs for all the
ports on the switch. The window also contains the current priority queue
settings for each port. To display the PVID settings on the switch,
perform the following procedure:
1. From the Main Menu, type 2 to select VLAN Menu.
2. From the VLAN Menu, type 3 to select Configure Port VLANS &
Priorities.
The Configure Port VLANS & Priorities window in Figure 42 on page
139 is displayed.
3. From the Configure Port VLANS & Priorities window, type 2 to select
Show Port VLANS & Priorities.
The Show Port VLANs and Priorities window is displayed. An example
of the window is shown in Figure 44.
Allied Telesyn Ethernet Switch AT-8024
Login Session: Manager
Show Port VLANs & Priorities
Port PVID
Priority
Override Priority
--------------------------------------------01
02
03
04
05
06
07
1
1
1
1
1
1
1
0
0
0
0
0
0
0
No
No
No
No
No
No
No
N - Next Page
U - Update Display
R - Return to Previous Menu
Enter your selection?
Figure 44 Show Port VLANs and Priorities Window
The PVID column displays the current PVID value for each switch port.
Note
The Priority and Override Priority columns relate to the switch’s
Class of Service feature. For information, refer to Chapter 12, Class
of Service on page 162.
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AT-S39 User’s Guide
Setting a Switch’s VLAN Mode
This section contains the procedure for setting a switch’s VLAN mode.
You can configure a switch to support port-based and tagged VLANs or
to operate in the Basic VLAN mode. Port-based and tagged VLANs and
the Basic VLAN mode are all described in earlier sections in this chapter.
To configure a switch’s VLAN mode, perform the following procedure:
1. From the Main Menu, type 5 to select System Config Menu.
2. Type 2 to select Switch Mode.
The following prompt is displayed:
Enter Switch Mode (T-Tagged, B-Basic):
3. Type T in order to create your own port-based and tagged VLANs, or
B to configure the switch for the Basic VLAN Mode. The default is
Tagged mode. Press Return.
4. Type S to select Save Configuration Changes.
5. Reset the switch using the Reset Switch option in the Administration
Menu or the reset button on the back of the unit.
A change to VLAN status is not activated until you reset the switch.
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Enabling or Disabling All VLANs
This procedure performs exactly the same function as the previous
procedure. It sets a switch’s VLAN mode. When VLANs are enabled, the
switch supports port-based and tagged VLANs. When VLANs are
disabled, the switch supports the Basic VLAN mode.
The only difference between the two procedures has to do with ingress
filtering. If you activate the Basic VLAN Mode using the previous
procedure, ingress filtering is disabled. Changing the VLAN mode of a
switch using this procedure does not change the current setting of
ingress filtering.
To configure a switch’s VLAN mode, perform the following procedure:
1. From the Main Menu, type 2 to select VLAN Menu.
2. From the VLAN Menu, type 1 to select Virtual LAN Support.
The Virtual LAN Support menu in Figure 45 is displayed.
Allied Telesyn Ethernet Switch AT-8024
Login Session: Manager
Virtual LAN Support
1 - Enable/Disable VLANs
2 - Enable/Disable Ingress Filtering
S - Save Configuration Changes
R - Return to Previous Menu
Enter your selection?
Figure 45 Virtual LAN Support Menu
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AT-S39 User’s Guide
3. Type 1 to select Enable/Disable VLANs.
The VLAN Support window in Figure 46 is displayed.
Allied Telesyn Ethernet Switch AT-8024
Login Session: Manager
VLAN Support
** VLANs are globally Enabled **
E - Enable VLANs Globally
D - Disable VLANs Globally
S - Save Configuration Changes
R - Previous Menu
Enter your selection?
Figure 46 VLAN Support Window
The prompt enclosed in asterisks gives the current status of the
VLANs.
4. Type E to enable the VLANs or D to activate the Basic VLAN Mode.
5. Press any key.
6. Type R to select Return to Previous Menu.
7. Type S to select Save Configuration Changes.
8. Reset the switch using the Reset Switch option in the Administration
Menu or the reset button on the back of the unit.
A change to VLAN status is not activated until you reset the switch.
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Section II: Local and Telnet Management
Enabling or Disabling Ingress Filtering
There are certain rules a switch follows as it receives and forwards an
Ethernet frame. There are rules for frames as they enter a port (called
ingress rules) and rules for when a frame is transmitted out a port (called
egress rules). A switch will not accept and forward a frame unless the
frame passes the ingress and egress rules.
There are quite a few ingress and egress rules for Fast Ethernet switches.
Fortunately, this discussion need only review the rules as they apply to
tagged frames, because ingress filtering does not apply to untagged
frames, nor to any frames, tagged or untagged, when the switch is
operating in the Basic VLAN Mode.
First, just as a reminder, a tagged frame is an Ethernet frame that
contains a tagged header. The header contains the VID of the VLAN to
which the frame originated. For further information, refer to Tagged
VLAN Overview on page 120.
Let’s first examine how the ingress rules are applied to tagged frames
when ingress filtering is activated. What the switch does is it examines
the tagged header of each tagged frame that enters a port and
determines whether the tagged frame and the port that received the
frame are members of the same VLAN. If they belong to the same VLAN,
the port accepts the frame. If they belong to different VLANs, the port
discards the frame.
Here is an example. Assume that a tagged frame with a VID of 4 is
received on a port that is a member of a VLAN also with a VID of 4. In this
case, the port accepts the frame, because both the frame and the port
belong to the same VLAN. If the frame and port had belonged to
different VLANs, the frame is discarded.
So how do the egress rules apply when ingress filtering is disabled? First,
any tagged frame is accepted on any port on the switch. It does not
matter whether the frame and the port belong to the same or different
VLANs.
Once the tagged frame is received, the switch examines the tagged
header and determines if the VID in the header corresponds to any
VLANs on the switch. If there isn’t a corresponding VLAN, the switch
discards the frame. If there is, the switch transmits the frame out the port
to the destination node, assuming that the destination node’s MAC
address is in the MAC address table, or floods the port to all ports on the
VLAN if the MAC address is not in the table.
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There is one other thing that should be mentioned about ingress
filtering and tagged packets, and that is the priority tag. Each tagged
frame has a priority tag in it that instructs the switch as to the
importance of the frame. Frames with a high priority are handled ahead
of frames with a low priority.
Activating or deactivating ingress filtering has no effect on the switch’s
handling of priority tags. A switch will always examine a priority tag in a
tagged frame, regardless of the status of ingress filtering.
In most cases, you will probably want to leave ingress filtering activated
on the switch, which is the default. You can enable or disable ingress
filtering on a per switch basis. You cannot set this per port.
To enable or disable ingress filtering, perform the following procedure:
1. From the Main Menu, type 2 to select VLAN Menu.
2. From the VLAN Menu, type 1 to select Virtual LAN Support.
The Virtual LAN Support menu in Figure 45 on page 143 is displayed
3. From the Virtual LAN Support menu, type 2 to select Enable/Disable
Ingress Filtering.
4. The Ingress Filtering window in Figure 47 is displayed.
Allied Telesyn Ethernet Switch AT-8024
Login Session: Manager
VLAN Support
** Ingress Filtering is Globally Enabled **
E - Enable Ingress Filtering Globally
D - Disable Ingress Filtering Globally
S - Save Configuration Changes
R - Return to Previous Menu
Enter your selection?
Figure 47 Ingress Filtering Window
5. Type E to activate ingress filtering or D to disable the feature on the
switch.
6. Type S to select Save Configuration Changes.
A change to the status of ingress filtering is immediately activated on
the switch.
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Section II: Local and Telnet Management
Specifying a Management VLAN
In order for you to remotely manage an AT-8300 Series Switch, there
must exist a communications path through which the management
station and the switch to be manage can communicate. If the
management station is connected directly to a port on the switch, either
through a tagged or untagged port, then the communications path
automatically exists and you can fully manage the switch.
However, if there is one or more intermediate Ethernet switches
between the management station and the switch to be managed, then
it may be necessary for you to manually create a communications path.
This is accomplished by specifying a management VLAN.
The management VLAN is the VLAN through which a remote
management station communicates with a managed switch. By default,
the management VLAN is the Default_VLAN. If you do not create any
new VLANs in your network and if your AT-8000 Series Switches are
interconnected with either tagged or untagged ports, then you will not
need to create or specify a new management VLAN.
However, if you do create additional VLANs in your network, then you
might need to change a management VLAN. Below are several rules to
observe when using this feature:
❑ The management VLAN must exist on each AT-8000 Series switch
that you want to manage.
❑ Using the following procedure, you must specify the
management VLAN in the AT-S39 software on each slave and
master switch of an enhanced stack.
❑ The uplink and downlink ports on each switch that are
functioning as the tagged or untagged data links between the
switches must be either tagged or untagged members of the
management VLAN.
❑ The port on the switch to which the management station is
connected must be a member of the management VLAN. (This
rule does not apply when managing the switch locally through
the RS232 Terminal Port.)
Here is an example. Let’s assume that you have an enhanced stack of
seven AT-S39 Series switches with one master switch. If the uplink and
downlink ports between the various switches are members of the
Default_VLAN and if the management station is connected to a port of
the Default_VLAN, you will be able to manage all the switches since the
Default_VLAN is by default the management VLAN.
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AT-S39 User’s Guide
Now let’s assume that you have decided to create a VLAN called NMS
with a VID of 24 for the sole purpose of remote network management.
For this, you would need to create the NMS VLAN on each AT-8000 Series
switch that you want to manage remotely, being sure to assign each
NMS VLAN the VID of 24. Then you would need to be sure that the uplink
and downlink ports connecting the switches together are either tagged
or untagged members of the NMS VLAN. You would also need to specify
the NMS VLAN as the management VLAN on each switch using the
management software. Finally, you must be sure to connect your
management station to a port on a switch that is a tagged or untagged
member of the management VLAN.
To specify the management VLAN in the AT-S39 software, do the
following:
1. From the Main Menu, type 2 to select VLAN Menu.
2. From the VLAN Menu, type 2 to select Virtual LAN Definitions.
3. From the Virtual LAN Definitions, type 6 to select Management VLAN.
The following prompt is displayed:
Enter Management VLAN ID [1 to 4094] ->
4. Specify the VID of the VLAN that is to function as the management
VLAN. This VLAN must already exist on the switch.
The following prompt is displayed:
SUCCESS - Press any key to continue ...
5. Press any key.
6. Type S to select Save Configuration Changes.
148
Chapter 11
MAC Address Table
The chapter contains the procedures for viewing the static and dynamic
MAC address table. The sections in this chapter include:
❑ MAC Address Overview on page 150
❑ Displaying MAC Addresses on page 152
❑ Viewing MAC Addresses by Port on page 155
❑ Identifying a Port Number by MAC Address on page 156
❑ Viewing the MAC Addresses of a VLAN on page 157
❑ Deleting All Dynamic MAC Addresses on page 158
❑ Adding Static and Multicast MAC Addresses on page 159
❑ Deleting MAC Addresses on page 160
❑ Changing the Aging Time on page 161
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AT-S39 User’s Guide
MAC Address Overview
Every hardware device that you connect to your network has a unique
MAC address associated with it. A MAC address is assigned to a device by
the device’s manufacturer. For example, every network interface card
that you use to connect your computers to your network has a MAC
address assigned to it by the adapter’s manufacturer.
The AT-8000 Series switch contains a 4 kilobyte MAC address table. The
switch uses the table to store the MAC addresses of the network nodes
connected to its ports, along with the port number on which each
address was learned.
The switch learns the MAC addresses of the end nodes by examining the
source address of each packet received on a port. It adds the address
and port on which the packet was received to the MAC table if the
address has not already been entered in the table. The result is a table
that contains all the MAC addresses of the devices that are connected to
the switch’s ports, and the port number where each address was
learned.
When the switch receives a packet, it also examines the destination
address and, by referring to its MAC address table, determines the port
where the destination node is connected. It then forwards the packet to
the appropriate port and on to the end node. This increases network
bandwidth by limiting each frame to the appropriate port when the
intended end node is located, freeing the other switch ports for
receiving and transmitting data.
If the switch receives a packet with a destination address that is not in
the MAC address table, it floods the packet to all the ports on the switch.
If the ports have been grouped into virtual LANs, the switch floods the
packet only to those ports which belong to the same VLAN as the port
on which the packet was received. This prevents packets from being
forwarded onto inappropriate LAN segments and increases network
security. When the destination node responds, the switch adds its MAC
address and port number to the table.
If the switch receives a packet with a destination address that is on the
same port on which the packet was received, it discards the packet
without forwarding it on to any port. Since both the source node and the
destination node for the packet are located on the same port on the
switch, there is no reason for the switch to forward the packet. This too
increases network performance by preventing frames from being
forwarded unnecessarily to other network devices.
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Section II: Local and Telnet Management
The type of MAC address described above is referred to as a dynamic
MAC address. Dynamic MAC addresses are addresses that the switch
learns by examining the source MAC addresses of the frames received
on the ports.
Dynamic MAC addresses are not stored indefinitely in the MAC address
table. The switch deletes a dynamic MAC address from the table if it does
not receive any frames from the node over a specified period of time.
The switch assumes that the node with that MAC address is no longer
active and that its MAC address can be purged from the table. This
prevents the MAC address table from becoming filled with addresses of
nodes that are no longer active.
The period of time that the switch waits before purging an inactive
dynamic MAC address is called the aging timer. This value is adjustable
on the AT-8000 Series switch. The default value is 300 seconds (5
minutes). For instructions on changing the aging timer, refer to
Changing the Aging Time on page 161.
The MAC address table can also store static MAC addresses. A static MAC
address, once entered in the table, remains in the table indefinitely and
is never deleted, even when the end node is inactive.
You might need to enter static MAC addresses of end nodes the switch
will not learn in its normal dynamic learning process, or if you want a
MAC address to remain permanently in the table, even when the end
node is inactive.
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AT-S39 User’s Guide
Displaying MAC Addresses
The management software has two menu selections for displaying the
MAC addresses of a switch. One selection displays the static, dynamic,
and multicast MAC addresses while the other displays just the static and
multicast addresses, but no dynamic addresses.
To display the MAC address table, perform the following procedure:
1. From the Main Menu, type 6 to select MAC Address Tables.
The MAC Address Table menu in Figure 48 is displayed.
Allied Telesyn AT-8024 Ethernet Switch
Login Session: Manager
MAC Address Tables
1
2
3
4
5
6
7
8
9
A
-
Show all MAC Addresses
Add static MAC Address
Delete MAC Address
Delete all dynamic MAC Addresses
Show all static MAC addresses
View MAC addresses by Port
View the port of MAC address
View MAC addresses by VLAN ID
View IP Multicast MAC Addresses
View MAC addresses on base ports
R - Return to Previous Menu
Enter your selection?
Figure 48 MAC Address Table Menu
2. To display both static and dynamic MAC addresses, type 1 to select
Show All MAC Addresses or A to select View MAC Addresses on Base
Ports. The second selection is useful if you are managing an AT-8000
Series switch with GBIC or expansion modules installed, and you want
to view the MAC addresses only on Ports 1 to 24.
3. To display only static MAC addresses, type 5 to select Show All Static
MAC Addresses.
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Section II: Local and Telnet Management
The management software displays the MAC addresses. Figure 49
is an example of the Show All MAC Addresses window, which
displays both static and dynamic MAC addresses. The static MAC
address window is exactly the same, except for the title and the
fact that it displays only static MAC addresses.
Allied Telesyn Ethernet Switch AT-8024
Login Session: Manager
Show All MAC Addresses
MAC
Port PMAP
CPU MIR EMP VlanID Type
--------------------------------------------------------------------01:80:C1:00:02:01 0
00000000 Yes Yes Yes 0
Static (fixed, non-aging)
00:a0:d2:18:1a:c8 1
00000000 No No
No
1
Dynamic
00:a0:c4:16:3b:80 2
00000000 No No
No
1
Dynamic
00:a0:12:c2:10:c6 3
00000000 No No
No
1
Dynamic
00:a0:c2:09:10:d8 4
00000000 No No
No
1
Dynamic
00:a0:33:43:a1:87 5
00000000 No No
No
1
Dynamic
00:a0:12:a7:14:68 6
00000000 No No
No
1
Dynamic
00:a0:d2:22:15:10 7
00000000 No No
No
1
Dynamic
00:a0:d4:18:a6:89 8
00000000 No No
No
1
Dynamic
U - Update Display
R - Return to Previous Menu
Enter your selection?
Figure 49 Show All MAC Addresses Window
The information is for viewing purposes only. The columns in the
window are defined below.
MAC
The MAC address of the node connected to the switch.
Port
The port on the switch where the MAC address was learned.
PMAP
The ports on the switch that are members of a multicast group.
This column is useful in determining which ports belong to
different multicast groups. (The abbreviation PMAP is derived
from “port mapping.”)
Each “0” is a hexadecimal value for the binary value “0000”. Each
binary “0” represents a port on the switch. A binary “0” means that
the port is not a member of a multicast group while a “1” means
that it is.
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AT-S39 User’s Guide
The port numbering scheme is from right to left. As an example,
assume that ports 1 through 4 on the switch were members of the
same multicast group. This would be represented in the column
as follows: “0000000F”. Another example is “000020F. This
example would indicate that ports 1 to 4 and port 10 on the switch
were members of the same multicast group.
CPU
This feature is not supported.
MIR
Indicates whether the traffic on the port is being mirrored. Yes
means the traffic is being mirrored while No indicates that it is not.
EMP
Indicates whether multicast packets are being forwarded by ports
in the blocking state. This feature is not supported at this time.
This column will indicate “No” for all multicast addresses, except
for the switch’s MAC address. Multicast packets are forwarded
only by ports in the forwarding state.
VLANID
The VID of the VLAN to which the port is an untagged member.
Type
The MAC address type. The type can be either static or dynamic.
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Section II: Local and Telnet Management
Viewing MAC Addresses by Port
This section contains the procedure for viewing the dynamic MAC
addresses that have been learned on a particular port. You can also use
this procedure to view any static MAC addresses that have been
assigned to a port.
1. From the Main Menu, type 6 to select MAC Address Table.
2. From the MAC Address Tables menu, type 6 to select View MAC
Addresses by Port Menu.
The following prompt is displayed:
Please enter port number -> [1 to 26] ->
3. Enter the number of the port whose static and dynamic MAC
addresses you want to view and press Return.
A window is displayed with the MAC addresses of the end nodes
on the port. The columns in the window and the definitions of the
columns are the same as for the Show All MAC Addresses window
on page 153.
The information in this window is for viewing purposes only.
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AT-S39 User’s Guide
Identifying a Port Number by MAC Address
In some situations, you might want to know which port a particular MAC
address was learned. You could display the MAC address table and scroll
through the list looking for the MAC address. But if the switch is part of a
large network, finding the address could prove difficult.
The procedure in this section offers an easier way. You can specify the
MAC address and let the management software automatically locate the
port on the switch where the device is connected.
1. From the Main Menu, type 6 to select MAC Address Tables.
2. From the MAC Address Tables menu, type 7 to select View the Port of
MAC Address.
The following prompt is displayed:
Please enter MAC address:
3. Enter the MAC address of the node in the following format and press
Return:
XXXXXX XXXXXX
The management software displays a prompt containing the port
number on the switch to which the node is connected, if the
address was learned dynamically, or to which the address was
assigned, for a static address.
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Section II: Local and Telnet Management
Viewing the MAC Addresses of a VLAN
The procedure in this section can be useful if you created VLANs on the
switch and want to view the MAC addresses of the nodes of a particular
VLAN. (This procedure is not of much value if the switch contains only
the Default VLAN, in which case displaying the entire MAC address table,
as explained earlier in this chapter, produces the same result.)
Note
To perform this procedure, you need to know the VID number of the
VLAN whose MAC addresses you want to view. To obtain a VLAN’s
VID, refer to Displaying VLAN Information on page 135.
To view the MAC addresses of a VLAN on the switch, perform the
following procedure.
1. From the Main Menu, type 6 to select MAC Address Tables.
2. From the MAC Address Tables menu, type 8 to select View MAC
Addresses by VLAN ID Menu.
The following prompt is displayed:
Please enter a VLAN ID: [1 to 4095] ->
3. Enter the VID of the desired VLAN and press Return.
The management software displays a window with a list of the
MAC addresses of the nodes in the VLAN. For an example of the
window and for definitions of the columns, refer to the Show All
MAC Addresses window on page 153.
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AT-S39 User’s Guide
Deleting All Dynamic MAC Addresses
The management software allows you to purge the MAC address table
of all dynamic MAC addresses. Once the table has been purged, the
switch immediately begins to relearn the MAC addresses as frames are
received on the ports.
Note
This procedure does not delete static MAC addresses.
To delete all dynamic MAC addresses from the MAC address table,
perform the following procedure.
1. From the Main Menu, type 6 to select MAC Address Tables.
2. From the MAC Address Tables menu, type 4 to select Delete All
Dynamic MAC Addresses.
A following prompt is displayed:
All learned MAC (non-static) addresses will be
deleted.
Do you want to continue? [Yes/No] ->
3. Type Y for yes to delete the dynamic MAC addresses or N for no to
cancel the procedure.
If you type Y for yes, the dynamic MAC addresses are deleted from
the MAC address table. The switch immediately begins to relearn
the addresses and to add them to the table.
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Section II: Local and Telnet Management
Adding Static and Multicast MAC Addresses
This section contains the procedure for adding static and multicast
addresses to the switch. You can assign up to 255 static MAC addresses
per port on an AT-8000 Series switch.
To add a static or multicast address to the MAC address table, perform
the following procedure:
1. From the Main Menu, type 6 to select MAC Address Tables.
2. From the MAC Address Tables menu, type 2 to select Add Static MAC
Address.
The following prompt is displayed:
Please enter a MAC address ->
3. Enter the static MAC address in the following format:
XXXXXX XXXXXX
Once you have specified the MAC address, the following prompt
is displayed:
Please enter a port number: [1 to 24] ->
4. Enter the number of the port on the switch to which you want to
assign the address.
The management software adds the address to the MAC address
table.
5. Repeat steps 2 to 4 to enter additional static or multicast MAC
addresses.
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AT-S39 User’s Guide
Deleting MAC Addresses
The following procedure explains how to delete a static, dynamic, or
multicast MAC address from the MAC address table.
To delete an address from the MAC address table, perform the following
procedure:
1. From the Main Menu, type 6 to select MAC Address Tables.
2. From the MAC Address Tables menu, type 3 to select Delete MAC
Address.
The following prompt is displayed:
Please enter a MAC address ->
3. Enter the MAC address to be deleted in the following format and
press Return:
XXXXXX XXXXXX
The MAC address is deleted from the switch’s MAC address table.
Note
You cannot delete a switch’s MAC address, an STP BPDU MAC
address, or a broadcast address.
4. Repeat the procedure to delete additional MAC addresses.
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Section II: Local and Telnet Management
Changing the Aging Time
The switch uses the aging time to delete inactive dynamic MAC
addresses from the MAC address table. When the switch detects that no
packets have been sent to or received from a particular MAC address in
the table after the period specified by the aging time, the switch deletes
the address. This prevents the table from becoming full of addresses of
nodes that are no longer active.
The default setting for the aging time is 300 seconds (5 minutes).
To adjust the aging time, perform the following procedure:
1. From the Main Menu, type 5 to select System Config Menu.
2. From the System Config Menu, type 1 to select MAC Aging Time.
The following prompt is displayed:
Enter your new value -> [1 to 1048575]
3. Enter a new value in seconds.
The value should be an increment of 5 seconds, for example 410,
415, or 420. A value that is not an increment of 5 is rounded down
to the next increment of 5. For example, the value 524 is rounded
down to 520.
The new value is immediately activated on the switch.
161
Chapter 12
Class of Service
This chapter contains the procedures for configuring the Class of Service
(CoS) feature of the AT-S39 software. Sections in the chapter include:
❑ Class of Service Overview on page 163
❑ Configuring CoS on page 164
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Section II: Local and Telnet Management
Class of Service Overview
The AT-8000 Series switch supports CoS as specified in the IEEE 802.1p
and 802.1Q standards. CoS can be important in network environments
where there are time-critical applications, such as voice transmission or
video conferencing, that can be adversely affected by packet transfer
delays.
Prior to CoS, network traffic was handled in a best-effort manner. File
transfer delays did occur, but were mostly transparent to network users.
But with the introduction of time-critical applications, packet transfer
delays can prove problematic. For example, transfer delays of voice
transmission can result in poor audio quality.
CoS was designed to address this problem. The 802.1p standard outlines
eight levels of priority, 0 to 7, with 0 the lowest priority and 7 the highest.
The AT-8000 Series switch has two priority queues, low and high. When a
tagged packet enters a switch port, the switch responds by placing the
packet into one of the two queues according to following assignments:
IEEE 802.1p
Priority Levels
AT-8000 Series Switch
Queue
7
6
5
4
3
2
1
0
high
high
high
high
low
low
low
low
For example, a tagged packet with a priority tag of 6 is placed in the high
priority queue, while a packet with a priority tag of 1 is placed in the low
priority queue.
These priority-to-queue assignments can be overridden using the
AT-S39 management software on a per port basis.
You can also use CoS to control which priority queue handles untagged
frames that ingress a port. By default, untagged frames (i.e., frames
without VLAN or priority level information) are automatically assigned to
the low priority buffer. But you can configure CoS on a port so that all
untagged frames received on the port are directed to the high priority
queue.
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Configuring CoS
To configure CoS for a port, perform the following procedure:
1. From the Main Menu, type 2 to select VLAN Menu.
2. From the VLAN Menu, type 3 to select Configure Port VLANS &
Priorities.
3. Type 1 to select Configure Port VLANs & Priorities. The following
prompt is displayed:
Enter port number -> [1 to 24] ->
4. Enter the number of the port on the switch where you want to
configure CoS. Press Return. The Port VLANS & Priorities window in
Figure 43 on page 140 is displayed.
5. Type 3 to select Priority (0 - 7). The following prompt is displayed:
Enter new value -> [0 to 7]
6. If you want all tagged and untagged frames received on the port to
go to the low priority queue, enter a value from 0 to 3. (It does not
matter which value you enter so long as it’s from 0 to 3.) If you want
all frames received on the port to go to the high priority queue, enter
a value from 4 to 7. (Again, it does not matter which number it is so
long as it is from 4 to 7.)
7. If you are configuring a tagged port and you want the switch to
ignore the priority tag in the tagged frames that ingress the port, type
4 to select Override Priority and type Y.
All tagged frames will be directed to either the low or high priority
queue as specified in Step 6.
Note
The tagged information in a frame is not changed as the frame
traverses the switch. A tagged frame leaves a switch with the same
priority level that it had when it entered.
The default for this parameter is No, meaning that the priority
level of tagged frames is determined by the priority level specified
in the frame itself.
8. Type C to select Configure Port VLANS & Priorities.
9. Type S to select Save Configuration Changes.
10. Repeat this procedure to configure CoS on other ports on the switch.
Note
To view the priority queue assignment for each port and the
override priority status, refer to Displaying PVIDs and Port
Priorities on page 141.
164
Chapter 13
IGMP Snooping
This chapter explains how to activate and configure the Internet Group
Management Protocol (IGMP) snooping feature on the switch. Sections
in the chapter include:
❑ IGMP Snooping Overview on page 166
❑ Activating IGMP Snooping on page 168
❑ Displaying a List of Host Nodes on page 171
❑ Displaying a List of Multicast Routers on page 172
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AT-S39 User’s Guide
IGMP Snooping Overview
IGMP snooping is best explained by first defining IGMP. This protocol
enables routers to create lists of nodes that are members of multicast
groups. (A multicast group is a group of end nodes that want to receive
multicast packets from a multicast application.) The router creates a
multicast membership list by periodically sending out queries to the
local area networks connected to its ports.
A node wanting to become a member of a particular multicast group
responds to a query by sending a report. A report indicates an end
node’s intention to become a member of a multicast group. Nodes that
join a multicast group are referred to as host nodes. Once a host node has
been made a member of a multicast group, it must continue to
periodically issue reports to remain a member.
Once the router has received a report from a host node, it notes the
multicast group that the host node wants to join and the port on the
router where the node is located. Any multicast packets belonging to
that multicast group are then forwarded by the router out the port. If a
particular port on the router has no nodes that want to be members of
multicast groups, the router does not send multicast packets out the
port. This improves network performance by restricting multicast
packets only to router ports where host nodes are located.
There are two versions of IGMP, referred to as Version 1 and Version 2.
One of the differences between the two versions is how a host node
indicates that it no longer wants to be a member of a multicast group. In
Version 1, it simply stops sending reports. If a router does not receive a
report from a host node after a predefined length of time, referred to as
a time-out value, it assumes that the host node no longer wants to
receive multicast frames, and removes it from the membership list of the
multicast group.
In Version 2, a host node exits from a multicast group by sending a leave
request. Once a router receives a leave request from a host node, it
removes the node from appropriate membership list. The router will also
stop sending out multicast packets out the port to which the node is
connected if it determines there are no further host nodes on the port.
IGMP snooping enables the Fast Ethernet switch to monitor the flow of
queries from a router and reports from host nodes to build its own
multicast membership lists. It uses the lists to forward multicast packets
only to switch ports where there are host nodes that are members of
multicast groups. This improves switch performance and network
security by restricting the flow of multicast packets only to those switch
ports connected to host nodes.
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Without IGMP snooping, a switch would have to flood multicast packets
out all of its ports, except the port on which it received the packet. Such
flooding of packets can negatively impact switch and network
performance.
The AT-8000 Series switch supports both IGMP Version 1 and Version 2.
The switch maintains its multicast groups through an adjustable timeout value, which controls how frequently it expects to see reports from
end nodes that want to remain members of multicast groups, and by
processing leave requests.
Note
By default, IGMP snooping is disabled on the switch.
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AT-S39 User’s Guide
Activating IGMP Snooping
To activate or deactivate IGMP snooping on the switch and to configure
IGMP snooping parameters, perform the following procedure:
1. From the Main Menu, type 5 to select System Config Menu.
2. From the System Configuration Menu, type A to select Advanced
Configuration.
3. From the Advanced Configuration window, type 1 to select IGMP
Snooping Configuration.
The IGMP Snooping Configuration window in Figure 50 is
displayed.
Allied Telesyn Ethernet Switch AT-8024
Login Session: Manager
IGMP Snooping Configuration
1
2
3
4
5
6
7
-
IGMP Snooping Status .........
Multicast Host Topology ......
Host/Router Timeout Interval .
Maximum Multicast Groups .....
Multicast Router Port(s) .....
View Multicast Hosts List
View Multicast Router List
Disabled
Single-Host/Port (Edge)
260 seconds
256
Auto Detect
S - Save Configuration Changes
R - Return to Previous Men
Enter your selection:
Figure 50 IGMP Snooping Configuration Window
The options in the window are defined below:
1 - IGMP Snooping Status
Enables and disables IGMP snooping on the switch. After
selecting this option, type E to enable or D to disable this feature.
2 - Multicast Host Topology
Defines whether there is only one host node per switch port or
multiple host nodes per port. Possible settings are SingleHost/Port (Edge) and Multi-Host/Port (Intermediate).
The Single-Host/Port setting is appropriate when there is only one
host node connected to each port on the switch. This setting
causes the switch to immediately stop sending multicast packets
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Section II: Local and Telnet Management
out a switch port when a host node signals its desire to leave a
multicast group by sending a leave request or when the host node
stops sending reports. The switch responds by immediately
ceasing the transmission of further multicast packets out the port
where the host node is connected.
The Multi-Host setting is appropriate if there is more than one
host node connected to a switch port, such as when a port is
connected to an Ethernet hub to which multiple host nodes are
connected. With this setting selected the switch continues
sending multicast packets out a port even after it receives a leave
request from a host node on the port. This ensures that the
remaining active host nodes on the port will continue to receive
the multicast packets. Only after all the host nodes connected to
a switch port have transmitted leave requests (or have timed out)
will the switch stop sending multicast packets out the port.
If a switch has a mixture of host nodes, that is, some connected
directly to the switch and others through an Ethernet hub, you
should select the Multi-Host Port (Intermediate) selection.
3 - Host/Router Timeout Interval
Specifies the time period in seconds after which the switch
determines that a host node has become inactive. An inactive
host node is a node that has not sent an IGMP report during the
specified time interval. The range is from 1 second to 86,400
seconds (24 hours). The default is 260 seconds.
This parameter also specifies the time interval used by the switch
in determining whether a multicast router is still active. The switch
makes the determination by watching for queries from the router.
If the switch does not detect any queries from a multicast router
during the specified time interval, it assumes that the router is no
longer active on the port.
4 - Maximum Multicast Groups
Specifies the maximum number of multicast groups the switch
will learn. The range is 1 to 2048 groups. The default is 256
multicast groups.
This parameter is useful with networks that contain a large
number of multicast groups. You can use the parameter to
prevent the switch’s MAC address table from filling up with
multicast addresses, leaving no room for dynamic or static MAC
addresses. The range is 1 address to 2048 addresses. The default is
256 multicast addresses.
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AT-S39 User’s Guide
5 - Multicast Router Port(s)
Specifies the port on the switch to which the multicast router is
detected. You can let the switch determine this automatically by
selecting Auto Detect, or you can specify the port yourself by
entering a port number. To select Auto Detect, enter “0” (zero) for
this parameter. You can specify more than one port.
Note
Selections 6 and 7 in the menu are discussed later in this chapter.
4. After making the desired changes, type S to select Save Configuration
Changes.
Your changes are activated immediately on the switch.
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Section II: Local and Telnet Management
Displaying a List of Host Nodes
You can use the AT-S39 software to display a list of the multicast groups
on a switch, as well as the host nodes. To display the list, perform the
following procedure:
1. From the Main Menu, type 5 to select System Config Menu.
2. From the System Configuration Menu, type A to select Advanced
Configuration.
3. From the Advanced Configuration window, type 1 to select IGMP
Snooping Configuration.
The IGMP Snooping Configuration window in Figure 50 is
displayed.
4. From the IGMP Snooping Configuration window, type 6 to select
View Multicast Host List.
The View Multicast Host List in Figure 51 is displayed.
Allied Telesyn Ethernet Switch AT-8024
Login Session: Manager
View Multicast Hosts List
============================================
MulticastGroup MemberPort VLAN
Host IP
============================================
U - Update Display
R - Return to Previous Menu
Enter your selection?
Figure 51 View Multicast Hosts List Window
The information in this window is for viewing purposes only. The
columns are defined below:
Multicast Group
The multicast address of the group.
Membership Port
The port(s) on the switch to which one or more host nodes of the
multicast group are connected.
VLAN
The VID of the VLAN in which the port is an untagged member.
Host IP
The IP address(es) of the host node(s) connected to the port.
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AT-S39 User’s Guide
Displaying a List of Multicast Routers
A multicast router is a router that is receiving multicast packets from a
multicast application and transmitting the packets to host nodes. You
can use the AT-S39 software to display a list of the multicast routers that
are connected to the switch.
To display a list of the multicast routers, perform the following
procedure:
1. From the Main Menu, type 5 to select System Config Menu.
2. From the System Configuration Menu, type A to select Advanced
Configuration.
3. From the Advanced Configuration window, type 1 to select IGMP
Snooping Configuration.
The IGMP Snooping Configuration window in Figure 50 is
displayed.
4. From the IGMP Snooping Configuration window, type 7 to select
View Multicast Routers List.
The View Multicast Router List in Figure 51 is displayed.
Allied Telesyn Ethernet Switch AT-8024
Login Session: Manager
View Multicast Routers List
============================================
Port
VLAN
Router IP
============================================
U - Update Display
R - Return to Previous Menu
Enter your selection?
Figure 52 View Multicast Routers List Window
The information in this window is for viewing purposes only. The
columns are defined below:
Port
The port on the switch where the multicast router is connected.
VLAN
The VID of the VLAN in which the port is an untagged member.
Router IP
The IP address of the multicast router.
172
Chapter 14
Broadcast Frame Control
This chapter contains the procedures for configuring the broadcast
frame control feature of the AT-S39 management software. Sections in
the chapter include:
❑ Broadcast Frame Control Overview on page 174
❑ Configuring the Interval Timer on page 176
❑ Configuring the Maximum Broadcast Frame Count on page
178
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AT-S39 User’s Guide
Broadcast Frame Control Overview
Most frames on an Ethernet network are unicast frames. A unicast frame
is a frame that is sent to a single destination. That is, the node sending a
unicast frame intends the frame for a particular node on the network. For
example, when a node needs to send a file to a network server for
storage, the node sends the file in unicast Ethernet frames containing
the destination address of the server where the file is to be stored.
Broadcast frames are different. Broadcast frames are directed to all
nodes on the network or all nodes within a particular virtual LAN.
Broadcast packets can perform a variety of functions in an Ethernet
network. For example, some network operating systems use broadcast
frames to announce the presence of devices on the network.
The problem with broadcast frames is that too many of them traversing
a network can impact network performance. The more bandwidth
consumed by broadcast frames, the less available for unicast frames.
Should the performance of your network be impacted by heavy
broadcast traffic, you can use the AT-S39 management software to limit
the number of broadcast frames that are forwarded by the switch and so
limit the number of broadcast frames on your network.
You accomplish this by specifying the maximum number of broadcast
frames that you want the switch to forward within a specified time
interval. Broadcast frames that exceed the maximum on a port during
the time interval are not forwarded and are dropped by the switch.
In order to use this feature, you must set two values: the interval timer
and the maximum broadcast frame limit.
The interval timer defines the time period used in counting the number
of forwarded broadcast frames on a port. There are two interval timers.
One timer is for ports operating at 10 Mbps or 100 Mbps. The second
timer is for 1000 Mbps ports. The timer interval for 10 and 100 Mbps
ports is measured in milliseconds. The timer interval for 1000 Mbps ports
is measured in microseconds. A time interval setting applies to all ports
operating at the corresponding speed on the switch.
The maximum broadcast frame limit specifies the maximum number of
broadcast frames the switch will forward on a port during the specified
timer interval. Broadcast frames received once the maximum has been
exceeded are not forwarded by the port and are discarded. You can
specify a different maximum for each port on the switch.
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It is important to note that the maximum number applies to the egress
port of a broadcast frame, not the ingress port. That is, any port on the
switch will accept any number of broadcast frames. But a port will
transmit out (forward) a broadcast frame only if it has not exceeded the
maximum number of broadcast frames it can transmit.
Here’s an example. Let’s assume you set the timer interval for 10 and 100
Mbps ports to 100 milliseconds and the maximum broadcast frame limit
for a particular 100 Mbps port on the switch to 200 broadcast frames. At
these settings, the port will forward (transmit out) up to 200 broadcast
frames every 100 milliseconds. If the maximum is exceeded during the
specified time interval, the port discards any additional broadcast frames
and does not forward them.
Note
The AT-S39 default setting is no broadcast frame control on the
switch.
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AT-S39 User’s Guide
Configuring the Interval Timer
To set the interval timer for the broadcast frame control feature, perform
the following procedure:
1. From the Main Menu, type 5 to select System Config Menu.
2. From the System Configuration Menu, type A to select Advanced
Configuration.
3. From the Advanced Configuration Menu, type 2 to select Broadcast
Timers Setup.
The Broadcast Storm Control window in Figure 53 is displayed.
Allied Telesyn Ethernet Switch AT-8024
Login Session: Manager
Broadcast Storm Control
1 - Timer for 10/100 MB ports ..... 10 milli sec
2 - Timer for 1000 MB ports ....... 100 micro sec
S - Save Configuration Changes
R - Return to Previous Menu
Enter your selection?
Figure 53 Broadcast Storm Control Window
4. Type 1 or 2 and enter a value when prompted.
The interval timer for 10 Mbps and 100 Mbps ports is in
milliseconds and has a range of 10 to 120 milliseconds. The value
should be entered in increments of 10.
The interval timer for 1000 Mbps ports is in microseconds and has
a range of 100 to 120000 microseconds. The value should be
entered in increments of 100.
A value for an interval timer applies to all ports operating at the
corresponding speed.
Note
The 1000 Mbps speed applies only to GBIC modules in an
AT-8024GB switch and expansion modules in an AT-8016F Series
switch.
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Section II: Local and Telnet Management
5. Once you have set the desired timer intervals, type S to select Save
Configuration Changes.
Your changes are immediately activated on the switch.
6. Go to the next procedure and specify the maximum number of
broadcast frames the ports on the switch can receive.
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AT-S39 User’s Guide
Configuring the Maximum Broadcast Frame Count
To specify the maximum number of broadcast frames a port on the
switch can receive and forward, perform the following procedure:
1. From the Main Menu, type 1 to select Port Menu.
2. From the Port Menu, type 1 to select Port Configuration.
The following prompt is displayed:
Starting Port to Configure [1 to 24] ->
3. Enter the number of the port you want to configure and press Return.
To configure a range of ports, enter the first port of the range.
The following prompt is displayed:
Ending Port to Configure [1 to 24] ->
4. To configure only one port, enter the same port number here as you
entered in Step 3 and press Return. To configure a range of ports,
enter the last port number in the range.
The Port Configuration window in Figure 14 on page 64 is
displayed.
5. Type B to select Broadcast Control.
The following prompt is displayed:
Enter Max. Broadcasts (0 -> No limit) :
[0 to 1023] - >
6. Specify the maximum number of broadcast frames the port can
receive during the timer interval. Press Return.
For example, assume that you are specifying the maximum
broadcast frame count for a port operating at 100 Mbps, and you
specified a 10 millisecond interval timer for 100 Mbps ports. If you
entered a value of 200 at the prompt, the switch will transmit a
maximum of 200 broadcast frames on the port every 10
milliseconds. If more than 200 broadcast frames are transmitted
by the port during the time interval, all broadcast frames over 200
are discarded by the port and are not forwarded.
Entering a value of “0” displays broadcast frame control on the
port.
7. Type S to select Save Configuration Changes.
Your changes are immediately activated on the switch.
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Chapter 15
TACACS+ and RADIUS Protocols
This chapter contains the procedure for configuring the two
authentication protocols TACACS+ and RADIUS. Sections in the chapter
include:
❑ TACACS+ and RADIUS Overview on page 180
❑ Configuring an Authorization Protocol on page 183
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AT-S39 User’s Guide
TACACS+ and RADIUS Overview
The AT-S39 software has two standard management login accounts:
Manager and Operator. The Manager account lets you change a switch’s
parameter settings while the Operator account only lets you view the
settings. Each account has its own password. The Manager account has a
default password of “admin” and the Operator account has a default
password “friend.”
For those networks that are managed by just one or two network
managers, the standard accounts may be all you need. However, for
larger networks managed by several network managers, you might want
to give each manager his or her own management login account rather
than have them share an account.
This is where TACACS+ and RADIUS can be useful. (TACACS+ is an
acronym for Terminal Access Controller Access Control System. RADIUS
is an acronym for Remote Authentication Dial In User Services.) These
are authentication protocols. They can be used to transfer the task of
validating management access from an AT-8000 Series switch to an
authentication protocol server.
With the protocols, you can create a series of username and password
combinations that define who can manage an AT-8000 Series switch.
Note
The authentication protocols cannot be used to control the flow of
data packets through the switch. They can only control who can and
cannot log onto the device to manage it. If you want to control the
flow of data packets, refer to Chapter 15, Port Security on page 70.
There are three basic functions an authentication protocol provides:
❑ Authentication
❑ Authorization
❑ Accounting
When a network manager logs in to a switch, the switch passes the
username and password entered by the manager to the authentication
protocol server. The server checks to see if the username and password
are valid for that switch. This is referred to as authentication.
If the combination is valid, the authentication protocol server notifies
the switch and the switch completes the login process, allowing the
manager to manage the switch.
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Section II: Local and Telnet Management
If the username and password combination is invalid, the authentication
protocol server notifies the switch and the switch cancels the login.
Authorization defines what a manager can do once logged in to a
switch. You assign an authorization level to each username and
password combination that you create on the server software. The
access level will be either Manager or Operator.
The final function of the TACACS+ protocol is accounting, which is used
to keep track of user activity on network devices. The AT-8000 Series
switch does not support this function.
Note
The AT-S39 management software does not support the two earlier
versions of the TACACS+ protocol, TACACS and XTACACS.
So what does it take to use the TACACS+ and RADIUS protocols on an
AT-8000 Series switch? Here are the main points.
❑ First, you need to install TACACS+ or RADIUS server software on
one or more of your network servers or management stations.
Authentication protocol server software is not available from
Allied Telesyn.
❑ The authentication protocol server can be on the same subnet or
a different subnet as the AT-8000 Series switch. If the server and
switch are on different subnets, be sure to specify a default
gateway in the Administration Menu so that the switch and server
can communicate with each other.
❑ You need to configure the TACACS+ or RADIUS server software.
This involves the following:
—
Specifying the username and password combinations.
—
Assigning each combination an authorization level. This will
differ depending on the server software you are using.
TACACS+ controls this through the sixteen (0 to 15) different
levels of the Privilege attribute. A privilege level of “0” gives
the combination Operator status., while any value from 1 to
15 gives it Manager status.
For RADIUS, management level is controlled by the Service
Type attribute. This attribute has 11 different values, of
which only two are functional with an AT-8000 Series
switch. A value of Administrative for this attribute gives the
username and password combination Manager access. A
value of NAS Prompt assigns the combination Operator
status.
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Note
This manual does not explain how to configure TACACS+ or RADIUS
server software. For that you need to refer to the documentation
that came with the software.
By default, authentication protocol is disabled on an AT-8000 Series
switch. Once you activate it, you will need to provide the following
information:
❑ Which authentication protocol you want to use. Only one
authentication protocol can be active on a switch at a time.
❑ IP addresses of up to three authentication servers.
❑ The encryption key used by the authentication servers.
Note
For more information on TACACS+, refer to the RFC 1492 standard.
For more information on RADIUS, refer to the RFC 2865 standard.
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Section II: Local and Telnet Management
Configuring an Authorization Protocol
To enable or disable the server-based authentication feature on the
switch and to configure the TACACS+ and RADIUS settings, perform the
following procedure:
1. From the Main Menu, type 4 to select Administration Menu.
2. From the Administration Menu, type A to select Server-based
Authentication.
The Authentication Menu in Figure 54 is displayed.
Allied Telesyn Ethernet Switch AT-8024
Login Session: Manager
Authentication Menu
1
2
3
4
-
Server-based Authentication ..... Disabled
Authentication Method ........... TACACS+
TACACS+ Configuration
RADIUS Configuration
S - Save Configuration Changes
R - Return to Previous Menu
Enter your selection?
Figure 54 Authentication Menu
3. To enable or disable the authentication feature on the switch, type 1
to select Server-based Authentication. The following prompt is
displayed:
Server Based User Authentication (E-Enabled, DDisabled) ->
4. Type E to enable the TACACS+ and RADIUS protocols on the switch or
D to disable them. The default is disabled.
If you enable the authentication feature, continue to the next
step. If you disabled it, type S to save your change. You can now
return to the Main Menu.
5. To select an authentication protocol, type 2 to select Authentication
Method. The following prompt is displayed:
Enter T-TACACS+, R-RADIUS ->
6. Type T to select TACACS+ or R for RADIUS. The default is TACACS+.
Only one protocol can be active on the switch at a time.
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Once you have activated the authentication feature on the switch
and designated which authentication protocol you intend to use,
you are ready to configure the selected protocol. If you selected
TACACS+, go to Step 7. If you selected RADIUS, go to Step 8.
7. To configure TACACS+, do the following:
a. Type 3 to select TACACS+ Configuration.
The following window is displayed:
Allied Telesyn Ethernet Switch AT-8024
Login Session: Manager
Authentication Menu
1
2
3
4
5
6
-
TAC
TAC
TAC
TAC
TAC
TAC
Server 1 ..................
Server 2 ..................
Server 3 ..................
Server Order ..............
Global Secret .............
Timeout ...................
0.0.0.0
0.0.0.0
0.0.0.0
1 2 3
30 seconds
S - Save Configuration Changes
R - Return to Previous Menu
Enter your selection?
Figure 55 Authentication Menu (TACACS+)
b. Configure the settings as needed. The settings are described
below:
1 - TAC Server 1
2 - TAC Server 2
3 - TAC Server 3
Use these parameters to specify the IP addresses of up to
three network servers containing TACACS+ server software.
After you have entered an IP address, you will see the
following prompt:
Use per-server secret [Y/N] ->
If you will be specifying more than one TACACS+ server and if
all of the servers use the same encryption secret, you can
answer No to this prompt and enter the encryption secret
using the TAC Global Secret parameter.
However, if you are specifying only one TACACS+ server or if
the servers have difference encryption secrets, then respond
with Yes to this prompt. You will see:
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Section II: Local and Telnet Management
Enter per-server secret [max 40 characters] ->
Use this prompt to enter the encryption secret for the
TACACS+ server whose IP address you are specifying.
4 - TAC Server Order
You use this selection to indicate the order in which you want
the switch to query the TACACS+ servers for logon
authentication. Of course, you can skip this option if you
specified only one IP address. The default is 1, 2, and 3, in that
order.
5 - TAC Global Secret
If all of the TACACS+ servers have the same encryption secret,
rather then entering the same secret when you enter the IP
addresses, you can use this option to enter the secret just
once.
3 - TAC Timeout
This parameter specifies the maximum amount of time the
switch waits for a response from a TACACS+ server before
assuming the server cannot respond. If the timeout expires
and the server has not responded, the switch queries the next
TACACS+ server in the list. If there aren’t any more servers, the
switch defaults to the standard Manager and Operator
accounts. The default is 30 seconds. The range is 1 to 30
seconds.
c. After you have finished configuring the parameters, type S to
select Save Configuration Changes.
8. To configure the RADIUS protocol, from the Authentication Menu in
Figure 54 on page 183 do the following:
a. Type 4 to select RADIUS Configuration.
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AT-S39 User’s Guide
The following window is displayed:
Allied Telesyn Ethernet Switch AT-8024
Login Session: Manager
RADIUS Client Configuration
1
2
3
4
5
6
-
Global Encryption Key .............
Global Server Timeout period.......
RADIUS Server 1 Configuration .....
RADIUS Server 2 Configuration .....
RADIUS Server 3 Configuration .....
Show Status
0.0.0.0
0.0.0.0
0.0.0.0
0.0.0.0
0.0.0.0
S - Save Configuration Changes
R - Return to Previous Menu
Enter your selection?
Figure 56 RADIUS Client Configuration
b. Configure the parameters as needed. The parameters are defined
below:
Global Encryption Key
This parameter specifies the encryption key for the RADIUS
servers. This option is useful if you will be entering more than
one RADIUS server and all the servers share the same
encryption key. If the servers use different encryption keys,
leave this option blank.
Global Server Timeout period
This parameter specifies the maximum amount of time the
switch will wait for a response from a RADIUS server before
assuming that the server cannot respond. If the timeout
expires and the server hasn’t responded, the switch queries
the next RADIUS server in the list. If there aren’t any more
servers, than the switch will default to the standard Manager
and Operator accounts. The default is 30 seconds. The range is
1 to 30 seconds.
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Section II: Local and Telnet Management
3 - RADIUS Server 1 Configuration
4 - RADIUS Server 1 Configuration
5 - RADIUS Server 1 Configuration
Use these parameters to specify the IP addresses of up to
three network servers containing the RADIUS server software.
Selecting one of the options displays the following window:
Allied Telesyn Ethernet Switch AT-8024
Login Session: Manager
RADIUS Server 1 Configuration
1 - Server IP Address ................. 0.0.0.0
2 - Server Authentication UDP Port .... 1812
3 - Server Encryption Key ........ <Not Defined>
S - Save Configuration Changes
R - Return to Previous Menu
Enter your selection?
Figure 57 RADIUS Server Configuration
The options are described below:
1 - Server IP Address
Use this option to specify the IP address of the RADIUS server.
2 - Server Authentication UDP Port
Use this option to specify the UDP port of the RADIUS
protocol.
3 - Server Encryption Key
Use this option to specify the encryption key for the RADIUS
server.
c. After you have finished configuring the parameters, type S to
select Save Configuration Changes.
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Chapter 16
Ethernet Statistics
This chapter contains the procedures for displaying data traffic statistics.
Sections in the chapter include:
❑ Displaying Port Statistics on page 189
❑ Displaying Switch Statistics on page 191
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Section II: Local and Telnet Management
Displaying Port Statistics
To display Ethernet port statistics, perform the following procedure:
1. From the Main Menu, type 7 to select Ethernet Statistics.
The Ethernet Statistics menu in Figure 58 is displayed.
Allied Telesyn AT-8024 Ethernet Switch
Login Sesion: Manager
Ethernet Statistics
1 - Display Port Statistics
2 - Display Module Statistics
3 - Clear Statistics
R - Return to Previous Menu
Enter your selection?
Figure 58 Ethernet Statistics Menu
2. From the Ethernet Statistics menu, type 1 to select Display Port
Statistics.
A window is displayed containing the statistics for each port. The
information in this window is for viewing purposes only. The
statistics are defined below:
Total Count
Number of bytes received and transmitted on the port.
Transmit Packets (TX_COUNT)
Number of bytes transmitted out the port.
Received Packets (RX_COUNT)
Number of bytes received on the port.
Received Broadcast (RX_BRDCAST)
Number of broadcast packets received on the port.
Received Multicast (RX_MLTCAST)
Number of multicast packets received on the port.
Received Unicast (RX_UNICAST)
Number of unicast packets received on the port.
Received Overflow (RX_OVERFLOW)
Number of times the capacity of the port’s buffer has been
exceeded.
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CRC Error (CRC_ERROR)
Number of packets with a cyclic redundancy check (CRC) error but
with the proper length (64-1518 bytes) received on the port.
Undersize Packets (UNDERSIZE)
Number of packets that were less than the minimum length
specified by IEEE 802.3 (64 bytes including the CRC) received on
the port.
Oversize Packets (OVERSIZE)
Number of packets exceeding the maximum specified by IEEE
802.3 (1518 bytes including the CRC) received on the port.
Fragmented Packets (FRAGMENT)
Number of undersized packets, packets with alignment errors,
and packets with FCS errors (CRC errors) received on the port.
Port in Discards (PRT_DISCARD)
Number of frames successfully received and buffered by the port,
but discarded and not forwarded.
If you want to clear the counters on the port and return them to “0”,
select the option “3 - Clear Statistics” from the Ethernet Statistics
window.
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Displaying Switch Statistics
To display Ethernet statistics for an entire switch, perform the following
procedure:
1. From the Main Menu, type 7 to select Ethernet Statistics.
2. From the Ethernet Statistics menu, type 2 to select Display Module
Statistics.
The statistics for the port are displayed in the Display Module
Statistics window, shown in Figure 59.
Allied Telesyn Ethernet Switch AT-8024
Login Session: Manager
Display Module Statistics
Ethernet statistics for this module
TOTAL_COUNT .................
TX_COUNT ....................
RX_COUNT ....................
RX_BRDCAST ..................
RX_MLTCAST ..................
RX_UNICAST ..................
RX_OVERFLOW .................
CRC_ERROR ...................
UNDERSIZE ...................
OVERSIZE ....................
FRAGMENT ....................
PORT_IN_DISCARDS ............
0
0
0
0
0
0
0
0
0
0
0
0
U - Update Display
C - Clear Module Statistics
R - Return to Previous Menu
Enter your selection?
Figure 59 Display Module Statistics Window
The information in this window is for viewing purposes only. The
statistics are defined below:
Total Count
Number of valid packets received and transmitted by the switch.
Transmit Packets
Number of packets transmitted from the switch.
Received Packets
Number of packets received by the switch.
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Received Overflow
Number of times the capacity of the port buffers have been
exceeded.
Received Broadcast
Number of broadcast packets received on the switch.
Received Multicast
Number of multicast packets received on the switch.
CRC Error
Number of packets with a cyclic redundancy check (CRC) error but
with the proper length (64-1518 bytes) received by the switch.
Undersize Packets
Number of packets that were less than the minimum length
specified by IEEE 802.3 (64 bytes including the CRC) received on
the switch.
Fragmented Packets
Number of undersized packets, packets with alignment errors,
and packets with FCS errors (CRC errors) received on the switch.
Oversize Packets
Number of packets exceeding the maximum specified by IEEE
802.3 (1518 bytes including the CRC) received on the switch.
Port in Discards
Number of frames successful received and buffered by the switch,
but discarded and not forwarded.
If you want to clear the counters on the switch and return them to “0”,
select the option “3 - Clear Statistics” from the Ethernet Statistics Menu.
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Chapter 17
File Downloads and Uploads
There are three files that coexist on an AT-8000 Series switch while the
device is operating. They are:
❑ AT-S39 management software
This is the operating software for the switch.
❑ AT-S39 bootloader
This image contains the code that initially controls the switch
whenever you power on or reset the unit.
❑ Switch configuration file
This file contains the settings for the different switch parameters.
such as VLANs, STP settings, and so forth.
Note
In versions previous to AT-S39 Version 2.0.1, the management
software and bootloader were offered as separate files. In all later
versions, the files are combined into one image file.
You can use the AT-S39 management software to download new
versions of the management software and bootloader onto a switch so
that a switch always has the latest software.
You can also upload a configuration file from a switch onto a
management workstation and then download it onto another switch.
This can be useful in network environments containing a large number
of AT-8000 Series switches that will all be configure the same, or nearly
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the same. What you can do is configure one of the AT-8000 Series
switches in your network, and then download its configuration file to the
other switches. This can save you the trouble of having to configure each
switch individually.
There are a several different ways for downloading and uploading files
onto a switch. They are:
❑ Local management session
One method for downloading or uploading files is from a local
management session on the switch using either Xmodem or TFTP.
The procedure for this is explains in Transferring Files from a
Local Management Session on page 196.
❑ Switch to switch
This procedure is useful if you have a large number of AT-8000
Series switches in your network. What you can do is upgrade the
software on one master switch and then instruct the master
switch to upgrade the software in the other switches in the same
subnet. This procedure is explained in Downloading Files Switch
to Switch on page 201.
❑ Management workstation
You can also use TFTP from a management workstation on your
network to upload and download files, as explained in
Downloading and Uploading Files using TFTP from a
Management Workstation on page 205.
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Section II: Local and Telnet Management
Obtaining Software Updates
New releases of the AT-S39 management software are available from the
Allied Telesyn web site at www.alliedtelesyn.com and our FTP server at
ftp.alliedtelesyn.com. To log on to the FTP server, enter “anonymous” for
the user name and your email address for the password. Management
software for these switches will have “S39” as part of the filename.
Note
All switch models in the AT-8000 Series use the same management
software image.
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Transferring Files from a Local Management Session
This section contains the procedure for downloading or uploading the
following files onto a switch from a local management session.
❑ New AT-S39 software image and bootloader software
❑ Configuration file
You can transfer a file using Xmodem or TFTP. In order to use TFTP, there
must be a node on your network with the TFTP server software and the
file to download must be stored on the same node.
Caution
The switch will stop forwarding Ethernet traffic during the
download of the AT-S39 software image.
Note
Installing a new AT-S39 software image does not change the current
configuration of a switch (e.g., IP address, subnet mask, and virtual
LANs). To return a switch to its default configuration values, refer to
Returning the AT-S39 Software to the Factory Default Values on
page 50.
This procedure assumes that you have already obtained the new
software from Allied Telesyn and stored it on the management
workstation from which you will be performing the procedure, or on the
TFTP server.
To download a new software image or configuration file onto a switch,
perform the following procedure:
1. Establish a local management session on the switch where you intend
to download the new management software or configuration file.
For instructions, refer to Starting a Local Management Session
on page 28.
2. From the Main Menu, type 4 to select Administration Menu.
3. From the Administration Menu, type D to select Downloads &
Uploads.
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Section II: Local and Telnet Management
The following menu is displayed:
Allied Telesyn Ethernet Switch AT-8024
Login Session: Manger
Downloads & Uploads
1 - Download Application Image/Bootloader
2 - Download Configuration Data
3 - Upload Application Image
4 - Upload Configuration Data
R - Return to Previous Menu
Enter your selection?
Figure 60 Downloads & Uploads Menu
Note
Options 3 and 4 in the menu are described in Uploading Files on
page 203.
4. To download a new software image and bootloader onto the switch,
type 1. To download a configuration file, type 2.
The following prompt is displayed:
Download Method/Protocol [X-Xmodem, T-TFTP]:
5. To download a file using Xmodem, go to Step 6. To download a file
using TFTP, do the following:
a. Type T.
The following prompt is displayed:
TFTP Server IP address:
b. Enter the IP address of the TFTP server.
The following prompt is displayed:
Remote File Name:
c. Enter the directory path and file name of the image file or
configuration file that you want to download.
Note
The image file or configuration file must be stored on the TFTP
server.
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Once the filename has been specified, the download begins.
Downloading a configuration file takes only a few moments.
Downloading an AT-S39 image file can take several minutes.
If you are installing a new management image, the switch
begins to initialize the software after it is installed, a process
that takes approximately one minute to complete. Once the
management software is initialized, the switch automatically
resets.
Note
Do not interrupt the initialization process. Do not reboot the switch.
6. To download a file using Xmodem, type X at the prompt displayed in
Step 4.
The following prompt is displayed:
You are going to invoke the Xmodem download utility.
Do you wish to continue? [Yes/No]
7. Type Y for Yes.
The prompt “Downloading” is displayed.
8. Begin the file transfer of the new management software image.
Note
The transfer protocol must be Xmodem or 1K Xmodem.
Steps 9 through 12 illustrate how you would download a file using
the Hilgraeve HyperTerminal program.
9. From the HyperTerminal main window, select the Transfer menu.
Then select Send File from the pull-down menu, as shown in Figure
61.
Figure 61 Local Management Window
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Section II: Local and Telnet Management
The Send File window in Figure 62 is displayed.
Figure 62 Send File Window
10. Click the Browse button and specify the location and file to be
downloaded onto the switch.
11. Click on the Protocol field and select as the transfer protocol either
Xmodem or, for a faster download, 1K XModem.
12. Click Send.
The software immediately begins to download onto the switch.
The Xmodem File Send window in Figure 63 displays current
status of the software download. The download process takes a
couple minutes to complete.
Figure 63 XModem File Send Window
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AT-S39 User’s Guide
If you are installing a new management image, the switch begins
to initialize the software after it is installed, a process that takes
approximately one minute to complete. Once the management
software is initialized, the switch automatically resets.
Note
Do not interrupt the initialization process. Do not reboot the switch.
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Section II: Local and Telnet Management
Downloading Files Switch to Switch
The previous procedure explained how to download an AT-S39 software
image or configuration file onto a switch from a local management
session. This procedure explains how to download an AT-S39 software
image or configuration file from one AT-8000 Series switch to another
switch.
This procedure is useful in networks that contain a large number of AT8000 Series switches. Once you have updated the software on the
master switch of an enhanced stack, you can instruct the master switch
to automatically upgrade the other AT-8000 Series switches in the same
subnet.
Note
The following procedure can only be performed from a local
management session.
To download a management software image or configuration file from a
master switch to other switches in the same subnet, perform the
following procedure:
1. From the Main Menu, type 9 to select Enhanced Stacking.
The Enhanced Stacking window in Figure 10 on page 56 is
displayed.
2. From the Enhanced Stacking window, type 2 to select Stacking
Services.
Note
The “2 - Stacking Services” selection is available only on master
switches.
The window in Figure 11 on page 58 is displayed.
3. Do one of the following:
❑ To download both the AT-S39 software image and bootloader on
the master switch to another AT-8000 Series switch, type I to
select Image Download to Remote Switches.
❑ To download the configuration file on the master switch to
another AT-8000 Series switch, type C to select Config Download
to Remote Switches.
❑ To download just the bootloader on the master switch to another
switch, type B to select Bootloader Download to Remote
Switches.
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The following prompt is displayed:
Enter the starting remote switch number -> [1 to 12]
4. Enter the number of the switch whose software or configuration file
you want to update. To update a range of switches, enter the number
of the first switch.
The following prompt is displayed:
Enter the ending remote switch number -> [1 to 12]
5. Enter the last switch in the range you want to update. To update just
one switch, enter the same number here as you entered in the
previous step.
The following prompt is displayed:
Do you want to show remote switch burning flash ->
[Yes/No]
6. You can respond with Yes or No to this prompt. It does not affect the
download.
The following prompt is displayed:
Do you want confirmation before downloading each
switch -> [Yes/No]
7. Answering Yes to this prompt means that the management software
will prompt you with a confirmation message before it begins to
upgrade each switch. Answering No means the management
software will not display a confirmation prompt before downloading.
The management software begins the download. The
management software notifies you when the download is
complete.
Caution
Once a switch image file has been downloaded, the switch must
decompress it and write it to flash. This can require one to two
minutes to complete. Do not reset or power off the unit while it is
decompressing the file. Once the file has been decompressed, the
switch automatically resets.
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Section II: Local and Telnet Management
Uploading Files
To upload a management software image or configuration from a switch
onto your management station, perform the following procedure:
Note
It is not recommended that you upload an AT-S39 software image
onto a management workstation for download onto another
switch. New AT-S39 software images for downloading onto a switch
should only be obtained from the Allied Telesyn web site.
1. Start a local management session on the switch where you intend to
upload the management software image or configuration file.
For instructions, refer to Starting a Local Management Session
on page 28.
2. From the Main Menu, type 4 to select Administration Menu.
3. From the Administration Menu, type D to select Downloads &
Uploads.
The Downloads and Uploads menu in Figure 60 on page 197 is
displayed.
4. To upload the AT-S39 software image and bootloader from the
switch, type 3. To upload a configuration file, type 4.
The following prompt is displayed:
Download Method/Protocol [X-Xmodem, T-TFTP]:
5. To upload a file using Xmodem, go to Step 6. Upload a file using TFTP,
do the following:
a. Type T.
The following prompt is displayed:
TFTP Server IP address:
b. Enter the IP address of the TFTP server.
The following prompt is displayed:
Remote File Name:
c. Enter the file name that the image file or configuration file is to be
stored under on the TFTP server.
Once the filename has been specified, the upload begins.
Uploading a configuration file takes only a few moments.
Uploading an AT-S39 image file can take several minutes.
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AT-S39 User’s Guide
6. To upload a file using Xmodem, type X at the prompt displayed in
Step 4.
The following prompt is displayed:
You are going to invoke the Xmodem download utility.
Do you wish to continue? [Yes/No]
7. Type Y for Yes.
The prompt “Uploading” is displayed.
8. Begin the file transfer of the new management software image.
Note
The transfer protocol must be Xmodem or 1K Xmodem.
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Section II: Local and Telnet Management
Downloading and Uploading Files using TFTP from a
Management Workstation
You can upload and download files onto an AT-8000 Series switch from a
management workstation on your network using TFTP.
Downloading
Files
The AT-S39 software comes with TFTP server software. If your network is
using the TCP/IP protocol and if there is a workstation on your network
with TFTP client software, you can use the client software to download
the AT-S39 image file or configuration file onto a switch:
TFTP software is available from various sources and is included in SNMPc
which is can be purchased through Allied Telesyn. A command line
version is included in most UNIX variants and in Windows NT. Please
consult the documentation or the manufacturer of the software used on
the proper use of the software.
You need to provide the following information when using the TFTP
client software to download a file:
Host - This is the IP address of the AT-8000 Series switch to which you
are downloading the file.
Binary - You must specify binary mode for the file transfer.
Put - The Put command is used to download a file to the switch.
Source file - The path and filename of the file to be downloaded onto
the switch. The filename must be one of the following:
❑ “ATS39.img” for a new software image and bootloader
❑ “ATS39.cfg for a configuration file
Note
The filename of the software image or configuration file to be
downloaded must match the corresponding filename above. This
may require renaming the file.
Caution
Once a switch image file has been downloaded, the switch must
decompress it and write it to flash. This can require one to two
minutes to complete. Do not reset or power off the unit while it is
decompressing the file.
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Example
The following example downloads a new management software image
onto a switch with an IP address of 149.35.1.1.
tftp -i 149.35.1.1 put c:\ats39.img ats39.img
Uploading a
Configuration
File
The switch configuration information can be uploaded and saved to a
file on a workstation. This file can then be used to restore the
configuration information to the same switch or can be uploaded to
other switches of the same family that need to be configured identically.
The basic TFTP parameters for uploading a switch configuration file to a
workstation are as follows:
Host - This is the IP address of the switch that you are uploading the
configuration file from.
Binary - You must specify binary mode for the file transfer.
Get - The Get command is used to upload the configuration file to the
workstation.
Source file - The source file name is “ATS39.cfg”.
Destination file - The path and filename where you want to store the
configuration file.
Note
The switch configuration file cannot be edited.
Example
The following example uploads the configuration file from a switch with
an IP address of 149.35.1.1 to local drive C: of the workstation.
tftp -i 149.35.1.1 get ats39.cfg c:\ats39.cfg
Once the file is stored on a local drive, you can download it to another
switch using TFTP, as explained in the previous section.
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Section III
Web Browser Management
The chapters in this section explain how to manage an AT-8024 or
AT-8024GB Fast Ethernet switch using a web browser. The chapters
include:
❑ Chapter 18, Starting a Web Browser Management Session on
page 208
❑ Chapter 19, Basic Switch Parameters on page 212
❑ Chapter 20, Enhanced Stacking on page 225
❑ Chapter 21, Port Parameters on page 230
❑ Chapter 22, Port Security on page 239
❑ Chapter 23, Port Trunks on page 241
❑ Chapter 24, Port Mirroring on page 244
❑ Chapter 25, STP and RSTP on page 247
❑ Chapter 26, Virtual LANs on page 259
❑ Chapter 27, MAC Address Table on page 270
❑ Chapter 28, Class of Service on page 277
❑ Chapter 29, IGMP Snooping on page 279
❑ Chapter 30, Broadcast Frame Control on page 285
❑ Chapter 31, TACACS+ and RADIUS Protocols on page 288
207
Chapter 18
Starting a Web Browser
Management Session
This chapter contains the procedure for starting a management session
on an AT-8000 Series switch using a web browser, such as Microsoft
Internet Explorer or Netscape Navigator.
208
Starting a Web Browser Management Session
This section explains how to start a web browser management session.
There must be at least one AT-8000 Series switch on your network that
has been assigned an IP address. The switch with the IP address is
referred to as the master switch. Once you have started a Telnet
management session on the master switch, you will have management
access to all other AT-8000 Series switches that reside in the same
subnet.
Note
For background information on enhanced stacking, refer to
Enhanced Stacking Overview on page 53.
To start a web browser management session, perform the following
procedure:
1. Start your web browser.
Note
If your PC with the web browser is connected directly to the switch
to be managed or is on the same side of a firewall as the switch, you
must configure your browser’s network options not to use proxies.
Consult your web browser’s documentation on how to configure
the switch’s web browser not to use proxies.
2. Enter the IP address of the master switch of the enhanced stack in the
URL field of the browser, as shown in Figure 64.
Switch’s IP Address
Figure 64 Entering a Switch’s IP Address in the URL Field
3. When prompted, enter a user name and password. For manager
access, enter “manager” as the user name. The default password is
“admin”. For operator access, enter “operator” as the user name. The
default password is “friend”. The passwords are case-sensitive. (For
information on the two access levels, refer to Management Access
Levels on page 24.)
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AT-S39 User’s Guide
The user names cannot be changed. To change a password, refer
to Configuring an IP Address and Switch Name on page 37.
The window shown in Figure 65 is displayed.
Figure 65 Home Page
This is the Home page of the management software. In the left portion of
the Home page is the main menu:
❑ Enhanced Stacking
❑ Configuration
❑ Monitoring
❑ CLI (Command Line Interface)
❑ Exit
Note
The Enhanced Stacking selection is available only if the switch is the
master switch of an enhanced stack.
The CLI selection is explained in the AT-S39 Command Line
Interface User’s Guide. This guide is available from the Allied
Telesyn web site.
210
Note
A web browser management session remains active even if you link
to other sites. You can return to the management web pages
anytime as long as you do not quit the browser.
Browser Tools
You can use the browser tools to move around the Omega menus.
Selecting Back on your browser’s toolbar returns you to the previous
display. You can also use the browser’s bookmark feature on
frequently-used Omega menus and windows.
Quitting from a
Web Browser
Management
Session
To exit from a web browser management session, return to the Home
page and select Exit from the main menu.
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Chapter 19
Basic Switch Parameters
This chapter contains the following sections:
❑ Configuring an IP Address and Switch Name on page 213
❑ Activating the BOOTP and DHCP Services on page 217
❑ Viewing System Information on page 218
❑ Configuring the SNMP Parameters and Trap IP Addresses on
page 220
❑ Resetting a Switch on page 222
❑ Pinging a Remote System on page 223
❑ Returning the AT-S39 Software to the Factory Default Values
on page 224
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Section III: Web Browser Management
Configuring an IP Address and Switch Name
Note
For guidelines on when to assign an IP address, subnet address, and
gateway address to an AT-8024 or AT-8024GB switch, refer to When
Does a Switch Need an IP Address? on page 35.
To set the basic switch parameters for an AT-8024 or AT-8024GB Fast
Ethernet switch, perform the following procedure:
1. From the Home Page, select Configuration.
The Configuration window is displayed with the System menu
option selected by default.
2. If the System menu option is not selected, select it and then select the
General tab.
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AT-S39 User’s Guide
The General tab in Figure 66 is displayed.
Figure 66 General Tab Window - Configuration
Note
This procedure describes the parameters in the Administration
section of the window. The parameters in the Configuration and
Broadcast Storm Control sections are discussed later in this guide.
Note
The Reset button at the bottom of the window is used to reset the
switch.
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Section III: Web Browser Management
3. Change the parameters as desired.
The parameters are described below:
System Name
This parameter specifies a name for the switch (for example, Sales
Ethernet switch). Entering a value for this parameter is optional.
Note
You should assign each switch a name. The names can help you
identify the various switches in your network. This can help you
avoid performing a configuration procedure on the wrong switch.
Administrator
This parameter specifies the name of the network administrator
responsible for managing the switch. Entering a value for this
parameter is optional.
Comments
This parameter specifies additional information about the Fast
Ethernet switch, such as its location (e.g., Floor 4, Wiring closet
402B). Entering a value for this parameter is optional.
Manager Password
Manager Confirm Password
These parameters are used to change the administrator’s login
password for the switch. The password can be from 0 to 20
characters in length. The same password is used for both local and
remote management sessions. To create a new password, enter
the new password into both fields. The default password is
“admin”.
Caution
You should not use spaces or special characters, such as asterisks (*)
and exclamation points (!), in a password if you will be managing the
switch from a web browser. Many web browsers cannot handle
special characters in passwords.
Operator Password
Operator Confirm Password
These parameters are used to change the operator’s login
password for the switch. The password can be from 0 to 20
characters in length. The same password is used for both local and
remote management sessions. To create a new password, enter
the new password into both fields. The default password is
“friend”.
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AT-S39 User’s Guide
Caution
You should not use spaces or special characters, such as asterisks (*)
and exclamation points (!), in a password if you will be managing the
switch from a web browser. Many web browsers cannot handle
special characters in passwords.
IP address
This parameter specifies the IP address of the switch. You must
specify an IP address if you intend to remotely manage the switch
using a web browser, a Telnet utility, or an SNMP management
program.
Subnet mask
This parameter specifies the subnet mask for the switch. You must
specify a subnet mask if you assigned an IP address to the switch.
Gateway address
This parameter specifies the default router’s IP address. This
address is required if you intend to remotely manage the switch
from a management station that is separated from the switch by
a router.
4. After you have set the parameters, click Apply. Your changes are not
stored by the switch until you select Apply.
Note
A change to any of the above parameters, including the IP address
and subnet mask, is immediately activated on the switch.
A change to the IP address of the switch will result in the loss of the
remote management session. You can restart the management
session using the switch’s new IP address.
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Activating the BOOTP and DHCP Services
For background information on BOOTP and DHCP, refer to the section
Activating the BOOTP and DHCP Services on page 40.
To activate or deactivate the BOOTP and DHCP protocols on the switch
from a web browser management session, perform the following
procedure:
1. From the Home Page, select Configuration.
The Configuration window is displayed with the System menu
option selected by default.
2. If the System menu option is not selected, select it and then select the
General tab.
The General Tab window is displayed, as shown in Figure 66 on
page 214.
3. In the BOOTP/DHCP options in the General tab window, click either
Enable or Disable.
Note
If you activated BOOTP/DHCP, the switch immediately begins to
query the network for a BOOTP or DHCP server. The switch
continues to query the network for its IP configuration until it
receives a response.
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Viewing System Information
To view basic information about the switch, perform the following
procedure:
1. From the Home page, select Monitoring.
2. From the Monitoring menu, select System.
3. Select the General tab.
The General tab window in Figure 67 is displayed.
Figure 67 General Tab Window - Monitoring
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This window is for viewing purposes only. You cannot change any
of the values from this window. The sections in the window are
defined below.
General
This section displays the switch’s serial number and the switch’s
MAC address. These values cannot be changed.
Administration
This section contains a variety of information, including the IP
address of the switch and the system name. These parameters are
defined in the procedure Configuring an IP Address and Switch
Name on page 213, which also explains how to change the
parameters.
Configuration
This section contains the following items:
❑ MAC Aging - Specifies how long an inactive dynamic MAC address
can remain in the MAC address table before it is deleted. The
default is 300 seconds (5 minutes). For background information
about MAC addresses, refer to MAC Address Overview on page
150.
❑ Switch Mode - Defines the switch’s current VLAN mode. If this
parameter displays “Tagged,” the switch supports port-based and
tagged VLANs. If this parameter displays “Basic,” the switch is
operating in the Basic VLAN Mode. For information about VLANs,
refer to the overview sections in Chapter 10, Virtual LANs on
page 110. For instructions on how to set the switch’s VLAN mode
from a web browser management session, refer to Setting a
Switch’s VLAN Mode on page 142.
❑ BOOTP/DHCP - Defines whether the switch obtains its IP address
from a BOOTP or DHCP server on your network. If this parameter
is enabled, the switch obtains its IP address from a BOOTP or
DHCP server.
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Configuring the SNMP Parameters and Trap IP Addresses
To change the switch’s SNMP community strings or to specify the IP
addresses of management stations to receive traps from the switch,
perform the following procedure:
1. From the Home page, select Configuration.
2. From the Configuration menu, select System.
3. Select the SNMP tab.
The SNMP window in Figure 68 is displayed.
Figure 68 SNMP Tab
4. Adjust the parameters as desired. The parameters are described
below.
GET Community
SET Community
Trap Community
Use these parameters to set a switch’s SNMP community strings.
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Trap Receiver 1
Trap Receiver 2
Trap Receiver 3
Trap Receiver 4
Use these selections to specify the IP addresses of up to four
management workstations on your network to receive traps from
the switch.
Note
The Enable SNMP Access check box in the window controls whether
the switch can be remotely managed using an SNMP application
program. If the check box is empty, the switch cannot be managed
through SNMP. This is the default.
5. Click Apply to save your changes to the switch.
Changes are immediately activated on the switch.
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Resetting a Switch
To reset a switch, perform the following procedure:
1. From the Home Page, select Configuration.
The Configuration window is displayed with the System option
selected by default.
2. If the System menu option is not selected, select it and then select the
General tab.
3. Click the Reset button at the bottom of the window.
A confirmation prompt is displayed.
4. Click OK to reset the switch or Cancel to cancel the procedure.
Resetting the switch ends your web browser management
session. You must restart the session to continue managing the
switch.
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Pinging a Remote System
You can instruct the switch to ping a node on your network. This
procedure is useful in determining whether a valid link exists between
the switch and another device.
To ping a network device, perform the following procedure:
1. From the Home Page, select Monitoring.
2. From the Monitoring window, select the System menu option.
3. Select the Ping Client tab.
The window in Figure 69 is displayed.
Figure 69 Ping Client Window
4. Enter the IP address of the end node you want the switch to ping.
5. Click OK.
The results of the ping are displayed in a new window.
6. To stop the pinging, click OK.
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Returning the AT-S39 Software to the Factory Default Values
The procedure in this section returns all AT-S39 software parameters,
except the IP address, subnet mask, and gateway address, to their
default values. This procedure also deletes any VLANs that you have
created on the switch.
Note
The AT-S39 software default values can be found in Appendix A,
AT-S39 Default Settings on page 293.
To return the AT-S39 management software to its default settings,
perform the following procedure:
1. From the Home Page, select Configuration.
2. Select the System menu option.
3. Select the Factory Default tab.
The Factory Default tab in Figure 70 is displayed.
Figure 70 Factory Default Tab
4. Click the check box next to Reset Switch.
5. Click Apply.
6. Follow the prompts.
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Chapter 20
Enhanced Stacking
This chapter contains the following procedures:
❑ Setting a Switch’s Enhanced Stacking Status on page 226
❑ Selecting a Switch in an Enhanced Stack on page 228
Note
For background information on enhanced stacking, refer to
Enhanced Stacking Overview on page 53.
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Setting a Switch’s Enhanced Stacking Status
The enhanced stacking status of the switch can be master, slave, or
unavailable. Each status is described below:
❑ Master - A master switch of a stack can be used to manage all
other AT-8000 Series switches in a subnet. Once you have
established a local or remote management session with the
master switch, you can access and manage all the switches in the
subnet.
A master switch must have a unique IP address. You can
manually assign a master switch an IP address or activate the
BOOTP and DHCP services on the switch.
❑ Slave - A slave switch can be remotely managed through a master
switch. It does not need an IP address or subnet mask.
❑ Unavailable - A switch with an unavailable stacking status cannot
be remotely managed through a master switch. A switch with this
designation can be managed locally. To be managed remotely, a
switch with an unavailable stacking status must be assigned a
unique IP address.
Note
The default setting for a switch is Slave.
To adjust a switch’s enhanced stacking status, perform the following
procedure:
1. From the Home page, select Configuration.
2. From the Configuration page, select Layer 2.
3. Select the Enhanced Stacking tab.
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The Enhanced Stacking tab is shown in Figure 71.
Figure 71 Enhanced Stacking Tab
4. Click the desired enhanced stacking status for the switch.
5. Click Apply.
The new enhanced stacking status is immediately activated on
the switch.
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Selecting a Switch in an Enhanced Stack
The first thing that you should do before you perform any procedure on
a switch in an enhanced stack is check to be sure that you are
performing it on the correct switch. If you assigned system names to
your switches, then it is very easy. The name of the switch being
managed is displayed at the top of every management window.
When you start a web browser management session on the master
switch of a subnet, you are by default addressing that particular switch.
The management tasks that you perform effect only the master switch.
To manage a slave switch or another master switch in the same subnet,
you need to select it from the management software.
To select a switch to manage in an enhanced stack, perform the
following procedure:
1. From the Home page, select Enhanced Stacking.
Note
If the Home page does not have an Enhanced Stacking menu
selection, the switch’s enhanced stacking status is either slave or
unavailable. For instructions on how to change a switch’s stacking
status, refer to the previous procedure.
The master switch polls the network for all AT-8000 Series slave
and master switches in the same subnet and displays a list of the
switches in the Stacking Switches window, shown in Figure 72.
Figure 72 Stacking Switches Window
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Note
The master switch on which you started the management session is
not included in the list, nor are any switches with an enhanced
stacking status of Unavailable.
You can sort the switches in the list by switch name or MAC
address by clicking on the column headers. By default, the list is
sorted by MAC address.
You can refresh the list by clicking Refresh. This instructs the
master switch to again poll the subnet for all AT-8000 Series
switches.
2. To manage another switch in an enhanced stack, click the dialog
circle to the left of the appropriate switch in the list.
3. Click Connect.
The Home page of the selected switch is displayed. You can now
manage the switch.
Returning to
the Master
Switch
When you have finished managing a slave switch and want to manage
another switch in the subnet, return to the Home page of the switch and
select Disconnect from the menu. This returns you to the Stacking
Switches window in Figure 72 on page 228. Once you see that window,
you are again addressing the master switch from which you started the
management session.
You can either select another switch in the list to manage or, if you want
to manage the master switch, return to the master switch’s Home page
by selecting Home.
To end a management session, select Exit.
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Chapter 21
Port Parameters
The procedures in this chapter allow you to view and change the
parameter settings for the individual ports on a switch. Examples of port
parameters that you can adjust include duplex mode and port speed.
This chapter contains the following procedures:
❑ Configuring Port Parameters on page 231
❑ Displaying Port Status and Statistics on page 234
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Configuring Port Parameters
To configure the parameter settings for a port on a switch, perform the
following procedure:
1. From the Home page, select Configuration.
2. From the Configuration page, select Layer 1.
3. Select the Port Setting tab.
The Port Setting tab is shown in Figure 73.
Figure 73 Port Setting Configuration Tab
4. Click the port in the graphical switch image that you want to
configure. The selected port turns white. You can select more than
one port at a time to configure. (To deselect a port, click it again.)
5. Click Modify.
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The Settings for Port window is displayed. An example of the
window is shown in Figure 74.
Figure 74 Settings for Port Window
Note
Clicking the Default button returns the port settings to the default
values. Default values are listed in Appendix A, AT-S39 Default
Settings on page 293.
6. Adjust the port parameters as desired.
The parameters are described below.
Disable Port
You can use this check box to enable or disable a port. A disabled
port will not accept or transmit frames. The default for this port
parameter is enabled.
Speed and Mode
The operating speed and duplex mode of the port. Possible
settings for this parameter are:
❑ Auto-Negotiate: The port will Auto-Negotiate both speed and
duplex mode. This is the default.
❑ 10Mbps - Half Duplex
❑ 10Mbps - Full Duplex
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❑ 100Mbps - Half Duplex
❑ 100Mbps - Full Duplex
Broadcast Storm Control
The maximum number of broadcast packets the port can receive
within a specified period of time. If the threshold is reach, any
additional broadcast packets received on the port are discarded
by the switch. For background information on this feature, refer to
Broadcast Frame Control Overview on page 174. For
instructions on how to set this value, refer to Setting the
Maximum Number of Broadcast Frames on page 287.
Flow Control
The flow control setting for the port. Possible values are:
None - No flow control on the port.
Transmit - Flow control only on packets being transmitted out of
the port.
Receive - Flow control only on packets being received on the port.
Both - Flow control for both packets entering and leaving the port.
MDI/MDIX
The wiring configuration of the port. The default setting of Auto
has the port configure itself automatically as MDI or MDIX,
depending on the end node. You can use this option to configure
a port’s wiring configuration manually.
Note
The Auto setting is not available if you set a port’s speed and duplex
mode manually.
7. Once you have made the desired changes, click Apply.
The switch immediately activates the parameter changes on the
port.
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Displaying Port Status and Statistics
The procedure in this section displays the operating status of the ports
on a switch and port statistics. You can view a port’s operating speed,
duplex mode, MDI/MDI-X configuration, and more. You can also view
the operating status of any GBIC modules installed in an AT-8024GB.
To display the status or statistics of a switch port, perform the following
procedure:
1. From the Home page, select Monitoring.
2. From the Monitoring page, select Layer 1.
3. Select the Port Settings tab. The tab is shown in Figure 75.
Figure 75 Port Monitoring Page
This page displays a graphical image of the front of the switch.
Ports with valid links to end nodes have a green light.
4. Click a port. You can select more than one port at a time when you
want to display port status. However, you can select only one port
when displaying statistics. A selected port turns white. (To deselect a
port, click it again.)
5. Click Status to display the port’s operating status or Statistics to
display port statistics.
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If you select port status, the Port Status window in Figure 76 is
displayed.
Figure 76 Port Status Window
The information in this window is for viewing purposes only. To
adjust port parameters, refer to Configuring Port Parameters on
page 231.
The columns in the window are described below:
Port
The port number.
Link
The status of the link between the port and the end node
connected to the port. Possible values are:
Up - indicates that a valid link exists between the port and the end
node.
Down - indicates that the port and the end node have not
established a valid link.
Neg
The status of Auto-Negotiation on the port. Possible values are:
Auto - Indicates that the port is using Auto-Negotiation to set
operating speed and duplex mode.
Manual - Indicates that the operating speed and duplex mode are
set manually.
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MDI
The operating configuration of the port. Possible values are MDI
and MDI-X.
Speed
The operating speed of the port. Possible values are:
0010 - 10 Mbps
0100 - 100 Mbps
1000 - 1000 Mbps
Dplx
The duplex mode of the port. Possible values are half-duplex and
full-duplex.
Flow Control
The port’s flow control setting. Possible values are:
None - No flow control on the port.
Transmit - Flow control only on packets being transmitted out the
port.
Receive - Flow control only on packets being received on the port.
Both - Flow control for both packets entering and leaving the port.
State
The operating status of the port. Possible values are Forwarding
and Disabled.
MAC Limit
The maximum number of MAC addresses the port can learn when
operating in the Limited security mode. This value is only
operational when the port is operating in the Limited security
mode.
PVID
The port VLAN identifier assigned to the port.
VLAN
The VID of the VLAN in which the port is an untagged member.
Priority Override
The status of the override priority feature. If the status is Yes,
tagged and untagged packets entering the port are directed to
either to low or high priority queue as specified in CoS. If the
status is No, tagged frames entering the port are directed to the
low or high queue according to the priority levels specified in the
tagged packets. For further information on this feature, refer to
Class of Service Overview on page 163.
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Priority Level
The priority queue to which untagged packets are directed when
received on the port. A value of 1 to 3 directs untagged packets to
the low priority queue while a value of 4 to 7 directs packets to the
high priority queue. If the override priority feature has been
activated on the port, tagged packets will be directed to the
priority queue reflected by this status parameter. For further
information on this feature, refer to Class of Service Overview on
page 163.
If you select Statistics, the Statistics window in Figure 77 is
displayed.
Figure 77 Port Statistics Window
The information in this window is for viewing purposes only. The
statistics are defined below:
Transmit Packets
Number of packets transmitted out the port.
Received Packets
Number of packets received on the port.
Received Overflow
Number of times frames entering the port have exceeded the
capacity of the port’s buffer.
Received Broadcast
Number of broadcast packets received on the port.
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Received Multicast
Number of multicast packets received on the port.
CRC Error
Number of packets with a cyclic redundancy check (CRC) error but
with the proper length (64-1518 bytes) received on the port
Total Packets
Number of packets received and transmitted on the port.
Undersize Packets
Number of packets that were less than the minimum length
specified by IEEE 802.3 (64 bytes including the CRC) received on
the port.
Fragmented Packets
Number of undersized packets, packets with alignment errors,
and packets with FCS errors (CRC errors) received on the port.
Oversize Packets
Number of packets exceeding the maximum specified by IEEE
802.3 (1518 bytes including the CRC) received on the port.
Port in Discards
Number of frames successfully received and buffered by the port,
but discarded and not forwarded.
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Chapter 22
Port Security
This chapter explains how to display the current port security level on
the switch from a web browser management session.
Note
For background information on port security, refer to Port Security
Overview on page 71.
Note
A switch’s port security level can be changed only from a local
management session.
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Displaying the Port Security Level
To display the switch’s port security level, perform the following
procedure:
1. From the Home page, select Monitoring.
2. From the Configuration page, select Layer 2.
3. From the Layer 2 page, select the Port Security tab.
The current security level is displayed.
Figure 78 Port Security Menu
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Chapter 23
Port Trunks
This chapter contains the procedure for creating or deleting a port trunk
from a web browser management session.
Note
For background information on port trunking, refer to Port
Trunking Overview on page 78.
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Creating or Deleting a Port Trunk
Caution
Do not connect the cables of a port trunk to the ports on the switch
until after you have configured the ports on both the switch and the
end node. Connecting the cables prior to configuring the ports can
create loops in your network topology. Loops can result in
broadcast storms, which can adversely effect the operations of your
network.
If you are deleting a port trunk, disconnect the cables from the ports
before you delete the trunk. Deleting the trunk without first
disconnecting the data cables can create a loop in your network
topology, which can result in broadcast storms.
To create or delete a port trunk, perform the following procedure:
1. From the Home page, select Configuration.
2. From the Configuration page, select Layer 1.
3. Select the Port Trunking tab.
The management software displays the Port Trunking window in
Figure 79.
Figure 79 Port Trunking Window
If the switch does not contain a port trunk, all ports in the switch
image will be black. If there is a port trunk, the ports of the trunk
will be white.
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4. To create a port trunk, do the following:
a. Click the ports that will make up the port trunk. A selected port
changes to white. An unselected port is black. A port trunk can
contain 2, 3, or 4 ports.
b. Click Apply.
Once you have selected the ports of the trunk, the following
appear under Trunk Method.
c. Click the desired load distribution method. The default is SA/DA.
d. Configure the ports on the remote switch for port trunking.
The new port trunk is immediately activated on the switch. You
can now connect the data cables to the ports of the trunk on the
switch.
5. To delete a port trunk, click Remove. The port trunk is immediately
deleted from the switch.
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Chapter 24
Port Mirroring
This chapter contains the procedure for creating or deleting a port
mirror.
Note
For background information on port mirroring, refer to Port
Mirroring Overview on page 88.
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Creating or Deleting a Port Mirror
To create or delete a port mirror, perform the following procedure:
1. From the Home page, select Configuration.
2. From the Configuration page, select Layer 1.
3. Select the Port Mirroring tab.
The management software displays the Port Mirroring window in
Figure 80.
Figure 80 Port Mirroring Window
4. To create a port mirror, do the following:
a. Use the pull-down menu from Mirroring Port to select the port to
function as the port mirror.
b. Click the port(s) in the graphical switch image whose traffic is to
be copied to the mirror port. You can select from 1 to 23 ports.
c. Click Apply.
The port mirror is immediately activated on the switch. You can
now connect a data analyzer to the mirror port to monitor the
traffic on the selected ports.
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5. To disable port mirroring, select “None“ from the Mirroring Port pulldown menu and click Apply.
The port mirror is deleted. The port that was functioning as the
mirror port can now be used for normal network operations.
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Chapter 25
STP and RSTP
This chapter explains how to configure the STP and RSTP parameters on
an AT-8000 Series switch from a web browser management session.
Sections in the chapter include:
❑ Enabling or Disabling STP or RSTP on page 248
❑ Configuring STP on page 249
❑ Configuring RSTP on page 253
❑ Displaying STP or RSTP Settings on page 257
Note
For background information on spanning tree, refer to STP and
RSTP Overview on page 92.
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Enabling or Disabling STP or RSTP
To enable or disable spanning tree on the bridge, do the following:
1. From the Home page, select Configuration.
2. From the Configuration page, select Layer 2.
3. From the Layer 2 page, select the Spanning Tree tab.
The Spanning Tree tab in Figure 81 is displayed.
Figure 81 Spanning Tree Tab
4. To enable or disable spanning tree, click the Enable Spanning Tree
check box. A check indicates that the feature is enabled while no
check indicates that the feature is disabled. The default is disabled.
5. If you are activating spanning tree, click either STP or RSTP in the
Active Protocol Version section of the window. The default is RSTP.
Note
Only one spanning tree protocol can be active on the switch at a
time.
6. Click Apply.
7. If you activated STP, go to Configuring STP on page 249. If you
activated RSTP go to Step Configuring RSTP on page 253.
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Configuring STP
Caution
The bridge provides default STP parameters that are adequate for
most networks. Changing them without prior experience and an
understanding of how STP works might have a negative effect on
your network. You should consult the IEEE 802.1d standard before
changing any of the STP parameters.
1. From the Spanning Tree tab window, click STP Configuration and
click Configure.
The Spanning Tree window in Figure 82 is displayed.
Figure 82 STP Bridge Configuration Window
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2. Adjust the bridge STP settings as needed. The parameters are
described below.
Bridge Identifier
The MAC address of the bridge. The bridge identifier is used as a
tie breaker in the selection of the root bridge when two or more
bridges have the same bridge priority value. This value cannot be
changed.
Bridge Priority
The priority number for the bridge. This number is used in
determining the root bridge for STP. The bridge with the lowest
priority number is selected as the root bridge. If two or more
bridges have the same priority value, the bridge with the
numerically lowest MAC address becomes the root bridge. When
a root bridge goes off-line, the bridge with the next priority
number automatically takes over as the root bridge. This
parameter can be from 0 (zero) to 65,535, with 0 being the highest
priority.
Bridge Hello Time
The time interval between generating and sending configuration
messages by the bridge. This parameter can be from 1 to 10
seconds. The default is 2 seconds.
Bridge Forwarding Delay
The waiting period before a bridge changes to a new state, for
example, becomes the new root bridge after the topology
changes. If the bridge transitions too soon, not all links may have
yet adapted to the change, possibly resulting in a network loop.
The default is 15 seconds.
Bridge Max Age
The length of time after which stored bridge protocol data units
(BPDUs) are deleted by the bridge. All bridges in a bridged LAN
use this aging time to test the age of stored configuration
messages called bridge protocol data units (BPDUs). For example,
if you use the default 20, all bridges delete current configuration
messages after 20 seconds. This parameter can be from 6 to 40
seconds. The default is 20 seconds.
In selecting a value for maximum age, the following must be
observed:
MaxAge must be less then (2 x (HelloTime + 1)).
MaxAge must be less then (2 x (ForwardingDelay - 1)).
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Note
The aging time for BPDUs is different from the aging time used by
the MAC address table.
3. After you have made the desired changes, click Apply.
4. To adjust a port’s STP settings, click on the port in the switch image
and click Modify. You can select more than one port at a time.
The Port Spanning Tree Protocol window in Figure 83 is displayed.
Figure 83 STP Port Configuration Window
5. Adjust the settings as desired. The parameters are described below.
Participating
This parameter indicates whether the port is participating in the
spanning tree domain. You cannot change this value from a web
browser management session. It can be changed from a local or
Telnet management session, as explained in Configuring a Port’s
STP Settings on page 103.
Port Cost
The spanning tree algorithm uses the cost parameter to decide
which port provides the lowest cost path to the root bridge for
that LAN. The default values for this parameter are 100 for a 10
Mbps port, 10 for a 100 Mbps port, and 4 for a 1 Gbps port. The
range is 1 to 65535.
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Port Priority
This parameter is used as a tie breaker when two or more ports are
determined to have equal costs to the root bridge. The default
value for priority is 128. The range is 0-255.
Bridge Hello Time
The time interval between generating and sending configuration
messages by the bridge. The default is 2 seconds. This value
cannot be changed from this window. To change this value, refer
to earlier in this procedure.
Port State Forwarding
This field indicates whether the port is enabled or disabled.
Root Bridge
The MAC address of the bridge functioning as the root bridge in
the spanning tree domain. This value is for display purposes only
and cannot be changed.
6. Once you have configured the parameters, click Apply.
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Configuring RSTP
Caution
The bridge provides default RSTP parameters that are adequate for
most networks. Changing them without prior experience and an
understanding of how RSTP works might have a negative effect on
your network. You should consult the IEEE 802.1w standard before
changing any of the RSTP parameters.
1. From the Spanning Tree tab window, click RSTP Configuration and
click Configure.
The RSTP Bridge Configuration window in Figure 82 is displayed.
Figure 84 RSTP Bridge Configuration Window
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2. Adjust the parameters are desired. The parameters are defined below.
Force Version
This selection determines whether the bridge will operate with
RSTP or in an STP-compatible mode. If you select RSPT, the bridge
will operate all ports in RSTP, except for those ports that receive
STP BPDU packets. If you select Force STP Compatible, the bridge
will operate all ports in STP. The default is RSTP.
Bridge Priority
The priority number for the bridge. This number is used in
determining the root bridge for STP. The bridge with the lowest
priority number is selected as the root bridge. If two or more
bridges have the same priority value, the bridge with the
numerically lowest MAC address becomes the root bridge. When
a root bridge goes off-line, the bridge with the next priority
number automatically takes over as the root bridge. This
parameter can be from 0 (zero) to 61,440 in increments of 4096,
with 0 being the highest priority. For a list of the increments, refer
to Table 4, RSTP Bridge Priority Value Increments on page 93
Bridge Hello Time
The time interval between generating and sending configuration
messages by the bridge. This parameter can be from 1 to 10
seconds. The default is 2 seconds.
Bridge Forwarding
The waiting period before a bridge changes to a new state, for
example, becomes the new root bridge after the topology
changes. If the bridge transitions too soon, not all links may have
yet adapted to the change, possibly resulting in a network loop.
The range is 4 to 30 seconds. The default is 15 seconds.
Bridge Max Age
The length of time after which stored bridge protocol data units
(BPDUs) are deleted by the bridge. All bridges in a bridged LAN
use this aging time to test the age of stored configuration
messages called bridge protocol data units (BPDUs). For example,
if you use the default 20, all bridges delete current configuration
messages after 20 seconds. This parameter can be from 6 to 40
seconds. The default is 20 seconds.
In selecting a value for maximum age, the following must be
observed:
MaxAge must be less then (2 x (HelloTime + 1)).
MaxAge must be less then (2 x (ForwardingDelay - 1)).
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Bridge Identifier
The MAC address of the bridge. The bridge identifier is used as a
tie breaker in the selection of the root bridge when two or more
bridges have the same bridge priority value. This value cannot be
changed.
Root Bridge
The MAC address of the bridge functioning as the root bridge in
the spanning tree domain. This value is for display purposes only
and cannot be changed.
Root Priority
The priority number of the root bridge.
3. After you have made your changes, click Apply.
4. To adjust a port’s RSTP settings, click on the port in the switch image
and click Modify. You can select more than one port at a time.
The Port Rapid Spanning Tree Protocol window in Figure 85 is
displayed.
Figure 85 RSTP Port Configuration Window
5. Adjust the settings as desired. The parameters are described below.
Port Priority
This parameter is used as a tie breaker when two or more ports are
determined to have equal costs to the root bridge. The range is 0
to 240 in increments of 16. The default value is 8 (priority value of
128). For a list of the increments, refer to Table 7, RSTP Port
Priority Value Increments on page 95.
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Port Cost
The spanning tree algorithm uses the cost parameter to decide
which port provides the lowest cost path to the root bridge for
that LAN. The range is 0 to 20 000 000. The default setting is Autodetect, which sets port cost depending on the speed of the port.
Default values are 100 for a 10 Mbps port, 10 for a 100 Mbps port,
and 4 for a 1 Gbps port.
MCHECK
This option instructs the bridge to send out RSTP BPDU packets
for several seconds from the selected port. The purpose is to
determine if there are any RSTP or STP bridges connected to the
port. If the port receives STP BPDU packets in response, the port
changes to STP compatible mode.
Point-to-Point
This parameter defines whether the port is functioning as a pointto-point port. For an explanation of this parameter, refer to Pointto-Point Ports and Edge Ports on page 97.
Edge Port
This parameter defines whether the port is functioning as an edge
port. For an explanation of this parameter, refer to Point-to-Point
Ports and Edge Ports on page 97.
6. Once you have configured the parameters, click Apply.
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Displaying STP or RSTP Settings
To display STP or RSTP parameter settings, perform the following
procedure:
1. From the Home page, select Monitoring.
2. From the Monitoring menu, select Layer 2.
3. From the Layer 2 page, select the Spanning Tree tab.
The Spanning Tree window in Figure 87 is displayed. This window
displays information on whether spanning tree is enable or
disabled and which protocol version, STP or RSTP, is active.
Figure 86 Spanning Tree Tab - Monitoring
4. To view STP or RSTP parameter settings, click either STP
Configuration or RSTP Configuration and click View.
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The example in Figure 87 is for RSTP. The information in this
window is for viewing purposes only.
Figure 87 Rapid Spanning Tree Window - Monitoring
5. To view port settings, click a port in the switch and click Status or
Settings.
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Chapter 26
Virtual LANs
This chapter explains how to create, modify, and delete VLANs from a
web browser management session. This chapter also explains how to
change a switch’s VLAN operating mode.
Note
For background information on VLANs and on the Basic VLAN
mode, refer to Chapter 10, Virtual LANs.
This chapter contains the following sections:
❑ Creating a VLAN on page 260
❑ Modifying a VLAN on page 263
❑ Deleting VLANs on page 264
❑ Displaying VLANs on page 265
❑ Setting the Switch’s VLAN Mode on page 266
❑ Changing a PVID on page 268
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Creating a VLAN
To create a new VLAN, perform the following procedure:
1. From the Home page, select Configuration.
2. From the Configuration menu, select Layer 2.
3. From the Layer 2 window, select the VLAN tab.
The VLAN window in Figure 88 is displayed.
Figure 88 VLAN Window
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4. Click Add.
The Add VLAN window in Figure 89 is displayed.
Figure 89 Add VLAN Window
5. Select the Name field and enter a name for the new VLAN.
The name can be from one to 10 characters in length. The name
should reflect the function of the nodes of the VLAN (for example,
Sales or Accounting). The name can contain spaces but not special
characters, such as asterisks (*) or exclamation points (!).
If the VLAN will be unique in your network, the name should be
unique as well. If the VLAN will be part of a larger VLAN that spans
multiple switches, the name for the VLAN should be the same on each
switch where nodes of the VLAN are connected.
Note
A VLAN must be assigned a name.
6. Select the VID field and enter a VID value for the new VLAN. The range
of the VID value is 2 to 4096. The default will be the next available VID
number on the switch.
If this will be a unique VLAN in your network, its VID must be unique
as well.If the VLAN will be part of a larger VLAN that spans multiple
switches, its VID value should be the same on each switch. For
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example, if you are creating a VLAN called Sales that will span three
switches, you must assign the same VID value to each Sales VLAN on
the three switches.
Note
A VLAN must have a VID.
7. If you want all received traffic on the ports of the VLAN to be mirrored
to another port on the switch, select the mirroring port from the
Mirroring Port pull-down menu.
This feature is useful when troubleshooting a VLAN. You can analyze
the VLAN traffic by placing a network analyzer on the mirroring port.
In most cases, you should not change this parameter’s default value
of “—“. This value disables port mirroring.
Note
For background information on port mirroring, refer to Port
Mirroring Overview on page 88.
8. To select ports for the VLAN, click on the appropriate ports in the
switch image.
Clicking repeatedly on a port toggles the port through the
following possible settings:
Untagged port
Tagged port
Port not a member of the VLAN
9. Click Apply.
Note
The untagged ports that you assign to the new VLAN are
automatically removed from their current VLAN assignment.
The VLAN is now ready for network operations.
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Modifying a VLAN
To modify a VLAN, perform the following procedure:
1. From the Home page, select Configuration.
2. From the Configuration menu, select Layer 2.
3. From the Layer 2 window, select the VLAN tab.
The VLAN window in Figure 88 on page 260 is displayed.
4. Click the circle next to the name of the VLAN you want to modify.
5. Click Modify.
The configuration window for the VLAN is displayed.
6. Modify the VLAN parameters by referring to Step 5 to Step 8 in the
previous procedure, Creating a VLAN.
When modifying a VLAN, observe the following guidelines:
❑ You cannot change the VID of a VLAN.
❑ You cannot change the name of the Default_VLAN.
❑ When changing a VLAN’s name or VID, be sure that the new name
or VID is unique on the switch.
7. After making the desired changes, click Apply.
Note
Untagged ports that are added to a VLAN are automatically
removed from their current VLAN assignment. Untagged ports that
are removed from a VLAN are returned to the Default_VLAN.
Removing an untagged port from the Default_VLAN without
assigning it to another VLAN will leave the port as an untagged
member of no VLAN.
The modified VLAN is now ready for network operations.
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Deleting VLANs
To delete a VLAN from the switch, perform the following procedure:
1. From the Home page, select Configuration.
2. From the Configuration menu, select Layer 2.
3. From the Layer 2 window, select the VLAN tab.
The VLAN window in Figure 88 on page 260 is displayed.
4. Click the circle next to the name of the VLAN you want to delete.
5. Click Remove.
A confirmation prompt is displayed.
6. Click OK to delete the VLAN or Cancel to cancel the procedure.
If you click OK, the VLAN is deleted from the switch. The untagged
ports in the VLAN are returned to the Default_VLAN as untagged
ports.
Note
You cannot delete the Default_VLAN.
To delete all VLANs from the switch, perform the following procedure:
1. From the Home page, select Configuration.
2. From the Configuration menu, select Layer 2.
3. From the Layer 2 window, select the VLAN tab.
The VLAN window in Figure 88 on page 260 is displayed.
4. Click Clear All.
A confirmation prompt is displayed.
5. Click OK to delete all the VLANs or Cancel to cancel the procedure.
If you click OK, all VLANs except for the Default_VLAN are deleted
from the switch. The ports in the VLANs are returned to the
Default_VLAN as untagged ports.
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Displaying VLANs
To display all the existing VLANs on a switch, perform the following
procedure:
1. From the Home page, select Monitoring.
2. From the Monitoring page, select Layer 2.
3. From the Layer 2 page, select the VLAN tab.
The management software displays the window in Figure 90. The
information in this window is for viewing purposes only.
Figure 90 VLAN Monitoring Window
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Setting the Switch’s VLAN Mode
This section contains the procedure for setting a switch’s VLAN mode.
You can configure a switch to support port-based and tagged VLANs or
to operate in the Basic VLAN mode.
Note
Refer to Chapter 10, Virtual LANs, for descriptions of port-based
and tagged VLANs and the Basic VLAN mode.
To set the switch’s VLAN mode, perform the following procedure:
1. From the Home Page, select Configuration.
2. From the Configuration menu, choose System.
3. Select the General tab.
4. In the Switch Mode section of the window, click either Tagged or
Basic.
If you select Tagged, which is the default, the switch will support
both port-based VLANs and tagged VLANs. If you select Basic, the
switch will operate in the Basic VLAN mode.
5. Click Apply.
6. Click Reset to reset the switch.
A change to VLAN status is not activated until the switch is reset.
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Enabling or Disabling VLANs
This procedure performs exactly the same function as the previous
procedure. It sets a switch’s VLAN mode. When VLANs are enabled, the
switch supports port-based and tagged VLANs. When VLANs are
disabled, the switch supports the Basic VLAN mode.
The difference between the two procedures has to do with ingress
filtering. If you activate the Basic VLAN Mode using the previous
procedure, ingress filtering is disabled. Performing this procedure does
not change the current setting of ingress filtering.
To configure a switch’s VLAN mode, perform the following procedure:
1. From the Home page, select Configuration.
2. From the Configuration menu, select Layer 2.
3. From the Layer 2 window, select the VLAN tab.
The VLAN window in Figure 88 on page 260 is displayed.
4. Click the Enable VLAN check box. A check in the box indicates that
the switch supports tagged and untagged VLANs. No check in the box
indicates that the switch is operating in the Basic VLAN Mode.
5. Click Apply.
6. Reset the switch. For instructions, refer to Resetting a Switch on
page 222. A change to VLAN status is not activated until the switch is
reset.
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Changing a PVID
The procedure in this section explains how to change a PVID value for a
port. As explained in Port-based VLAN Overview on page 113, a port
receives a PVID when it is assigned as an untagged port to a VLAN. A
port’s PVID will be the same as the VLAN’s VID to which it has been
assigned. For example, if you assign Port 4 on the switch as an untagged
port to a VLAN with a VID of 7, the port is assigned a PVID also of 7.
The assignment of PVIDs is performed automatically by the AT-S39
software. There should be little need for you to manually change a PVID
yourself. But the AT-S39 software does allow you to adjust the value if
necessary.
To change a PVID for a port, perform the following procedure:
1. From the Home page, select Configuration.
2. From the Configuration page, select Layer 2.
3. From the Layer 2 page, select the COS tab.
A graphical image of the switch is displayed.
4. Click the port whose PVID you want to configure. You can select only
one port at a time. A selected port turns white. To deselect a port, click
it again.
5. Click Modify.
The CoS Setting window in Figure 91 is displayed.
Figure 91 CoS Setting Window
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6. Use the pull-down menu from the Port VLAN ID selection to specify
the new PVID value for the port. The pull-down menu displays the
VIDs of the VLANs existing on the switch.
7. Click Apply.
The new value is immediately activated on the port.
Note
The Priority and Override Priority selections in the CoS Setting
window are explained in Configuring CoS on page 278.
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Chapter 27
MAC Address Table
This chapter contains instructions on how to view the dynamic and
static addresses in the MAC address table of the switch. This chapter
contains the following procedure:
❑ Viewing the MAC Address Table on page 271
❑ Adding Static and Multicast MAC Addresses on page 274
❑ Deleting MAC Addresses on page 275
❑ Changing the Aging Time on page 276
Note
For background information on MAC addresses, refer to MAC
Address Overview on page 150.
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Viewing the MAC Address Table
To view the MAC address table, perform the following procedure:
1. From the Home page, select either Configuration or Monitoring.
2. Select Layer 2.
3. From the Layer 2 page, select the MAC Address tab.
The MAC Address window is displayed. Figure 92 shows how this
window appears when you display it through the Configuration
main menu selection. If displayed through the Monitoring main
menu selection, the Add button is not included. This button is
used to add static and multicast address to the switch. For
instructions on how to add static and multicast MAC addresses,
refer to the next procedure.)
Figure 92 Forwarding Database Tab
The options for displaying MAC addresses are described below.
View All MAC Addresses
This option displays both static and dynamic MAC addresses.
View All Dynamic Addresses
This option displays only dynamic MAC address. Dynamic MAC
addresses are addresses that the switch has learned by examining
the source addresses of frames received on the ports.
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View All Static Addresses
This option displays only the static MAC addresses. Static MAC
addresses are addresses that you entered manually into the MAC
address table.
View All IP Multicast Addresses
This option displays the multicast MAC addresses.
View By Port
The pull-down menu with this option is used to display the MAC
addresses learned on a particular port.
View By VLAN ID
This option displays the MAC addresses learned by a particular
VLAN on the switch. You specify the VLAN by its VID.
View Port by MAC Address
This option is used to determine the port on the switch to which
an end node is communicating with the switch. To use this option,
enter the MAC address of the node in the field.
4. Once you have selected one of the options, click View.
The MAC addresses are displayed in a window. The columns in the
window are defined below:
MAC
The MAC address of the node connected to the switch.
Port
The port on the switch where the MAC address was learned.
PMAP
The ports on the switch that are members of a multicast group.
This column is useful in determining which ports belong to
different multicast groups. It maps ports to multicast groups. (The
abbreviation PMAP is derived from “port mapping.”)
Each “0” is a hexadecimal value for the binary value “0000”. Each
binary “0” represents a port on the switch. A binary “0” means that
the port is not a member of a multicast group while a “1” means
that it is.
The port numbering scheme is from right to left. As an example,
assume that ports 1 through 4 on the switch were members of the
same multicast group. The PMAP column for the address would
represent this as follows: “0000000F”. Another example is
“000020F. This example would indicate that ports 1 to 4 and port
10 on the switch were members of the same multicast group.
CPU
Indicates whether the traffic received on the port is sent to the
switch’s CPU. Yes indicates that the traffic is being sent to the CPU
while No indicates it is not.
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MIR
Indicates whether the traffic on the port is being mirrored. Yes
means the traffic is being mirrored while No indicates that it is not.
EMP
Indicates whether multicast packets are being forwarded by ports
in the blocking state. This feature is not supported at this time.
This column will indicate “No” for all multicast addresses, except
for the switch’s MAC address. Multicast packets are forwarded
only by ports in the forwarding state.
VLANID
The VID of the VLAN to which the port is an untagged member.
Type
The MAC address type. The type can be either static or dynamic.
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Adding Static and Multicast MAC Addresses
This section contains the procedure for assigning static or multicast
address to ports on the switch. You can assign up to 255 static MAC
addresses per port.
To add a static or multicast address to the MAC address table, perform
the following procedure:
1. From the Home page, select Configuration.
2. From the Configuration page, select Layer 2.
3. From the Layer 2 page, select the MAC Address tab.
The MAC Address window in Figure 92 on page 271 is displayed.
4. Click Add.
The window in Figure 93 is displayed.
Figure 93 Add Static MAC Address window
5. In the MAC Address section of the window, enter the new static or
multicast MAC address.
6. In the graphical image of the switch click the port to which you want
to assign the address. A selected port turns white. You can select only
one port.
7. Click Apply.
8. Repeat this procedure to add other static or multicast addresses to
the switch.
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Deleting MAC Addresses
To delete a static, dynamic, or multicast MAC address from the switch,
perform the following procedure:
1. From the Home page, select Configuration.
2. From the Configuration page, select Layer 2.
3. From the Layer 2 page, select the MAC Address tab.
The MAC Address window in Figure 92 on page 271 is displayed.
4. Display the MAC addresses on the switch by selecting one of the
options. For instructions, refer to Viewing the MAC Address Table
on page 271.
5. Click on the dialog circle next to the MAC address that you want
deleted from the switch.
6. Click Remove.
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Changing the Aging Time
The switch uses the aging time to delete inactive dynamic MAC
addresses from the MAC address table. When the switch detects that no
packets have been sent to or received from a particular MAC address in
the table after the period specified by the aging time, the switch deletes
the address. This prevents the table from becoming full of addresses of
nodes that are no longer active.
The default setting for the aging time is 300 seconds (5 minutes).
To adjust the aging time, perform the following procedure:
1. From the Home page, select Configuration.
2. From the Configuration page, select System.
3. From the System page, select the General tab.
The General tab in Figure 66 on page 214 is displayed.
4. Enter a new value in seconds in the MAC Aging Time field of the
window.
The value should be an increment of 5 seconds, for example 410,
415, or 420. A value that is not an increment of 5 is rounded down
to the next increment of 5. For example, the value 524 is rounded
down to 520. The default is 300 seconds (5 minutes).
5. Click Apply.
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Chapter 28
Class of Service
This chapter contains instructions on how to configure CoS. This chapter
contains the following procedure:
❑ Configuring CoS on page 278
Note
For background information on CoS, refer to Class of Service
Overview on page 163.
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Configuring CoS
To configure CoS, perform the following procedure:
1. From the Home page, select Configuration.
2. From the Configuration page, select Layer 2.
3. From the Layer 2 page, select the CoS tab.
A graphical image of the switch is displayed.
4. Click the port where you want to configure CoS. You can select only
one port at a time. A selected port turns white. (To deselect a port,
click it again.)
5. Click Modify.
The CoS Settings window in page 268 is displayed.
6. If you want all tagged and untagged frames received on the port to
go to the low priority queue, select any level from Level 0 to Level 3
from the Priority pull-down menu. (It does not matter which of these
levels you select.) If you want all frames received on the port to go to
the high priority queue, select any level from Level 4 to Level 7.
(Again, it does not matter which level you select.)
7. If you are configuring a tagged port and you want the switch to
ignore the priority tag in the tagged frames entering the port, click
the Override Priority option.
All tagged frames will be directed to either the low or high priority
queue specified in Step 5.
Note
The tagged information in a frame is not changed as the frame
traverses the switch. A tagged frame exits the switch with the same
priority level that it had when it entered.
The default for this parameter is No, meaning that the priority
level of tagged frames is determined by the priority level specified
in the frame itself.
8. Click Apply.
Configuration changes are immediately activated on the switch.
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Chapter 29
IGMP Snooping
This chapter describes how to configure the IGMP snooping feature on
the switch.
Note
For background information on this feature, refer to IGMP
Snooping Overview on page 166.
Sections in the chapter include:
❑ Configuring IGMP Snooping on page 280
❑ Displaying a List of Host Nodes and Multicast Routers on page
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Configuring IGMP Snooping
To configure IGMP snooping from a web browser management session,
perform the following procedure:
1. From the Home page, select Configuration.
2. From the Configuration menu, select System.
3. Select the IGMP tab.
The IGMP tab in Figure 94 is displayed.
Figure 94 IGMP Window - Configuration
4. Adjust the IGMP parameters as necessary.
The parameters are explained below:
Enable IGMP Snooping Status
Enables and disables IGMP snooping on the switch. A check in the
box indicates that IGMP is enabled.
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Snoop Topology
Defines whether there is only one host node per switch port or
multiple host nodes per port. Possible settings are Edge (SingleHost/Port) and Intermediate (Multi-Host/Port).
The Edge (Single-Host/Port) setting is appropriate when there is
only one host node connected to each port on the switch. This
setting causes the switch to immediately stop sending multicast
packets out a switch port when a host node signals its desire to
leave a multicast group by sending a leave request or when the
host node stops sending reports and times-out. The switch
forwards the leave request to the router and simultaneously
ceases transmission of any further multicast packets out the port
where the host node is connected.
The Intermediate (Multi-Host) setting is appropriate if there is
more than one host node connected to a switch port, such as
when a port is connected to an Ethernet hub to which multiple
host nodes are connected. With this setting selected the switch
continues sending multicast packets out a port even after it
receives a leave request from a host node on the port. This
ensures that the remaining active host nodes on the port will
continue to receive the multicast packets. Only after all of the host
nodes connected to a switch port have transmitted leave requests
(or have timed out) will the switch stop sending multicast packets
out the port.
If a switch has a mixture of host nodes, that is, some connected
directly to the switch and others through an Ethernet hub, you
should select the Intermediate Multi-Host Port selection.
Host/Router Timeout Interval
Specifies the time period in seconds after which the switch
determines that a host node has become inactive. An inactive
host node is a node that has not sent an IGMP report during the
specified time interval. The range is from 1 second to 86,400
seconds (24 hours). The default is 260 seconds.
This parameter also specifies the time interval used by the switch
in determining whether a multicast router is still active. The switch
makes the determination by watching for queries from the router.
If the switch does not detect any queries from a multicast router
during the specified time interval, it assumes that the router is no
longer active on the port.
Maximum Multicast Groups
Specifies the maximum number of multicast groups the switch
will learn. The range is 1 to 2048 groups. The default is 256
multicast groups.
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This parameter is useful with networks that contain a large
number of multicast groups. You can use the parameter to
prevent the switch’s MAC address table from filling up with
multicast addresses, leaving no room for dynamic or static MAC
addresses. The range is 1 address to 2048 addresses. The default is
256 multicast addresses.
Multicast Router Port(s)
Specifies the port on the switch to which the multicast router is
detected. You can let the switch determine this automatically by
selecting Auto Detect, or you can specify the port yourself by
clicking on the ports in the graphical image. A white port indicates
a multicast router port.
5. If desired, you can use the graphical image in the window to indicate
which ports on the switch are connected to multicast routers.
By default, the switch automatically detects the presence of
multicast routers by watching for queries on its ports. Once it has
received a query, it notes the port on which the query was
received and identifies the port as a multicast port.
If desired, you can deactivate the auto-detection of multicast
routers and indicate the multicast router ports yourself. To
deactivate the auto-detection, click on the Auto Detect check
box. If the check box is empty, auto-detect is deactivated.
To indicate the multicast router ports manually, use the graphical
image of the switch. Clicking a port toggles it to white, indicating
that the port is connected to a multicast router.
6. After setting the IGMP parameters, click Apply.
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Displaying a List of Host Nodes and Multicast Routers
You can use the AT-S39 software to display a list of the multicast groups
on a switch, as well as the host nodes. You can also view the multicast
routers. A multicast router is a router that is receiving multicast packets
from a multicast application and transmitting the packets to host nodes.
To view host nodes and multicast routers, perform the following
procedure:
1. From the Home Page, select Monitoring.
2. From the Monitoring window, select the System menu option.
3. Select the IGMP tab.
The window in Figure 95 is displayed.
Figure 95 IGMP Window - Monitoring
4. To view the multicast addresses and the host nodes, click View
Multicast Host List and then click View. To view the multicast
routers, click View Multicast Router List and then click View.
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Viewing a list of host nodes displays a window containing the
following information. The information in the window is for
viewing purposes only.
Multicast Group
The multicast address of the group.
Member Port
The port(s) on the switch to which one or more host nodes of the
multicast group are connected.
VLAN ID
The VID of the VLAN in which the port is an untagged member.
Host IP
The IP address(es) of the host node(s) connected to the port.
Viewing a list of multicast routers displays a window containing
the following information. The information in the window is for
viewing purposes only.
Port
The port on the switch where the multicast router is connected.
VLAN ID
The VID of the VLAN in which the port is an untagged member.
Router IP
The IP address of the port on the router.
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Chapter 30
Broadcast Frame Control
This chapter contains instructions on how to configure the broadcast
frame control feature on the switch.
Note
For background information on this feature, refer to Broadcast
Frame Control Overview on page 174.
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Configuring the Interval Timer
The interval timer defines the time period used in counting the number
of broadcast packets transmitted by a port. A port will not transmit more
than its maximum number of broadcast frames during the specified
timer interval. If a port reaches its maximum number, it will discard and
not forward any additional broadcast frames. You can specify a different
interval timer for 10 and 100 Mbps ports and 1000 Mbps ports.
To specify an interval timer, perform the following procedure:
1. From the Home page, select Configuration.
The System menu option is selected by default along with the
General tab when you open the Configuration page. If they are
not already selected, select them now.
2. In the Broadcast Storm Control section of the window tab, enter
values for the two interval timers.
The interval timer for 10 Mbps and 100 Mbps ports is in
milliseconds and has a range of 10 to 120 milliseconds. The value
should be entered in increments of 10.
The interval timer for 1000 Mbps ports is in microseconds and has
a range of 100 to 120000 microseconds. The value should be
entered in increments of 100.
A value for an interval timer applies to all ports operating at the
corresponding speed.
3. After you have entered your values, click Apply.
4. Go to the next procedure to set values for the maximum number of
broadcast frames the ports on the switch will transmit.
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Setting the Maximum Number of Broadcast Frames
To set the maximum number of broadcast frames you want the ports on
the switch to transmit, perform the following procedure:
1. From the Home page, select Configuration.
2. From the Configuration page, select Layer 1.
When you open the Layer 1 page, the Port Settings tab is selected
by default. If it is not selected, select it now.
3. In the graphical switch image, click a port where you want to specify
the maximum number of broadcast frames.
The selected port turns white. To deselect a port, click it again. You
can select only one port at a time.
4. Click Modify.
The current settings for the port are displayed in the Port
Configuration window.
5. In the Broadcast Storm Control section of the window, enter the
maximum number of broadcast packets you want the port to be able
to transmit.
The range is 0 to 1023 broadcast frames. Specifying a value of “0”
disables broadcast frame control on the port. The port will
forward all broadcast frames.
As an example, assume that you enter a value of 300 as the
maximum number of broadcast frames for a port. Also assume
that the port is operating at 100 Mbps and that you specified an
interval timer of 100 milliseconds for 100 Mbps ports. The result
would be that the port could transmit up to 300 broadcast frames
every 100 milliseconds. If it received more than 300 broadcast
frames for transmission during a 100 millisecond period, the extra
broadcast frames would be discarded by the port and would not
forwarded.
6. Click Apply.
7. Repeat this procedure to set the maximum number of broadcast
frames for other ports on the switch.
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Chapter 31
TACACS+ and RADIUS Protocols
This chapter contains instructions on how to configure the
authentication protocols. This chapter contains the following procedure:
❑ Configuring TACACS+ and RADIUS on page 289
Note
For background information on the authentication protocols, refer
to TACACS+ and RADIUS Overview on page 180.
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Section III: Web Browser Management
Configuring TACACS+ and RADIUS
To configure the authentication protocols, perform the following
procedure:
1. From the Home page, select Configuration.
2. From the Configuration page, select System.
3. From the System page, select the Server-based Authentication tab.
The tab is shown in Figure 96.
Figure 96 Server-based Authentication Tab
4. To enable or disable the authentication feature on the switch, click
the Disable Server-based Authentication check box. A check in the
box indicates that this feature is disabled. No check indicate the
feature is enabled. The default is disabled.
5. To select an authentication protocol, click either TACACS+ or RADIUS
in the Authentication Method section of the window. The default is
TACACS+.
Note
Only one authentication protocol can be active on the switch at a
time.
6. Click Apply.
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AT-S39 User’s Guide
Note
If you activated the authentication feature, go to Step 6 to configure
TACACS+ or Step 7 to configure RADIUS.
7. To configure TACACS+, do the following:
a. From the Server-based Authentication tab, click the check
circle next to TACACS+ Configuration and click Configure.
The TACACS+ Configuration window in Figure 97 is
displayed.
Figure 97 TACACS+ Configuration Window
b. Configure the parameters as needed. They are described
below.
Global Secret
If all of the TACACS+ servers have the same encryption
secret, you can enter the key here. If the servers have
different keys, you must specify each key when you specify
a server’s IP address.
Global Server Timeout
This parameter specifies the maximum amount of time the
switch will wait for a response from a TACACS+ server
before assuming the server cannot respond. If the timeout
expires and the server has not responded, the switch
queries the next TACACS+ server in the list. If there aren’t
any more servers, than the switch will default to the
standard Manager and Operator accounts. The default is
30 seconds. The range is 1 to 30 seconds.
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Section III: Web Browser Management
IP Address and Encryption Secret
Use these fields to specify the IP addresses and encryption
secrets of up to three network servers containing
TACACS+ server software. You can leave an encryption
field blank if you entered the server’s secret in the Global
Secret field.
c. After you have finished configuring the parameters, click Apply.
8. To configure RADIUS, do the following:
a. From the Server-based Authentication tab, click the check
circle next to RADIUS Configuration and click Configure.
The RADIUS Configuration window in Figure 97 is
displayed.
Figure 98 RADIUS Configuration
b. Configure the parameters as needed. They are described
below.
Global Encryption Key
If all of the TACACS+ servers have the same encryption
secret, you can enter the key here. If the servers have
different keys, you must specify each key when you specify
a server’s IP address.
Global Server Timeout
This parameter specifies the maximum amount of time the
switch will wait for a response from a TACACS+ server
before assuming the server cannot respond. If the timeout
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AT-S39 User’s Guide
expires and the server has not responded, the switch
queries the next TACACS+ server in the list. If there aren’t
any more servers, than the switch will default to the
standard Manager and Operator accounts. The default is
30 seconds. The range is 1 to 30 seconds.
IP Address, Port #, and Encryption Key
Use these fields to specify the IP address, UDP port
number, and encryption key of each RADIUS server. You
can specify up to a maximum of three servers. You can
leave the encryption field blank if you entered the server’s
key in the Global Secret field.
c. After you have finished configuring the parameters, click Apply.
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Appendix A
AT-S39 Default Settings
This appendix lists the AT-S39 factory default settings.
Settings
Default
IP Address
Subnet Mask
0.0.0.0
255.255.0.0
Gateway Address
System Name
MAC Aging Time
Community Strings
Get Community String
Set Community String
Trap Community String
Spanning Tree Protocol
Status
Bridge Priority
Bridge Max Age Time
Bridge Hello Time
Bridge Forwarding Delay
Port Costs
0.0.0.0
None
300 seconds
Port Priority
Fast Mode
Rapid Spanning Tree Protocol
Status
Bridge Priority
public
private
public
Disabled
32768
20
2
15
10 - 10 Mbps
10 - 100 Mbps
4 - 1000 Mbps
128
No
Disabled
Increment 8 (32768)
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AT-S39 User’s Guide
Settings
Default
Bridge Max Age Time
Bridge Hello Time
Bridge Forwarding Delay
Port Costs
20
2
15
Auto detect
2 000 000 - 10 Mbps
200 000 - 100 Mbps
20 000 - 1000 Mbps
Increment 8 (128)
Auto Detect
Yes
Port Priority
Point-to-Point
Edge Port
IGMP Snooping
Status
Topology
Host/Router Time-out Interval
Maximum Multicast Groups
TACACS+ and RADIUS
TACACS+
RADIUS
Management Interface
Manager Login Name (web browser
session only)
Manager Password
Operator Login Name (web browser
session only)
Operator Password
Time Out Value
Twisted Pair Ports
Status
Duplex Mode
Speed
Flow Control
Broadcast Packets
Security
VLANs
Default VLAN Name
VID
Basic VLAN Mode
Disabled
Single Host/ Port (Edge)
260 seconds
256
Disabled
Disabled
manager
admin (case-sensitive)
operator
friend (case-sensitive)
10 minutes
Enabled
Auto-negotiation
Auto-negotiation
Disabled
Forwarded
Automatic
Default_VLAN (all ports)
1
Disabled
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AT-S39 Default Settings
Settings
Broadcast Frame Control
10/100 Mbps Interval Timer
1000 Mbps Interval Timer
Maximum Number of Frames per Port
Management Access
Telnet
SNMP
TFTP
RS232 Port
Data Bits
Stop Bits
Parity
Flow Control
Data Rate
Default
10 milliseconds
100 microseconds
0 (disabled)
Enabled
Disabled
Enabled
8
1
None
Full-duplex
Auto-detect (default
9600 bps)
295
Index
A
aging time
changing, 161, 276
defined, 151
AT-S39 default settings, 50, 224, 293
AT-S39 software security, 45
AT-S39 software updates
downloading from a local session, 196
downloading via TFTP, 205
obtaining, 195
AT-S39 version number, 48
authentication protocols, 180, 289
Automatic port security level, 71
Auto-Negotiation, 65, 232
B
Basic VLAN mode
defined, 125
setting, 142, 266
bootloader version number, 48
BOOTP
activating, 40, 217
defined, 40
BPDU, see bridge protocol data unit
bridge forwarding delay parameter, 102, 106,
250, 254
bridge hello time parameter, 102, 106, 250, 254
bridge identifier, 93, 107, 250, 255
bridge max age parameter, 102, 106, 250, 254
bridge priority, 93, 102, 106, 250, 254
bridge protocol data unit (BPDU), 102, 106, 250,
254
broadcast frame control
configuring, 173, 285
defined, 174
broadcast frames
maximum number, configuring, 178, 287
browser tools, 211
C
Class of Service
configuring, 164, 278
defined, 163
console timeout, 45
D
default values, AT-S39, 50, 224, 293
DHCP
activating, 40, 217
defined, 40
document conventions, 13
documentation, 14
E
enhanced stacking
changing switches, 58, 228
defined, 31, 35, 53
guidelines, 53
setting switch status, 56, 226
F
Fast Mode, 104
flow control, 66, 233
force version, 106, 254
296
forwarding delay, 96, 102
G
gateway address, 38, 216
H
hello time, 97, 102, 252
host nodes
defined, 166
displaying, 171, 283
host/router timeout interval, 169, 281
I
IEEE 802.1d standard, 101, 105, 249, 253
IGMP snooping
configuring, 168, 280
defined, 166
ingress filtering, 145
Internet Protocol (IP) address, 35, 38, 216
interval timer
configuring, 176, 286
defined, 174
L
limited security mode
configuring, 75
defined, 71
load distribution methods, 79
local management session
defined, 20
quitting, 31
starting, 27
Lock All Ports security level, 72
M
MAC address table, 149, 271
MAC address, switch, 48
management access levels, 24, 46
Management Information Base (MIB), 23
management VLAN, 147
Manager access, 24, 46
Manager password, 46
master switch
assigning, 56, 226
defined, 56, 226
returning to, 59, 229
MDI/MDIX mode, 66, 233
MIBs, supported, 23
multicast groups, maximum, 169, 281
multicast MAC address
adding, 159, 274
deleting, 160, 275
displaying, 152
multicast router, displaying, 172, 283
O
Operator access, 24, 46
Operator password, 46
P
password
changing, 38, 215
default, 29, 32, 209
pinging, 49, 223
port
configuring parameters, 64, 231
disable, 65, 232
displaying status, 61, 234
speed, 65, 232
statistics, 189, 237
port cost
defined, 94
setting, 104, 108, 251, 256
port mirroring
creating, 89, 245
defined, 88
deleting, 90, 245
port security
configuring, 73
defined, 71
displaying, 240
port trunking
creating, 84, 242
defined, 78
deleting, 86, 242
guidelines, 78
load distribution methods, 79
port VLAN identifier (PVID)
changing, 139, 268
defined, 114, 121
port-based VLAN
creating, 126, 130, 260
defined, 113
deleting all, 138
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AT-S39 User’s Guide
deleting, 136, 264
displaying, 135, 265
modifying, 132, 263
priority queues, 163
priority, 104, 108, 252, 255
PVID. See Port VLAN identifier
Q
quitting
local session, 31
Telnet session, 33
web browser session, 211
R
RADIUS
configuring, 183, 289
overview, 180
Rapid Spanning Tree Protocol
configuring port parameters, 107
resetting a switch, 44, 222
root bridge, 93
RS232 port, default settings, 28
S
Secure level, port security, 72
serial number, switch, 48
slave switch
assigning, 56, 226
defined, 56, 226
SNMP community strings, 42, 220
SNMP management session, 23, 45
snoop topology, 168, 281
software updates
downloading from a local session, 196
downloading via TFTP, 205
obtaining, 16, 195
Spanning Tree Protocol
configuring bridge parameters, 101, 105,
248
configuring port parameters, 103
defined, 92
port cost, 94, 104, 108, 251, 256
viewing bridge parameters, 257
starting session
local, 27
Telnet, 32
web browser, 209
static MAC address
adding, 159, 274
deleting, 160, 275
displaying, 152
statistics
port, 189, 237
switch, 191
STP. See Spanning Tree Protocol
subnet mask, 38, 216
switch statistics, 191
system name, 38, 215
T
TACACS+
configuring, 183, 289
overview, 180
tagged VLAN
creating, 126, 131, 260
defined, 120
deleting all, 138
deleting, 136, 264
displaying, 135, 265
modifying, 132, 263
Telnet management session
defined, 21
quitting, 33
starting, 32
TFTP server access 45
TFTP, downloading and uploading files, 196,
205
U
unavailable status, defined, 56, 226
user name, default, 209
V
version number, AT-S39, 48
virtual LAN
creating, 126, 130, 131, 260
defined, 111
deleting all, 138
deleting, 136, 264
disabling, 143, 267
displaying, 135, 265
enabling, 143, 267
mode, changing, 142, 266
modifying, 132, 263
298
port-based, defined, 113
tagged, defined, 120
VLAN identifier (VID), 113, 127, 133
VLAN identifier, 261
VLAN. See virtual LAN
W
web browser management session
defined, 22
disabling, 45
limitations, 22
quitting, 211
starting, 209
299