Catalyst 2940 Switch Command Reference

Catalyst 2940 Switch Command Reference
Cisco IOS Release 12.1(22)EA7
January 2006
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Catalyst 2940 Switch Command Reference
Copyright © 2006 Cisco Systems, Inc. All rights reserved.
CONTENTS
Preface
xi
Audience
Purpose
xi
xi
Conventions
xi
Related Publications
xii
Obtaining Documentation xiii
Cisco.com xiii
Product Documentation DVD xiii
Ordering Documentation xiii
Documentation Feedback
xiv
Cisco Product Security Overview xiv
Reporting Security Problems in Cisco Products
xiv
Obtaining Technical Assistance xv
Cisco Technical Support & Documentation Website
Submitting a Service Request xvi
Definitions of Service Request Severity xvi
Obtaining Additional Publications and Information
CHAPTER
1
Using the Command-Line Interface
Type of Memory
Platforms
xv
xvi
1-1
1-1
1-1
CLI Command Modes 1-2
User EXEC Mode 1-3
Privileged EXEC Mode 1-3
Global Configuration Mode 1-4
Interface Configuration Mode 1-4
config-vlan Mode 1-4
VLAN Configuration Mode 1-5
Line Configuration Mode 1-5
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Contents
CHAPTER
2
Catalyst 2940 Cisco IOS Commands
aaa accounting dot1x
2-1
aaa authentication dot1x
archive download-sw
archive tar
2-3
2-5
2-7
archive upload-sw
2-10
banner config-save
boot host
2-1
2-12
2-13
boot private-config-file
channel-group
2-15
channel-protocol
2-18
clear interface
clear lacp
2-14
2-20
2-21
clear mac address-table
clear pagp
2-22
2-23
clear port-security
2-24
clear spanning-tree counters
2-26
clear spanning-tree detected-protocols
clear vmps statistics
clear vtp counters
2-28
2-29
cluster commander-address
2-30
cluster discovery hop-count
2-32
cluster enable
2-33
cluster holdtime
2-34
cluster management-vlan
cluster member
cluster run
2-38
2-39
2-41
define interface-range
delete
dot1x
2-35
2-36
cluster standby-group
cluster timer
2-27
2-42
2-44
2-45
dot1x auth-fail max-attempts
dot1x auth-fail vlan
2-47
2-49
dot1x control-direction
2-51
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dot1x default
2-53
dot1x guest-vlan
2-54
dot1x host-mode
2-56
dot1x initialize
2-57
dot1x max-req
2-58
dot1x multiple-hosts
dot1x port-control
2-59
2-60
dot1x re-authenticate
2-62
dot1x re-authentication
2-63
dot1x reauthentication
dot1x timeout
duplex
2-64
2-65
2-67
errdisable detect cause
errdisable recovery
flowcontrol
interface
2-69
2-71
2-73
2-77
interface port-channel
interface range
ip address
2-79
2-80
2-82
ip dhcp snooping
2-83
ip dhcp snooping information option
2-84
ip dhcp snooping information option allow-untrusted
ip dhcp snooping limit rate
ip dhcp snooping trust
2-89
ip dhcp snooping vlan
2-90
ip igmp filter
2-86
2-88
2-91
ip igmp max-groups
ip igmp profile
ip igmp snooping
2-92
2-94
2-96
ip igmp snooping mrouter learn pim v2
ip igmp snooping report-suppression
ip igmp snooping source-only-learning
ip igmp snooping vlan
2-97
2-99
2-101
2-103
ip igmp snooping vlan immediate-leave
2-104
ip igmp snooping vlan last-member-query interval
2-105
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Contents
ip igmp snooping vlan mrouter
ip igmp snooping vlan static
ip ssh
2-106
2-108
2-109
lacp port-priority
2-111
lacp system-priority
2-113
mac address-table aging-time
2-115
mac address-table notification
2-117
mac address-table static
macro apply
2-119
2-121
macro description
macro global
2-124
2-125
macro global description
macro name
mdix auto
2-128
2-130
mls qos cos
2-131
mls qos trust
2-133
monitor session
mvr
2-127
2-135
2-138
mvr immediate
mvr type
2-141
2-142
mvr vlan group
2-144
pagp learn-method
pagp port-priority
2-145
2-147
port-channel load-balance
rcommand
2-150
rmon collection stats
2-152
service password-recovery
setup express
show boot
show cluster
2-148
2-153
2-155
2-157
2-159
show cluster candidates
show cluster members
2-161
2-163
show controllers ethernet-controller
show controllers utilization
show dot1x
2-166
2-170
2-172
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show env
2-176
show errdisable recovery
show etherchannel
show file
2-177
2-179
2-182
show flowcontrol
2-185
show interfaces
2-187
show interfaces counters
show inventory
2-195
2-198
show ip dhcp snooping
2-199
show ip dhcp snooping binding
show ip igmp profile
2-202
show ip igmp snooping
show lacp
2-200
2-203
2-206
show mac address-table
2-208
show mac address-table multicast
show mac address-table notification
show mls qos interface
show monitor
show mvr
2-216
2-218
2-219
show mvr members
2-221
show pagp
2-223
show parser macro
2-225
show port-security
2-228
show running-config vlan
show setup express
2-232
show spanning-tree
2-233
show storm-control
2-238
show system mtu
show udld
show vtp
2-230
2-241
2-242
show version
show vmps
2-213
2-214
show mvr interface
show vlan
2-211
2-245
2-247
2-250
2-253
show wrr-queue bandwidth
2-258
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Contents
show wrr-queue cos-map
shutdown
2-259
2-260
shutdown vlan
2-261
snmp-server enable traps
snmp-server host
2-262
2-265
snmp trap mac-notification
2-268
spanning-tree backbonefast
spanning-tree bpdufilter
2-269
2-270
spanning-tree bpduguard
spanning-tree cost
2-272
2-274
spanning-tree etherchannel guard misconfig
spanning-tree extend system-id
spanning-tree guard
2-278
2-280
spanning-tree link-type
2-282
spanning-tree loopguard default
spanning-tree mode
2-283
2-285
spanning-tree mst configuration
spanning-tree mst cost
2-287
2-289
spanning-tree mst forward-time
spanning-tree mst hello-time
spanning-tree mst max-age
2-291
2-292
2-293
spanning-tree mst max-hops
2-294
spanning-tree mst port-priority
spanning-tree mst priority
spanning-tree mst root
2-295
2-297
2-298
spanning-tree port-priority
2-300
spanning-tree portfast (global configuration)
spanning-tree portfast (interface configuration)
spanning-tree uplinkfast
spanning-tree vlan
speed
2-276
2-302
2-304
2-306
2-308
2-311
storm-control
2-313
switchport access
switchport host
switchport mode
2-315
2-317
2-319
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switchport nonegotiate
2-321
switchport port-security
2-323
switchport port-security aging
switchport priority extend
switchport protected
switchport trunk
2-331
2-334
2-336
traceroute mac
2-337
traceroute mac ip
udld
2-329
2-330
switchport voice vlan
system mtu
2-327
2-340
2-342
udld port
2-344
udld reset
2-346
vlan (global configuration)
2-347
vlan (VLAN configuration)
2-352
vlan database
2-358
vmps reconfirm (global configuration)
vmps reconfirm (privileged EXEC)
vmps retry
vmps server
2-364
vtp (global configuration)
2-366
vtp (VLAN configuration)
2-370
wrr-queue cos-map
A
2-362
2-363
wrr-queue bandwidth
APPENDIX
2-361
2-374
2-375
Catalyst 2940 Switch Debug Commands
debug dot1x
A-2
debug etherchannel
debug pagp
debug pm
A-1
A-3
A-4
A-5
debug spanning-tree
A-7
debug spanning-tree backbonefast
debug spanning-tree bpdu
A-10
debug spanning-tree bpdu-opt
debug spanning-tree mstp
debug spanning-tree switch
A-9
A-11
A-12
A-14
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Contents
debug spanning-tree uplinkfast
debug switch dhcp
debug sw-vlan
A-17
A-18
debug sw-vlan ifs
A-20
debug sw-vlan notification
debug sw-vlan vtp
debug udld
A-16
A-21
A-23
A-25
INDEX
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Preface
Audience
This guide is for the networking professional using the Cisco IOS command-line interface (CLI) to
manage the Catalyst 2940 switch, hereafter referred to as the switch. Before using this guide, you should
have experience working with the Cisco IOS and be familiar with the concepts and terminology of
Ethernet and local area networking.
Purpose
This guide provides the information you need about the commands that have been created or changed
for use with the Catalyst 2940 family of switches. For information about the standard Cisco IOS Release
12.1 commands, see the Cisco IOS documentation set available from the Cisco.com home page by
selecting Service and Support > Technical Documents. On the Cisco Product Documentation home
page, select Release 12.1 from the Cisco IOS Software drop-down list.
This guide does not provide procedures for configuring your switch. For detailed configuration
procedures, see the software configuration guide for this release.
This guide does not describe system messages you might encounter. For more information, see the
system message guide for this release.
For documentation updates, see the release notes for this release.
Conventions
This guide uses these conventions to convey instructions and information:
Command descriptions use these conventions:
•
Commands and keywords are in boldface text.
•
Arguments for which you supply values are in italic.
•
Square brackets ([ ]) mean optional elements.
•
Braces ({ }) group required choices, and vertical bars ( | ) separate the alternative elements.
•
Braces and vertical bars within square brackets ([{ | }]) mean a required choice within an optional
element.
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Preface
Related Publications
Interactive examples use these conventions:
•
Terminal sessions and system displays are in screen font.
•
Information you enter is in boldface screen font.
•
Nonprinting characters, such as passwords or tabs, are in angle brackets (< >).
Notes, cautions, and tips use these conventions and symbols:
Note
Caution
Means reader take note. Notes contain helpful suggestions or references to materials not contained in
this manual.
Means reader be careful. In this situation, you might do something that could result in equipment
damage or loss of data.
Related Publications
These documents provide complete information about the switch and are available from this URL:
http://www.cisco.com/en/US/products/hw/switches/ps5213/tsd_products_support_series_home.html
You can order printed copies of documents with a DOC-xxxxxx= number from the Cisco.com sites and
from the telephone numbers listed in the “Obtaining Documentation” section on page xiii.
•
Release Notes for the Catalyst 2955, Catalyst 2950, and Catalyst 2940 Switches (not orderable but
available on Cisco.com)
•
Catalyst 2955, 2950 and 2940 Switch System Message Guide (not orderable but available on
Cisco.com)
Note
Switch requirements and procedures for initial configurations and software upgrades tend to
change and therefore appear only in the release notes. Before installing, configuring, or
upgrading the switch, see the release notes on Cisco.com for the latest information.
For information about the switch, see these documents:
•
Catalyst 2940 Switch Software Configuration Guide (not orderable but available on Cisco.com)
•
Catalyst 2940 Switch Command Reference (not orderable but available on Cisco.com)
•
Device manager online help (available on the switch)
•
Catalyst 2940 Switch Hardware Installation Guide (not orderable but available on Cisco.com)
•
Catalyst 2940 Switch Getting Started Guide (order number DOC-7816576=)
•
Regulatory Compliance and Safety Information for the Catalyst 2940 Switch (order number
DOC-7816656=)
For information about related products, see these documents:
•
Getting Started with Cisco Network Assistant (not orderable but available on Cisco.com)
•
Release Notes for Cisco Network Assistant (not orderable but available on Cisco.com)
•
Cisco Small Form-Factor Pluggable Modules Installation Notes (order number DOC-7815160=)
Catalyst 2940 Switch Command Reference
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Preface
Obtaining Documentation
•
Cisco CWDM GBIC and CWDM SFP Installation Note (not orderable but available on Cisco.com)
•
For information about the Network Admission Control (NAC) features, see the Network Admission
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Obtaining Technical Assistance
Tip
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Preface
Obtaining Additional Publications and Information
Submitting a Service Request
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Preface
Obtaining Additional Publications and Information
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1
Using the Command-Line Interface
The Catalyst 2940 switches are supported by Cisco IOS software. This chapter describes how to use the
switch command-line interface (CLI) to configure the software features.
For a complete description of the commands that support these features, see Chapter 2, “Catalyst 2940
Cisco IOS Commands.” For more information on Cisco IOS Release 12.1, see the command references
for Cisco IOS Release 12.1 at this URL:
http://www.cisco.com/univercd/cc/td/doc/product/software/ios121/121cgcr/index.htm
For task-oriented configuration steps, see the software configuration guide for this release.
The switches are preconfigured and begin forwarding packets as soon as they are attached to compatible
devices.
Note
In this document, IP refers to IP version 4 (IPv4). Layer 3 IP version 6 (IPv6) packets are treated as
non-IP packets.
Type of Memory
The switch flash memory stores the Cisco IOS software image, the startup and private configuration
files, and helper files.
Platforms
This software release runs on a variety of switches. For a complete list, see the release notes.
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CLI Command Modes
CLI Command Modes
This section describes the CLI command mode structure. Command modes support specific Cisco IOS
commands. For example, the interface type_number command works only when entered in global
configuration mode. These are the main command modes:
•
User EXEC
•
Privileged EXEC
•
Global configuration
•
Interface configuration
•
Config-vlan
•
VLAN configuration
•
Line configuration
Table 1-1 lists the command modes, how to access each mode, the prompt you see in that mode, and how
to exit that mode. The prompts listed assume the default name Switch.
Table 1-1
Command Modes Summary
Command Mode
Access Method
Prompt
Exit or Access Next Mode
User EXEC
This is the first level of access.
Switch>
Enter the logout command.
Privileged EXEC
(For the switch) Change terminal
settings, perform basic tasks, and
list system information.
To enter privileged EXEC mode, enter
the enable command.
From user EXEC mode, enter the Switch#
enable command.
To exit to user EXEC mode, enter the
disable command.
To enter global configuration mode,
enter the configure command.
Global
configuration
From privileged EXEC mode,
enter the configure command.
Switch(config)#
To exit to privileged EXEC mode,
enter the exit or end command, or press
Ctrl-Z.
To enter interface configuration mode,
enter the interface command.
Interface
configuration
From global configuration mode, Switch(config-if)#
specify an interface by entering
the interface command.
To exit to privileged EXEC mode,
enter the end command, or press
Ctrl-Z.
To exit to global configuration mode,
enter the exit command.
To enter subinterface configuration
mode, specify a subinterface with the
interface command.
Config-vlan
Switch(config-vlan)#
In global configuration mode,
enter the vlan vlan-id command.
To exit to global configuration mode,
enter the exit command.
To return to privileged EXEC mode,
enter the end command, or press
Ctrl-Z.
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CLI Command Modes
Table 1-1
Command Modes Summary (continued)
Command Mode
Access Method
Prompt
Exit or Access Next Mode
VLAN
configuration
From privileged EXEC mode,
enter the vlan database
command.
Switch(vlan)#
To exit to privileged EXEC mode,
enter the exit command.
Line configuration
From global configuration mode, Switch(config-line)#
specify a line by entering the line
command.
To exit to global configuration mode,
enter the exit command.
To return to privileged EXEC mode,
enter the end command, or press
Ctrl-Z.
User EXEC Mode
After you access the device, you are automatically in user EXEC command mode. The EXEC commands
available at the user level are a subset of those available at the privileged level. In general, use the user
EXEC commands to change terminal settings temporarily, to perform basic tests, and to list system
information.
The supported commands can vary depending on the version of software in use. To view a
comprehensive list of commands, enter a question mark (?) at the prompt.
Switch> ?
Privileged EXEC Mode
Because many of the privileged commands configure operating parameters, privileged access should be
password-protected to prevent unauthorized use. The privileged command set includes those commands
contained in user EXEC mode, as well as the configure command through which you access the
remaining command modes.
If your system administrator has set a password, you are prompted to enter it before being granted access
to privileged EXEC mode. The password does not appear on the screen and is case sensitive.
The privileged EXEC mode prompt is the device name followed by the pound sign (#).
Switch#
Enter the enable command to access privileged EXEC mode:
Switch> enable
Switch#
The supported commands can vary depending on the version of software in use. To view a
comprehensive list of commands, enter a question mark (?) at the prompt.
Switch# ?
To return to user EXEC mode, enter the disable command.
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CLI Command Modes
Global Configuration Mode
Global configuration commands apply to features that affect the device as a whole. Use the configure
privileged EXEC command to enter global configuration mode. The default is to enter commands from
the management console.
When you enter the configure command, a message prompts you for the source of the configuration
commands:
Switch# configure
Configuring from terminal, memory, or network [terminal]?
You can specify either the terminal or NVRAM as the source of configuration commands.
This example shows you how to access global configuration mode:
Switch# configure terminal
Enter configuration commands, one per line.
End with CNTL/Z.
The supported commands can vary depending on the version of software in use. To view a
comprehensive list of commands, enter a question mark (?) at the prompt.
Switch(config)# ?
To exit global configuration command mode and to return to privileged EXEC mode, enter the end or
exit command, or press Ctrl-Z.
Interface Configuration Mode
Interface configuration commands modify the operation of the interface. Interface configuration
commands always follow a global configuration command, which defines the interface type.
Use the interface type_number.subif command to access interface configuration mode. The new prompt
shows interface configuration mode.
Switch(config-if)#
The supported commands can vary depending on the version of software in use. To view a
comprehensive list of commands, enter a question mark (?) at the prompt.
Switch(config-if)# ?
To exit interface configuration mode and to return to global configuration mode, enter the exit command.
To exit interface configuration mode and to return to privileged EXEC mode, enter the end command,
or press Ctrl-Z.
config-vlan Mode
Use this mode to configure normal-range VLANs (VLAN IDs 1 to 1005) or, when VTP mode is
transparent, to configure extended-range VLANs (VLAN IDs 1006 to 4094). When VTP mode is
transparent, the VLAN and VTP configuration is saved in the running configuration file, and you can
save it to the switch startup configuration file by using the copy running-config startup-config
privileged EXEC command. The configurations of VLAN IDs 1 to 1005 are saved in the VLAN database
if VTP is in transparent or server mode. The extended-range VLAN configurations are not saved in the
VLAN database.
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CLI Command Modes
Enter the vlan vlan-id global configuration command to access config-vlan mode:
Switch(config)# vlan 2000
Switch(config-vlan)#
The supported keywords can vary but are similar to the commands available in VLAN configuration
mode. To view a comprehensive list of commands, enter a question mark (?) at the prompt.
Switch(config-vlan)# ?
For extended-range VLANs, all characteristics except MTU size must remain at the default setting.
To return to global configuration mode, enter exit; to return to privileged EXEC mode, enter end. All
commands except shutdown take effect when you exit config-vlan mode.
VLAN Configuration Mode
You can use the VLAN configuration commands to create or modify VLAN parameters for VLANs 1 to
1005. Enter the vlan database privileged EXEC command to access VLAN configuration mode:
Switch# vlan database
Switch(vlan)#
The supported commands can vary depending on the version of software in use. To view a
comprehensive list of commands, enter a question mark (?) at the prompt.
Switch(vlan)# ?
To return to privileged EXEC mode, enter the abort command to abandon the proposed database.
Otherwise, enter exit to implement the proposed new VLAN database and to return to privileged EXEC
mode.
Line Configuration Mode
Line configuration commands modify the operation of a terminal line. Line configuration commands
always follow a line command, which defines a line number. Use these commands to change terminal
parameter settings line-by-line or for a range of lines.
Use the line vty line_number [ending_line_number] command to enter line configuration mode. The
new prompt indicates line configuration mode.
This example shows how to enter line configuration mode for virtual terminal line 7:
Switch(config)# line vty 0 7
The supported commands can vary depending on the version of software in use. To view a
comprehensive list of commands, enter a question mark (?) at the prompt.
Switch(config-line)# ?
To exit line configuration mode and to return to global configuration mode, use the exit command.
To exit line configuration mode and to return to privileged EXEC mode, enter the end command, or press
Ctrl-Z.
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Catalyst 2940 Cisco IOS Commands
aaa accounting dot1x
Use the aaa accounting dot1x global configuration command to enable authentication, authorization,
and accounting (AAA) accounting and to create method lists defining specific accounting methods on a
per-line or per-interface basis for IEEE 802.1x sessions. Use the no form of this command to disable
IEEE 802.1x accounting.
aaa accounting dot1x {name | default} start-stop {broadcast group {name | radius | tacacs+}
[group {name | radius | tacacs+} ... ] | group {name | radius | tacacs+} [group {name | radius
| tacacs+} ...]}
no aaa accounting dot1x {name | default}
Syntax Description
name
Name of a server group. This is optional when you enter it after the
broadcast group and group keywords.
default
Use the accounting methods that follow as the default list for accounting
services.
start-stop
Send a start accounting notice at the beginning of a process and a stop
accounting notice at the end of a process. The start accounting record is sent
in the background. The requested-user process begins regardless of whether
or not the start accounting notice was received by the accounting server.
broadcast
Enable accounting records to be sent to multiple AAA servers and send
accounting records to the first server in each group. If the first server is
unavailable, the switch uses the list of backup servers to identify the first
server.
group
Specify the server group to be used for accounting services. These are valid
server group names:
•
name—Name of a server group.
•
radius—List of all RADIUS hosts.
•
tacacs+—List of all TACACS+ hosts.
The group keyword is optional when you enter it after the broadcast group
and group keywords. You can enter more than optional group keyword.
radius
(Optional) Enable RADIUS authorization.
tacacs+
(Optional) Enable TACACS+ accounting.
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aaa accounting dot1x
Defaults
AAA accounting is disabled.
Command Modes
Global configuration
Command History
Release
Modification
12.1(20)EA2
This command was introduced.
Usage Guidelines
Note
Examples
This command requires access to a RADIUS server.
We recommend that you enter the dot1x re-authentication interface configuration command before
configuring IEEE 802.1x RADIUS accounting on an interface.
This example shows how to configure IEEE 802.1x accounting:
Switch(config)# aaa new model
Switch(config)# aaa accounting dot1x default start-stop group radius
Note
Related Commands
The RADIUS authentication server must be properly configured to accept and log update or watchdog
packets from the AAA client.
Command
Description
aaa authentication
dot1x
Specifies one or more AAA methods for use on interfaces running
IEEE 802.1x.
dot1x reauthentication
Enables or disables periodic re-authentication.
dot1x timeout
reauth-period
Sets the number of seconds between re-authentication attempts.
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aaa authentication dot1x
aaa authentication dot1x
Use the aaa authentication dot1x global configuration command to specify the authentication,
authorization, and accounting (AAA) method to use on ports complying with IEEE 802.1x
authentication. Use the no form of this command to disable authentication.
aaa authentication dot1x {default} method1
no aaa authentication dot1x {default}
Syntax Description
Note
default
Use the listed authentication method that follows this argument as the default
method when a user logs in.
method1
Enter the group radius keywords to use the list of all RADIUS servers for
authentication.
Though other keywords are visible in the command-line help strings, only the default and group radius
keywords are supported.
Defaults
No authentication is performed.
Command Modes
Global configuration
Command History
Release
Modification
12.1(13)AY
This command was introduced.
Usage Guidelines
The method argument identifies the method that the authentication algorithm tries in the given sequence
to validate the password provided by the client. The only method that is truly IEEE 802.1x-compliant is
the group radius method, in which the client data is validated against a RADIUS authentication server.
If you specify group radius, you must configure the RADIUS server by entering the radius-server host
global configuration command.
Use the show running-config privileged EXEC command to display the configured lists of
authentication methods.
Examples
This example shows how to enable AAA and how to create an IEEE 802.1x-compliant authentication
list. This authentication first tries to contact a RADIUS server. If this action returns an error, the user is
not allowed access to the network.
Switch(config)# aaa new model
Switch(config)# aaa authentication dot1x default group radius
You can verify your settings by entering the show running-config privileged EXEC command.
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aaa authentication dot1x
Related Commands
Command
Description
aaa new-model
Enables the AAA access control model. For syntax information, select Cisco
IOS Security Command Reference for Release 12.1 > Authentication,
Authorization, and Accounting > Authentication Commands.
show running-config
Displays the configuration information running on the switch. For syntax
information, select Cisco IOS Configuration Fundamentals Command
Reference for Release 12.1 > Cisco IOS File Management Commands >
Configuration File Commands.
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archive download-sw
archive download-sw
Use the archive download-sw privileged EXEC command to download a new image from a TFTP server
to the switch and to overwrite or to keep the existing image.
archive download-sw {/force-reload | /imageonly | /leave-old-sw | /no-set-boot | /overwrite |
/reload | /safe} source-url
Syntax Description
/force-reload
Unconditionally force a system reload after successfully downloading the
software image.
/imageonly
Download only the software image but not the files associated with the device
manager. The device manager files for the existing version are deleted only if
the existing version is being overwritten or removed.
/leave-old-sw
Keep the old software version after a successful download.
/no-set-boot
Do not alter the setting of the BOOT environment variable to point to the new
software image after it is successfully downloaded.
/overwrite
Overwrite the software image in flash memory with the downloaded image.
/reload
Reload the system after successfully downloading the image unless the
configuration has been changed and not been saved.
/safe
Keep the current software image; do not delete it to make room for the new
software image before the new image is downloaded. The current image is
deleted after the download.
source-url
The source URL alias for a local or network file system. These options are
supported:
•
The syntax for the local flash file system:
flash:
•
The syntax for the FTP:
ftp:[[//username[:password]@location]/directory]/image-name.tar
•
The syntax for the Remote Copy Protocol (RCP):
rcp:[[//username@location]/directory]/image-name.tar
•
The syntax for the TFTP: tftp:[[//location]/directory]/image-name.tar
The image-name.tar is the software image to download and install on the
switch.
Defaults
Both the software image and device manager files are downloaded.
The new image is downloaded to the flash: file system.
The BOOT environment variable is changed to point to the new software image on the flash: file system.
Image names are case sensitive; the image file is provided in tar format.
Command Modes
Privileged EXEC
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archive download-sw
Command History
Usage Guidelines
Release
Modification
12.1(13)AY
This command was introduced.
Use the /overwrite option to overwrite the image on the flash device with the downloaded one.
If the flash device has sufficient space to hold two images and you want to overwrite one of these images
with the same version, you must specify the /overwrite option.
If you specify the command without the /overwrite option, the download algorithm verifies that the new
image is not the same as the one on the switch flash device. If the images are the same, the download
does not occur. If the images are different, the old image is deleted, and the new one is downloaded.
The /imageonly option removes the device manager files for the existing image if the existing image is
being removed or replaced. Only the software image (without the device manager files) is downloaded.
Using the /safe or /leave-old-sw option can cause the new image download to fail if there is insufficient
flash space.
If you used the /leave-old-sw option and did not overwrite the old image when you downloaded the new
one, you can remove the old image by using the delete privileged EXEC command. For more
information, see the delete command.
If you leave the existing software in place before downloading the new image, an error results if the
existing software prevents the new image from fitting onto flash memory.
After downloading a new image, enter the reload privileged EXEC command to begin using the new
image, or specify the /reload or /force-reload option in the archive download-sw command.
Examples
This example shows how to download a new image from a TFTP server at 172.20.129.10 and to
overwrite the image on the switch:
Switch# archive download-sw /overwrite tftp://172.20.129.10/test-image.tar
This example shows how to download only the software image from a TFTP server at 172.20.129.10 to
the switch:
Switch# archive download-sw /imageonly tftp://172.20.129.10/test-image.tar
This example shows how to keep the old software version after a successful download:
Switch# archive download-sw /leave-old-sw tftp://172.20.129.10/test-image.tar
Related Commands
Command
Description
archive tar
Creates a tar file, lists the files in a tar file, or extracts the files from a tar file.
archive upload-sw
Uploads an existing image on the switch to a server.
delete
Deletes a file or directory on the flash memory device.
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archive tar
archive tar
Use the archive tar privileged EXEC command to create a tar file, to list files in a tar file, or to extract
the files from a tar file.
archive tar {/create destination-url flash:/file-url} | {/table source-url} | {/xtract source-url
flash:/file-url [dir/file...]}
Syntax Description
/create destination-url
flash:/file-url
Create a new tar file on the local or network file system.
For destination-url, specify the destination URL alias for the local or
network file system and the name of the tar file to create. These options
are supported:
•
The syntax for the local flash file system:
flash:
•
The syntax for the FTP:
ftp:[[//username[:password]@location]/directory]/tar-filename.tar
•
The syntax for the Remote Copy Protocol (RCP) is:
rcp:[[//username@location]/directory]/tar-filename.tar
•
The syntax for the TFTP:
tftp:[[//location]/directory]/tar-filename.tar
The tar-filename.tar is the tar file to be created.
For flash:/file-url, specify the location on the local flash file system from
which the new tar file is created.
An optional list of files or directories within the source directory can be
specified to write to the new tar file. If none are specified, all files and
directories at this level are written to the newly created tar file.
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archive tar
/table source-url
Display the contents of an existing tar file to the screen.
For source-url, specify the source URL alias for the local or network file
system. These options are supported:
•
The syntax for the local flash file system:
flash:
•
The syntax for the FTP:
ftp:[[//username[:password]@location]/directory]/tar-filename.tar
•
The syntax for the RCP:
rcp:[[//username@location]/directory]/tar-filename.tar
•
The syntax for the TFTP:
tftp:[[//location]/directory]/tar-filename.tar
The tar-filename.tar is the tar file to display.
/xtract source-url
flash:/file-url [dir/file...]
Extract files from a tar file to the local file system.
For source-url, specify the source URL alias for the local file system.
These options are supported:
•
The syntax for the local flash file system:
flash:
•
The syntax for the FTP:
ftp:[[//username[:password]@location]/directory]/tar-filename.tar
•
The syntax for the RCP:
rcp:[[//username@location]/directory]/tar-filename.tar
•
The syntax for the TFTP:
tftp:[[//location]/directory]/tar-filename.tar
The tar-filename.tar is the tar file from which to extract.
For flash:/file-url [dir/file...], specify the location on the local flash file
system into which the tar file is extracted. Use the dir/file... option to
specify an optional list of files or directories within the tar file to be
extracted. If none are specified, all files and directories are extracted.
Defaults
No default is defined.
Command Modes
Privileged EXEC
Command History
Release
Modification
12.1(13)AY
This command was introduced.
Usage Guidelines
Filenames and directory names are case sensitive.
Image names are case sensitive.
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archive tar
Examples
This example shows how to create a tar file. The command writes the contents of the new-configs
directory on the local flash device to a file named saved.tar on the TFTP server at 172.20.136.9:
Switch# archive tar /create tftp:172.20.136.9/saved.tar flash:/new-configs
This example shows how to display the contents of the c2940-tv0-m.tar file that is in flash memory. The
contents of the tar file appear on the screen.
Switch# archive tar /table flash:c2940-tv0-m.tar
info (219 bytes)
c2940-tv0-mz-121/ (directory)
c2940-tv0-mz-121/html/ (directory)
c2940-tv0-mz-121/html/foo.html (0 bytes)
c2940-tv0-mz-121/vegas-tv0-mz-121.bin (610856 bytes)
c2940-tv0-mz-121/info (219 bytes)
info.ver (219 bytes)
This example shows how to extract the contents of a tar file on the TFTP server at 172.20.10.30. This
command extracts just the new-configs directory into the root directory on the local flash file system.
The remaining files in the saved.tar file are ignored.
Switch# archive tar /xtract tftp:/172.20.10.30/saved.tar flash:/ new-configs
Related Commands
Command
Description
archive download-sw
Downloads a new image to the switch.
archive upload-sw
Uploads an existing image on the switch to a server.
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archive upload-sw
archive upload-sw
Use the archive upload-sw privileged EXEC command to upload an existing switch image to a server.
archive upload-sw [/version version_string] destination-url
Syntax Description
/version version_string
(Optional) Specify the version string of the image to be uploaded.
destination-url
The destination URL alias for a local or network file system. These options
are supported:
•
The syntax for the local flash file system:
flash:
•
The syntax for the FTP:
ftp:[[//username[:password]@location]/directory]/image-name.tar
•
The syntax for the Remote Copy Protocol (RCP):
rcp:[[//username@location]/directory]/image-name.tar
•
The syntax for the TFTP:
tftp:[[//location]/directory]/image-name.tar
The image-name.tar is the name of software image to be stored on the
server.
Defaults
The switch uploads the currently running image from the flash: file system.
Command Modes
Privileged EXEC
Command History
Release
Modification
12.1(13)AY
This command was introduced.
Usage Guidelines
Use the upload feature only if the files associated with the device manager have been installed with the
existing image.
The files are uploaded in this sequence: info, the software image, the device manager files, and info.ver.
After these files are uploaded, the software creates the tar file.
Image names are case sensitive.
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archive upload-sw
Examples
This example shows how to upload the currently running image to a TFTP server at 172.20.140.2:
Switch# archive upload-sw tftp://172.20.140.2/test-image.tar
Related Commands
Command
Description
archive download-sw
Downloads a new image to the switch.
archive tar
Creates a tar file, lists the files in a tar file, or extracts the files from a tar file.
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banner config-save
banner config-save
To display a configuration banner, use the banner config-save global configuration command. The no
form of this command deletes the configuration banner.
banner config-save ^c message ^c
no banner config-save
Syntax Description
^c
Delimiting character of your choice—a pound sign (#), for example. You
cannot use the delimiting character in the banner message.
message
Message text. You can include tokens in the form $(token) in the message
text. Tokens are replaced with the corresponding configuration variable.
Tokens are described in Table 11.
Defaults
No banner is displayed.
Command Modes
Global configuration
Command History
Release
Modification
12.1(22)EA7
This command was introduced.
Usage Guidelines
To customize the banner, use tokens in the form $(token) in the message text. Tokens display current IOS
configuration variables, such as the switch hostname and IP address. The tokens are described in
Table 2-1.
Table 2-1
Examples
banner login commandtokens
Token
Information displayed in the banner
$(hostname)
Displays the switch hostname.
$(domain)
Displays the switch domain name.
$(line)
Displays the VTY or TTY (async) line number.
$(line-desc)
Displays the description attached to the line.
The following example sets a config-save banner:
Switch(config)# banner config-save ^c
Caution-Downloading Running Configuration File
^C
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boot host
boot host
To specify the mechanism used to download a configuration file at the next system startup, use the boot
host global configuration command. To restore the host configuration filename to the default, use the
no form of this command.
boot host {dhcp | retry timeout}
no boot host {dhcp | retry timeout}
Syntax Description
dhcp
Directs the system to get an IP address, configuration file, and TFTP
server address by using DHCP.
retry timeout
Specifies the amount of time between retries; valid values are between 60
and 65,535 seconds.
Defaults
The timeout is zero.
Command Modes
Global configuration
Command History
Release
Modification
12.1(22)EA7
This command was introduced.
Usage Guidelines
If you configure boot host dhcp, it does not take effect until the next reboot.
If you enter the no boot host dhcp command while the boot host dhcp is waiting for the retry timer to
expire, the system will stops trying. However, if the configuration download is in progress, the system
continues to download.
Examples
The following example enables the download of a configuration file at the next system startup:
Switch(config)# boot host dhcp
The following example sets the time between retries to 420 seconds:
Switch(config)# boot host retry timeout 420
Related Commands
Command
Description
banner config-save
Displays a configuration banner.
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boot private-config-file
boot private-config-file
Use the boot private-config-file global configuration command to specify the filename that the software
uses to read and write a nonvolatile copy of the private configuration. Use the no form of this command
to return to the default setting.
boot private-config-file filename
no boot private-config-file
Syntax Description
filename
Defaults
The default configuration file is private-config.text.
Command Modes
Global configuration
Command History
Release
Modification
12.1(13)AY
This command was introduced.
Usage Guidelines
The name of the private configuration file.
Only the software can read and write a copy of the private configuration file. You cannot read, write,
delete, or display a copy of this file.
Filenames are case sensitive.
Examples
This example shows how to specify the name of the private configuration file as pconfig:
Switch(config)# boot private-config-file pconfig
Related Commands
Command
Description
show boot
Displays the settings of the boot environment variables.
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channel-group
channel-group
Use the channel-group interface configuration command to assign an Ethernet interface to an
EtherChannel group and to enable an EtherChannel mode. Use the no form of this command to remove
an Ethernet interface from an EtherChannel group.
channel-group channel-group-number mode {active | {auto [non-silent]} | {desirable
[non-silent]} | on | passive}
no channel-group
PAgP modes:
channel-group channel-group-number mode {{auto [non-silent]} | {desirable [non-silent}}
LACP modes:
channel-group channel-group-number mode {active | passive}
On mode:
channel-group channel-group-number mode on
Syntax Description
channel-group-number
Specify the channel group number. The range is 1 to 6.
mode
Specify the EtherChannel Port Aggregation Protocol (PAgP) or Link
Aggregration Control Protocol (LACP). mode of the interface.
active
Unconditionally enable LACP.
Active mode places an interface into a negotiating state in which the
interface initiates negotiations with other interfaces by sending LACP
packets. A channel is formed with another port group in either the active
or passive mode. When active is enabled, silent operation is the default.
auto
Enable PAgP only if a PAgP device is detected.
Auto mode places an interface into a passive negotiating state, in which the
interface responds to PAgP packets it receives but does not initiate PAgP
packet negotiation. A channel is formed only with another port group in
desirable mode. When auto is enabled, silent operation is the default.
desirable
Unconditionally enable PAgP.
Desirable mode places an interface into a negotiating state in which the
interface initiates negotiations with other interfaces by sending PAgP
packets. A channel is formed with another port group in either the
desirable or auto mode. When desirable is enabled, silent operation is the
default.
non-silent
(Optional) Used with the auto or desirable keyword when PAgP traffic is
expected from the other device.
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channel-group
on
Enable on mode.
In on mode, a usable EtherChannel exists only when both connected port
groups are in the on mode.
passive
Enable LACP only if an LACP device is detected.
Passive mode places an interface into a negotiating state in which the
interface responds to LACP packets it receives but does not initiate LACP
packet negotiation. A channel is formed only with another port group in
active mode. When passive is enabled, silent operation is the default.
Defaults
No channel groups are assigned.
There is no default mode.
Command Modes
Interface configuration
Command History
Release
Modification
12.1(13)AY
This command was introduced.
Usage Guidelines
You must specify the mode when entering this command. If the mode is not entered, an Ethernet
interface is not assigned to an EtherChannel group, and an error message appears.
You do not have to create a port-channel interface before assigning a physical interface to a channel
group. A port-channel interface is created automatically when the channel group gets its first physical
interface.
You do not have to disable the IP address that is assigned to a physical interface that is part of a channel
group, but we highly recommend that you do so.
You can create port channels by entering the interface port-channel global configuration command or
when the channel group gets its first physical interface assignment. The port channels are not created at
runtime or dynamically.
Any configuration or attribute changes you make to the port-channel interface are propagated to all
interfaces within the same channel group as the port channel (for example, configuration changes are
also propagated to the physical interfaces that are not part of the port channel, but are part of the channel
group).
In the on mode, a PAgP EtherChannel exists only when a port group in on mode is connected to another
port group in on mode.
If you do not specify non-silent with the auto or desirable mode, silent is assumed. The silent mode is
used when the switch is connected to a device that is not PAgP-capable and seldom, if ever, sends
packets. An example of a silent partner is a file server or a packet analyzer that is not generating traffic.
In this case, running PAgP on a physical port prevents that port from ever becoming operational;
however, it allows PAgP to operate, to attach the interface to a channel group, and to use the interface
for transmission. Both ends of the link cannot be set to silent.
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channel-group
Note
Caution
You cannot enable both PAgP and LACP modes on an EtherChannel group.
You should use care when using the on mode. This is a manual configuration, and ports on both ends of
the EtherChannel must have the same configuration. If the group is misconfigured, packet loss or
spanning-tree loops can occur.
Do not configure a port that is an active or a not-yet-active member of an EtherChannel as an
IEEE 802.1x port. If you try to enable IEEE 802.1x authentication on an EtherChannel port, an error
message appears, and IEEE 802.1x authentication is not enabled.
Examples
This example shows how to add an interface to the EtherChannel group specified as channel group 1:
Switch(config)# interface gigabitethernet0/1
Switch(config-if)# channel-group 1 mode on
This example shows how to set an Etherchannel into PAgP mode:
Switch(config-if)# channel-group 1 mode auto
Creating a port-channel interface Port-channel 1
This example shows how to set an Etherchannel into LACP mode:
Switch(config-if)# channel-group 1 mode passive
Creating a port-channel interface Port-channel 1
You can verify your settings by entering the show etherchannel or show running-config privileged
EXEC command.
Related Commands
Command
Description
interface port-channel
Accesses or creates the port channel.
port-channel
load-balance
Sets the load distribution method among the ports in the EtherChannel.
show etherchannel
Displays EtherChannel information for a channel.
show running-config
Displays the configuration information running on the switch. For syntax
information, select Cisco IOS Configuration Fundamentals Command
Reference for Release 12.1 > Cisco IOS File Management Commands >
Configuration File Commands.
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channel-protocol
channel-protocol
Use the channel-protocol interface configuration command to configure an EtherChannel for the Port
Aggregation Protocol (PAgP) or Link Aggregation Control Protocol (LACP). Use the no form of this
command to disable PAgP or LACP on the EtherChannel.
channel-protocol {lacp | pagp}
no channel-protocol
Syntax Description
lacp
Configure an EtherChannel with the LACP protocol.
pagp
Configure an EtherChannel with the PAgP protocol.
Defaults
No protocol is assigned to the EtherChannel.
Command Modes
Interface configuration
Command History
Release
Modification
12.1(13)AY
This command was introduced.
Usage Guidelines
Use the channel-protocol command only to restrict a channel to LACP or PAgP.
You must use the channel-group interface command to configure the EtherChannel parameters. The
channel-group command can also set the EtherChannel for a channel.
Note
Caution
Examples
You cannot enable both PAgP and LACP modes on an EtherChannel group.
Do not enable Layer 3 addresses on the physical EtherChannel interfaces. To prevent loops, do not
assign bridge groups on the physical EtherChannel interfaces.
This example shows how to set an EtherChannel into PAgP mode:
Switch(config-if)# channel-protocol pagp
This example shows how to set an EtherChannel into LACP mode:
Switch(config-if)# channel-protocol lacp
You can verify your settings by entering the show running-config privileged EXEC command.
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channel-protocol
Related Commands
Command
Description
show lacp
Display LACP information.
show pagp
Display PAgP information.
show running-config
Displays the current operating configuration. For syntax information, select
Cisco IOS Configuration Fundamentals Command Reference for
Release 12.1 > Cisco IOS File Management Commands > Configuration
File Commands.
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clear interface
clear interface
Use the clear interface privileged EXEC command to clear the hardware logic on an interface
or a VLAN.
clear interface {interface-id | vlan vlan-id}
Syntax Description
interface-id
ID of the interface.
vlan-id
VLAN ID. The range is 1 to 4094.
Defaults
No default is defined.
Command Modes
Privileged EXEC
Command History
Release
Modification
12.1(13)AY
This command was introduced.
Examples
This example shows how to clear the hardware logic on an interface:
Switch# clear interface gigabitethernet0/1
This example shows how to clear the hardware logic on a specific VLAN:
Switch# clear interface vlan 5
You can verify that the interface-reset counter for an interface is incremented by entering the show
interfaces privileged EXEC command.
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clear lacp
clear lacp
Use the clear lacp privileged EXEC command to clear Link Aggregration Control Protocol (LACP)
channel-group information.
clear lacp {channel-group-number | counters}
Syntax Description
channel-group-number
Channel group number. The range is 1 to 6.
counters
Clear traffic counters.
Defaults
This command has no default setting.
Command Modes
Privileged EXEC
Command History
Release
Modification
12.1(13)AY
This command was introduced.
Examples
This example shows how to clear channel-group information for a specific group:
Switch# clear lacp 4
This example shows how to clear channel-group traffic counters:
Switch# clear lacp counters
You can verify that the information was deleted by entering the show lacp privileged EXEC command.
Related Commands
Command
Description
show lacp
Displays LACP channel-group information.
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clear mac address-table
clear mac address-table
Use the clear mac address-table privileged EXEC command to delete from the MAC address table a
specific dynamic address, all dynamic addresses on a particular interface, or all dynamic addresses on a
particular VLAN. This command also clears the MAC address notification global counters.
clear mac address-table {dynamic [address mac-addr | interface interface-id | vlan vlan-id] |
notification}
Syntax Description
dynamic
Delete all dynamic MAC addresses.
dynamic address
mac-addr
(Optional) Delete the specified dynamic MAC address.
dynamic interface
interface-id
(Optional) Delete all dynamic MAC addresses on the specified physical port
or port channel.
dynamic vlan vlan-id
(Optional) Delete all dynamic MAC addresses for the specified VLAN. The
range is 1 to 4094.
notification
Clear the notifications in the history table and reset the counters.
Defaults
No default is defined.
Command Modes
Privileged EXEC
Command History
Release
Modification
12.1(13)AY
This command was introduced.
Examples
This example shows how to remove a specific dynamic address from the MAC address table:
Switch# clear mac address-table dynamic address 0008.0070.0007
You can verify that the information was deleted by entering the show mac address-table privileged
EXEC command.
Related Commands
Command
Description
mac address-table notification
Enables the MAC address notification feature.
show mac address-table
Displays the MAC address table static and dynamic entries.
show mac address-table notification
Displays the MAC address notification settings for all
interfaces or the specified interface.
snmp trap mac-notification
Enables the Simple Network Management Protocol (SNMP)
MAC address notification trap on a specific interface.
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clear pagp
clear pagp
Use the clear pagp privileged EXEC command to clear Port Aggregation Protocol (PAgP)
channel-group information.
clear pagp {channel-group-number [counters] | counters}
Syntax Description
channel-group-number
Channel group number. The range is 1 to 6.
counters
Clear traffic counters.
Defaults
This command has no default setting.
Command Modes
Privileged EXEC
Command History
Release
Modification
12.1(13)AY
This command was introduced.
Examples
This example shows how to clear channel-group information for a specific group:
Switch# clear pagp 4
This example shows how to clear channel-group traffic counters:
Switch# clear pagp counters
You can verify that the information was deleted by entering the show pagp privileged EXEC command.
Related Commands
Command
Description
show pagp
Displays PAgP channel-group information.
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clear port-security
clear port-security
Use the clear port-security privileged EXEC command to delete from the MAC address table a specific
or all dynamic or sticky secure address on an interface or on the switch.
clear port-security {dynamic | sticky} [address mac-address] | [interface interface-id]
Syntax Description
dynamic
Delete all dynamic secure MAC addresses.
sticky
Delete all sticky secure MAC addresses.
address mac-address
(Optional) Delete the specified secure MAC address.
interface interface-id
(Optional) Delete secure MAC addresses on the specified physical port or
port channel.
Defaults
No default is defined.
Command Modes
Privileged EXEC
Command History
Release
Modification
12.1(13)AY
This command was introduced.
Usage Guidelines
If you enter the clear port-security dynamic interface interface-id command, the switch removes all
dynamic secure MAC addresses on an interface from the MAC address table.
If you enter the clear port-security sticky command, the switch removes all sticky secure MAC
addresses from the MAC address table.
Examples
This example shows how to remove all the dynamic secure addresses learned on a specific interface:
Switch# clear port-security dynamic interface fastethernet0/1
This example shows how to remove all the sticky secure addresses from the address table:
Switch# clear port-security sticky
You can verify that the information was deleted by entering the show port-security privileged EXEC
command.
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clear port-security
Related Commands
Command
Description
show port-security
Displays the port security settings for an interface or for the
switch.
switchport port-security
Enables port security on an interface.
switchport port-security
mac-address mac-address
Configures secure MAC addresses.
switchport port-security maximum Configures a maximum number of secure MAC addresses on a
value
secure interface.
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clear spanning-tree counters
clear spanning-tree counters
Use the clear spanning-tree counters privileged EXEC command to clear the spanning-tree counters.
clear spanning-tree counters [interface interface-id]
Syntax Description
interface interface-id
Defaults
No default is defined.
Command Modes
Privileged EXEC
Command History
Release
Modification
12.1(13)AY
This command was introduced.
Examples
(Optional) Clear all spanning-tree counters on the specified interface. If
interface-id is not specified, spanning-tree counters are cleared for all
interfaces.
This example shows how to clear spanning-tree counters for all interfaces:
Switch# clear spanning-tree counters
Related Commands
Command
Description
show spanning-tree
Displays spanning-tree state information.
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clear spanning-tree detected-protocols
clear spanning-tree detected-protocols
Use the clear spanning-tree detected-protocols privileged EXEC command to restart the protocol
migration process (force the renegotiation with neighboring switches) on all interfaces or on the
specified interface.
clear spanning-tree detected-protocols [interface interface-id]
Syntax Description
interface interface-id
Command Modes
Privileged EXEC
Command History
Release
Modification
12.1(20)EA2
This command was introduced.
Usage Guidelines
(Optional) Restart the protocol migration process on the specified interface.
Valid interfaces include physical ports, VLANs, and port channels. The
VLAN range is 1 to 4094. The port-channel range is 1 to 6.
A switch running the rapid per-VLAN spanning-tree plus (rapid-PVST+) protocol or the Multiple
Spanning Tree Protocol (MSTP) supports a built-in protocol migration mechanism that enables it to
interoperate with legacy IEEE 802.1D switches. If a rapid-PVST+ switch or an MSTP switch receives a
legacy IEEE 802.1D configuration bridge protocol data unit (BPDU) with the protocol version set to 0,
it sends only IEEE 802.1D BPDUs on that port. A multiple spanning-tree (MST) switch can also detect
that a port is at the boundary of a region when it receives a legacy BPDU, an MST BPDU (version 3)
associated with a different region, or an RST BPDU (version 2).
However, the switch does not automatically revert to the rapid-PVST+ or the MSTP mode if it no longer
receives IEEE 802.1D BPDUs because it cannot determine whether the legacy switch has been removed
from the link unless the legacy switch is the designated switch. Use the clear spanning-tree
detected-protocols command in this situation.
Examples
This example shows how to restart the protocol migration process on an interface:
Switch# clear spanning-tree detected-protocols interface fastethernet0/1
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clear vmps statistics
clear vmps statistics
Use the clear vmps statistics privileged EXEC command to clear the statistics maintained by the VLAN
Query Protocol (VQP) client.
clear vmps statistics
Syntax Description
This command has no arguments or keywords.
Defaults
No default is defined.
Command Modes
Privileged EXEC
Command History
Release
Modification
12.1(13)AY
This command was introduced.
Examples
This example shows how to clear VLAN Membership Policy Server (VMPS) statistics:
Switch# clear vmps statistics
You can verify that the information was deleted by entering the show vmps statistics privileged EXEC
command.
Related Commands
Command
Description
show vmps statistics
Displays the VQP version, reconfirmation interval, retry count, VMPS IP
addresses, and the current and primary servers.
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clear vtp counters
clear vtp counters
Use the clear vtp counters privileged EXEC command to clear the VLAN Trunking Protocol (VTP) and
pruning counters.
clear vtp counters
Syntax Description
This command has no arguments or keywords.
Defaults
No default is defined.
Command Modes
Privileged EXEC
Command History
Release
Modification
12.1(13)AY
This command was introduced.
Examples
This example shows how to clear the VTP counters:
Switch# clear vtp counters
You can verify that the information was deleted by entering the show vtp counters privileged EXEC
command.
Related Commands
Command
Description
show vtp counters
Displays general information about the VTP management domain, status,
and counters.
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cluster commander-address
cluster commander-address
You do not need to enter this command. The command switch automatically provides its MAC address
to member switches when these switches join the cluster. The member switch adds this information and
other cluster information to its running configuration file. Enter the no form of this global configuration
command from the member switch service port to remove it from a cluster only during debugging or
recovery procedures.
cluster commander-address mac-address [member number name name]
no cluster commander-address
Syntax Description
mac-address
MAC address of the cluster command switch.
member number
(Optional) Number of a configured member switch. The range is from 0 to 15.
name name
(Optional) Name of the configured cluster up to 31 characters.
Defaults
The switch is not a member of any cluster.
Command Modes
Global configuration
Command History
Release
Modification
12.1(13)AY
This command was introduced.
Usage Guidelines
A cluster member can have only one command switch.
The member switch retains the identity of the command switch during a system reload by using the
mac-address parameter.
You can enter the no form on a member switch to remove it from the cluster during debugging or
recovery procedures. You would normally use this command from the member switch consoleservice
port only when the member has lost communication with the command switch. With normal switch
configuration, we recommend that you remove member switches only by entering the no cluster
member n global configuration command on the command switch.
When a standby command-switch becomes active (becomes the command switch), it removes the cluster
commander-address line from its configuration.
Examples
This is an example of text from the running configuration of a cluster member:
Switch(config)# show running-config
<output truncated>
cluster commander-address 00e0.9bc0.a500 member 4 name my_cluster
<output truncated>
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cluster commander-address
This example shows how to remove a member from the cluster by using the cluster member console:
Switch# configure terminal
Enter configuration commands, one per line. End with CNTL/Z.
Switch(config)# no cluster commander-address
You can verify your settings by entering the show cluster privileged EXEC command.
Related Commands
Command
Description
show cluster
Displays the cluster status and a summary of the cluster to which the switch
belongs.
show running-config
Displays the configuration information running on the switch. For syntax
information, select Cisco IOS Configuration Fundamentals Command
Reference for Release 12.1 > Cisco IOS File Management Commands >
Configuration File Commands.
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cluster discovery hop-count
cluster discovery hop-count
Use the cluster discovery hop-count global configuration command on the command switch to set the
hop-count limit for extended discovery of candidate switches. Use the no form of this command to return
to the default setting.
cluster discovery hop-count number
no cluster discovery hop-count
Syntax Description
number
Defaults
The hop count is set to 3.
Command Modes
Global configuration
Command History
Release
Modification
12.1(13)AY
This command was introduced.
Usage Guidelines
Number of hops from the cluster edge that the command switch limits the
discovery of candidates. The range is 1 to 7.
Enter this command only on the command switch. This command does not operate on member switches.
If the hop count is set to 1, it disables extended discovery. The command switch discovers only
candidates that are one hop from the edge of the cluster. The edge of the cluster is the point between the
last discovered member switch and the first discovered candidate switch.
Examples
This example shows how to set the hop count limit to 4. This command is entered on the command
switch.
Switch(config)# cluster discovery hop-count 4
You can verify your settings by entering the show cluster privileged EXEC command on the command
switch.
Related Commands
Command
Description
show cluster
Displays the cluster status and a summary of the cluster to which the
switch belongs.
show cluster candidates
Displays a list of candidate switches.
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cluster enable
cluster enable
Use the cluster enable global configuration command on a command-capable switch to enable it as the
cluster command switch, assign a cluster name, and optionally assign a member number to it. Use the
no form of this command to remove all members and make the command switch a candidate switch.
cluster enable name [command-switch-member-number]
no cluster enable
Syntax Description
Defaults
name
Name of the cluster up to 31 characters. Valid characters include
only alphanumerics, dashes, and underscores.
command-switch-member-number
(Optional) Assign a member number to the command switch of
the cluster. The range is 0 to 15.
The switch is not a command switch.
No cluster name is defined.
The member number is 0 when this is the command switch.
Command Modes
Global configuration
Command History
Release
Modification
12.1(13)AY
This command was introduced.
Usage Guidelines
This command runs on any command-capable switch that is not part of any cluster. This command fails
if a device is already configured as a member of the cluster.
You must name the cluster when you enable the command switch. If the switch is already configured as
the command switch, this command changes the cluster name if it is different from the previous name.
Examples
This example shows how to enable the command switch, name the cluster, and set the command switch
member number to 4:
Switch(config)# cluster enable Engineering-IDF4 4
You can verify your settings by entering the show cluster privileged EXEC command on the command
switch.
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cluster holdtime
cluster holdtime
Use the cluster holdtime global configuration command on the command switch to set the duration in
seconds before a switch (either the command or member switch) declares the other switch down after
not receiving heartbeat messages. Use the no form of this command to return to the default setting.
cluster holdtime holdtime-in-secs
no cluster holdtime
Syntax Description
holdtime-in-secs
Defaults
The holdtime is 80 seconds.
Command Modes
Global configuration
Command History
Release
Modification
12.1(13)AY
This command was introduced.
Usage Guidelines
Duration in seconds before a switch (either a command or member switch)
declares the other switch down. The range is 1 to 300 seconds.
Use this command with the cluster timer global configuration command only on the command switch.
The command switch propagates the values to all its cluster members so that the setting is consistent
among all switches in the cluster.
The holdtime is typically set as a multiple of the interval timer (cluster timer). For example, it takes
(holdtime-in-secs divided by interval-in-secs) number of heartbeat messages to be missed in a row to
declare a switch down.
Examples
This example shows how to change the interval timer and the duration on the command switch:
Switch(config)# cluster timer 3
Switch(config)# cluster holdtime 30
You can verify your settings by entering the show cluster privileged EXEC command.
Related Commands
Command
Description
show cluster
Displays the cluster status and a summary of the cluster to which the switch
belongs.
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cluster management-vlan
cluster management-vlan
Use the cluster management-vlan global configuration command on the command switch to change the
management VLAN for the entire cluster. Use the no form of this command to change the
management VLAN to VLAN 1.
cluster management-vlan n
no cluster management-vlan
Syntax Description
n
Defaults
The default management VLAN is VLAN 1.
Command Modes
Global configuration
Command History
Release
Modification
12.1(13)AY
This command was introduced.
Usage Guidelines
VLAN ID of the new management VLAN. The range is 1 to 4094.
Enter this command only on the command switch. This command changes the management VLAN of
the command switch and member switches. Member switches must have either a trunk connection or
connection to the new command-switch management VLAN to maintain communication with the
command switch.
This command is not written to the configuration file.
Examples
This example shows how to change the management VLAN to VLAN 5 on the entire cluster:
Switch(config)# cluster management-vlan 5
You can verify your settings by entering the show interfaces vlan vlan-id privileged EXEC command.
Related Commands
Command
Description
show interfaces
Displays the administrative and operational status of a switching
(nonrouting) port.
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cluster member
cluster member
Use the cluster member global configuration command on the command switch to add members to a
cluster. Use the no form of this command to remove members from the cluster.
cluster member [n] mac-address H.H.H [password enable-password] [vlan vlan-id]
no cluster member n
Syntax Description
n
(Optional) The number that identifies a cluster member. The range is
0 to 15.
mac-address H.H.H
MAC address of the member switch in hexadecimal format.
password enable-password
(Optional) Enable password of the candidate switch. The password is
not required if there is no password on the candidate switch.
vlan vlan-id
(Optional) VLAN ID through which the candidate is added to the
cluster by the command switch. The range is 1 to 4094.
Defaults
A newly enabled command switch has no associated cluster members.
Command Modes
Global configuration
Command History
Release
Modification
12.1(13)AY
This command was introduced.
Usage Guidelines
Enter this command only on the command switch to add a member to or remove a member from the
cluster. If you enter this command on a switch other than the command switch, the switch rejects the
command and displays an error message.
You must enter a member number to remove a switch from the cluster. However, you do not need to
enter a member number to add a switch to the cluster. The command switch selects the next available
member number and assigns it to the switch that is joining the cluster.
You must enter the enable password of the candidate switch for authentication when it joins the cluster.
The password is not saved in the running or startup configuration. After a candidate switch becomes a
member of the cluster, its password becomes the same as the command-switch password.
If a switch does not have a configured host name, the command switch appends a member number to the
command-switch host name and assigns it to the member switch.
If you do not specify a VLAN ID, the command switch automatically chooses a VLAN and adds the
candidate to the cluster.
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cluster member
Examples
This example shows how to add a switch as member 2 with MAC address 00E0.1E00.2222 and the
password key to a cluster. The command switch adds the candidate to the cluster through VLAN 3.
Switch(config)# cluster member 2 mac-address 00E0.1E00.2222 password key vlan 3
This example shows how to add a switch with MAC address 00E0.1E00.3333 to the cluster. This switch
does not have a password. The command switch selects the next available member number and assigns it
to the switch joining the cluster.
Switch(config)# cluster member mac-address 00E0.1E00.3333
You can verify your settings by entering the show cluster members privileged EXEC command on the
command switch.
Related Commands
Command
Description
show cluster
Displays the cluster status and a summary of the cluster to which the
switch belongs.
show cluster candidates
Displays a list of candidate switches.
show cluster members
Displays information about the cluster members.
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cluster run
cluster run
Use the cluster run global configuration command to enable clustering on a switch. Use the no form of
this command to disable clustering on a switch.
cluster run
no cluster run
Defaults
Clustering is enabled on all switches.
Command Modes
Global configuration
Command History
Release
Modification
12.1(13)AY
This command was introduced.
Usage Guidelines
When you enter the no cluster run command on a command switch, the command switch is disabled.
Clustering is disabled, and the switch cannot become a candidate switch.
When you enter the no cluster run command on a member switch, it is removed from the cluster.
Clustering is disabled, and the switch cannot become a candidate switch.
When you enter the no cluster run command on a switch that is not part of a cluster, clustering is
disabled on this switch. This switch cannot then become a candidate switch.
Examples
This example shows how to disable clustering on the command switch:
Switch(config)# no cluster run
You can verify that clustering is disabled by entering the show cluster privileged EXEC command.
Related Commands
Command
Description
show cluster
Displays the cluster status and a summary of the cluster to which the switch
belongs.
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cluster standby-group
cluster standby-group
Use the cluster standby-group global configuration command to enable command switch redundancy
by binding the Hot Standby Router Protocol (HSRP) standby group to the cluster. Use the no form of
this command to unbind the cluster from the HSRP standby group.
cluster standby-group HSRP-group-name
no cluster standby-group
Syntax Description
HSRP-group-name
Defaults
The cluster is not bound to any HSRP group.
Command Modes
Global configuration
Command History
Release
Modification
12.1(13)AY
This command was introduced.
Usage Guidelines
Name of the HSRP group that is bound to the cluster. The group name is
limited to 32 characters.
You must enter this command only on the command switch. If you enter it on a member switch, an error
message appears.
The command switch propagates the cluster-HSRP binding information to all members. Each member
switch stores the binding information in its NVRAM.
The HSRP group name must be a valid standby group; otherwise, the command entry produces an error.
Use the same group name on all members of the HSRP standby group that is to be bound to the cluster.
Use the same HSRP group name on all cluster-HSRP capable members for the HSRP group that is to be
bound. (When not binding a cluster to an HSRP group, you can use different names on the cluster
command and the member switches.)
Examples
This example shows how to bind the HSRP group named my_hsrp to the cluster. This command is
entered on the command switch.
Switch(config)# cluster standby-group my_hsrp
This example shows the error message when this command is entered on a command switch and the
specified HSRP standby group does not exist:
Switch(config)# cluster standby-group my_hsrp
%ERROR:Standby (my_hsrp) group does not exist
This example shows the error message when this command is entered on a member switch:
Switch(config)# cluster standby-group my_hsrp
%ERROR:This command runs on a cluster command switch
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cluster standby-group
You can verify your settings by entering the show cluster privileged EXEC command.
Related Commands
Command
Description
show cluster
Displays the cluster status and a summary of the cluster to which the switch
belongs.
show standby
Displays standby group information.
standby ip
Enables HSRP on the interface.
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cluster timer
cluster timer
Use the cluster timer global configuration command on the command switch to set the interval in
seconds between heartbeat messages. Use the no form of this command to return to the default setting.
cluster timer interval-in-secs
no cluster timer
Syntax Description
interval-in-secs
Defaults
The interval is 8 seconds.
Command Modes
Global configuration
Command History
Release
Modification
12.1(13)AY
This command was introduced.
Usage Guidelines
Interval in seconds between heartbeat messages. The range is 1 to 300
seconds.
Use this command with the cluster holdtime global configuration command only on the command
switch. The command switch propagates the values to all its cluster members so that the setting is
consistent among all switches in the cluster.
The holdtime is typically set as a multiple of the heartbeat interval timer (cluster timer). For example,
it takes (holdtime-in-secs divided by the interval-in-secs) number of heartbeat messages to be missed in
a row to declare a switch down.
Examples
This example shows how to change the heartbeat interval timer and the duration on the command switch:
Switch(config)# cluster timer 3
Switch(config)# cluster holdtime 30
You can verify your settings by entering the show cluster privileged EXEC command.
Related Commands
Command
Description
show cluster
Displays the cluster status and a summary of the cluster to which the switch
belongs.
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define interface-range
define interface-range
Use the define interface-range global configuration command to create an interface-range macro. Use
the no form of this command to delete the defined macro.
define interface-range macro-name interface-range
no define interface-range macro-name interface-range
Syntax Description
macro-name
Name of the interface-range macro; up to 32 characters.
interface-range
Interface range; for valid values for interface ranges, see “Usage Guidelines.”
Defaults
This command has no default setting.
Command Modes
Global configuration
Command History
Release
Modification
12.1(13)AY
This command was introduced.
Usage Guidelines
The macro name is a 32-character maximum character string.
A macro can contain up to five ranges.
All interfaces in a range must be the same type; that is, all Fast Ethernet ports, all Gigabit Ethernet ports,
all EtherChannel ports, or all VLANs, but you can combine multiple interface types in a macro.
When entering the interface-range, use this format:
•
type {first-interface} - {last-interface}
•
You must add a space between the first interface number and the hyphen when entering an
interface-range. For example, fastethernet0/1 -2 is a valid range; fastethernet0/1-2 is not a valid
range.
Valid values for type and interface:
•
vlan vlan-id, where vlan-id is 1 to 4094.
•
port-channel port-channel-number, where port-channel-number is 1 to 6
•
fastethernet interface-id
•
gigabitethernet interface-id
VLAN interfaces must have been configured with the interface vlan command (the show
running-config privileged EXEC command displays the configured VLAN interfaces). VLAN
interfaces not displayed by the show running-config command cannot be used in interface-ranges.
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define interface-range
For physical interfaces, the interface-id is defined as a slot/number (where slot is always 0 for the
switch), and the range can be entered as type 0/number - number (for example, fastethernet0/1 - 2). You
can also enter multiple ranges.
When you define a range, you must enter a space before and after the hyphen (-):
interface range fastethernet0/1 - 2
When you define multiple ranges, you must enter a space before and after the comma (,):
interface range fastethernet0/1 - 2 , gigabitethernet0/1
Examples
This example shows how to create a multiple-interface macro:
Switch(config)# define interface-range macro1 fastethernet0/3 -7 , gigabitethernet0/1
Related Commands
Command
Description
interface range
Executes a command on multiple ports at the same time.
show running-config
Displays the current operating configuration, including defined
macros. For syntax information, select Cisco IOS Configuration
Fundamentals Command Reference for Release 12.1 > Cisco IOS
File Management Commands > Configuration File Commands.
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delete
delete
Use the delete privileged EXEC command to delete a file or directory on the flash memory device.
delete [/force] [/recursive] filesystem:/file-url
Syntax Description
/force
(Optional) Suppress the prompt that confirms the deletion.
/recursive
(Optional) Delete the named directory and all subdirectories and the files
contained in it.
filesystem:
Alias for a flash file system. Use flash: for the system board flash device.
/file-url
The path (directory) and filename to delete.
Command Modes
Privileged EXEC
Command History
Release
Modification
12.1(13)AY
This command was introduced.
Usage Guidelines
If you use the /force keyword, you are prompted once at the beginning of the deletion process to confirm
the deletion.
If you use the /recursive keyword without the /force keyword, you are prompted to confirm the deletion
of every file.
The prompting behavior depends on the setting of the file prompt global configuration command. By
default, the switch prompts for confirmation on destructive file operations. For more information about
this command, see the Cisco IOS Command Reference for Cisco IOS Release 12.1.
Examples
This example shows how to delete a file from the switch flash memory:
Switch# delete flash:filename
You can verify that the directory was removed by entering the dir filesystem: privileged EXEC
command.
Related Commands
Command
Description
copy
Downloads a file from a source, such as a TFTP server, to a destination, such
as the flash memory.
dir filesystem:
Displays a list of files on a file system.
rename
Renames a file.
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dot1x
dot1x
Use the dot1x global configuration command to enable IEEE 802.1x authentication globally. Use the no
form of this command to return to the default setting.
dot1x {system-auth-control} | {guest-vlan supplicant}
no dot1x {system-auth-control} | {guest-vlan supplicant}
Syntax Description
system-auth-control
Enable IEEE 802.1x authentication globally on the switch.
guest-vlan supplicant
Enable optional guest VLAN behavior globally on the switch.
Defaults
IEEE 802.1x authentication is disabled, and the optional guest VLAN behavior is disabled.
Command Modes
Global configuration
Command History
Release
Modification
12.1(19)EA1
This command was introduced.
12.1(22)EA2
The guest-vlan supplicant keywords were added.
Usage Guidelines
You must enable authentication, authorization, and accounting (AAA) and specify the authentication
method list before enabling IEEE 802.1x authentication globally. A method list describes the sequence
and authentication methods to be queried to authenticate a user.
Before globally enabling IEEE 802.1x authentication on a switch, remove the EtherChannel
configuration from the interfaces on which IEEE 802.1x authentication and EtherChannel are
configured.
If you are using a device running the Cisco Access Control Server (ACS) application for IEEE 802.1x
authentication with EAP-Transparent LAN Services (TLS) and with EAP-MD5 and your switch is
running Cisco IOS Release 12.1(14)EA1, make sure that the device is running ACS Version 3.2.1 or
later.
You can use the guest-vlan supplicant keywords to enable the optional IEEE 802.1x guest VLAN
behavior globally on the switch. For more information, see the dot1x guest-vlan command.
Examples
This example shows how to globally enable IEEE 802.1x authentication on a switch:
Switch(config)# dot1x system-auth-control
This example shows how to globally enable the optional guest VLAN behavior on a switch:
Switch(config)# dot1x guest-vlan supplicant
You can verify your settings by entering the show dot1x privileged EXEC command.
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dot1x
Related Commands
Command
Description
dot1x guest-vlan
Enables and specifies an active VLAN as an IEEE 802.1x guest VLAN.
dot1x port-control
Enables manual control of the authorization state of the port.
show dot1x
Displays IEEE 802.1x statistics, administrative status, and operational status
for the switch or for the specified interface.
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dot1x auth-fail max-attempts
dot1x auth-fail max-attempts
Use the dot1x auth-fail max-attempts interface configuration command to configure the maximum
number of authentication attempts allowed before a port is moved to the restricted VLAN. To return to
the default setting, use the no form of this command.
dot1x auth-fail max-attempts max-attempts
no dot1x auth-fail max-attempts
Syntax Description
max-attempts
Defaults
The default is 3 attempts.
Command Modes
Interface configuration
Command History
Release
Modification
12.1(22)EA7
This command was introduced.
Specify a maximum number of authentication attempts allowed before a port
is moved to the restricted VLAN. The range is 1 to 3.
Usage Guidelines
If you reconfigure the maximum number of authentication failures allowed by the VLAN, the change
takes effect after the re-authentication timer expires.
Examples
This example shows how to set 2 as the maximum number of authentication attempts allowed before the
port is moved to the restricted VLAN on Gigabit Ethernet interface 1:
Switch# configure terminal
Enter configuration commands, one per line. End with CNTL/Z.
Switch(config)# interface gigabitethernet0/1
Switch(config-if)# dot1x auth-fail max-attempts 2
Switch(config-if)# end
Switch(config)# end
Switch#
You can verify your settings by entering the show dot1x [interface interface-id] privileged EXEC
command.
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dot1x auth-fail max-attempts
Related Commands
Command
Description
dot1x auth-fail vlan [vlan id]
Enables the optional restricted VLAN feature.
show dot1x [interface interface-id]
Displays IEEE 802.1x status for the specified port.
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dot1x auth-fail vlan
dot1x auth-fail vlan
Use the dot1x auth-fail vlan interface configuration command to enable the restricted VLAN on a port.
To return to the default setting, use the no form of this command.
dot1x auth-fail vlan vlan-id
no dot1x auth-fail vlan vlan-id
Syntax Description
vlan-id
Defaults
No restricted VLAN is configured.
Command Modes
Interface configuration
Command History
Release
Modification
12.1(22)EA7
This command was introduced.
Usage Guidelines
Specify a VLAN in the range of 1 to 4094.
You can configure a restricted VLAN on ports configured as follows:
•
single-host (default) mode only
•
auto mode for authorization
You should enable re-authentication. The ports in restricted VLANs do not receive re-authentication
requests if re-authentication is disabled. To start the re-authentication process, the restricted VLAN must
receive a link down event or an Extensible Authentication Protocol (EAP) logoff event from the port. If
the host is connected through a hub, the port might never receive a link down event and might not detect
the new host until the next re-authentication attempt occurs. Therefore, re-authentication should be
enabled.
If the user fails authentication, the port is moved to a restricted VLAN, and an EAP success message is
sent to the user. Because the user is not notified of the authentication failure, there might be confusion
as to why there is restricted access to the network. An EAP success message is sent for these reasons:
•
If the EAP success message is not sent, the user tries to authenticate every 60 seconds (the default)
by sending an EAP-start message.
•
Some hosts (for example, devices running Windows XP) cannot implement DHCP until they receive
an EAP success message.
A user might cache an incorrect username and password combination after receiving an EAP success
message from the authenticator and re-use that information in every re-authentication. Until the user
passes the correct username and password combination, the port remains in the restricted VLAN.
Internal VLANs that are used for Layer 3 ports cannot be configured as a restricted VLAN.
You cannot configure a VLAN to be both a restricted VLAN and a voice VLAN. If you do this, a syslog
message appears.
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dot1x auth-fail vlan
When a restricted VLAN port is moved to an unauthorized state, the authentication process is restarted.
If the user fails the authentication process again, the authenticator waits in the held state. After the user
has correctly re-authenticated, all IEEE 802.1x ports are reinitialized and treated as normal IEEE 802.1x
ports.
When you reconfigure a restricted VLAN to a different VLAN, any ports in the restricted VLAN are also
moved, and the ports stay in their current authorized state.
When you shut down or remove a restricted VLAN from the VLAN database, any ports in the restricted
VLAN are immediately moved to an unauthorized state, and the authentication process is restarted. The
authenticator does not wait in a held state because the restricted VLAN configuration still exists. While
the restricted VLAN is inactive, all authentication attempts are counted. As soon as the restricted VLAN
becomes active, the port is placed in the restricted VLAN.
The restricted VLAN is supported only in single-host mode (the default port mode).
When a port is placed in a restricted VLAN, the user’s MAC address is added to the MAC address table.
If a new MAC address appears on the port, it is treated as a security violation.
Examples
This example shows how to configure a restricted VLAN on Gigabit Ethernet interface 1:
Switch# configure terminal
Enter configuration commands, one per line. End with CNTL/Z.
Switch(config)# interface gigabitethernet0/1
Switch(config-if)# dot1x auth-fail vlan 40
Switch(config-if)# end
Switch(config)# end
Switch#
You can verify your configuration by entering the show dot1x [interface interface-id] privileged EXEC
command.
Related Commands
Command
Description
dot1x auth-fail max-attempts
[max-attempts]
Configures the number of authentication attempts allowed
before assigning a user to the restricted VLAN.
show dot1x [interface interface-id]
Displays IEEE 802.1x status for the specified port.
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dot1x control-direction
dot1x control-direction
Use the dot1x control-direction command to change the port to unidirectional or bidirectional control.
dot1x control-direction {in | both}
no dot1x control-direction {in | both}
Syntax Description
dot1x control-direction in
Enable unidirectional control on port.
dot1x control-direction both
Enable bidirectional control on port.
Command Default
The port is set to bidirectional mode.
Command Modes
Interface configuration
Command History
Release
Modification
12.1(22)EA6
This command was introduced.
Usage Guidelines
Using the keyword both or using the no form of this command are the same command.
The keyword both and the no form of the command change the port to its bidirectional default setting.
Examples
This example shows how to enable unidirectional control:
Switch(config-if)# dot1x control-direction in
These examples show how to enable bidirectional control:
Switch(config-if)# dot1x control-direction both
Switch(config-if)# no dot1x control-direction
You can verify your settings by entering the show dot1x all privileged EXEC command.
The show dot1x all privileged EXEC command output is the same for all switches except for the port
names and the state of the port. If a host is attached to the port but is not yet authenticated, a display
similar to this appears:
Supplicant MAC 0002.b39a.9275
AuthSM State = CONNECTING
BendSM State = IDLE
PortStatus = UNAUTHORIZED
If you enter the dot1x control-direction in interface configuration command to enable unidirectional
control, this appears in the show dot1x all command output:
ControlDirection
= In
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dot1x control-direction
If you enter the dot1x control-direction in interface configuration command and the port cannot support
this mode due to a configuration conflict, this appears in the show dot1x all command output:
ControlDirection
Related Commands
= In (Disabled due to port settings)
Command
Description
show dot1x all [interface
interface-id]
Displays control-direction port setting status for the specified
interface.
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dot1x default
dot1x default
Use the dot1x default interface configuration command to reset the configurable IEEE 802.1x
parameters to their default values.
dot1x default
Syntax Description
This command has no arguments or keywords.
Defaults
These are the default values:
•
The per-interface IEEE 802.1x protocol enable state is disabled (force-authorized).
•
The number of seconds between re-authentication attempts is 3600 seconds.
•
The periodic re-authentication is disabled.
•
The quiet period is 60 seconds.
•
The retransmission time is 30 seconds.
•
The maximum retransmission number is 2 times.
•
The host mode is single host.
•
The client timeout period is 30 seconds.
•
The authentication server timeout period is 30 seconds.
Command Modes
Interface configuration
Command History
Release
Modification
12.1(13)AY
This command was introduced.
12.1(19)EA1
This command was changed to the interface configuration mode.
Examples
This example shows how to reset the configurable IEEE 802.1x parameters on an interface:
Switch(config-if)# dot1x default
You can verify your settings by entering the show dot1x [interface interface-id] privileged EXEC
command.
Related Commands
Command
Description
show dot1x [interface interface-id]
Displays IEEE 802.1x status for the specified interface.
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dot1x guest-vlan
dot1x guest-vlan
Use the dot1x guest-vlan interface configuration command to specify an active VLAN as an
IEEE 802.1x guest VLAN for switches running the enhanced software image (EI). Use the no form of
this command to return to the default setting.
dot1x guest-vlan vlan-id
no dot1x guest-vlan
Syntax Description
vlan-id
Specify an active VLAN as an IEEE 802.1x guest VLAN. The range is 1
to 4094.
Defaults
No guest VLAN is configured.
Command Modes
Interface configuration
Command History
Release
Modification
12.1(22)EA2
This command was introduced.
Usage Guidelines
You can configure a guest VLAN for each IEEE 802.1x port on the switch to provide limited services
to clients (a device or workstation connected to the switch) not currently running IEEE 802.1x
authentication. These users might be upgrading their system for IEEE 802.1x authentication, and some
hosts, such as Windows 98 systems, might not be IEEE 802.1x-capable.
When you enable a guest VLAN on an IEEE 802.1x port, the switch assigns clients to a guest VLAN
when it does not receive a response to its Extensible Authentication Protocol over LAN (EAPOL)
request/identity frame or when EAPOL packets are not sent by the client.
Before Cisco IOS Release 12.1(22)EA2, the switch did not maintain the EAPOL packet history and
allowed clients that failed authentication access to the guest VLAN, regardless of whether EAPOL
packets had been detected on the interface. You can use the dot1x guest-vlan supplicant global
configuration command to enable this optional behavior.
With Cisco IOS Release 12.1(22)EA2 and later, the switch maintains the EAPOL packet history. If
another EAPOL packet is detected on the interface during the lifetime of the link, the guest VLAN
feature is disabled. If the port is already in the guest VLAN state, the port is returned to the unauthorized
state, and authentication is restarted. The EAPOL history is reset upon loss of link.
Entering the dot1x guest-vlan supplicant global configuration command disables this behavior.
Any number of non-IEEE-802.1x-capable clients are allowed access when the switch port is moved to
the guest VLAN. If an IEEE 802.1x-capable client joins the same port on which the guest VLAN is
configured, the port is put into the unauthorized state in the user-configured access VLAN, and
authentication is restarted.
Guest VLANs are supported on IEEE 802.1x ports in single-host or multiple-hosts mode.
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dot1x guest-vlan
You can configure any active VLAN except an RSPAN VLAN or a voice VLAN as an IEEE 802.1x
guest VLAN. The guest VLAN feature is not supported on trunk ports; it is supported only on access
ports.
After you configure a guest VLAN for an IEEE 802.1x port to which a DHCP client is connected, you
might need to get a host IP address from a DHCP server. You can also change the settings for restarting
the IEEE 802.1x authentication process on the switch before the DHCP process on the client times out
and tries to get a host IP address from the DHCP server. Decrease the settings for the IEEE 802.1x
authentication process (IEEE 802.1x quiet period and switch-to-client transmission time).
Examples
This example shows how to specify VLAN 5 as an IEEE 802.1x guest VLAN:
Switch(config-if)# dot1x guest-vlan 5
This example shows how to set 3 as the quiet time on the switch, to set 15 as the number of seconds that
the switch waits for a response to an EAP-request/identity frame from the client before resending the
request, and to enable VLAN 5 as an IEEE 802.1x guest VLAN when an IEEE 802.1x port is connected
to a DHCP client:
Switch(config-if)# dot1x timeout quiet-period 3
Switch(config-if)# dot1x timeout tx-period 15
Switch(config-if)# dot1x guest-vlan 5
This example shows how to enable the optional guest VLAN behavior and to specify VLAN 5 as an
IEEE 802.1x guest VLAN:
Switch(config)# dot1x guest-vlan supplicant
Switch(config)# interface FastEthernet0/1
Switch(config-if)# dot1x guest-vlan 5
You can verify your settings by entering the show dot1x [interface interface-id] privileged EXEC
command.
Related Commands
Command
Description
dot1x
Enables the optional guest VLAN supplicant feature.
show dot1x [interface interface-id]
Displays IEEE 802.1x status for the specified interface.
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dot1x host-mode
dot1x host-mode
Use the dot1x host-mode interface configuration command to allow a single host (client) or multiple
hosts on an IEEE 802.1x-authorized port that has the dot1x port-control interface configuration
command set to auto. Use the no form of this command to return to the default setting.
dot1x host-mode {multi-host | single-host}
no dot1x host-mode [multi-host | single-host]
Syntax Description
multi-host
Enable multiple-hosts mode on the switch.
single-host
Enable single-host mode on the switch.
Defaults
The default is single-host mode.
Command Modes
Interface configuration
Command History
Release
Modification
12.1(19)EA1
This command was introduced. It replaces the dot1x multiple-hosts
interface configuration command.
Usage Guidelines
You can use this command to limit an IEEE 802.1x-enabled port to a single client or to attach multiple
clients to an IEEE 802.1x-enabled port. In multiple-hosts mode, only one of the attached hosts must be
successfully authorized for all hosts to be granted network access. If the port becomes unauthorized
(re-authentication fails, or an Extensible Authentication Protocol over LAN [EAPOL]-logoff message
is received), all attached clients are denied access to the network.
Before entering this command, make sure that the dot1x port-control interface configuration command
is set to auto for the specified interface.
Examples
This example shows how to enable IEEE 802.1x authentication globally, enable IEEE 802.1x
authentication on an interface, and enable multiple-hosts mode:
Switch(config)# dot1x system-auth-control
Switch(config)# interface fastethernet0/1
Switch(config-if)# dot1x port-control auto
Switch(config-if)# dot1x host-mode multi-host
You can verify your settings by entering the show dot1x [interface interface-id] privileged EXEC
command.
Related Commands
Command
Description
show dot1x [interface interface-id]
Displays IEEE 802.1x status for the specified interface.
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dot1x initialize
dot1x initialize
Use the dot1x initialize privileged EXEC command to manually return an IEEE 802.1x-enabled port to
an unauthorized state before initiating a new authentication session on the interface.
dot1x initialize interface interface-id
Syntax Description
This command has no arguments or keywords.
Defaults
There is no default setting.
Command Modes
Privileged EXEC
Command History
Release
Modification
12.1(19)EA1
This command was introduced.
Usage Guidelines
Use this command to manually return a device connected to a switch interface to an unauthorized state
before initiating a new authentication session on the interface.
Examples
This example shows how to manually return a device connected to a port to an unauthorized state:
Switch# dot1x initialize interface fastethernet0/1
You can verify your settings by entering the show dot1x [interface interface-id] privileged EXEC
command.
Related Commands
Command
Description
show dot1x [interface interface-id]
Displays IEEE 802.1x status for the specified interface.
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dot1x max-req
dot1x max-req
Use the dot1x max-req interface configuration command to set the maximum number of times that the
switch sends an Extensible Authentication Protocol (EAP) frame from the authentication server
(assuming that no response is received) to the client before restarting the authentication process. Use the
no form of this command to return to the default setting.
dot1x max-req count
no dot1x max-req
Syntax Description
count
Defaults
The default is 2.
Command Modes
Interface configuration
Command History
Release
Modification
12.1(13)AY
This command was introduced.
12.1(19)EA1
This command was changed to the interface configuration mode.
Number of times that the switch sends an EAP frame from the authentication
server before restarting the authentication process. The range is 1 to 10.
Usage Guidelines
You should change the default value of this command only to adjust for unusual circumstances such as
unreliable links or specific behavioral problems with certain clients and authentication servers.
Examples
This example shows how to set 5 as the number of times that the switch sends an EAP frame before
restarting the authentication process:
Switch(config-if)# dot1x max-req 5
You can verify your settings by entering the show dot1x [interface interface-id] privileged EXEC
command.
Related Commands
Command
Description
dot1x timeout
Sets the number of seconds that the switch waits for a response to an
EAP-request/identity frame from the client before resending the
request.
show dot1x [interface
interface-id]
Displays IEEE 802.1x status for the specified interface.
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dot1x multiple-hosts
dot1x multiple-hosts
This is an obsolete command.
In past releases, the dot1x multiple-hosts interface configuration command was used to allow multiple
hosts (clients) on an IEEE 802.1x-authorized port.
Command History
Related Commands
Release
Modification
12.1(13)AY
This command was introduced.
12.1(19)EA1
The dot1x multiple-hosts interface configuration command was replaced by
the dot1x host-mode interface configuration command.
Command
Description
dot1x host-mode
Set the IEEE 802.1x host mode on an interface.
show dot1x
Displays IEEE 802.1x statistics, administrative status, and operational status
for the switch or for the specified interface.
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dot1x port-control
dot1x port-control
Use the dot1x port-control interface configuration command to enable manual control of the
authorization state of the port. Use the no form of this command to return to the default setting.
dot1x port-control {auto | force-authorized | force-unauthorized}
no dot1x port-control
Syntax Description
auto
Enable IEEE 802.1x authentication on the interface and cause the port to
transition to the authorized or unauthorized state based on the IEEE 802.1x
authentication exchange between the switch and the client.
force-authorized
Disable IEEE 802.1x authentication on the interface and cause the port to
transition to the authorized state without any authentication exchange required.
The port sends and receives normal traffic without IEEE 802.1x-based
authentication of the client.
force-unauthorized
Deny all access through this interface by forcing the port to transition to the
unauthorized state, ignoring all attempts by the client to authenticate. The
switch cannot provide authentication services to the client through the interface.
Defaults
The default is force-authorized.
Command Modes
Interface configuration
Command History
Release
Modification
12.1(13)AY
This command was introduced.
Usage Guidelines
You must enable IEEE 802.1x authentication globally on the switch by using the dot1x
system-auth-control global configuration command before enabling IEEE 802.1x authentication on a
specific interface.
The IEEE 802.1x protocol is supported on Layer 2 static-access ports.
You can use the auto keyword only if the port is not configured as one of these:
•
Trunk port—If you try to enable IEEE 802.1x authentication on a trunk port, an error message
appears, and IEEE 802.1x is not enabled. If you try to change the mode of an IEEE 802.1x-enabled
port to trunk, the port mode is not changed.
•
Dynamic ports—A port in dynamic mode can negotiate with its neighbor to become a trunk port. If
you try to enable IEEE 802.1x authentication on a dynamic port, an error message appears, and
IEEE 802.1x authentication is not enabled. If you try to change the mode of an IEEE 802.1x-enabled
port to dynamic, the port mode is not changed.
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dot1x port-control
•
Dynamic-access ports—If you try to enable IEEE 802.1x authentication on a dynamic-access
(VLAN Query Protocol [VQP]) port, an error message appears, and IEEE 802.1x authentication is
not enabled. If you try to change an IEEE 802.1x-enabled port to dynamic VLAN assignment, an
error message appears, and the VLAN configuration is not changed.
•
EtherChannel port—Do not configure a port that is an active or a not-yet-active member of an
EtherChannel as an IEEE 802.1x port. If you try to enable IEEE 802.1x authentication on an
EtherChannel port, an error message appears, and IEEE 802.1x authentication is not enabled.
•
Switched Port Analyzer (SPAN) destination port—You can enable IEEE 802.1x authentication on
a SPAN source port but not on a SPAN destination port.
To disable IEEE 802.1x authentication globally on the switch, use the no dot1x system-auth-control
global configuration command. To disable IEEE 802.1x authentication on a specific interface, use the
no dot1x port-control interface configuration command.
Examples
This example shows how to enable IEEE 802.1x authentication on an interface:
Switch(config)# interface fastethernet0/1
Switch(config-if)# dot1x port-control auto
You can verify your settings by entering the show dot1x [interface interface-id] privileged EXEC
command.
Related Commands
Command
Description
show dot1x [interface interface-id]
Displays IEEE 802.1x status for the specified interface.
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dot1x re-authenticate
dot1x re-authenticate
Use the dot1x re-authenticate privileged EXEC command to manually initiate a re-authentication of
the IEEE 802.1x-enabled port.
dot1x re-authenticate {interface interface-id}
Syntax Description
interface interface-id
Defaults
There is no default setting.
Command Modes
Privileged EXEC
Command History
Release
Modification
12.1(13)AY
This command was introduced.
Slot and port number of the interface to re-authenticate.
Usage Guidelines
You can use this command to re-authenticate a client without waiting for the configured number of
seconds between re-authentication attempts (re-authperiod) and automatic re-authentication.
Examples
This example shows how to manually re-authenticate the device connected to an interface:
Switch# dot1x re-authenticate interface fastethernet0/1
Related Commands
Command
Description
show dot1x
Displays IEEE 802.1x statistics, administrative status, and
operational status for the switch or for the specified interface.
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dot1x re-authentication
dot1x re-authentication
This is an obsolete command.
In past releases, the dot1x re-authentication global configuration command was used to set the amount
of time between periodic re-authentication attempts.
Command History
Related Commands
Release
Modification
12.1(13)AY
This command was introduced.
12.1(19)EA1
The dot1x reauthentication interface configuration command replaced the
dot1x re-authentication global configuration command.
Command
Description
dot1x reauthentication
Sets the number of seconds between re-authentication attempts.
show dot1x
Displays IEEE 802.1x statistics, administrative status, and
operational status for the switch or for the specified interface.
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dot1x reauthentication
dot1x reauthentication
Use the dot1x reauthentication interface configuration command to enable periodic re-authentication
of the client. Use the no form of this command to return to the default setting.
dot1x reauthentication
no dot1x reauthentication
Syntax Description
This command has no arguments or keywords.
Defaults
Periodic re-authentication is disabled.
Command Modes
Interface configuration
Command History
Release
Modification
12.1(19)EA1
This command was introduced. It replaces the dot1x re-authentication global
configuration command (with the hyphen).
Usage Guidelines
You configure the amount of time between periodic re-authentication attempts by using the dot1x
timeout reauth-period interface configuration command.
Examples
This example shows how to disable periodic re-authentication of the client:
Switch(config-if)# no dot1x reauthentication
This example shows how to enable periodic re-authentication and to set the number of seconds between
re-authentication attempts to 4000 seconds:
Switch(config-if)# dot1x reauthentication
Switch(config-if)# dot1x timeout reauth-period 4000
You can verify your settings by entering the show dot1x [interface interface-id] privileged EXEC
command.
Related Commands
Command
Description
dot1x timeout
Sets the number of seconds between re-authentication attempts.
show dot1x [interface
interface-id]
Displays IEEE 802.1x status for the specified interface.
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dot1x timeout
dot1x timeout
Use the dot1x timeout interface configuration command to set the IEEE 802.1x timers. Use the no form
of this command to return to the default setting.
dot1x timeout {quiet-period seconds | reauth-period {seconds | server} | server-timeout seconds
| supp-timeout seconds | tx-period seconds}
no dot1x timeout {quiet-period | reauth-period | server-timeout | supp-timeout | tx-period}
Syntax Description
quiet-period
seconds
Number of seconds that the switch remains in the quiet state following a failed
authentication exchange with the client. The range is 1 to 65535.
reauth-period
seconds
Set the number of seconds between re-authentication attempts.
The keywords have these meanings:
•
seconds—Sets the number of seconds from 1 to 65535; the default is
3600 seconds.
•
server—Sets the number of seconds as the value of the Session-Timeout
RADIUS attribute (Attribute[27]).
Note
Defaults
server-timeout
seconds
Number of seconds that the switch waits for the retransmission of packets by
the switch to the authentication server. The range is 1 to 65535.
supp-timeout
seconds
Number of seconds that the switch waits for the retransmission of packets by
the switch to the client. The range is 1 to 65535.
tx-period seconds
Number of seconds that the switch waits for a response to an
EAP-request/identity frame from the client before retransmitting the request.
The range is 1 to 65535.
These are the defaults:
quiet-period is 60 seconds.
reauth-period is 3600 seconds.
server-timeout is 30 seconds.
supp-timeout is 30 seconds.
tx-period is 30 seconds.
Command Modes
Interface configuration
Command History
Release
Modification
12.1(22)EA5
The reauth-period server keywords were added.
12.1(19)EA1
This command was introduced.
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dot1x timeout
Usage Guidelines
You should change the default values only to adjust for unusual circumstances such as unreliable links
or specific behavioral problems with certain clients and authentication servers.
The dot1x timeout reauth-period interface configuration command affects the behavior of the switch
only if you have enabled periodic re-authentication by using the dot1x reauthentication interface
configuration command.
During the quiet period, the switch does not accept or initiate any authentication requests. If you want
to provide a faster response time to the user, enter a number smaller than the default.
Examples
This example shows how to enable periodic re-authentication and to set the number of seconds between
re-authentication attempts to 4000 seconds:
Switch(config-if)# dot1x reauthentication
Switch(config-if)# dot1x timeout reauth-period 4000
This example shows how to enable periodic re-authentication and to specify the value of the
Session-Timeout RADIUS attribute as the number of seconds between re-authentication attempts:
Switch(config-if)# dot1x reauthentication
Switch(config-if)# dot1x timeout reauth-period server
This example shows how to set the quiet time on the switch to 30 seconds:
Switch(config-if)# dot1x timeout quiet-period 30
This example shows how to set 60 as the number of seconds to wait for a response to an
EAP-request/identity frame from the client before re-transmitting the request:
Switch(config-if)# dot1x timeout tx-period 60
This example shows how to set the switch-to-client retransmission time for the EAP request frame to 25
seconds:
Switch(config-if)# dot1x timeout supp-timeout 25
This example shows how to set the switch-to-authentication server retransmission time to 25 seconds:
Switch(config)# dot1x timeout server-timeout 25
This example shows how to return to the default re-authorization period:
Switch(config-if)# no dot1x timeout reauth-period
You can verify your settings by entering the show dot1x [interface interface-id] privileged EXEC
command.
Related Commands
Command
Description
dot1x max-req
Sets the maximum number of times that the switch sends an
EAP-request/identity frame before restarting the authentication process.
dot1x reauthentication
Enables periodic re-authentication of the client.
show dot1x [interface
interface-id]
Displays IEEE 802.1x status for the specified interface.
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duplex
duplex
Use the duplex interface configuration command to specify the duplex mode of operation for the switch
ports. Use the no form of this command to return to the default setting.
duplex {auto | full | half}
no duplex
Syntax Description
Defaults
auto
Port automatically detects whether it should run in full- or half-duplex mode.
full
Port is in full-duplex mode.
half
Port is in half-duplex mode.
For Fast Ethernet and 10/100/1000 ports, the default is auto.
For 100BASE-FX and small form-factor pluggable (SFP) ports, the default is full.
Command Modes
Interface configuration
Command History
Release
Modification
12.1(13)AY
This command was introduced.
Usage Guidelines
Certain ports, such as Fast Ethernet or 10/100/1000 ports, can be configured as either full duplex or half
duplex. How you apply this command depends on the device to which the switch is attached.
If the speed is set to auto, the switch negotiates with the device at the other end of the link for the speed
setting and then forces the speed setting to the negotiated value. The duplex setting remains as
configured on each end of the link, which could result in a duplex setting mismatch.
Beginning with Cisco IOS Release 12.1(22)EA1, you can configure the duplex setting when the speed
is set to auto.
If both the speed and duplex are set to specific values, autonegotiation is disabled.
For Fast Ethernet ports, setting the port to auto has the same effect as specifying half if the attached
device does not autonegotiate the duplex parameter.
The 100BASE-FX ports do not support the duplex interface configuration command. These ports only
operate in full-duplex and at 100 Mbps.
Note
For guidelines on setting the switch speed and duplex parameters, see the software configuration guide
for this release.
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duplex
Examples
This example shows how to set a port to half duplex:
Switch(config)# interface fastethernet0/1
Switch(config-if)# duplex half
This example shows how to set a port to full duplex:
Switch(config)# interface fastethernet0/1
Switch(config-if)# duplex full
You can verify your settings by entering the show interfaces transceiver properties or
show running-config privileged EXEC command.
Related Commands
Command
Description
show running-config
Displays the configuration information running on the switch. For syntax
information, select Cisco IOS Configuration Fundamentals Command
Reference for Release 12.1 > Cisco IOS File Management Commands >
Configuration File Commands.
speed
Sets the port speed.
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errdisable detect cause
errdisable detect cause
Use the errdisable detect global configuration command to enable error disable detection. Use the no
form of this command to disable this feature.
errdisable detect cause {all | dhcp-rate-limit | dtp-flap | link-flap | loopback | pagp-flap | vmps}
no errdisable detect cause {all | dhcp-rate-limit | dtp-flap | link-flap | loopback | pagp-flap |
vmps}
Syntax Description
Note
all
Enable detection for all error disable causes.
dhcp-rate-limit
Enable detection for the DHCP cause.
dtp-flap
Enable detection for the Dynamic Trunking Protocol (DTP)-flap cause.
link-flap
Enable detection for the link flap cause.
loopback
Enable detection for the loopback cause.
pagp-flap
Enable detection for the Port Aggregation Protocol (PAgP)-flap cause.
vmps
Enable error detection for the VLAN Membership Policy Server (VMPS).
Though visible in the command-line help string, the gbic-invalid keyword is not supported.
Defaults
The default is all, enabled for all causes.
Command Modes
Global configuration
Command History
Release
Modification
12.1(13)AY
This command was introduced.
12.1(14)EA1
The loopback keyword was added.
Usage Guidelines
A cause (for example, dtp-flap) is the reason why the error-disabled state occurred. When a cause is
detected on an interface, the interface is placed in error-disabled state, an operational state similar to
link-down state. If you do not enable errdisable recovery for the cause, the interface stays in the
error-disabled state until you enter the shutdown and no shutdown interface configuration commands.
If you enable the recovery for a cause, the interface is brought out of the error-disabled state and allowed
to retry the operation again when all the causes have timed out.
You must enter the shutdown and then the no shutdown commands to manually recover an interface
from the error-disabled state.
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errdisable detect cause
Examples
This example shows how to enable error disable detection for the link-flap error-disable cause:
Switch(config)# errdisable detect cause link-flap
You can verify your settings by entering the show errdisable detect privileged EXEC command.
Related Commands
Command
Description
errdisable recovery
Configures the recovery mechanism variables.
show errdisable detect
Displays errdisable detection status.
show interfaces trunk
Displays interface status or a list of interfaces in error-disabled
state.
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errdisable recovery
errdisable recovery
Use the errdisable recovery global configuration command to configure the recover mechanism
variables. Use the no form of this command to return to the default setting.
errdisable recovery {cause {all | bpduguard | channel-misconfig | dhcp-rate-limit | dtp-flap |
link-flap | loopback | pagp-flap | psecure-violation | security-violation | udld | vmps}} |
{interval interval}
no errdisable recovery {cause {all | bpduguard | channel-misconfig | dhcp-rate-limit | dtp-flap
| link-flap | loopback | pagp-flap | psecure-violation | security-violation | udld | vmps}} |
{interval interval}
Syntax Description
cause
Enable error disable to recover from a specific cause.
all
Enable the timer to recover from all error-disable causes.
bpduguard
Enable the timer to recover from the bridge protocol data unit
(BPDU)-guard error-disable state.
channel-misconfig
Enable the timer to recover from the EtherChannel misconfiguration
error-disable state.
dhcp-rate-limit
Enable the timer to recover from the DHCP error-disable state.
dtp-flap
Enable the timer to recover from the Dynamic Trunking Protocol (DTP)-flap
error-disable state.
link-flap
Enable the timer to recover from the link-flap error-disable state.
loopback
Enable the timer to recover from the loopback error-disable state.
pagp-flap
Enable the timer to recover from the Port Aggregation Protocol (PAgP)-flap
error-disable state.
psecure-violation
Enable the timer to recover from a port security violation disable state.
security-violation
Enable the timer to recover from an IEEE 802.1x violation disable state.
udld
Enable the timer to recover from the UniDirectional Link Detection
(UDLD) error-disable state.
vmps
Enable the timer to recover from a VLAN Membership Policy Server
(VMPS) error-disable state.
interval interval
Specify the time to recover from specified error-disable state. The range is
30 to 86400 seconds. The same interval is applied to all causes. The default
interval is 300 seconds.
Note
Note
The errdisable recovery timer initializes at a random differential
from the configured interval value. The difference between the
actual timeout value and the configured value can be up to
15 percent of the configured interval.
Though visible in the command-line help string, the gbic-invalid and unicast-flood keywords are not
supported.
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errdisable recovery
Defaults
Recovery is disabled for all causes.
The default interval is 300 seconds.
Command Modes
Global configuration
Command History
Release
Modification
12.1(13)AY
This command was introduced.
Usage Guidelines
A cause (for example, bpduguard) is defined as the reason why the error-disabled state occurred. When
a cause is detected on an interface, the interface is placed in error-disabled state, an operational state
similar to link-down state. If you do not enable errdisable recovery for the cause, the interface stays in
error-disabled state until you enter a shutdown and no shutdown interface configuration command. If
you enable the recovery for a cause, the interface is brought out of the error-disabled state and allowed
to retry the operation again when all the causes have timed out.
Otherwise, you must enter the shutdown and then no shutdown commands to manually recover an
interface from the error-disabled state.
Examples
This example shows how to enable the recovery timer for the BPDU guard error-disable cause:
Switch(config)# errdisable recovery cause bpduguard
This example shows how to set the timer to 500 seconds:
Switch(config)# errdisable recovery interval 500
You can verify your settings by entering the show errdisable recovery privileged EXEC command.
Related Commands
Command
Description
show errdisable recovery
Displays errdisable recovery timer information.
show interfaces status
Displays interface status.
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flowcontrol
flowcontrol
Use the flowcontrol interface configuration command to set the receive or send flow-control value for
a Gigabit Ethernet interface. When flow control send is on for a device and it detects any congestion at
its end, it notifies the link partner or the remote device of the congestion by sending a pause frame. When
flow control receive is on for the remote device and it receives a pause frame, it stops sending any data
packets. This prevents any loss of data packets during the congestion period.
Use the receive off and send off keywords to disable flow control.
flowcontrol {receive | send} {desired | off | on}
Note
Syntax Description
This flowcontrol command applies only to switch and module ports operating at 1000 Mbps.
receive
Sets whether the interface can receive flow-control packets from a remote device.
send
Sets whether the interface can send flow-control packets to a remote device.
desired
When used with receive, allows an interface to operate with an attached device
that is required to send flow-control packets or with an attached device that is not
required to but can send flow-control packets.
When used with send, the interface sends flow-control packets to a remote device
if the remote device supports it.
off
When used with receive, turns off an attached device’s ability to send flow-control
packets to an interface. When used with send, turns off the local port’s ability to
send flow-control packets to a remote device.
on
When used with receive, allows an interface to operate with an attached device
that is required to send flow-control packets or with an attached device that is not
required to but can send flow-control packets.
When used with send, the interface sends flow-control packets to a remote device
if the remote device supports it.
Defaults
The defaults for 10/100/1000 and small form-factor pluggable (SFP) -module ports are flowcontrol
receive off and flowcontrol send desired.
Command Modes
Interface configuration
Command History
Release
Modification
12.1(13)AY
This command was introduced.
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flowcontrol
Usage Guidelines
Use the flowcontrol command only on 10/100/1000 and SFP-module ports.
Note that when used with receive, the on and desired keywords have the same result.
When you use the flowcontrol command to set a port to control traffic rates during congestion, you are
setting flow control on a port to one of these conditions:
•
receive on and send on: Flow control operates in both directions; pause frames can be sent by both
the local device and the remote device to show link congestion.
•
receive on and send desired: The port can receive pause frames and is able to send pause frames if
the attached device supports them.
•
receive on and send off: The port cannot send pause frames, but can operate with an attached device
that is required to or is able to send pause frames; the port is able to receive pause frames.
•
receive off and send on: The port sends pause frames if the remote device supports them, but cannot
receive pause frames from the remote device.
•
receive off and send desired: The port cannot receive pause frames, but can send pause frames if
the attached device supports them.
•
receive off and send off: Flow control does not operate in either direction. In case of congestion, no
indication is given to the link partner, and no pause frames are sent or received by either device.
Table 2-2 shows the flow control resolution achieved on local and remote ports by a combination of
settings. The table assumes that for receive, using the desired keyword has the same results as using the
on keyword.
Table 2-2
Flow Control Settings and Local and Remote Port Flow Control Resolution
Flow Control Settings
Flow Control Resolution
Local Device
Remote Device
Local Device
Remote Device
send on/receive on
send on/receive on
Sends and receives
Sends and receives
send on/receive off
Does not send or receive
Does not send or receive
send desired/receive on
Sends and receives
Sends and receives
send desired/receive off
Does not send or receive
Does not send or receive
send off/receive on
Sends and receives
Receives only
send off/receive off
Does not send or receive
Does not send or receive
send on/receive on
Does not send or receive
Does not send or receive
send on/receive off
Does not send or receive
Does not send or receive
send desired/receive on
Sends only
Receives only
send desired/receive off
Does not send or receive
Does not send or receive
send off/receive on
Sends only
Receives only
send off/receive off
Does not send or receive
Does not send or receive
send on/receive off
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flowcontrol
Table 2-2
Flow Control Settings and Local and Remote Port Flow Control Resolution (continued)
Flow Control Settings
Flow Control Resolution
Local Device
Remote Device
Local Device
Remote Device
send desired/receive on
send on/receive on
Sends and receives
Sends and receives
send on/receive off
Receives only
Sends only
send desired/receive on
Sends and receives
Sends and receives
send desired/receive off
Receives only
Sends only
send off/receive on
Sends and receives
Receives only
send off/receive off
Does not send or receive
Does not send or receive
send on/receive on
Does not send or receive
Does not send or receive
send on/receive off
Does not send or receive
Does not send or receive
send desired/receive on
Sends only
Receives only
send desired/receive off
Does not send or receive
Does not send or receive
send off/receive on
Sends only
Receives only
send off/receive off
Does not send or receive
Does not send or receive
send on/receive on
Receives only
Sends and receives
send on/receive off
Receives only
Sends only
send desired/receive on
Receives only
Sends and receives
send desired/receive off
Receives only
Sends only
send off/receive on
Receives only
Receives only
send off/receive off
Does not send or receive
Does not send or receive
send on/receive on
Does not send or receive
Does not send or receive
send on/receive off
Does not send or receive
Does not send or receive
send desired/receive on
Does not send or receive
Does not send or receive
send desired/receive off
Does not send or receive
Does not send or receive
send off/receive on
Does not send or receive
Does not send or receive
send off/receive off
Does not send or receive
Does not send or receive
send desired/receive off
send off/receive on
send off/receive off
Examples
This example shows how to configure the local port to not support any level of flow control by the
remote port:
Switch(config-if)# flowcontrol receive off
Switch(config-if)# flowcontrol send off
You can verify your settings by entering the show interfaces or show flowcontrol privileged EXEC
command.
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flowcontrol
Related Commands
Command
Description
show interfaces flowcontrol Displays interface input and output flow control settings and status.
show flowcontrol
Displays flow control settings and status for specified interfaces or all
interfaces on the switch.
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interface
interface
Use the interface global configuration command to configure an interface type, create a switch virtual
interface to be used as the management VLAN interface, and to enter interface configuration mode.
interface {interface-id | vlan number}
no interface {interface-id | vlan number}
Syntax Description
interface-id
Specify the interface type and number.
vlan number
VLAN number from 1 to 4094 to be used as the management VLAN.
Defaults
The default management VLAN interface is VLAN 1.
Command Modes
Global configuration
Command History
Release
Modification
12.1(13)AY
This command was introduced.
Usage Guidelines
When creating a management VLAN interface, a space between vlan and number is accepted.
Only one management VLAN interface can be active.
You cannot delete the management VLAN 1 interface.
You can use the no shutdown interface configuration command to shut down the active management
VLAN interface and to enable a new one.
You can configure the management VLAN interface on static-access and trunk ports.
Examples
This example shows how enter interface configuration mode for an interface:
Switch(config)# interface fastethernet0/2
Switch(config-if)#
This example shows how to change the management VLAN from the default management VLAN to
VLAN 3. This series of commands should only be entered from the service port. If these commands are
entered through a Telnet session, the shutdown command disconnects the session, and there is no way
to use IP to access the system.
Switch# configure terminal
Switch(config)# interface vlan 3
Switch(config-if)# ip address 172.20.128.176 255.255.255.0
Switch(config-if)# no shutdown
Switch(config-if)# exit
You can verify your settings by entering the show interfaces and show interfaces vlan vlan-id
privileged EXEC commands.
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interface
Related Commands
Command
Description
show interfaces
Displays the administrative and operational status of a switching
(nonrouting) port.
shutdown
Disables a port and shuts down the management VLAN.
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interface port-channel
interface port-channel
Use the interface port-channel global configuration command to access or create the port-channel
logical interface for Layer 2 interfaces. Use the no form of this command to remove the port channel.
interface port-channel port-channel-number
no interface port-channel port-channel-number
Syntax Description
port-channel-number
Defaults
No port-channel logical interfaces are defined.
Command Modes
Global configuration
Command History
Release
Modification
12.1(13)AY
This command was introduced.
Usage Guidelines
Port-channel number. The range is 1 to 6.
Only one port channel in a channel group is allowed.
Follow these guidelines when you use the interface port-channel command:
Examples
•
If you want to use the Cisco Discovery Protocol (CDP), you must configure it only on the physical
interface and not on the port-channel interface.
•
On the port-channel interface, if you do not assign a static MAC address or if you assign a static
MAC address and then later remove it, the switch automatically assigns a MAC address to the
interface.
This example shows how to create a port-channel interface with a port-channel number of 5:
Switch(config)# interface port-channel 5
You can verify your settings by entering the show running-config or show etherchannel
channel-group-number detail privileged EXEC command.
Related Commands
Command
Description
channel-group
Assigns an Ethernet interface to an EtherChannel group.
show etherchannel
Displays EtherChannel information for a channel.
show running-config
Displays the configuration information running on the switch. For syntax
information, select Cisco IOS Configuration Fundamentals Command
Reference for Release 12.1 > Cisco IOS File Management Commands >
Configuration File Commands.
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interface range
interface range
Use the interface range global configuration command to enter interface range configuration mode and
to execute a command on multiple ports at the same time. Use the no form of this command to remove
an interface range.
interface range {port-range | macro name}
no interface range {port-range | macro name}
Syntax Description
port-range
Port range. For a list of valid values for port-range, see the “Usage Guidelines”
section.
macro name
Specify the name of a macro.
Defaults
This command has no default setting.
Command Modes
Global configuration
Command History
Release
Modification
12.1(13)AY
This command was introduced.
Usage Guidelines
From the interface range configuration mode, all interface parameters that you enter are applied to all
interfaces within the range.
For VLANs, you can use the interface range command only on existing VLAN interfaces. To display
VLAN interfaces, enter the show running-config privileged EXEC command. VLANs not displayed
cannot be used in the interface range command. The commands that you enter under the interface
range command are applied to all existing VLAN interfaces in the range.
All configuration changes made to an interface range are saved to NVRAM, but the interface range itself
is not saved to NVRAM.
You can enter the interface range in two ways:
•
Specifying up to five interface ranges
•
Specifying a previously defined interface-range macro
You can define up to five interface ranges with a single command, with each range separated by a
comma (,).
All interfaces in a range must be the same type; that is, all Fast Ethernet ports, all Gigabit Ethernet ports,
all EtherChannel ports, or all VLANs.
These are the valid values for port-range type and interface:
•
vlan vlan-id, where vlan-id is from 1 to4094
•
port-channel port-channel-number, where port-channel-number is from 1 to 6
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interface range
•
fastethernet interface-id
•
gigabitethernet interface-id
For physical interfaces, the interface-id is defined as a slot/number (where slot is always 0 for the
switch), and the range is entered as type 0/number - number (for example, fastethernet0/1 - 2). You can
also enter multiple ranges.
When you define a range, you must enter a space before and after the hyphen (-):
interface range fastethernet0/1 - 2
When you define multiple ranges, you must enter a space before and after the comma (,):
interface range fastethernet0/3 - 7 , gigabitethernet0/1
You cannot specify both a macro and an interface range in the same command.
A single interface can also be specified in port-range. (The command is then similar to the interface
interface-id global configuration command.)
Note
Examples
For more information about configuring interface ranges, see the software configuration guide for this
release.
This example shows how to use the interface range command to enter interface range configuration
mode and to enter commands for two ports:
Switch(config)# interface range fastethernet0/1 - 2
Switch(config-if-range)#
This example shows how to use a port-range macro macro1 for the same function. The advantage is that
you can reuse the macro1 until you delete it.
Switch(config)# define interface-range macro1 fastethernet0/1 - 2
Switch(config)# interface range macro macro1
Switch(config-if-range)#
Related Commands
Command
Description
show running-config
Displays the configuration information running on the switch. For syntax
information, select Cisco IOS Configuration Fundamentals Command
Reference for Release 12.1 > Cisco IOS File Management Commands >
Configuration File Commands.
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ip address
ip address
Use the ip address interface configuration command to set an IP address for a switch. Use the no form
of this command to remove an IP address or to disable IP processing.
ip address ip-address subnet-mask
no ip address ip-address subnet-mask
Syntax Description
ip-address
IP address.
subnet-mask
Mask for the associated IP subnet.
Defaults
No IP address is defined for the switch.
Command Modes
Interface configuration
Command History
Release
Modification
12.1(13)AY
This command was introduced.
Usage Guidelines
A switch can have one IP address.
The IP address of the switch can be accessed only by nodes connected to ports that belong to the
management VLAN. The default for the management VLAN is VLAN 1, but you can configure a
different VLAN as the management VLAN.
If you remove the IP address through a Telnet or Secure Shell (SSH) session, your connection to the
switch is lost.
If your switch receives its IP address from a Bootstrap Protocol (BOOTP) or a DHCP server and you
remove the switch IP address by using the no ip address command, IP processing is disabled, and the
BOOTP or DHCP server cannot reassign the address.
Examples
This example shows how to configure the IP address for the switch on a subnetted network:
Switch(config)# interface vlan 1
Switch(config-if)# ip address 172.20.128.2 255.255.255.0
You can verify your settings by entering the show running-config privileged EXEC command.
Related Commands
Command
Description
show running-config
Displays the configuration information running on the switch. For syntax
information, select Cisco IOS Configuration Fundamentals Command
Reference for Release 12.1 > Cisco IOS File Management Commands >
Configuration File Commands.
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ip dhcp snooping
ip dhcp snooping
Use the ip dhcp snooping global configuration command to globally enable DHCP snooping. Use the
no form of this command to return to the default setting.
ip dhcp snooping
no ip dhcp snooping
Syntax Description
This command has no arguments or keywords.
Defaults
DHCP snooping is disabled.
Command Modes
Global configuration
Command History
Release
Modification
12.1(22)EA7
This command was introduced.
Usage Guidelines
You must globally enable DHCP snooping for any DHCP snooping configuration to take effect.
DHCP snooping is not active until snooping is enabled on a VLAN by using the ip dhcp snooping vlan
vlan-id global configuration command.
Examples
This example shows how to enable DHCP snooping:
Switch(config)# ip dhcp snooping
You can verify your settings by entering the show ip dhcp snooping privileged EXEC command.
Related Commands
Command
Description
ip dhcp snooping vlan
Enables DHCP snooping on a VLAN.
show ip dhcp snooping
Displays the DHCP snooping configuration.
show ip dhcp snooping binding
Displays the DHCP snooping binding information.
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ip dhcp snooping information option
ip dhcp snooping information option
Use the ip dhcp snooping information option global configuration command to enable DHCP
option-82 data insertion. Use the no form of this command to disable DHCP option-82 data insertion.
ip dhcp snooping information option
no ip dhcp snooping information option
Syntax Description
This command has no arguments or keywords.
Defaults
DHCP option-82 data insertion is enabled.
Command Modes
Global configuration
Command History
Release
Modification
12.1(22)EA7
This command was introduced.
Usage Guidelines
You must globally enable DHCP snooping by using the ip dhcp snooping global configuration
command for any DHCP snooping configuration to take effect.
When the option-82 feature is enabled and a switch receives a DHCP request from a host, it adds the
option-82 information in the packet. The option-82 information contains the switch MAC address (the
remote ID suboption) and the port identifier, vlan-mod-port, from which the packet is received (circuit
ID suboption). The switch forwards the DHCP request that includes the option-82 field to the DHCP
server.
When the DHCP server receives the packet, it can use the remote ID, the circuit ID, or both to assign IP
addresses and implement policies, such as restricting the number of IP addresses that can be assigned to
a single remote ID or a circuit ID. Then the DHCP server echoes the option-82 field in the DHCP reply.
The DHCP server unicasts the reply to the switch if the request was relayed to server by the switch.
When the client and server are on the same subnet, the server broadcasts the reply. The switch inspects
the remote ID and possibly the circuit ID fields to verify that it originally inserted the option-82 data.
The switch removes the option-82 field and forwards the packet to the switch port that connects to the
DHCP host that sent the DHCP request.
Examples
This example shows how to enable DHCP option-82 data insertion:
Switch(config)# ip dhcp snooping information option
You can verify your settings by entering the show ip dhcp snooping privileged EXEC command.
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ip dhcp snooping information option
Related Commands
Command
Description
show ip dhcp snooping
Displays the DHCP snooping configuration.
show ip dhcp snooping binding
Displays the DHCP snooping binding information.
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ip dhcp snooping information option allow-untrusted
ip dhcp snooping information option allow-untrusted
Use the ip dhcp snooping information option allow-untrusted global configuration command on an
aggregation switch to configure it to accept DHCP packets with option-82 information that are received
on untrusted ports that might be connected to an edge switch. Use the no form of this command to
configure the switch to drop these packets from the edge switch.
ip dhcp snooping information option allow-untrusted
no ip dhcp snooping information option allow-untrusted
Syntax Description
This command has no arguments or keywords.
Defaults
The switch drops DHCP packets with option-82 information that are received on untrusted ports that
might be connected to an edge switch.
Command Modes
Global configuration
Command History
Release
Modification
12.1(22)EA7
This command was introduced.
Usage Guidelines
You might want an edge switch to which a host is connected to insert DHCP option-82 information at
the edge of your network. You might also want to enable DHCP security features, such as DHCP
snooping, IP source guard, or dynamic Address Resolution Protocol (ARP) inspection, on an
aggregation switch. However, if DHCP snooping is enabled on the aggregation switch, the switch drops
packets with option-82 information that are received on an untrusted port and does not learn DHCP
snooping bindings for connected devices on a trusted interface.
If the edge switch to which a host is connected inserts option-82 information and you want to use DHCP
snooping on an aggregation switch, enter the ip dhcp snooping information option allow-untrusted
command on the aggregation switch. The aggregation switch can learn the bindings for a host even
though the aggregation switch receives DHCP snooping packets on an untrusted port. You can also
enable DHCP security features on the aggregation switch. The port on the edge switch to which the
aggregation switch is connected must be configured as a trusted port.
Note
Do not enter the ip dhcp snooping information option allow-untrusted command on an aggregation
switch to which an untrusted device is connected. If you enter this command, an untrusted device might
spoof the option-82 information.
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ip dhcp snooping information option allow-untrusted
Examples
This example shows how to configure an access switch to not check the option-82 information in
untrusted packets from an edge switch and to accept the packets:
Switch(config)# ip dhcp snooping information option allow-untrusted
You can verify your settings by entering the show ip dhcp snooping privileged EXEC command.
Related Commands
Command
Description
show ip dhcp snooping
Displays the DHCP snooping configuration.
show ip dhcp snooping binding
Displays the DHCP snooping binding information.
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ip dhcp snooping limit rate
ip dhcp snooping limit rate
Use the ip dhcp snooping limit rate interface configuration command to configure the number of DHCP
messages an interface can receive per second. Use the no form of this command to return to the default
setting.
ip dhcp snooping limit rate rate
no ip dhcp snooping limit rate
Syntax Description
rate
Defaults
DHCP snooping rate limiting is disabled.
Command Modes
Interface configuration
Command History
Release
Modification
12.1(22)EA7
This command was introduced.
Usage Guidelines
Number of DHCP messages an interface can receive per second. The range is
1 to 4294967294.
Normally, the rate limit applies to untrusted interfaces. If you want to configure rate limiting for trusted
interfaces, keep in mind that trusted interfaces might aggregate DHCP traffic on multiple VLANs (some
of which might not be snooped) in the switch, and you will need to adjust the interface rate limits to a
higher value.
If the rate limit is exceeded, the interface is error-disabled. If you enabled error recovery by entering the
errdisable recovery dhcp-rate-limit global configuration command, the interface retries the operation
again when all the causes have timed out. If the error-recovery mechanism is not enabled, the interface
stays in the error-disabled state until you enter the shutdown and no shutdown interface configuration
commands.
Examples
This example shows how to set a message rate limit of 150 messages per second on an interface:
Switch(config-if)# ip dhcp snooping limit rate 150
You can verify your settings by entering the show ip dhcp snooping privileged EXEC command.
Related Commands
Command
Description
errdisable recovery
Configures the recover mechanism.
show ip dhcp snooping
Displays the DHCP snooping configuration.
show ip dhcp snooping binding
Displays the DHCP snooping binding information.
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ip dhcp snooping trust
ip dhcp snooping trust
Use the ip dhcp snooping trust interface configuration command to configure a port as trusted for
DHCP snooping purposes. Use the no form of this command to return to the default setting.
ip dhcp snooping trust
no ip dhcp snooping trust
Syntax Description
This command has no arguments or keywords.
Defaults
DHCP snooping trust is disabled.
Command Modes
Interface configuration
Command History
Release
Modification
12.1(22)EA7
This command was introduced.
Usage Guidelines
Configure ports that are connected to a DHCP server or to other switches or routers as trusted. Configure
ports that are connected to DHCP clients as untrusted.
Examples
This example shows how to enable DHCP snooping trust on a port:
Switch(config-if)# ip dhcp snooping trust
You can verify your settings by entering the show ip dhcp snooping privileged EXEC command.
Related Commands
Command
Description
show ip dhcp snooping
Displays the DHCP snooping configuration.
show ip dhcp snooping binding
Displays the DHCP snooping binding information.
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ip dhcp snooping vlan
ip dhcp snooping vlan
Use the ip dhcp snooping vlan global configuration command to enable DHCP snooping on a VLAN.
Use the no form of this command to disable DHCP snooping on a VLAN.
ip dhcp snooping vlan vlan-id [vlan-id]
no ip dhcp snooping vlan vlan-id [vlan-id]
Syntax Description
vlan vlan-id [vlan-id]
Specify a VLAN ID or range of VLANs on which to enable DHCP
snooping. The range is 1 to 4094.
You can enter a single VLAN ID identified by VLAN ID number, a series
of VLAN IDs separated by commas, a range of VLAN IDs separated by
hyphens, or a range of VLAN IDs separated by entering the starting and
ending VLAN IDs separated by a space.
Defaults
DHCP snooping is disabled on all VLANs.
Command Modes
Global configuration
Command History
Release
Modification
12.1(19)EA1
This command was introduced.
12.1(22)EA7
This command was introduced.
Usage Guidelines
You must first globally enable DHCP snooping before enabling DHCP snooping on a VLAN.
Examples
This example shows how to enable DHCP snooping on VLAN 10:
Switch(config)# ip dhcp snooping vlan 10
You can verify your settings by entering the show ip dhcp snooping privileged EXEC command.
Related Commands
Command
Description
show ip dhcp snooping
Displays the DHCP snooping configuration.
show ip dhcp snooping binding
Displays the DHCP snooping binding information.
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ip igmp filter
ip igmp filter
Use the ip igmp filter interface configuration command to control whether or not all hosts on a Layer 2
interface can join one or more IP multicast groups by applying an Internet Group Management Protocol
(IGMP) profile to the interface. Use the no form of this command to remove the specified profile from
the interface.
ip igmp filter profile number
no ip igmp filter
Syntax Description
profile number
Defaults
No IGMP filters are applied.
Command Modes
Interface configuration
Command History
Release
Modification
12.1(13)AY
This command was introduced.
Usage Guidelines
The IGMP profile number to be applied. The range is 1 to 4294967295.
You can apply IGMP filters only to Layer 2 physical interfaces; you cannot apply IGMP filters to routed
ports, switch virtual interfaces (SVIs), or ports that belong to an EtherChannel group.
An IGMP profile can be applied to one or more switch port interfaces, but one port can have only one
profile applied to it.
Examples
This example shows how to apply IGMP profile 22 to an interface.
Switch(config)# interface fastethernet0/1
Switch(config-if)# ip igmp filter 22
You can verify your setting by using the show running-config interface interface-id privileged EXEC
command.
Related Commands
Command
Description
ip igmp profile
Configures the specified IGMP profile number.
show ip igmp profile
Displays the characteristics of the specified IGMP profile.
show running-config interface Displays the running configuration on the switch interface, the IGMP
interface-id
profile (if any) that is applied to an interface. For syntax information,
select Cisco IOS Configuration Fundamentals Command Reference
for Release 12.1 > Cisco IOS File Management Commands >
Configuration File Commands.
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ip igmp max-groups
ip igmp max-groups
Use the ip igmp max-groups interface configuration command to set the maximum number of Internet
Group Management Protocol (IGMP) groups that a Layer 2 interface can join or to configure the IGMP
throttling action when the maximum number of entries is in the forwarding table. Use the no form of this
command to set the maximum back to the default, which is to have no maximum limit, or to return to
the default throttling action, which is to drop the report.
ip igmp max-groups {number | action {deny | replace}}
no ip igmp max-groups {number | action}
Syntax Description
Defaults
number
The maximum number of IGMP groups that an interface can join. The
range is 0 to 4294967294. The default is no limit.
action {deny | replace}
Set the throttling action. The keywords have these meanings:
•
deny—When the maximum number of entries is in the IGMP snooping
forwarding table, drop the next IGMP join report. This is the default
action.
•
replace—When the maximum number of entries is in the IGMP
snooping forwarding table, replace the existing group with the new
group for which the IGMP report was received.
The default maximum number of groups is no limit.
After the switch learns the maximum number of IGMP group entries on an interface, the default
throttling action is to drop the next IGMP report that the interface receives and to not add an entry for
the IGMP group to the interface.
Command Modes
Interface configuration
Command History
Release
Modification
12.1(13)AY
This command was introduced.
12.1(19)EA1
The action {deny | replace} keywords were added.
Usage Guidelines
You can use this command only on Layer 2 physical interfaces and on logical EtherChannel interfaces.
You cannot set IGMP maximum groups or configure the IGMP throttling action for ports that belong to
an EtherChannel group.
Follow these guidelines when configuring the IGMP throttling action:
•
If you configure the throttling action as deny and set the maximum group limitation, the entries that
were previously in the forwarding table are not removed but are aged out. After these entries are
aged out and the maximum number of entries is in the forwarding table, the switch drops the next
IGMP report received on the interface.
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ip igmp max-groups
Examples
•
If you configure the throttling action as replace and set the maximum group limitation, the entries
that were previously in the forwarding table are removed. When the maximum number of entries is
in the forwarding table, the switch replaces a randomly selected multicast entry with the received
IGMP report.
•
When the maximum group limitation is set to the default (no maximum), entering the ip igmp
max-groups {deny | replace} command has no effect.
This example shows how to limit to 25 the number of IGMP groups that an interface can join:
Switch(config)# interface fastethernet0/1
Switch(config-if)# ip igmp max-groups 25
This example shows how to configure the switch to replace the existing group with the new group for
which the IGMP report was received when the maximum number of entries is in the forwarding table:
Switch(config)# interface gigabitethernet0/1
Switch(config-if)# ip igmp max-groups action replace
You can verify your setting by using the show running-config interface interface-id privileged EXEC
command.
Related Commands
Command
Description
show running-config interface Displays the running configuration on the switch interface, including
interface-id
the maximum number of IGMP groups that an interface can join and
the throttling action. For syntax information, select Cisco IOS
Configuration Fundamentals Command Reference for Release 12.1
> Cisco IOS File Management Commands > Configuration File
Commands.
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ip igmp profile
ip igmp profile
Use the ip igmp profile global configuration command to create an Internet Group Management
Protocol (IGMP) profile and enter igmp profile configuration mode. From this mode, you can specify
the configuration of the IGMP profile to be used for filtering IGMP membership reports from a
switchport. Use the no form of this command to delete the IGMP profile.
ip igmp profile profile number
no ip igmp profile profile number
Syntax Description
profile number
Defaults
No IGMP profiles are defined. When configured, the default action for matching an IGMP profile is to
deny matching addresses.
Command Modes
Global configuration
Command History
Release
Modification
12.1(13)AY
This command was introduced.
Usage Guidelines
The IGMP profile number being configured. The range is 1 to 4294967295.
When you are in IGMP profile configuration mode, you can create the profile by using these commands:
•
deny: specifies that matching addresses are denied; this is the default condition.
•
exit: exits from igmp-profile configuration mode.
•
no: negates a command or resets to its defaults.
•
permit: specifies that matching addresses are permitted.
•
range: specifies a range of IP addresses for the profile. This can be a single IP address or a range
with a start and an end address.
When entering a range, enter the low IP multicast address, a space, and the high IP multicast address.
You can apply an IGMP profile to one or more Layer 2 interfaces, but each interface can have only one
profile applied to it.
Examples
This example shows how to configure IGMP profile 40 that permits the specified range of IP multicast
addresses:
Switch # configure terminal
Switch(config)# ip igmp profile 40
Switch(config-igmp-profile)# permit
Switch(config-igmp-profile)# range 233.1.1.1 233.255.255.255
You can verify your settings by using the show ip igmp profile privileged EXEC command.
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ip igmp profile
Related Commands
Command
Description
ip igmp filter
Applies the IGMP profile to the specified interface.
show ip igmp profile
Displays the characteristics of all IGMP profiles or the specified
IGMP profile number.
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ip igmp snooping
ip igmp snooping
Use the ip igmp snooping global configuration command to globally enable Internet Group
Management Protocol (IGMP) snooping. Use the no form of this command to disable IGMP snooping.
ip igmp snooping
no ip igmp snooping
Syntax Description
Note
This command has no arguments or keywords.
Though visible in the command-line help string, the tcn keyword is not supported.
Defaults
IGMP snooping is globally enabled.
Command Modes
Global configuration
Command History
Release
Modification
12.1(13)AY
This command was introduced.
Usage Guidelines
When IGMP snooping is globally enabled, IGMP snooping is enabled on all the existing VLAN
interfaces. When IGMP snooping is globally disabled, IGMP snooping is disabled on all the existing
VLAN interfaces.
The configuration is saved in NVRAM.
Examples
This example shows how to globally enable IGMP snooping:
Switch(config)# ip igmp snooping
To verify your settings, enter the show ip igmp snooping privileged EXEC command.
Related Commands
Command
Description
ip igmp snooping vlan
Enables IGMP snooping on a VLAN interface.
ip igmp snooping vlan immediate-leave
Enables IGMP Immediate-Leave processing.
ip igmp snooping vlan mrouter
Configures a Layer 2 port as a multicast router port.
ip igmp snooping vlan static
Configures a Layer 2 port as a member of a group.
show ip igmp snooping
Displays the IGMP snooping configuration.
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ip igmp snooping mrouter learn pim v2
ip igmp snooping mrouter learn pim v2
Use the ip igmp snooping mrouter learn pim v2 global configuration command to enable multicast
router detection by Protocol-Independent Multicast protocol version 2 (PIMv2) packets when Internet
Group Management Protocol (IGMP) snooping is enabled. Use the no form of this command to disable
multicast router detection by PIMv2 packets.
ip igmp snooping mrouter learn pim v2
no ip igmp snooping mrouter learn pim v2
Syntax Description
This command has no arguments or keywords.
Defaults
Multicast router discovery using PIMv2 packets is enabled.
Command Modes
Global configuration
Command History
Release
Modification
12.1(20)EA2
This command was introduced.
Usage Guidelines
When IGMP snooping is globally enabled, PIMv2 packets and IGMP query packets are used for
multicast router discovery and sent to the switch CPU. This is the default condition. Use the no ip igmp
snooping mrouter learn pim v2 global configuration command to disable multicast router discovery
by PIMv2.
To prevent PIMv2 packets from being sent to the switch CPU, you must also disable source-only
learning on the switch. Source-only learning sends IP multicast data packets to the CPU and PIMv2
packets are treated as IP multicast data. Use the no ip igmp snooping source-only learning global
configuration command to disable source-only learning.
Examples
This example shows how to prevent PIMv2 packets from being sent to the CPU, by disabling source-only
learning and PIMv2 multicast router detection:
Switch(config)# no ip igmp snooping source-only-learning
Switch(config)# no ip igmp snooping mrouter learn pim v2
You can verify your settings by entering the show running-config | include mrouter learn pim v2
privileged EXEC command.
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ip igmp snooping mrouter learn pim v2
Related Commands
Command
Description
ip igmp snooping
Globally enables IGMP snooping.
ip igmp snooping
source-only-learning
Enable IGMP snooping source-only learning. To prevent
PIMv2 packets from being sent to the CPU, you must also use
the no form of this command to disable source-only-learning.
show running-config | include
mrouter learn pim v2
Displays the configuration information running on the switch.
For syntax information, select Cisco IOS Configuration
Fundamentals Command Reference for Release 12.1 >
Cisco IOS File Management Commands > Configuration
File Commands.
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ip igmp snooping report-suppression
ip igmp snooping report-suppression
Use the ip igmp snooping report-suppression global configuration command to enable Internet Group
Management Protocol (IGMP) report suppression. Use the no form of this command to disable IGMP
report suppression and forward all IGMP reports to multicast routers.
ip igmp snooping report-suppression
no ip igmp snooping report-suppression
Syntax Description
This command has no arguments or keywords.
Defaults
IGMP report suppression is enabled.
Command Modes
Global configuration
Command History
Release
Modification
12.1(19)EA1
This command was introduced.
Usage Guidelines
IGMP report suppression is supported only when the multicast query has IGMPv1 and IGMPv2 reports.
This feature is not supported when the query includes IGMPv3 reports.
The switch uses IGMP report suppression to forward only one IGMP report per multicast router query
to multicast devices. When IGMP router suppression is enabled (the default), the switch sends the first
IGMP report from all hosts for a group to all the multicast routers. The switch does not send the
remaining IGMP reports for the group to the multicast routers. This feature prevents duplicate reports
from being sent to the multicast devices.
If the multicast router query includes requests only for IGMPv1 and IGMPv2 reports, the switch
forwards only the first IGMPv1 or IGMPv2 report from all hosts for a group to all the multicast routers.
If the multicast router query also includes requests for IGMPv3 reports, the switch forwards all IGMPv1,
IGMPv2, and IGMPv3 reports for a group to the multicast devices.
If you disable IGMP report suppression by entering the no ip igmp snooping report-suppression
command, all IGMP reports are forwarded to all the multicast routers.
Examples
This example shows how to disable report suppression:
Switch(config)# no ip igmp snooping report-suppression
This example shows how to enable report suppression:
Switch(config)# ip igmp snooping report-suppression
You can verify your settings by entering the show ip igmp snooping privileged EXEC command.
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ip igmp snooping report-suppression
Related Commands
Command
Description
ip igmp snooping
Globally enables IGMP snooping. IGMP snooping must be globally
enabled in order to be enabled on a VLAN.
show ip igmp snooping
Displays the IGMP snooping configuration of the switch or the
VLAN.
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ip igmp snooping source-only-learning
ip igmp snooping source-only-learning
Use the ip igmp snooping source-only-learning global configuration command to enable IP
multicast-source-only learning on the switch and optionally set the aging time of the forwarding-table
entries that are learned. Use the no form of this command to disable IP multicast-source-only learning
or to disable aging.
ip igmp snooping source-only-learning [age-timer value]
no ip igmp snooping source-only-learning [age-timer]
Syntax Description
Defaults
age-timer
(Optional) Configure the aging time of the forwarding-table entries that the
switch learns by using the source-only learning method.
time
Aging time is seconds. The range is 0 to 2880 seconds. If you set time to 0, aging
of the forward-table entries is disabled.
IP multicast-source-only learning is enabled.
The aging feature is enabled. The default is 600 seconds (10 minutes).
Command Modes
Global configuration
Command History
Release
Modification
12.1(13)AY
This command was introduced.
Usage Guidelines
Note
When IP multicast-source-only learning is enabled, the switch learns the IP multicast group from the IP
multicast data stream and only forwards traffic to the multicast router ports.
We strongly recommend that you do not disable IP multicast-source-only learning. IP
multicast-source-only learning should be disabled only if your network is not composed of IP
multicast-source-only networks and if disabling this learning method improves the network
performance.
In a source-only network, switch ports are connected to multicast source ports and multicast router ports.
The switch ports are not connected to hosts that send IGMP join or leave messages.
The switch learns about IP multicast groups from the IP multicast data stream by using the source-only
learning method. The switch forwards traffic only to the multicast router ports. You can disable
source-only learning by using the no ip igmp snooping source-only learning global configuration
command.
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ip igmp snooping source-only-learning
The aging time only affects the forwarding-table entries that the switch learns by using the source-only
learning method. If the aging time is too long or is disabled, the forwarding table is filled with unused
multicast addresses that the switch learned by using source-only learning or by using the IGMP join
messages. When the switch receives traffic for new IP multicast groups, it floods the packet to all ports
in the same VLAN. This unnecessary flooding can impact switch performance.
To disable the aging of the forwarding-table entries, enter the ip igmp snooping source-only-learning
age-timer 0 global configuration command. If aging is disabled and you want to delete multicast
addresses that the switch learned by using source-only learning, re-enable aging of the forwarding-table
entries. The switch can now age out the multicast addresses that were learned by the source-only learning
method and that re not in use.
If you disable source-only learning, the aging time has no effect on the switch.
Examples
This example shows how to disable source-only learning:
Switch(config)# no ip igmp snooping source-only-learning
This example shows how to enable source-only learning:
Switch(config)# ip igmp snooping source-only-learning
This example shows how to set the aging time as 1200 seconds (20 minutes):
Switch(config)# ip igmp snooping source-only-learning age-timer 1200
This example shows how to disable aging of the forward-table entries:
Switch(config)# ip igmp snooping source-only-learning age-timer 0
You can verify your settings by entering the show running-config | include source-only-learning
privileged EXEC command.
Related Commands
Command
Description
ip igmp snooping
Globally enables IGMP snooping. IGMP snooping must be globally
enabled in order to be enabled on a VLAN.
show running-config | include Displays the configuration information running on the switch. For
source-only-learning
syntax information, select Cisco IOS Configuration Fundamentals
Command Reference for Release 12.1 > Cisco IOS File
Management Commands > Configuration File Commands.
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ip igmp snooping vlan
ip igmp snooping vlan
Use the ip igmp snooping vlan global configuration command to enable Internet Group Management
Protocol (IGMP) snooping on a specific VLAN. Use the no form of this command to disable IGMP
snooping on a VLAN interface.
ip igmp snooping vlan vlan-id
no ip igmp snooping vlan vlan-id
Syntax Description
vlan-id
Defaults
IGMP snooping is enabled when each VLAN is created.
Command Modes
Global configuration
Command History
Release
Modification
12.1(13)AY
This command was introduced.
VLAN ID. The range is 1 to 4094.
Usage Guidelines
This command automatically configures the VLAN if it is not already configured. The configuration is
saved in NVRAM.
Examples
This example shows how to enable IGMP snooping on VLAN 2:
Switch(config)# ip igmp snooping vlan 2
This example shows how to disable IGMP snooping on VLAN 2:
Switch(config)# no ip igmp snooping vlan 2
You can verify your settings by entering the show ip igmp snooping vlan privileged EXEC command.
Related Commands
Command
Description
ip igmp snooping
Globally enables IGMP snooping. IGMP snooping must be
globally enabled in order to be enabled on a VLAN.
ip igmp snooping vlan
immediate-leave
Enables IGMP Immediate-Leave processing.
ip igmp snooping vlan mrouter
Configures a Layer 2 port as a multicast router port.
ip igmp snooping vlan static
Configures a Layer 2 port as a member of a group.
show ip igmp snooping
Displays the IGMP snooping configuration.
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ip igmp snooping vlan immediate-leave
ip igmp snooping vlan immediate-leave
Use the ip igmp snooping vlan immediate-leave global configuration command to enable Internet
Group Management Protocol (IGMP) Immediate-Leave processing on a VLAN interface. Use the no
form of this command to disable Immediate-Leave processing on the VLAN interface.
ip igmp snooping vlan vlan-id immediate-leave
no ip igmp snooping vlan vlan-id immediate-leave
Syntax Description
vlan-id
Defaults
IGMP Immediate-Leave processing is disabled.
Command Modes
Global configuration
Command History
Release
Modification
12.1(13)AY
This command was introduced.
Usage Guidelines
VLAN ID value. The range is 1 to 4094.
Use the Immediate-Leave feature only when there is only one IP multicast receiver present on every port
in the VLAN. The Immediate-Leave configuration is saved in NVRAM.
The Immediate-Leave feature is supported only with IGMP version 2 hosts.
Examples
This example shows how to enable IGMP Immediate-Leave processing on VLAN 1:
Switch(config)# ip igmp snooping vlan 1 immediate-leave
This example shows how to disable IGMP Immediate-Leave processing on VLAN 1:
Switch(config)# no ip igmp snooping vlan 1 immediate-leave
You can verify your settings by entering the show ip igmp snooping vlan privileged EXEC command.
Related Commands
Command
Description
ip igmp snooping
Enables IGMP snooping.
ip igmp snooping vlan mrouter
Configures a Layer 2 port as a multicast router port.
show ip igmp snooping
Displays the IGMP snooping configuration.
ip igmp snooping vlan static
Configures a Layer 2 port as a member of a group.
show mac address-table multicast Displays the Layer 2 multicast entries for a VLAN.
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ip igmp snooping vlan last-member-query interval
ip igmp snooping vlan last-member-query interval
Use the ip igmp snooping vlan last-member-query-interval global configuration command to globally
enable the Internet Group Management Protocol (IGMP) configurable-leave timer. Use the no form of
this command to return the IGMP configurable-leave timer to the default setting (100 milliseconds).
ip igmp snooping vlan vlan-id last-member-query-interval time
no ip igmp snooping vlan vlan-id last-member-query-interval
Syntax Descriptiont
vlan-id
VLAN ID value. The range is 1 to 4094.
time
Interval time out in seconds. The range is 100 to 5000 milliseconds.
Defaults
The default timeout setting is 100 milliseconds.
Command History
Release
Modification
12.1(22)EA3
This command was introduced.
Usage Guidelines
When IGMP snooping is globally enabled, IGMP snooping is enabled on all the existing VLAN
interfaces. When IGMP snooping is globally disabled, IGMP snooping is disabled on all the existing
VLAN interfaces.
The configuration is saved in NVRAM.
Examples
This example shows how to globally enable the IGMP configurable-leave timer:
Switch(config)# ip igmp snooping vlan vlan-id last-member-query-interval time
To verify your settings, enter the show ip igmp snooping privileged EXEC command.
Related Commands
Command
Description
ip igmp snooping vlan
Enables IGMP snooping on a VLAN interface.
ip igmp snooping vlan immediate-leave
Enables IGMP Immediate-Leave processing.
ip igmp snooping vlan mrouter
Configures a Layer 2 port as a multicast router port.
ip igmp snooping vlan static
Configures a Layer 2 port as a member of a group.
show ip igmp snooping
Displays the IGMP snooping configuration.
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ip igmp snooping vlan mrouter
ip igmp snooping vlan mrouter
Use the ip igmp snooping vlan mrouter global configuration command to add a multicast router port
and to configure the multicast router learning method. Use the no form of this command to remove the
configuration.
ip igmp snooping vlan vlan-id mrouter {interface interface-id | learn {cgmp | pim-dvmrp}}
no ip igmp snooping vlan vlan-id mrouter {interface interface-id | learn {cgmp | pim-dvmrp}}
Syntax Description
vlan vlan-id
Specify the VLAN ID. The range is 1 to 4094.
interface interface-id
Specify the interface of the member port that is configured to a static
router port.
learn {cgmp | pim-dvmrp}
Specify the multicast router learning method. The keywords have
these meanings:
•
cgmp—Set the switch to learn multicast router ports by snooping
on Cisco Group Management Protocol (CGMP) packets.
•
pim-dvmrp—Set the switch to learn multicast router ports by
snooping on IGMP queries and Protocol-Independent
Multicasting-Distance Vector Multicast Routing Protocol
(PIM-DVMRP) packets.
Defaults
The default learning method is pim-dvmrp.
Command Modes
Global configuration
Command History
Release
Modification
12.1(13)AY
This command was introduced.
Usage Guidelines
The CGMP learning method is useful for controlling traffic in Cisco router environments.
The configured learning method is saved in NVRAM.
Static connections to multicast routers are supported only on switch ports.
Examples
This example shows how to configure an interface as a multicast router port:
Switch(config)# ip igmp snooping vlan 1 mrouter interface fastethernet0/1
This example shows how to specify the multicast router learning method as CGMP:
Switch(config)# no ip igmp snooping vlan 1 mrouter learn cgmp
You can verify your settings by entering the show ip igmp snooping mrouter privileged EXEC
command.
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ip igmp snooping vlan mrouter
Related Commands
Command
Description
ip igmp snooping
Globally enables Internet Group Management Protocol (IGMP)
snooping.
ip igmp snooping vlan
Enables IGMP snooping on the VLAN interface.
ip igmp snooping vlan
immediate-leave
Configures IGMP Immediate-Leave processing.
ip igmp snooping vlan static
Configures a Layer 2 port as a member of a group.
show ip igmp snooping mrouter
Displays the statically and dynamically learned multicast router
ports.
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ip igmp snooping vlan static
ip igmp snooping vlan static
Use the ip igmp snooping vlan vlan-id static global configuration command to add a Layer 2 port as a
member of a multicast group. Use the no form of this command to remove the configuration.
ip igmp snooping vlan vlan-id static mac-address interface interface-id
no ip igmp snooping vlan vlan-id static mac-address interface interface-id
Syntax Description
vlan vlan-id
Specify the VLAN ID. The range is 1 to 4094.
static mac-address
Specify the static group MAC address.
interface interface-id
Specify the interface configured to a static router port.
Defaults
None configured.
Command Modes
Global configuration
Command History
Release
Modification
12.1(13)AY
This command was introduced.
Usage Guidelines
The command is used to statically configure the IP multicast group member ports.
The static ports and groups are saved in NVRAM.
Static connections to multicast routers are supported only on switch ports.
Examples
This example shows how to statically configure a host on an interface:
Switch(config)# ip igmp snooping vlan 1 static 0100.5e02.0203 interface fastethernet0/1
Configuring port FastEthernet 0/1 on group 0100.5e02.0203
You can verify your settings by entering the show mac address-table multicast privileged EXEC
command.
Related Commands
Command
Description
ip igmp snooping
Enables Internet Group Management Protocol (IGMP)
snooping.
ip igmp snooping vlan
Enables IGMP snooping on the VLAN interface.
ip igmp snooping vlan
immediate-leave
Configures IGMP Immediate-Leave processing.
ip igmp snooping vlan mrouter
Configures a Layer 2 port as a multicast router port.
show mac address-table multicast
Displays the Layer 2 multicast entries for a VLAN.
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ip ssh
ip ssh
Use the ip ssh global configuration command to configure the switch to run Secure Shell (SSH)
version 1 or SSH version 2. Use the no form of this command to return to the default setting.
ip ssh version [1 | 2]
no ip ssh [1 | 2]
This command is available only when your switch is running the cryptographic (encrypted) software
image.
Syntax Description
1
(Optional) Configure the switch to run SSH version 1 (SSHv1).
2
(Optional) Configure the switch to run SSH version 2 (SSHv1).
Defaults
The default version is the latest SSH version supported by the SSH client.
Command Modes
Global configuration
Command History
Release
Modification
12.1(22)EA2
This command was introduced.
Usage Guidelines
If you do not enter this command or if you do not specify a keyword, the SSH server selects the latest
SSH version supported by the SSH client. For example, if the SSH client supports SSHv1 and SSHv2,
the SSH server selects SSHv2.
The switch supports an SSHv1 or SSHv2 server. It also supports an SSHv1 client. For more information
about the SSH server and the SSH client, see the software configuration guide for this release.
A Rivest, Shamir, and Adelman (RSA) key pair generated by an SSHv1 server can be used by an SSHv2
server, and the reverse.
Examples
This example shows how to configure the switch to run SSH version 2:
Switch(config)# ip ssh version 2
You can verify your settings by entering the show ip ssh or show ssh privileged EXEC command.
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ip ssh
Related Commands
Command
Description
show ip ssh
Displays if the SSH server is enabled and displays the version and configuration
information for the SSH server. For syntax information, select Cisco IOS Release 12.2
Configuration Guides and Command References > Cisco IOS Security Command
Reference, Release 12.2 > Other Security Features > Secure Shell Commands.
show ssh
Displays the status of the SSH server. For syntax information, select Cisco IOS Release
12.2 Configuration Guides and Command References > Cisco IOS Security
Command Reference, Release 12.2 > Other Security Features > Secure Shell
Commands.
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lacp port-priority
lacp port-priority
Use the lacp port-priority interface configuration command to set the port priority for the Link
Aggregration Control Protocol (LACP). Use the no form of this command to return to the default setting.
lacp port-priority priority-value
no lacp port-priority
Syntax Description
priority-value
Defaults
The default priority value is 32768.
Command Modes
Interface configuration
Command History
Release
Modification
12.1(13)AY
This command was introduced.
Usage Guidelines
Port priority for LACP. The range is from 1 to 65535.
This command only takes effect on EtherChannel interfaces that are already configured for LACP.
The lacp port-priority interface configuration command determines which ports are bundled and which
ports are put in hot-standby mode when there are more than eight ports in an LACP channel group.
An LACP channel group can have up to 16 Ethernet ports of the same type. Up to eight ports can be active,
and up to eight ports can be in standby mode.
In port-priority comparisons, a numerically lower value has a higher priority: When there are more than
eight ports in an LACP channel-group, the eight ports with the numerically lowest values (highest
priority values) for LACP port priority are bundled into the channel group, and the lower-priority ports
are put in hot-standby mode. If two or more ports have the same LACP port priority (for example, they
are configured with the default setting of 65535) an internal value for the port number determines the
priority.
Note
The LACP port priorities are only effective if the ports are on the switch that controls the LACP link.
See the lacp system-priority global configuration command for determining which switch controls the
link.
Use the show lacp internal privileged EXEC command to to display LACP port priorities and internal
port number values.
For more information about configuring LACP on physical interfaces, see the “Configuring
EtherChannels” chapter in the software configuration guide for this release.
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lacp port-priority
Examples
This example shows set the port priority for LACP:
Switch(config)# lacp port-priority 32764
You can verify your settings by entering the show etherchannel privileged EXEC command.
Related Commands
Command
Description
lacp system-priority
Globally sets the LACP priority.
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lacp system-priority
lacp system-priority
Use the lacp system-priority global configuration command to set the system priority for Link
Aggregration Control Protocol (LACP). Use the no form of this command to return to the default setting.
lacp system-priority priority-value
no lacp system-priority
Syntax Description
priority-value
Defaults
The default priority value is 32768.
Command Modes
Global configuration
Command History
Release
Modification
12.1(13)AY
This command was introduced.
Usage Guidelines
System priority for LACP. The range is from 1 to 65535.
The lacp system-priority command determines which switch in an LACP link controls port priorities.
An LACP channel group can have up to 16 Ethernet ports of the same type. Up to eight ports can be active,
and up to eight ports can be in standby mode. When there are more than eight ports in an LACP
channel-group, the switch on the controlling end of the link uses port priorities to determine which ports
are bundled into the channel and which ports are put in hot-standby mode. Port priorities on the other
switch (the noncontrolling end of the link) are ignored.
In priority comparisons, numerically lower values have higher priority. Therefore, the system with the
numerically lower value (higher priority value) for LACP system priority becomes the controlling system. If
both switches have the same LACP system priority (for example, they are both configured with the
default setting of 32768), the LACP system ID (the switch MAC address) determines which switch is in
control.
The lacp system-priority command applies to all LACP EtherChannels on the switch.
Use the show etherchannel summary privileged EXEC command to see which ports are in the
hot-standby mode (denoted with an H port-state flag in the output display).
For more information about configuring LACP on physical interfaces, see the “Configuring
Etherchannels” chapter in the software configuration guide for this release.
Examples
This example shows set the system priority for LACP:
Switch(config)# lacp system-priority 32764
You can verify your settings by entering the show lacp sys-id privileged EXEC command.
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lacp system-priority
Related Commands
Command
Description
lacp port-priority
Sets the LACP priority for a specific port.
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mac address-table aging-time
mac address-table aging-time
Use the mac address-table aging-time global configuration command to set the length of time that a
dynamic entry remains in the MAC address table after the entry is used or updated. Use the no form of
this command to return to the default setting. The aging time applies to all VLANs.
mac address-table aging-time [0 | 10–1000000]
no mac address-table aging-time [0 | 10–1000000]
Syntax Description
0
This value disables aging. Static address entries are never aged or removed from
the table.
10–100000
Aging time in seconds. The range is 10 to 1000000 seconds.
Defaults
The default is 300 seconds.
Command Modes
Global configuration
Command History
Release
Modification
12.1(13)AY
This command was introduced.
Usage Guidelines
If hosts do not send continuously, increase the aging time to record the dynamic entries for a longer time.
This reduces the possibility of flooding when the hosts send again.
Examples
This example shows how to set the aging time to 200 seconds:
Switch(config)# mac address-table aging-time 200
This example shows how to disable aging in VLAN 1.
Switch(config)# mac address-table aging-time 0
This example shows how to set aging time to 450 seconds for all VLANs for which the user did not
specify aging time:
Switch(config)# mac address-table aging-time 450
You can verify your settings by entering the show mac address-table privileged EXEC command.
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mac address-table aging-time
Related Commands
Command
Description
clear mac address-table
Deletes dynamic entries from the MAC address table.
show mac address-table
Displays the MAC address table.
show mac address-table aging-time
Displays the MAC address table aging time for all VLANs or
the specified VLAN.
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mac address-table notification
mac address-table notification
Use the mac address-table notification global configuration command to enable the MAC notification
feature and to configure the notification-trap interval or history table. Use the no form of this command
to disable this feature.
mac address-table notification [history-size size | interval interval]
no mac address-table notification [history-size size | interval interval]
Syntax Description
Defaults
history-size size
(Optional) Configures the maximum number of entries in the MAC
notification history table. The range is 0 to 500.
interval interval
(Optional) Configures the notification-trap interval in seconds. The range is
0 to 2147483647. The switch sends the notification traps when this amount
of time has elapsed.
The MAC notification feature is disabled.
The default trap-interval value is 1 second.
The default number of entries in the history table is 1.
Command Modes
Global configuration
Command History
Release
Modification
12.1(13)AY
This command was introduced.
Usage Guidelines
The MAC address notification feature sends Simple Network Management Protocol (SNMP) traps to the
network management system (NMS) whenever a MAC address is added or deleted from the forwarding
tables. MAC notifications are generated only for dynamic and secure MAC addresses. Events are not
generated for self addresses, multicast addresses, or other static addresses.
When you configure the history-size option, the existing MAC address history table is deleted, and a
new table is created.
You enable the MAC address notification feature by using the mac address-table notification
command. You must also enable MAC address notification traps on an interface by using the snmp trap
mac-notification interface configuration command, and configure the switch to send MAC address traps
to the NMS by using the snmp-server enable traps mac-notification global configuration command.
Examples
This example shows how to enable the MAC notification feature:
Switch(config)# mac address-table notification
This example shows how to set the notification-trap interval to 60 seconds:
Switch(config)# mac address-table notification interval 60
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mac address-table notification
This example shows how to set the number of entries in the history table to 32:
Switch(config)# mac address-table notification history-size 32
You can verify your settings by entering the show mac address-table notification privileged EXEC
command.
Related Commands
Command
Description
clear mac address-table notification
Clears the MAC address notification global counters.
show mac address-table notification
Displays the MAC address notification settings for all
interfaces or the specified interface.
snmp-server enable traps
Sends the SNMP MAC notification traps when the
mac-notification keyword is appended.
snmp trap mac-notification
Enables the SNMP MAC notification trap on a specific
interface.
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mac address-table static
mac address-table static
Use the mac address-table static global configuration command to add static addresses to the MAC
address table. Use the no form of this command to remove static entries from the MAC address table.
mac address-table static mac-addr vlan vlan-id interface interface-id
no mac address-table static mac-addr vlan vlan-id [interface interface-id]
Syntax Description
Note
mac-addr
Destination MAC address (unicast or multicast) to add to the address table.
Packets with this destination address received in the specified VLAN are
forwarded to the specified interface.
vlan vlan-id
Specify the VLAN for which the packet with the specified MAC address is
received. The range is 1 to 4094.
interface interface-id
Interface to which the received packet is forwarded. Valid interfaces include
physical ports and port channels.
Though visible in the command-line help string the drop keyword is not supported.
Defaults
None configured.
Command Modes
Global configuration
Command History
Release
Modification
12.1(13)AY
This command was introduced.
Usage Guidelines
Follow these guidelines when using this feature:
A static unicast MAC address can be assigned to one interface.
A static multicast MAC address can be assigned to one interface.
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mac address-table static
Examples
This example shows how to add the static address 0004.5600.67ab to the MAC address table:
Switch(config)# mac address-table static 0004.5600.67ab vlan 1 interface fastethernet0/2
This example shows how to add the static address c2f3.220a.12f4 to the MAC address table. When a
packet is received in VLAN 4 with this MAC address as its destination, the packet is forwarded to the
specified interface.
Switch(config)# mac address-table static c2f3.220a.12f4 vlan 4 interface
gigabitethernet0/1
You can verify your settings by entering the show mac address-table privileged EXEC command.
Related Commands
Command
Description
clear mac address-table
Deletes entries from the MAC address table.
mac address-table aging-time
Sets the length of time that a dynamic entry remains in the MAC
address table after the entry is used or updated.
show mac address-table
Displays the MAC address table.
show mac address-table static
Displays static MAC address table entries only.
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macro apply
macro apply
Use the macro apply interface configuration command to apply a macro to an interface or to apply and
trace a macro configuration on an interface.
macro {apply | trace} macro-name [parameter {value}] [parameter {value}]
[parameter {value}]
Syntax Description
apply
Apply a macro to the specified interface.
trace
Use the trace keyword to apply a macro to an interface and to debug the macro.
macro-name
Specify the name of the macro.
parameter value (Optional) Specify unique parameter values that are specific to the interface. You
can enter up to three keyword-value pairs. Parameter keyword matching is case
sensitive. All matching occurrences of the keyword are replaced with the
corresponding value.
Defaults
This command has no default setting.
Command Modes
Interface configuration
Command History
Release
Modification
12.1(19)EA1
This command was introduced.
12.1(20)EA1
The parameter value keywords were added.
Usage Guidelines
You can use the macro trace macro-name interface configuration command to apply and show the
macros running on an interface or to debug the macro to find any syntax or configuration errors.
If a command fails because of a syntax error or a configuration error when you apply a macro, the macro
continues to apply the remaining commands to the interface.
When creating a macro that requires the assignment of unique values, use the parameter value keywords
to designate values specific to the interface.
Keyword matching is case sensitive. All matching occurrences of the keyword are replaced with the
corresponding value. Any full match of a keyword, even if it is part of a larger string, is considered a
match and is replaced by the corresponding value.
Some macros might contain keywords that require a parameter value. You can use the macro apply
macro-name ? command to view a list of any required values in the macro. If you apply a macro without
entering the keyword values, the commands are invalid and are not applied.
There are Cisco-default Smartports macros embedded in the switch software. You can display these
macros and the commands they contain by using the show parser macro user EXEC command.
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macro apply
Follow these guidelines when you apply a Cisco-default Smartports macro on an interface:
•
Display all macros on the switch by using the show parser macro user EXEC command. Display
the contents of a specific macro by using the show parser macro name macro-name user EXEC
command.
•
Keywords that begin with $ mean that a unique parameter value is required. Append the
Cisco-default macro with the required values by using the parameter value keywords.
The Cisco-default macros use the $ character to help identify required keywords. There is no
restriction on using the $ character to define keywords when you create a macro.
When you apply a macro to an interface, the macro name is automatically added to the interface. You
can display the applied commands and macro names by using the show running-configuration
interface interface-id user EXEC command.
A macro applied to an interface range behaves the same way as a macro applied to a single interface.
When you use an interface range, the macro is applied sequentially to each interface within the range. If
a macro command fails on one interface, it is still applied to the remaining interfaces.
You can delete a macro-applied configuration on an interface by entering the default interface
interface-id interface configuration command.
Examples
After you have created a macro by using the macro name global configuration command, you can apply
it to an interface. This example shows how to apply a user-created macro called duplex to an interface:
Switch(config-if)# macro apply duplex
To debug a macro, use the macro trace interface configuration command to find any syntax or
configuration errors in the macro as it is applied to an interface. This example shows how troubleshoot
the user-created macro called duplex on an interface:
Switch(config-if)# macro trace duplex
Applying command...‘duplex auto’
%Error Unknown error.
Applying command...‘speed nonegotiate’
This example shows how to display the Cisco-default cisco-desktop macro and how to apply the macro
and set the access VLAN ID to 25 on an interface:
Switch# show parser macro cisco-desktop
-------------------------------------------------------------Macro name : cisco-desktop
Macro type : default
# Basic interface - Enable data VLAN only
# Recommended value for access vlan (AVID) should not be 1
switchport access vlan $AVID
switchport mode access
# Enable port security limiting port to a single
# MAC address -- that of desktop
switchport port-security
switchport port-security maximum 1
# Ensure port-security age is greater than one minute
# and use inactivity timer
switchport port-security violation restrict
switchport port-security aging time 2
switchport port-security aging type inactivity
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macro apply
# Configure port as an edge network port
spanning-tree portfast
spanning-tree bpduguard enable
-------------------------------------------------------------Switch#
Switch# configure terminal
Switch(config)# interface fastethernet0/4
Switch(config-if)# macro apply cisco-desktop $AVID 25
Related Commands
Command
Description
macro description
Adds a description about the macros that are applied to an interface.
macro global
Applies a macro on a switch or applies and traces a macro on a switch.
macro global
description
Adds a description about the macros that are applied to the switch.
macro name
Creates a macro.
show parser macro
Displays the macro definition for all macros or for the specified macro.
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macro description
macro description
Use the macro description interface configuration command to enter a description about which macros
are applied to an interface. Use the no form of this command to remove the description.
macro description text
no macro description text
Syntax Description
description text
Defaults
This command has no default setting.
Command Modes
Interface configuration
Command History
Release
Modification
12.1(19)EA1
This command was introduced.
Usage Guidelines
Enter a description about the macros that are applied to the specified interface.
Use the description keyword to associate comment text, or the macro name, with an interface. When
multiple macros are applied on a single interface, the description text will be from the last applied macro.
This example shows how to add a description to an interface:
Switch(config-if)# macro description duplex settings
You can verify your settings by entering the show parser macro description privileged EXEC
command.
Related Commands
Command
Description
macro apply
Applies a macro on an interface or applies and traces a macro on an
interface.
macro global
Applies a macro on a switch or applies and traces a macro on a switch
macro global
description
Adds a description about the macros that are applied to the switch.
macro name
Creates a macro.
show parser macro
Displays the macro definition for all macros or for the specified macro.
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macro global
macro global
Use the macro global global configuration command to apply a macro to a switch or to apply and trace
a macro configuration on a switch.
macro global {apply | trace} macro-name [parameter {value}] [parameter {value}]
[parameter {value}]
Syntax Description
apply
Apply a macro to the switch.
trace
Use the trace keyword to apply a macro to a switch and to debug the macro.
macro-name
Specify the name of the macro.
parameter value (Optional) Specify unique parameter values that are specific to the switch. You can
enter up to three keyword-value pairs. Parameter keyword matching is case
sensitive. All matching occurrences of the keyword are replaced with the
corresponding value.
Defaults
This command has no default setting.
Command Modes
Global configuration
Command History
Release
Modification
12.1(20)EA2
This command was introduced.
Usage Guidelines
You can use the macro trace macro-name global configuration command to apply and to show the
macros running on a switch or to debug the macro to find any syntax or configuration errors.
If a command fails because of a syntax error or a configuration error when you apply a macro, the macro
continues to apply the remaining commands to the switch.
When creating a macro that requires the assignment of unique values, use the parameter value keywords
to designate values specific to the switch.
Keyword matching is case sensitive. All matching occurrences of the keyword are replaced with the
corresponding value. Any full match of a keyword, even if it is part of a larger string, is considered a
match and is replaced by the corresponding value.
Some macros might contain keywords that require a parameter value. You can use the macro global
apply macro-name ? command to display a list of any required values in the macro. If you apply a macro
without entering the keyword values, the commands are invalid and are not applied.
There are Cisco-default Smartports macros embedded in the switch software. You can display these
macros and the commands they contain by using the show parser macro user EXEC command.
Follow these guidelines when you apply a Cisco-default Smartports macro on a switch:
•
Display all macros on the switch by using the show parser macro user EXEC command. Display
the contents of a specific macro by using the show parser macro name macro-name user EXEC
command.
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macro global
•
Keywords that begin with $ mean that a unique parameter value is required. Append the
Cisco-default macro with the required values by using the parameter value keywords.
The Cisco-default macros use the $ character to help identify required keywords. There is no
restriction on using the $ character to define keywords when you create a macro.
When you apply a macro to a switch, the macro name is automatically added to the switch. You can view
the applied commands and macro names by using the show running-configuration user EXEC
command.
You can delete a global macro-applied configuration on a switch only by entering the no version of each
command contained in the macro.
Examples
After you have created a new macro by using the macro name global configuration command, you can
apply it to a switch. This example shows how display the snmp macro and how to apply the macro and
set the host name to test-server and set the IP precedence value to 7:
Switch# show parser macro name snmp
Macro name : snmp
Macro type : customizable
#enable port security, linkup, and linkdown traps
snmp-server enable traps port-security
snmp-server enable traps linkup
snmp-server enable traps linkdown
#set snmp-server host
snmp-server host ADDRESS
#set SNMP trap notifications precedence
snmp-server ip precedence VALUE
-------------------------------------------------Switch(config)# macro global apply snmp ADDRESS test-server VALUE 7
To debug a macro, use the macro global trace global configuration command to find any syntax or
configuration errors in the macro when it is applied to a switch. In this example, the ADDRESS parameter
value was not entered, causing the snmp-server host command to fail while the remainder of the macro
is applied to the switch:
Switch(config)# macro global trace snmp VALUE 7
Applying command...‘snmp-server enable traps port-security’
Applying command...‘snmp-server enable traps linkup’
Applying command...‘snmp-server enable traps linkdown’
Applying command...‘snmp-server host’
%Error Unknown error.
Applying command...‘snmp-server ip precedence 7’
Related Commands
Command
Description
macro apply
Applies a macro on an interface or applies and traces a macro on an
interface.
macro description
Adds a description about the macros that are applied to an interface.
macro global
description
Adds a description about the macros that are applied to the switch.
macro name
Creates a macro.
show parser macro
Displays the macro definition for all macros or for the specified macro.
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macro global description
macro global description
Use the macro global description global configuration command to enter a description about the
macros that are applied to the switch. Use the no form of this command to remove the description.
macro global description text
no macro global description text
Syntax Description
description text
Defaults
This command has no default setting.
Command Modes
Global configuration
Command History
Release
Modification
12.1(20)EA2
This command was introduced.
Usage Guidelines
Enter a description about the macros that are applied to the switch.
Use the description keyword to associate comment text, or the macro name, with a switch. When
multiple macros are applied on a switch, the description text will be from the last applied macro.
This example shows how to add a description to a switch:
Switch(config)# macro global description udld aggressive mode enabled
You can verify your settings by entering the show parser macro description privileged EXEC
command.
Related Commands
Command
Description
macro apply
Applies a macro on an interface or applies and traces a macro on an
interface.
macro description
Adds a description about the macros that are applied to an interface.
macro global
Applies a macro on a switch or applies and traces a macro on a switch.
macro name
Creates a macro.
show parser macro
Displays the macro definition for all macros or for the specified macro.
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macro name
macro name
Use the macro name global configuration command to create a configuration macro. Use the no form
of this command to delete the macro definition.
macro name macro-name
no macro name macro-name
Syntax Description
macro-name
Defaults
This command has no default setting.
Command Modes
Global configuration
Command History
Release
Modification
12.1(19)EA1
This command was introduced.
12.1(20)EA2
The help string # macro keywords was added.
Usage Guidelines
Name of the macro.
A macro can contain up to 3000 characters. Enter one macro command per line. Use the @ character to
end the macro. Use the # character at the beginning of a line to enter comment text within the macro.
You can define mandatory keywords within a macro by using a help string to specify the keywords. Enter
# macro keywords word to define the keywords that are available for use with the macro. You can enter
up to three help string keywords separated by a space. If you enter more than three macro keywords,
only the first three are shown.
Macro names are case sensitive. For example, the commands macro name Sample-Macro and macro
name sample-macro will result in two separate macros.
When creating a macro, do not use the exit or end commands or change the command mode by using
interface interface-id. This could cause commands that follow exit, end, or interface interface-id to
execute in a different command mode.
The no form of this command only deletes the macro definition. It does not affect the configuration of
those interfaces on which the macro is already applied. You can delete a macro-applied configuration
on an interface by entering the default interface interface-id interface configuration command.
Alternatively, you can create an anti-macro for an existing macro that contains the no form of all the
corresponding commands in the original macro. Then apply the anti-macro to the interface.
You can modify a macro by creating a new macro with the same name as the existing macro. The newly
created macro overwrites the existing macro but does not affect the configuration of those interfaces on
which the original macro was applied.
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macro name
Examples
This example shows how to create a macro that defines the duplex mode and speed:
Switch(config)# macro name duplex
Enter macro commands one per line. End with the character ‘@’.
duplex full
speed auto
@
This example shows how create a macro with # macro keywords:
Switch(config)# macro name test
switchport access vlan $VLANID
switchport port-security maximum $MAX
#macro keywords $VLANID $MAX
@
This example shows how to display the mandatory keyword values before you apply the macro to an
interface:
Switch(config)# interface fa1/1
Switch(config-if)# macro apply test ?
WORD keyword to replace with a value e.g
<cr>
$VLANID,$MAX
Switch(config-if)# macro apply test $VLANID ?
WORD Value of first keyword to replace
Switch(config-if)# macro apply test $VLANID 2
WORD keyword to replace with a value e.g $VLANID,$MAX
<cr>
Switch(config-if)# macro apply test $VLANID 2 $MAX ?
WORD Value of second keyword to replace
Related Commands
Command
Description
macro apply
Applies a macro on an interface or applies and traces a macro on an
interface.
macro description
Adds a description about the macros that are applied to an interface.
macro global
Applies a macro on a switch or applies and traces a macro on a switch
macro global description
Adds a description about the macros that are applied to the switch.
show parser macro
Displays the macro definition for all macros or for the specified macro.
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mdix auto
mdix auto
Use the mdix auto interface configuration command to enable the automatic medium-dependent
interface crossover (Auto-MDIX) feature on the interface. When Auto-MDIX is enabled, the interface
automatically detects the required cable connection type (straight-through or crossover) and configures
the connection appropriately. Use the no form of this command to disable Auto-MDIX.
mdix auto
no mdix auto
Syntax Description
This command has no arguments or keywords.
Defaults
Auto-MDIX is disabled.
Command Modes
Interface configuration
Command History
Release
Modification
12.1(19)EA1
This command was introduced.
Usage Guidelines
When you enable Auto-MDIX on an interface, you must also set the speed and duplex on the interface
to auto so that the feature operates correctly.
When Auto-MDIX (along with autonegotiation of speed and duplex) is enabled on one or both of
connected interfaces, link up occurs, even if the cable type (straight-through or crossover) is incorrect.
Auto-MDIX is supported on all 10/100 and 10/100/1000-Mbps interfaces. It is not supported on the
small form-factor pluggable (SFP) module interfaces.
Examples
This example shows how to enable Auto-MDIX on a port:
Switch# configure terminal
Switch(config)# interface fastethernet0/1
Switch(config-if)# speed auto
Switch(config-if)# duplex auto
Switch(config-if)# mdix auto
Switch(config-if)# end
You can verify the operational state of Auto-MDIX on the interface by entering the show controllers
ethernet-controller interface-id phy 32 privileged EXEC command.
Related Commands
Command
Description
show controllers ethernet-controller
interface-id phy 32
Displays general information about internal registers of an
interface, including the operational state of Auto-MDIX.
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mls qos cos
mls qos cos
Use the mls qos cos interface configuration command to define the default class of service (CoS) value
of a port or to assign the default CoS to all incoming packets on the port. Use the no form of this
command to return to the default setting.
mls qos cos {default-cos | override}
no mls qos cos {default-cos | override}
Syntax Description
Defaults
default-cos
Assign a default CoS value to a port. If the port is CoS trusted and packets are
untagged, the default CoS value becomes a CoS value used to select one output
queue to index into the CoS-to-Differentiated Services Code Point (DSCP) map. The
range is 0 to 7.
override
Override the CoS of the incoming packets, and apply the default CoS value on the
port to all incoming packets.
The default CoS value for a port is 0.
CoS override is disabled.
Command Modes
Interface configuration
Command History
Release
Modification
12.1(13)AY
This command was introduced.
Usage Guidelines
You can use the default value to assign CoS and DSCP values to all packets entering a port if the port
has been configured by using the override keyword.
Use the override keyword when all incoming packets on certain ports deserve higher or lower priority
than packets entering from other ports. Even if a port was previously set to trust DSCP or CoS, this
command overrides that trust state, and all the incoming CoS values are assigned the default CoS value
configured with the mls qos cos command. If an incoming packet is tagged, the CoS value of the packet
is modified with the default CoS of the port at the ingress port.
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mls qos cos
Examples
This example shows how to configure the default port CoS to 4:
Switch(config)# interface gigabitethernet0/1
Switch(config-if)# mls qos trust cos
Switch(config-if)# mls qos cos 4
This example shows how to assign all the packets entering a port to the default port CoS value of 4:
Switch(config)# interface gigabitethernet0/1
Switch(config-if)# mls qos cos 4
Switch(config-if)# mls qos cos override
You can verify your settings by entering the show mls qos interface privileged EXEC command.
Related Commands
Command
Description
mls qos trust
Configures the port trust state.
show mls qos interface
Displays quality of service (QoS) information.
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mls qos trust
mls qos trust
Use the mls qos trust interface configuration command to configure the port trust state. Ingress traffic
can be trusted, and classification is performed by examining the class of service (CoS) or the
Differentiated Services Code Point (DSCP) value. Use the no form of this command to return to the
default setting.
mls qos trust [cos [pass-through dscp] | device cisco-phone]
no mls qos trust [cos [pass-through dscp] | device cisco-phone]
Syntax Description
Defaults
cos
(Optional) Classify ingress packets with packet CoS values. For untagged
packets, the port default CoS value is used.
cos pass-through
dscp
(Optional) Configure the interface to classify ingress packets by trusting the
CoS value and to send packets without modifying the DSCP value
(pass-through mode).
device cisco-phone
(Optional) Classify ingress packets by trusting the value sent from the Cisco IP
phone (trusted boundary).
The port is not trusted.
Pass-through mode is disabled.
Trusted boundary is disabled.
Command Modes
Interface configuration
Command History
Release
Modification
12.1(13)AY
This command was introduced.
Usage Guidelines
Packets entering a quality of service (QoS) domain are classified at the edge of the QoS domain. When
the packets are classified at the edge, the switch port within the QoS domain can be configured to one
of the trusted states because there is no need to classify the packets at every switch within the domain.
Use this command to specify whether the port is trusted and which fields of the packet to use to classify
traffic.
If CoS is trusted, DSCP is modified according to the COS-to-DSCP map value.
To return a port to the untrusted state, use the no mls qos trust interface configuration command.
The trusted boundary feature prevents security problems if users disconnect their PCs from networked
Cisco IP phones and connect them into the switch port to take advantage of trusted CoS settings. You
must globally enable the Cisco Discovery Protocol (CDP) on both the switch and on the interface
connected to the IP phone. If the phone is not detected, trusted boundary disables the trust setting on the
switch port and prevents misuse of a high-priority queue.
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mls qos trust
If trusted boundary is enabled and the no mls qos trust command is entered, the port returns to the
untrusted state and cannot be configured to trust if it is connected to a Cisco IP phone.
To disable trusted boundary, use the no mls qos trust device interface configuration command.
Pass-through mode uses the CoS value of incoming packets without modifying the DSCP value and
sends the packets from one of the four egress queues. The switch assigns a CoS value of 0 to all incoming
packets without modifying the packets. It offers best-effort service to each packet regardless of the
packet contents or size and sends it from a single egress queue.
You can enable pass-through mode by using the mls qos trust cos pass-through dscp interface
configuration command. To disable pass-through mode, use the no mls qos trust cos pass-through
interface configuration command.
Examples
This example shows how to configure a port to be a CoS-trusted port:
Switch(config)# interface gigabitethernet0/17
Switch(config-if)# mls qos trust cos
This example shows how to specify that the Cisco IP phone is a trusted device:
Switch(config)# interface fastethernet0/1
Switch(config-if)# mls qos trust device cisco-phone
This example shows how to configure the interface to trust the CoS of incoming packets and to send
them without modifying the DSCP field:
Switch(config)# interface fastethernet0/1
Switch(config-if)# mls qos trust cos pass-through dscp
You can verify your settings by entering the show mls qos interface privileged EXEC command.
Related Commands
Command
Description
show mls qos interface
Displays QoS information.
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monitor session
monitor session
Use the monitor session global configuration command to start a new Switched Port Analyzer (SPAN)
session. Use the no form of this command to remove the SPAN session or to remove source or
destination interfaces from the SPAN session.
monitor session session_number {destination {interface interface-id [, | -] [encapsulation
{dot1q}] [ingress vlan vlan id] | {source {interface interface-id [, | -] [both | rx | tx]}}
no monitor session session_number {destination {interface interface-id [, | -] [encapsulation
{dot1q}] [ingress vlan vlan id] | {source {interface interface-id [, | -] [both | rx | tx]}}
no monitor session {session_number | all | local}
Syntax Description
Note
Defaults
session_number
Specify the session number identified with the SPAN session.
destination interface
interface-id
Specify the destination interface for a local SPAN session. Valid interfaces
are physical ports.
encapsulation
(Optional) Specify the encapsulation header for outgoing packets through a
destination port. If encapsulation type is not specified, packets are sent in
native form. To reconfigure a destination port in native form, enter the
command without the encapsulation keyword.
dot1q
Specify the encapsulation type as IEEE 802.1Q.
ingress vlan vlan id
(Optional) Specify whether forwarding is enabled for ingress traffic on the
destination port. If encapsulation type is not specified, packets are sent in
native form.
source interface
interface-id
Specify the SPAN source interface type, slot, and port number. Valid
interfaces include physical ports and port channels.
,
(Optional) Specify a series of interfaces, or separate a range of interfaces
from a previous range. Enter a space after the comma.
-
(Optional) Specify a range of interfaces. Enter a space before and after the
hyphen.
both, rx, tx
(Optional) Specify the traffic direction for each source.
all, local, remote
Specify all or local to clear all SPAN sessions or all local SPAN sessions.
Both of these keywords have the same effect.
Though visible in the command-line help strings, the destination remote vlan, reflector-port, and
source remote vlan keywords are not supported. The no monitor session remote command is also
visible, but not supported.
On a source interface, the default is to monitor both received and transmitted traffic.
If encapsulation type is not specified on a destination port, packets are sent in native form with no
encapsulation.
Ingress forwarding is disabled on SPAN destination ports.
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monitor session
Command Modes
Global configuration
Command History
Release
Modification
12.1(13)AY
This command was introduced.
Usage Guidelines
Traffic that enters or leaves source ports can be monitored by using SPAN. Traffic routed to source ports
cannot be monitored.
You can configure (and store in NVRAM) one local SPAN session on a switch. The SPAN source (rx,
tx, both) is limited to one active session.
You can monitor traffic on a single port or on a series or range of ports. You select a series or range of
interfaces by using the [, | -] options.
If you specify a series of interfaces, you must enter a space before and after the comma. If you specify
a range of interfaces, you must enter a space before and after the hyphen (-).
EtherChannel ports cannot be configured as SPAN destination ports. A physical port that is a member
of an EtherChannel group can be used as a source or destination port. It cannot participate in the
EtherChannel group while it is configured for SPAN.
A port used as a destination port cannot be a SPAN source port, nor can a port be a destination port for
more than one session at a time.
You can enable IEEE 802.1x authentication on a SPAN source port but not on a SPAN destination port.
If ingress forwarding is enabled, you can use the SPAN destination port to inject traffic from a network
security device. For example, if you connect a Cisco Intrusion Detection System (IDS) Sensor Appliance
to a destination port, the IDS device can send TCP Reset packets to close down the TCP session of a
suspected attacker.
Examples
This example shows how to create SPAN session 1 to monitor both sent and received traffic on source
port 1 on destination port 8:
Switch(config)# monitor session 1 source interface fastethernet0/1 both
Switch(config)# monitor session 1 destination interface fastethernet0/8
This example shows how to delete a destination port from an existing SPAN session:
Switch(config)# no monitor session 2 destination fastethernet0/4
This example shows how to configure the destination port for ingress traffic on VLAN 5 by using a
security device that does not support IEEE 802.1Q encapsulation:
Switch(config)# monitor session 1 destination interface fastethernet0/5 ingress vlan 5
This example shows how to configure the destination port for ingress traffic on VLAN 5 by using a
security device that supports IEEE 802.1Q encapsulation:
Switch(config)# monitor session 1 destination interface fastethernet0/5 encapsulation
dot1q ingress vlan 5
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monitor session
This example shows how to disable ingress traffic forwarding on the destination port:
Switch(config)# monitor session 1 destination interface fastethernet0/5 encapsulation
dot1q
You can verify your settings by entering the show monitor privileged EXEC command.
Related Commands
Command
Description
show monitor
Displays SPAN and RSPAN session information.
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mvr
mvr
Use the mvr global configuration command without keywords to enable the multicast VLAN
registration (MVR) feature on the switch. Use the no form of this command to disable MVR and its
options. Use the command with keywords to set the MVR mode for a switch, to configure the MVR IP
multicast address, to set the maximum time to wait for a query reply before removing a port from group
membership, and to specify the MVR multicast VLAN. Use the no form of this command to return to
the default settings.
mvr [group ip-address [count] | mode {compatible | dynamic} | querytime value | vlan vlan-id]
no mvr [group ip-address | mode {compatible | dynamic} | querytime value | vlan vlan-id]
Syntax Description
group ip-address
(Optional) Statically configure an MVR group IP multicast address on the
switch.
Use the no form of this command to remove a statically configured IP
multicast address or contiguous addresses or, when no IP address is
entered, to remove all statically configured MVR IP multicast addresses.
count
(Optional) Configure multiple contiguous MVR group addresses. The
range is 1 to 256. The default is 1.
mode
(Optional) Specify the MVR mode of operation.
The default is compatible mode.
compatible
Set MVR mode to provide compatibility with Catalyst 2900 XL
and 3500 XL switches. This mode does not allow dynamic membership
joins on source ports.
dynamic
Set MVR mode to allow dynamic MVR membership on source ports.
querytime value
(Optional) Set the maximum time to wait for Internet Group Management
Protocol (IGMP) report memberships on a receiver port. This time applies
only to receiver-port leave processing. When an IGMP query is sent from
a receiver port, the switch waits for the default or configured MVR query
time for an IGMP group membership report before removing the port from
multicast group membership.
The value is the response time in units of tenths of a second. The default
is 5 tenths or one-half second. The range is 1 to 100 tenths of a second.
Use the no form of the command to return to the default setting.
vlan vlan-id
(Optional) Specify the VLAN on which MVR multicast data is expected to
be received. This is also the VLAN to which all the source ports belong.
The default is VLAN. The range is 1 to 4094.
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mvr
Defaults
MVR is disabled.
The default MVR mode is compatible mode.
No IP multicast addresses are configured on the switch.
The default group IP address count is 0.
The default query response time is 5 tenths of or one-half second.
The default multicast VLAN for MVR is VLAN 1.
Command Modes
Global configuration
Command History
Release
Modification
12.1(13)AY
This command was introduced.
Usage Guidelines
A maximum of 256 MVR multicast groups can be configured on a switch.
Use the mvr group command to statically configure all the IP multicast addresses that will take part in
MVR. Any multicast data sent to a configured multicast address is sent to all the source ports on the
switch and to all receiver ports registered to receive data on that IP multicast address.
Note
The mvr group command prevents adding IP multicast addresses that cause address aliasing between
MVR multicast groups or with the reserved IP multicast addresses (in the range 224.0.0.xx). Each IP
multicast address translates to a multicast 48-bit MAC address. If the IP address being configured
translates (aliases) to the same 48-bit MAC address as a previously configured IP multicast address or
the reserved MAC multicast addresses, the command fails.
The mvr querytime parameter applies only to receiver ports.
The mvr group and mvr vlan commands only apply to ports configured as receiver ports.
If the switch MVR is interoperating with Catalyst 2900 XL or Catalyst 3500 XL switches, set the
multicast mode to compatible.
When in compatible mode, MVR does not support IGMP dynamic joins on MVR source ports.
Examples
This example shows how to enable MVR:
Switch(config)# mvr
This example shows how to configure 228.1.23.4 as an IP multicast address:
Switch(config)# mvr group 228.1.23.4
This command fails because of address aliasing:
Switch(config)# mvr group 230.1.23.4
Cannot add this IP address - aliases with previously configured IP address 228.1.23.4.
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mvr
This example shows how to configure ten contiguous IP multicast groups with multicast addresses from
228.1.23.1 to 228.1.23.10:
Switch(config)# mvr group 228.1.23.1 10
This example shows how to set the maximum query response time as 1 second (10 tenths):
Switch(config)# mvr querytime 10
This example shows how to set VLAN 2 as the multicast VLAN:
Switch(config)# mvr vlan 2
Use the show mvr members privileged EXEC command to display the IP multicast group addresses
configured on the switch.
You can verify your settings by entering the show mvr privileged EXEC command.
Related Commands
Command
Description
mvr immediate
Enables the Immediate-Leave feature on an interface.
mvr type
Configures a port as a receiver or source port.
mvr vlan group
Configures a receiver port as a member of an MVR group.
show mvr
Displays MVR global parameters or port parameters.
show mvr interface
Displays the configured MVR interfaces with their type,
status, and Immediate-Leave configuration.
show mvr interface interface-id member Displays all MVR groups of which the interface is a
member.
show mvr members
Displays all ports that are members of an MVR multicast
group; if the group has no members, its status is shown as
Inactive.
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mvr immediate
mvr immediate
Use the mvr immediate interface configuration command to enable the Immediate-Leave feature on an
interface. Use the no form of this command to disable the feature on the interface.
mvr immediate
no mvr immediate
Syntax Description
This command has no arguments or keywords.
Defaults
The Immediate-Leave feature is disabled.
Command Modes
Interface configuration
Command History
Release
Modification
12.1(13)AY
This command was introduced.
Usage Guidelines
The Immediate-Leave feature applies only to receiver ports. When the Immediate-Leave feature is
enabled, a receiver port leaves a multicast group more quickly. When the switch receives an Internet
Group Management Protocol (IGMP) leave message from a group on a receiver port, it sends an IGMP
query on that port and waits for IGMP group membership reports. If no reports are received in a
configured time period, the receiver port is removed from multicast group membership. With the
Immediate-Leave feature, an IGMP query is not sent from the receiver port on which the IGMP leave
was received. As soon as the leave message is received, the receiver port is removed from multicast
group membership, thus speeding up leave latency.
The Immediate-Leave feature should only be enabled on receiver ports to which a single receiver device
is connected.
Examples
This example shows how to enable the Immediate-Leave feature on a port:
Switch(config-if)# mvr immediate
You can verify your settings by entering the show mvr privileged EXEC command.
Related Commands
Command
Description
mvr
Enables multicast VLAN registration (MVR).
mvr type
Configures a port as a receiver or source port.
mvr vlan group
Configures a receiver port as a member of an MVR group.
show mvr
Displays MVR global parameters or port parameters.
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mvr type
mvr type
Use the mvr type interface configuration command to configure a port as a multicast VLAN registration
(MVR) receiver or source port. Use the no form of this command to return to the default setting.
mvr type {receiver | source}
no mvr type {receiver | source}
Syntax Description
receiver
Port that receives multicast data and cannot send multicast data to multicast
groups.
source
Port that can send and receive multicast data to multicast groups.
Defaults
A port is configured as neither receiver nor source.
Command Modes
Interface configuration
Command History
Release
Modification
12.1(13)AY
This command was introduced.
Usage Guidelines
Configure a port as a source port if that port should be able to both send and receive multicast data bound
for the configured multicast groups. Multicast data is received on all ports configured as source ports.
Configure a port as a receiver port if that port should only be able to receive multicast data and should
not be able to send multicast data to the configured multicast groups. None of the receiver ports receives
multicast data unless it sends an Internet Group Management Protocol (IGMP) group join message for
a multicast group.
A receiver port configured as a static member of a multicast group remains a member until statically
removed from membership.
Note
All receiver ports must not be trunk ports and must not belong to the MVR source VLAN.
A port that is not taking part in MVR should not be configured as an MVR receiver port or source port.
This port is a normal switch port and is able to send and receive multicast data with normal switch
behavior.
Examples
This example shows how to configure a port as an MVR receiver port:
Switch(config)# interface fastethernet0/1
Switch(config-if)# mvr type receiver
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mvr type
This example shows how to configure a port as an MVR source port:
Switch(config)# interface fastethernet0/3
Switch(config-if)# mvr type source
You can verify your settings by entering the show mvr privileged EXEC command.
Related Commands
Command
Description
mvr
Enables MVR.
mvr immediate
Enables the Immediate-Leave feature on an interface.
mvr vlan group
Configures a receiver port as a member of an MVR group.
show mvr
Displays MVR global parameters or port parameters.
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mvr vlan group
mvr vlan group
Use the mvr vlan group interface configuration command to statically configure a receiver port as a
member of a multicast VLAN registration (MVR) group in a particular VLAN. Use the no form of this
command to remove the port from the MVR group.
mvr vlan vlan-id group ip-address
no mvr vlan vlan-id group ip-address
Syntax Description
vlan vlan-id
Specify the VLAN ID to which the receiver port belongs. The range is 1 to
4094.
group ip-address
Specify the MVR group address for which the interface is statically
configured to be a member.
Defaults
A port is configured as neither receiver nor source.
Command Modes
Interface configuration
Command History
Release
Modification
12.1(13)AY
This command was introduced.
Usage Guidelines
The receiver port belongs to a multicast VLAN.
The group address is configured as a MVR group address.
Examples
This example shows how to configure a static MVR group entry on port 1 in VLAN 10:
Switch(config)# interface fastethernet0/1
Switch(config-if)# mvr vlan 10 group 225.1.1.1
This example shows how to remove an entry on port 3 in VLAN 10:
Switch(config)# interface fastethernet0/3
Switch(config-if)# no mvr 10 group 255.1.1.2
You can verify your settings by entering the show mvr privileged EXEC command.
Related Commands
Command
Description
mvr
Enables MVR.
mvr immediate
Enables the Immediate-Leave feature on an interface.
mvr type
Configures a port as a receiver or source port.
show mvr
Displays MVR global parameters or port parameters.
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pagp learn-method
pagp learn-method
Use the pagp learn-method interface configuration command to set the source-address learning method
of incoming packets received from an EtherChannel port. Use the no form of this command to return to
the default setting.
pagp learn-method aggregation-port
no pagp learn-method
Syntax Description
Note
aggregation-port
Specify address learning on the logical port-channel. The switch transmits
packets to the source by using any of the interfaces in the EtherChannel. This
setting is the default. With aggregate-port learning, it is not important on
which physical port the packet arrives.
Though visible in the command-line help strings, the physical-port keyword is not supported.
Defaults
The default is aggregation-port (logical port channel).
Command Modes
Interface configuration
Command History
Release
Modification
12.1(13)AY
This command was introduced.
Usage Guidelines
Note
The switch supports address learning only on aggregate ports even though the physical-port keyword
is provided in the command-line interface (CLI). The pagp learn-method and the pagp port-priority
interface configuration commands have no affect on the switch hardware.
You should not set the learn method to physical-port because the switch is an aggregate-learning
device.
If the link partner to the switch is a physical learner that has the channel-group interface configuration
command set to auto or desirable, the switch automatically uses the load-distribution method based on
the source-MAC address, regardless of the configured load-distribution method.
If the link partner to the switch is a physical learner that has the channel-group interface configuration
command set to on, set the load-distribution method based on the source-MAC address by using the
port-channel load-balance src-mac global configuration command.
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pagp learn-method
Examples
This example shows how to set the learning method to aggregation-port (the default):
Switch(config-if)# pagp learn-method aggregation-port
You can verify your settings by entering the show running-config or show pagp channel-group-number
internal privileged EXEC command.
Related Commands
Command
Description
channel-group
Assigns an Ethernet interface to an EtherChannel group.
pagp port-priority
Selects an interface through which all Port Aggregation Protocol (PAgP)
traffic through the EtherChannel is sent.
show pagp
Displays PAgP channel-group information.
show running-config
Displays the configuration information running on the switch. For syntax
information, select Cisco IOS Configuration Fundamentals Command
Reference for Release 12.1 > Cisco IOS File Management Commands >
Configuration File Commands.
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pagp port-priority
pagp port-priority
You do not need to enter this command. It is documented for informational purposes only. Though
visible in the command-line help strings, the switch does not support the pagp port-priority command.
Use the pagp port-priority interface configuration command to select an interface through which all
Port Aggregation Protocol (PAgP) traffic through the EtherChannel is sent. Use the no form of this
command to return to the default setting.
pagp port-priority priority
no pagp port-priority
Syntax Description
priority
Defaults
The default value is 128.
Command Modes
Interface configuration
Command History
Release
Modification
12.1(13)AY
This command was introduced.
Usage Guidelines
Note
Related Commands
A priority number ranging from 0 to 255.
The pagp learn-method and the pagp port-priority interface configuration commands have no affect
on the switch hardware.
You should not change the port priority because the switch does not support this command.
Command
Description
pagp learn-method
Sets the source-address learning method of incoming packets received from
an EtherChannel port.
show pagp
Displays PAgP channel-group information.
show running-config
Displays the configuration information running on the switch. For syntax
information, select Cisco IOS Configuration Fundamentals Command
Reference for Release 12.1 > Cisco IOS File Management Commands >
Configuration File Commands.
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port-channel load-balance
port-channel load-balance
Use the port-channel load-balance global configuration command to set the load-distribution method
among the ports in the EtherChannel. Use the no form of this command to return to the default setting.
port-channel load-balance method
no port-channel load-balance
Syntax Description
method
Load distribution method.
These are the method values:
•
src-mac—Load distribution using the source-MAC address.
•
dst-mac—Load distribution using the destination-MAC address.
•
Defaults
The default method is src-mac.
Command Modes
Global configuration
Command History
Release
Modification
12.1(13)AY
This command was introduced.
Usage Guidelines
If the link partner to the switch is a physical learner that has the channel-group interface configuration
command set to auto or desirable, the switch automatically uses the load-distribution method based on
the source-MAC address, regardless of the configured load-distribution method.
If the link partner to the switch is a physical learner that has the channel-group interface configuration
command set to on, set the load-distribution method based on the source-MAC address by using the
port-channel load-balance src-mac global configuration command.
Examples
This example shows how to set the load-distribution method to dst-mac:
Switch(config)# port-channel load-balance dst-mac
You can verify your settings by entering the show etherchannel privileged EXEC command.
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port-channel load-balance
Related Commands
Command
Description
channel-group
Assigns an Ethernet interface to an EtherChannel group.
interface port-channel
Access or creates the port channel.
show etherchannel
Displays EtherChannel information for a channel.
show running-config
Displays the configuration information running on the switch. For syntax
information, select Cisco IOS Configuration Fundamentals Command
Reference for Release 12.1 > Cisco IOS File Management Commands >
Configuration File Commands.
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rcommand
rcommand
Use the rcommand user EXEC command to start a Telnet session and to enter commands from a cluster
command switch for a member switch. To end the session, enter the exit command.
rcommand {n | commander | mac-address hw-addr}
Syntax Description
n
Provide the number that identifies a cluster member. The range is 0 to 15.
commander
Provide access to the command switch from a member switch.
mac-address hw-addr
MAC address of the member switch.
Command Modes
User EXEC
Command History
Release
Modification
12.1(13)AY
This command was introduced.
Usage Guidelines
If the switch is the cluster command switch but the member switch n does not exist, an error message
appears. To obtain the switch number, enter the show cluster members privileged EXEC command on
the command switch.
You can use this command to access a member switch from the command-switch prompt or to access a
command switch from the member-switch prompt.
For Catalyst 2900 XL, 2940, 2950, 2955, 3500 XL, and 3550 switches, the Telnet session accesses the
member-switch command-line interface (CLI) at the same privilege level as on the command switch. For
example, if you enter this command at user level on the cluster command switch, the member switch is
accessed at user level. If you use this command on the command switch at privileged level, the command
accesses the remote device at privileged level. If you use an intermediate enable-level lower than
privileged, access to the member switch is at user level.
For Catalyst 1900 and 2820 switches running standard edition software, the Telnet session accesses the
menu console (the menu-driven interface) if the command switch is at privilege level 15. If the command
switch is at privilege level 1, you are prompted for the password before being able to access the menu
console. Command switch privilege levels map to the member switches running standard edition
software as follows:
•
If the command switch privilege level is from 1 to 14, the member switch is accessed at privilege
level 1.
•
If the command switch privilege level is 15, the member switch is accessed at privilege level 15.
This command does not work if the vty lines of the command switch have access-class configurations.
You are not prompted for a password because the member switches inherited the password of the
command switch when they joined the cluster.
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rcommand
Examples
This example shows how to start a session with member 3. All subsequent commands are directed to
member 3 until you enter the exit command or close the session.
Switch# rcommand 3
Switch-3# show version
Cisco Internet Operating System Software ...
...
Switch-3# exit
Switch#
Related Commands
Command
Description
show cluster members
Displays information about the cluster members.
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rmon collection stats
rmon collection stats
Use the rmon collection stats interface configuration command to collect Ethernet group statistics. The
Ethernet group statistics include utilization statistics about broadcast and multicast packets and error
statistics about Cyclic Redundancy Check (CRC) alignment errors and collisions. Use the no form of
this command to return to the default setting.
rmon collection stats index [owner name]
no rmon collection stats index [owner name]
Syntax Description
index
Remote Network Monitoring (RMON) collection control index. The range is
1 to 65535.
owner name
(Optional) Owner of the RMON collection.
Defaults
The RMON statistics collection is disabled.
Command Modes
Interface configuration
Command History
Release
Modification
12.1(13)AY
This command was introduced.
Usage Guidelines
The RMON statistics collection command is based on hardware counters.
Examples
This example shows how to collect RMON statistics for the owner root on an interface:
Switch(config)# interface fastethernet0/1
Switch(config-if)# rmon collection stats 2 owner root
You can verify your settings by entering the show rmon statistics privileged EXEC command.
Related Commands
Command
Description
show rmon statistics
Displays RMON statistics.
For more information on this command, select Cisco IOS
Configuration Fundamentals Command Reference for
Release 12.1 > Cisco IOS System Management Commands >
RMON Commands.
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service password-recovery
service password-recovery
Use the service password-recovery global configuration command to enable the password-recovery
mechanism (the default). An end user with physical access to the switch can hold down the Mode button
and interrupt the boot process while the switch is powering up and can assign a new password. Use the
no form of this command to disable part of the password-recovery functionality. When the
password-recovery mechanism is disabled, interrupting the boot process is allowed only if the user
agrees to set the system back to the default configuration.
service password-recovery
no service password-recovery
Syntax Description
This command has no arguments or keywords.
Defaults
The password-recovery mechanism is enabled.
Command Modes
Global configuration
Command History
Release
Modification
12.1(13)AY
This command was introduced.
Usage Guidelines
As a system administrator, you can use the no service password-recovery command to disable some of
the functionality of the password recovery feature by allowing an end user to reset a password only by
agreeing to return to the default configuration.
To use the password-recovery procedure, a user with physical access to the switch holds down the Mode
button while the unit powers up and for a second or two after the LED above port 1X goes off. When the
button is released, the system continues with initialization. If the password-recovery mechanism is disabled,
this message appears:
The password-recovery mechanism has been triggered, but
is currently disabled. Access to the boot loader prompt
through the password-recovery mechanism is disallowed at
this point. However, if you agree to let the system be
reset back to the default system configuration, access
to the boot loader prompt can still be allowed.
Would you like to reset the system back to the default configuration (y/n)?
If the user chooses not to reset the system back to the default configuration, the normal boot process
continues, as if the Mode button had not been pressed. If you choose to reset the system back to the
default configuration, the configuration file in flash memory is deleted and the VLAN database file,
flash:vlan.dat (if present) is deleted.
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service password-recovery
Note
If you use the no service password-recovery command to control end user access to passwords, we
recommend that you save a copy of the config file in a location away from the switch in case the end
user uses the password recovery procedure and sets the system back to default values. Do not keep a
backup copy of the config file on the switch.
If the switch is operating in VTP transparent mode, we recommend that you also save a copy of the
vlan.dat file in a location away from the switch.
You can verify if password recovery is enabled or disabled by entering the show version privileged
EXEC command.
Examples
This example shows how to disable password recovery on a switch so that a user can only reset a
password by agreeing to return to the default configuration:
Switch(config)# no service-password recovery
Switch(config)# exit
Related Commands
Command
Description
show version
Displays version information for the hardware and firmware.
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setup express
setup express
Use the setup express global configuration command to enable Express Setup mode on the switch. This
is the default setting. Use the no form of this command to disable Express Setup mode.
setup express
no setup express
This command is available only on Catalyst 2950 switches.
Syntax Description
This command has no arguments or keywords.
Defaults
Express Setup is enabled.
Command Modes
Global configuration
Command History
Release
Modification
12.1(13)AY
This command was introduced.
Usage Guidelines
When Express Setup is enabled on a new (unconfigured) switch, pressing the Mode button for 2 seconds
activates Express Setup. You can access the switch through an Ethernet port by using the IP address
10.0.0.1 and then can configure the switch with the web-based Express Setup program or the
command-line interface (CLI)-based setup program.
When you press the Mode button for 2 seconds on a configured switch, the mode LEDs start blinking.
If you press the Mode button for a total of 10 seconds, the switch configuration is deleted, and the switch
reboots. The switch can then be configured like a new switch, either through the web-based Express
Setup program or the CLI-based setup program.
Note
As soon as you make any change to the switch configuration (including entering no at the beginning of
the CLI-based setup program), configuration by Express Setup is no longer available. You can only run
Express Setup again by pressing the Mode button for 10 seconds. This deletes the switch configuration
and reboots the switch.
If Express Setup is active on the switch, entering the write memory or copy running-configuration
startup-configuration privileged EXEC commands deactivates Express Setup. The IP address 10.0.0.1
is no longer valid on the switch, and your connection using this IP address ends.
The primary purpose of the no setup express command is to prevent someone from deleting the switch
configuration by pressing the Mode button for 10 seconds.
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setup express
Examples
This example shows how to enable Express Setup mode:
Switch(config)# setup express
You can verify that Express Setup mode is enabled by pressing the Mode button:
Caution
•
On an unconfigured switch, the mode LEDs begin blinking green after 2 seconds.
•
On a configured switch, the mode LEDs turn solid green after a total of 10 seconds.
If you hold the Mode button down for a total of 10 seconds, the configuration is deleted, and the switch
reboots.
This example shows how to disable Express Setup mode:
Switch(config)# no setup express
You can verify that Express Setup mode is disabled by pressing the Mode button. The mode LEDs only
turn solid green or begin blinking green if Express Setup mode is enabled on the switch.
Related Commands
Command
Description
show setup express
Displays if Express Setup mode is active on the switch.
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show boot
show boot
Use the show boot privileged EXEC command to display the settings of the boot environment variables.
show boot [ | {begin | exclude | include} expression]
Syntax Description
| begin
(Optional) Display begins with the line that matches the expression.
| exclude
(Optional) Display excludes lines that match the expression.
| include
(Optional) Display includes lines that match the specified expression.
expression
Expression in the output to use as a reference point.
Command Modes
Privileged EXEC
Command History
Release
Modification
12.1(13)AY
This command was introduced.
12.1(22)EA7
Updated output to display Timeout for Config Download and Config
Download by way of DHCP.
Usage Guidelines
Note
Examples
Expressions are case sensitive. For example, if you enter | exclude output, the lines that contain output
do not appear, but the lines that contain Output appear.
Only the software can read and write a copy of the private configuration file. You cannot read, write,
delete, or display a copy of this file.
This is an example of output from the show boot command. Table 2-3 describes each field in the output.
Switch# show boot
BOOT path-list:
flash:boot
Config file:
flash:config.text
Private Config file: flash:private-config.text
Enable Break:
no
Manual Boot:
yes
HELPER path-list:
NVRAM/Config file
buffer size:
32768
Timeout for Config
Download: 200 seconds
Config Download
via DHCP: enabled (next boot: enabled)
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show boot
Table 2-3
show boot Field Descriptions
Field
Description
BOOT path-list
Displays a semicolon-separated list of executable files to load
and to execute when automatically booting.
If the BOOT environment variable is not set, the system attempts
to load and execute the first executable image it can find by
using a recursive, depth-first search through the flash file
system. In a depth-first search of a directory, each encountered
subdirectory is completely searched before continuing the
search in the original directory.
If the BOOT variable is set but the specified images cannot be
loaded, the system attempts to boot the first bootable file that it
can find in the flash file system.
Related Commands
Config file
Displays the filename that the software uses to read and write a
nonvolatile copy of the system configuration.
Private Config file
Displays the filename that the software uses to read and write a
nonvolatile copy of the private configuration.
Enable Break
Displays whether a break during booting is enabled or disabled.
If it is set to yes, on, or 1, you can interrupt the automatic boot
process by pressing the Break key on the console after the flash
file system is initialized.
Manual Boot
Displays whether the switch automatically or manually boots. If
it is set to no or 0, the boot loader attempts to automatically boot
the system. If it is set to anything else, you must manually boot
the switch from the boot loader mode.
Helper path-list
Displays a semicolon-separated list of loadable files to
dynamically load during the boot loader initialization. Helper
files extend or patch the functionality of the boot loader.
NVRAM/Config file buffer size
Displays the buffer size that the software uses to hold a copy of
the configuration file in memory. The configuration file cannot
be larger than the buffer size allocation.
Timeout for Config Download
Displays the retry timeout, the time between boot host DHCP
re-tries.
Config Download via DHCP
Displays whether boot host DHCP feature is enabled for this
boot and the subsequent boot.
Command
Description
boot private-config-file
Specifies the filename that the software uses to read and write a nonvolatile
copy of the private configuration.
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show cluster
show cluster
Use the show cluster privileged EXEC command to display the cluster status and a summary of the
cluster to which the switch belongs. This command can be entered on command and member switches.
show cluster [ | {begin | exclude | include} expression]
Syntax Description
| begin
(Optional) Display begins with the line that matches the expression.
| exclude
(Optional) Display excludes lines that match the expression.
| include
(Optional) Display includes lines that match the specified expression.
expression
Expression in the output to use as a reference point.
Command Modes
Privileged EXEC
Command History
Release
Modification
12.1(13)AY
This command was introduced.
Usage Guidelines
On a member switch, this command displays the identity of the command switch, the switch member
number, and the state of its connectivity with the command switch.
On a command switch, this command displays the cluster name and the total number of members. It also
shows the cluster status and time since the status changed. If redundancy is enabled, it displays the
primary and secondary command-switch information.
If you enter this command on a switch that is not a cluster member, the error message Not a management
cluster member appears.
Expressions are case sensitive. For example, if you enter | exclude output, the lines that contain output
do not appear, but the lines that contain Output appear.
Examples
This is an example of output when this command is entered on the active command switch:
Switch# show cluster
Command switch for cluster "Switch1"
Total number of members:
Status:
Time since last status change:
Redundancy:
Standby command switch:
Standby Group:
Standby Group Number:
Heartbeat interval:
Heartbeat hold-time:
Extended discovery hop count:
7
1 members are unreachable
0 days, 0 hours, 2 minutes
Enabled
Member 1
Switch1_standby
110
8
80
3
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show cluster
This is an example of output when this command is entered on a member switch:
Switch# show cluster
Member switch for cluster "commander"
Member number:
Management IP address:
Command switch mac address:
Heartbeat interval:
Heartbeat hold-time:
3
192.192.192.192
0000.0c07.ac14
8
80
This is an example of output when this command is entered on a member switch that is configured as
the standby command switch:
Switch# show cluster
Member switch for cluster "commander"
Member number:
Management IP address:
Command switch mac address:
Heartbeat interval:
Heartbeat hold-time:
3 (Standby command switch)
192.192.192.192
0000.0c07.ac14
8
80
This is an example of output when this command is entered on the command switch that has lost
connectivity from member 1:
Switch# show cluster
Command switch for cluster "Switch1"
Total number of members:
Status:
Time since last status change:
Redundancy:
Heartbeat interval:
Heartbeat hold-time:
Extended discovery hop count:
7
1 members are unreachable
0 days, 0 hours, 5 minutes
Disabled
8
80
3
This is an example of output when this command is entered on a member switch that has lost
connectivity with the command switch:
Switch# show cluster
Member switch for cluster "commander"
Member number:
Management IP address:
Command switch mac address:
Heartbeat interval:
Heartbeat hold-time:
Related Commands
<UNKNOWN>
192.192.192.192
0000.0c07.ac14
8
80
Command
Description
cluster enable
Enables a command-capable switch as the cluster command switch,
assigns a cluster name, and optionally assigns a member number to it.
show cluster candidates
Displays a list of candidate switches.
show cluster members
Displays information about the cluster members.
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show cluster candidates
show cluster candidates
Use the show cluster candidates privileged EXEC command on the command switch to display a list
of candidate switches.
show cluster candidates [detail | mac-address H.H.H.] [ | {begin | exclude | include} expression]
Syntax Description
detail
(Optional) Display detailed information for all candidates.
mac-address H.H.H.
(Optional) Hexadecimal MAC address of the cluster candidate.
| begin
(Optional) Display begins with the line that matches the specified
expression.
| exclude
(Optional) Display excludes lines that match the specified expression.
| include
(Optional) Display includes lines that match the specified expression.
expression
Expression in the output to use as a reference point.
Command Modes
Privileged EXEC
Command History
Release
Modification
12.1(13)AY
This command was introduced.
Usage Guidelines
You should only enter this command on a command switch.
If the switch is not a command switch, the command displays an empty line at the prompt.
The SN in the output means switch member number. If E is in the SN column, it means that the switch
is discovered through extended discovery. If E does not appear in the SN column, it means that the switch
member number is the upstream neighbor of the candidate switch. The hop count is the number of
devices the candidate is from the command switch.
Expressions are case sensitive. For example, if you enter | exclude output, the lines that contain output
do not appear, but the lines that contain Output appear.
Examples
This is an example of output from the show cluster candidates command:
Switch# show cluster candidates
|---Upstream---|
MAC Address
Name
Device Type
0030.85f5.8e80 3550-12T
WS-C3550-12T
0005.313c.5880 Switch2
WS-C3550-12T
0005.dcc8.01c0 2950-145
WS-C2950T-24
0002.b922.7180 C2820
WS-C2820-24
PortIf
Gi0/4
Gi0/1
Fa0/1
Fa0/3
FEC Hops SN PortIf
1
0 Fa0/1
2
E Gi0/5
3
E Gi0/2
Up
FEC
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show cluster candidates
This is an example of output from the show cluster candidates command that uses the MAC address of
a member switch directly connected to the command switch:
Switch# show cluster candidates mac-address 00d0.7961.c4c0
Device 'c2950-12' with mac address number 00d0.7961.c4c0
Device type:
cisco WS-C2950-12
Upstream MAC address:
00d0.796d.2f00 (Cluster Member 0)
Local port:
Fa0/3 FEC number:
Upstream port:
Fa0/13 FEC Number:
Hops from cluster edge: 1
Hops from command device: 1
This is an example of output from the show cluster candidates command that uses the MAC address of
a member switch three hops from the cluster edge:
Switch# show cluster candidates mac-address 0010.7bb6.1cc0
Device 'c2950-24' with mac address number 0010.7bb6.1cc0
Device type:
cisco WS-C2950-24
Upstream MAC address:
0010.7bb6.1cd4
Local port:
Fa2/1 FEC number:
Upstream port:
Fa0/24 FEC Number:
Hops from cluster edge: 3
Hops from command device: -
This is an example of output from the show cluster candidates detail command:
Switch# show cluster candidates detail
Device 'c2950-12' with mac address number 00d0.7961.c4c0
Device type:
cisco WS-C2950-12
Upstream MAC address:
00d0.796d.2f00 (Cluster Member 1)
Local port:
Fa0/3 FEC number:
Upstream port:
Fa0/13 FEC Number:
Hops from cluster edge: 1
Hops from command device: 2
Device '1900_Switch' with mac address number 00e0.1e7e.be80
Device type:
cisco 1900
Upstream MAC address:
00d0.796d.2f00 (Cluster Member 2)
Local port:
3
FEC number: 0
Upstream port:
Fa0/11 FEC Number:
Hops from cluster edge: 1
Hops from command device: 2
Device 'c2924-XL' with mac address number 00e0.1e9f.7a00
Device type:
cisco WS-C2924-XL
Upstream MAC address:
00d0.796d.2f00 (Cluster Member 3)
Local port:
Fa0/5
FEC number:
Upstream port:
Fa0/3
FEC Number:
Hops from cluster edge: 1
Hops from command device: 2
Related Commands
Command
Description
show cluster
Displays the cluster status and a summary of the cluster to which the
switch belongs.
show cluster members
Displays information about the cluster members.
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show cluster members
show cluster members
Use the show cluster members privileged EXEC command on the command switch to display
information about the cluster members.
show cluster members [n | detail] [ | {begin | exclude | include} expression]
Syntax Description
n
(Optional) Number that identifies a cluster member. The range is 0 to 15.
detail
(Optional) Display detailed information for all cluster members.
| begin
(Optional) Display begins with the line that matches the specified expression.
| exclude
(Optional) Display excludes lines that match the specified expression.
| include
(Optional) Display includes lines that match the specified expression.
expression
Expression in the output to use as a reference point.
Command Modes
Privileged EXEC
Command History
Release
Modification
12.1(13)AY
This command was introduced.
Usage Guidelines
You should only enter this command on a command switch.
If the cluster has no members, this command displays an empty line at the prompt.
Expressions are case sensitive. For example, if you enter | exclude output, the lines that contain output
do not appear, but the lines that contain Output appear.
Examples
This is an example of output from the show cluster members command. The SN in the display means
switch number.
Switch# show cluster members
SN
0
1
2
3
4
MAC Address
0002.4b29.2e00
0030.946c.d740
0002.b922.7180
0002.4b29.4400
0002.4b28.c480
Name
StLouis1
tal-switch-1
nms-2820
SanJuan2
GenieTest
PortIf FEC Hops
0
Fa0/13
1
10
0
2
Gi0/1
2
Gi0/2
2
|---Upstream---|
SN PortIf FEC State
Up
(Cmdr)
0 Gi0/1
Up
1 Fa0/18
Up
1 Fa0/11
Up
1 Fa0/9
Up
PortIf FEC Hops
0
|---Upstream---|
SN PortIf FEC State
Up
Switch# show cluster members
SN MAC Address
Name
0 0404.0400.0001 Switch
(Cmdr)
1 0003.fd62.9240 b10-2940TT
Fa0/1
1
0
Gi0/20
Up
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show cluster members
This is an example of output from the show cluster members 3 command for cluster member 3:
Switch# show cluster members 3
Device 'SanJuan2' with member number 3
Device type:
cisco WS-C3550-12T
MAC address:
0002.4b29.4400
Upstream MAC address:
0030.946c.d740 (Cluster member 1)
Local port:
Gi0/1
FEC number:
Upstream port:
Fa0/11 FEC Number:
Hops from command device: 2
This is an example of output from the show cluster members detail command:
Switch# show cluster members detail
Device 'StLouis1' with member number 0 (Command Switch)
Device type:
cisco WS-C3550-12T
MAC address:
0002.4b29.2e00
Upstream MAC address:
Local port:
FEC number:
Upstream port:
FEC Number:
Hops from command device: 0
Device 'tal-switch-14' with member number 1
Device type:
cisco WS-C3548-XL
MAC address:
0030.946c.d740
Upstream MAC address:
0002.4b29.2e00 (Cluster
Local port:
Fa0/13 FEC number:
Upstream port:
Gi0/1
FEC Number:
Hops from command device: 1
Device 'nms-2820' with member number 2
Device type:
cisco 2820
MAC address:
0002.b922.7180
Upstream MAC address:
0030.946c.d740 (Cluster
Local port:
10
FEC number: 0
Upstream port:
Fa0/18 FEC Number:
Hops from command device: 2
Device 'SanJuan2' with member number 3
Device type:
cisco WS-C3550-12T
MAC address:
0002.4b29.4400
Upstream MAC address:
0030.946c.d740 (Cluster
Local port:
Gi0/1
FEC number:
Upstream port:
Fa0/11 FEC Number:
Hops from command device: 2
Device 'Test' with member number 4
Device type:
cisco SeaHorse
MAC address:
0002.4b28.c480
Upstream MAC address:
0030.946c.d740 (Cluster
Local port:
Gi0/2
FEC number:
Upstream port:
Fa0/9
FEC Number:
Hops from command device: 2
Device 'Palpatine' with member number 5
Device type:
cisco WS-C2924M-XL
MAC address:
00b0.6404.f8c0
Upstream MAC address:
0002.4b29.2e00 (Cluster
Local port:
Gi2/1
FEC number:
Upstream port:
Gi0/7
FEC Number:
Hops from command device: 1
member 0)
member 1)
member 1)
member 1)
member 0)
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Related Commands
Command
Description
show cluster
Displays the cluster status and a summary of the cluster to which the
switch belongs.
show cluster candidates
Displays a list of candidate switches.
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show controllers ethernet-controller
show controllers ethernet-controller
Use the show controllers ethernet-controller privileged EXEC command without keywords to display
per-interface send and receive statistics read from the hardware. Use this command with keywords to
display the interface internal registers.
show controllers ethernet-controller interface-id [asic | phy 32] [ | {begin | exclude | include}
expression]
Syntax Description
interface-id
ID of the switch interface.
phy 32
(Optional) Display the status of the internal registers on the switch physical layer
device (PHY) for the interface. This display includes the operational state of the
automatic medium-dependent interface crossover (Auto-MDIX) feature on an
interface.
| begin
(Optional) Display begins with the line that matches the expression.
| exclude
(Optional) Display excludes lines that match the expression.
| include
(Optional) Display includes lines that match the specified expression.
expression
Expression in the output to use as a reference point.
Command Modes
Privileged EXEC (only supported with the interface-id keywords in user EXEC mode)
Command History
Release
Modification
12.1(13)AY
This command was introduced.
12.1(19)EA1
The phy keyword was changed to phy 32.
Usage Guidelines
Use this command without keywords to display traffic statistics, particularly the RMON statistics for the
interface.
When you enter the phy 32 keyword, the displayed information is primarily useful for Cisco technical
support representatives troubleshooting the switch. However, the phy 32 keyword also displays the
Auto-MDIX status of the interface.
Expressions are case sensitive. For example, if you enter | exclude output, the lines that contain output
do not appear, but the lines that contain Output appear.
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show controllers ethernet-controller
Examples
This is an example of output from the show controllers ethernet-controller command. For this
example, Table 2-4 describes the Transmit fields, Table 2-5 describes the Receive fields, and Table 2-6
describes the Transmit and Receive fields.
Switch# show controllers ethernet-controller fastethernet0/2
Transmit
Receive
19555003 Bytes
23485398 Bytes
222479 Frames
313530 Frames
161490 Multicast frames
0 FCS errors
256 Broadcast frames
313467 Multicast frames
0 Pause frames
1 Broadcast frames
0 Single defer frames
0 Control frames
0 Multiple defer frames
0 Pause frames
0 1 collision frames
0 Unknown opcode frames
0 2-15 collisions
0 Alignment errors
0 Late collisions
0 Length out of range
0 Excessive collisions
0 Symbol error frames
0 Total collisions
0 False carrier errors
0 Control frames
0 Valid frames, too small
0 VLAN discard frames
0 Valid frames, too large
0 Too old frames
0 Invalid frames, too small
0 Tagged frames
0 Invalid frames, too large
0 Aborted Tx frames
0 Discarded frames
Transmit and Receive
384595 Minimum size frames
131178 65 to 127 byte frames
6 128 to 255 byte frames
20229 256 to 511 byte frames
1 512 to 1023 byte frames
0 1024 to 1518 byte frames
0 1519 to 1522 byte frames
Table 2-4
Transmit Field Descriptions
Field
Description
Bytes
The total number of bytes sent on an interface.
Frames
The total number of frames sent on an interface.
Multicast frames
The total number of frames sent to multicast addresses.
Broadcast frames
The total number of frames sent to broadcast addresses.
Pause frames
The number of pause frames sent on an interface.
Single defer frames
The number of frames for which the first transmission attempt on an interface is not successful. This
value excludes frames in collisions.
Multiple defer frames
The number of frames that are not sent after the time exceeds 2*maximum-packet time.
1 collision frames
The number of frames that are successfully sent on an interface after one collision occurs.
2-15 collisions
The number of frames that are successfully sent on an interface after more than one collision occurs.
Late collisions
After a frame is sent, the number of times that a collision is detected on an interface later than 512
bit times.
Excessive collisions
The number of frames that could not be sent on an interface because more than 16 collisions
occurred.
Total collisions
The total number of collisions on an interface.
Control frames
The number of control frames sent on an interface, such as STP1 BPDUs2.
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show controllers ethernet-controller
Table 2-4
Transmit Field Descriptions (continued)
Field
Description
VLAN discard frames
The number of frames dropped on an interface because the CFI3 bit is set.
Too old frames
The number of frames dropped on the egress port because the packet aged out.
Tagged frames
The number of tagged frames sent on an interface.
Aborted Tx frames
The number of aborted transmission attempts on the interface.
1. STP = Spanning Tree Protocol
2. BPDU = bridge protocol data unit
3. CFI = Canonical Format Indicator
Table 2-5
Receive Field Descriptions
Field
Description
Bytes
The total amount of memory (in bytes) used by frames received on an interface, including the
FCS1 value and the incorrectly formed frames. This value excludes the frame header bits.
Frames
The total number of frames received on an interface, including multicast frames, broadcast
frames, and incorrectly formed frames.
FCS errors
The total number of frames received on an interface that have a valid length (in bytes) but do not
have the correct FCS values.
Multicast frames
The total number of frames successfully received on the interface that are directed to multicast
addresses.
Broadcast frames
The total number of frames successfully received on an interface that are directed to broadcast
addresses.
Control frames
The number of control frames received on an interface, such as STP BPDUs.
Pause frames
The number of pause frames received on an interface.
Unknown opcode frames
The number of frames received with an unknown operation code.
Alignment errors
The total number of frames received on an interface that have alignment errors.
Length out of range
The number of frames received on an interface that have an out-of-range length.
Symbol error frames
The number of frames received on an interface that have symbol errors.
False carrier errors
The number of occurrences in which the interface detects a false carrier when frames are not sent
or received.
Valid frames, too small
The number of frames received on an interface that are smaller than 64 bytes (or 68 bytes for
VLAN-tagged frames) and have valid FCS values. The frame size includes the FCS bits but
excludes the frame header bits.
Valid frames, too large
The number of frames received on an interface that are larger than the maximum allowed frame
size.
Invalid frames, too small
The number of frames received that are smaller than 64 bytes (including the FCS bits and
excluding the frame header) and that have either an FCS error or an alignment error.
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show controllers ethernet-controller
Table 2-5
Receive Field Descriptions (continued)
Field
Description
Invalid frames, too large
The number of frames received that were larger than maximum allowed MTU2 size (including
the FCS bits and excluding the frame header) and that have either an FCS error or an alignment
error.
Note
Discarded frames
For information about the maximum allowed MTU size on the switch, see the system mtu
global configuration command.
The number of frames discarded because of lack of receive buffer memory.
1. FCS = frame check sequence
2. MTU = maximum transmission unit
Table 2-6
Transmit and Receive Field Descriptions
Field
Description
Minimum size frames
The total number of frames that are the minimum frame size.
65 to 127 byte frames
The total number of frames that are from 65 to 127 bytes.
128 to 255 byte frames
The total number of frames that are from 128 to 255 bytes.
256 to 511 byte frames
The total number of frames that are from 256 to 511 bytes.
512 to 1023 byte frames
The total number of frames that are from 512 to 1023 bytes.
1024 to 1518 byte frames
The total number of frames that are from 1024 to 1518 bytes.
1519 to 1522 byte frames
The total number of frames that are from 1519 to 1522 bytes.
This is an example of output from the show controllers ethernet-controller interface interface-id
phy 32 command for a specific interface. Note that the last line of the display is the setting for
Auto-MDIX on the interface.
Switch# show controllers ethernet-controller gigabitethernet0/1 phy 32
Control Register
: 3100
Control STATUS
: 7809
Phy ID 1
: 0040
Phy ID 2
: 6203
Auto-Negotiation Advertisement
: 01E1
Auto-Negotiation Link Partner
: 0000
100 Base-X Auxiliary Control R
: D000
100 Base-X Auxiliary Status Re
: 0001
Auxiliary Status Summary Regis
: 1002
Auxiliary Mode Register
: C000
Auxiliary Mode 2 Register
: 009A
Auxiliary Mode 4 Register
: 1F00
Broadcom Test Register
: 000B
Auto-MDIX
: Off
Related Commands
Command
Description
show interfaces
Displays the administrative and operational status of all interfaces or a
specified interface.
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show controllers utilization
show controllers utilization
Use the show controllers utilization user EXEC command to display bandwidth utilization on
the switch or specific ports.
show controllers [interface-id] utilization [ | {begin | exclude | include} expression]
Syntax Description
interface-id
(Optional) ID of the switch interface.
| begin
(Optional) Display begins with the line that matches the specified expression.
| exclude
(Optional) Display excludes lines that match the specified expression.
| include
(Optional) Display includes lines that match the specified expression.
expression
Expression in the output to use as a reference point.
Command Modes
User EXEC
Command History
Release
Modification
12.1(22)EA1
This command was introduced.
Usage Guidelines
Expressions are case sensitive. For example, if you enter | exclude output, the lines that contain output
do not appear, but the lines that contain Output appear.
Examples
This is an example of output from the show controllers utilization command.
Switch> show controllers utilization
Port
Receive Utilization Transmit Utilization
Fa0/1
0
0
Fa0/2
0
0
<output truncated>
Total Ports : 9
Switch Receive Bandwidth Percentage Utilization : 0
Switch Transmit Bandwidth Percentage Utilization : 0
Switch Fabric Percentage Utilization : 0
This is an example of output from the show controllers utilization command on a specific port:
Switch> show controllers fastethernet0/1 utilization
Receive Bandwidth Percentage Utilization
: 0
Transmit Bandwidth Percentage Utilization : 0
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show controllers utilization
Table 2-7
show controllers utilization Field Descriptions
Field
Description
Receive Bandwidth Percentage Displays the received bandwidth usage of the switch, which is the
Utilization
sum of the received traffic on all the ports divided by the switch
receive capacity.
Related Commands
Transmit Bandwidth
Percentage Utilization
Displays the transmitted bandwidth usage of the switch, which is the
sum of the transmitted traffic on all the ports divided it by the switch
transmit capacity.
Fabric Percentage Utilization
Displays the average of the transmitted and received bandwidth usage
of the switch.
Command
Description
show controllers
ethernet-controller
Displays the interface internal registers.
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show dot1x
show dot1x
Use the show dot1x privileged EXEC command to display IEEE 802.1x statistics, administrative status,
and operational status for the switch or for the specified interface.
show dot1x [all] | [interface interface-id] | [statistics [interface interface-id]] [ | {begin | exclude
| include} expression]
Syntax Description
all
(Optional) Display the IEEE 802.1x status for all interfaces.
interface interface-id
(Optional) Display the IEEE 802.1x status for the specified interface.
statistics [interface
interface-id]
(Optional) Display IEEE 802.1x statistics for the switch or the specified
interface.
| begin
(Optional) Display begins with the line that matches the expression.
| exclude
(Optional) Display excludes lines that match the expression.
| include
(Optional) Display includes lines that match the specified expression.
expression
Expression in the output to use as a reference point.
Command Modes
Privileged EXEC
Command History
Release
Modification
12.1(13)AY
This command was introduced.
12.1(19)EA1
The all keyword was added.
Usage Guidelines
If you do not specify an interface, global parameters and a summary appear. If you specify an interface,
details for that interface appear.
If you specify the statistics keyword without the interface interface-id option, statistics appear for all
interfaces. If you specify the statistics keyword with the interface interface-id option, statistics appear
for the specified interface.
Expressions are case sensitive. For example, if you enter | exclude output, the lines that contain output
do not appear, but the lines that contain Output appear.
Examples
These are examples of output from the show dot1x and the show dot1x all privileged EXEC commands:
Switch# show dot1x
Sysauthcontrol
Supplicant Allowed In Guest Vlan
Dot1x Protocol Version
Dot1x Oper Controlled Directions
Dot1x Admin Controlled Directions
=
=
=
=
=
Enabled
Disabled
1
Both
Both
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show dot1x
Switch# show dot1x all
Dot1x Info for interface FastEthernet 0/3
---------------------------------------------------Supplicant MAC 00d0.b71b.35de
AuthSM State
= CONNECTING
BendSM State
= IDLE
PortStatus
= UNAUTHORIZED
MaxReq
= 2
HostMode
= Single
Port Control
= Auto
QuietPeriod
= 60 Seconds
Re-authentication = Disabled
ReAuthPeriod
= 3600 Seconds
ServerTimeout
= 30 Seconds
SuppTimeout
= 30 Seconds
TxPeriod
= 30 Seconds
Guest-Vlan
= 0
Dot1x Info for interface FastEthernet 0/7
---------------------------------------------------PortStatus
= UNAUTHORIZED
MaxReq
= 2
HostMode
= Multi
Port Control
= Auto
QuietPeriod
= 60 Seconds
Re-authentication = Disabled
ReAuthPeriod
= 3600 Seconds
ServerTimeout
= 30 Seconds
SuppTimeout
= 30 Seconds
TxPeriod
= 30 Seconds
Guest-Vlan
= 0
This is an example of output from the show dot1x all privileged EXEC command when a restricted
VLAN is configured:
Switch# show dot1x all
Dot1x Info for interface GigabitEthernet0/1
---------------------------------------------------Supplicant MAC 0002.b3eb.0df6
AuthSM State
= AUTHENTICATED(AUTH-FAIL-VLAN)
BendSM State
= IDLE
Posture
= N/A
PortStatus
= AUTHORIZED(AUTH-FAIL-VLAN)
MaxReq
= 2
MaxAuthReq
= 2
HostMode
= Single
PortControl
= Auto
ControlDirection
= Both
QuietPeriod
= 10 Seconds
Re-authentication
= Disabled
ReAuthPeriod
= 3600 Seconds
ServerTimeout
= 30 Seconds
SuppTimeout
= 30 Seconds
TxPeriod
= 10 Seconds
Guest-Vlan
= 3
AuthFail-Vlan
= 4
AuthFail-Max-Attempts = 3
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show dot1x
This is an example of output from the show dot1x interface fastethernet0/3 privileged EXEC
command:
Switch# show dot1x interface fastethernet0/3
Supplicant MAC 00d0.b71b.35de
AuthSM State
= AUTHENTICATED (AUTH-FAIL-VLAN)
BendSM State
= IDLE
ReAuthPeriod = 4000 Seconds { (From Authentication Server) | (Locally Configured) }
ReAuthAction = { Terminate | Reauthenticate }
TimeToNextReauth = 1453 Seconds
PortStatus
= AUTHORIZED
MaxReq
= 2
HostMode
= Single (AUTH-FAIL-VLAN)
Port Control
= Auto
QuietPeriod
= 60 Seconds
Re-authentication = Disabled
ReAuthPeriod
= 3600 Seconds
ServerTimeout
= 30 Seconds
SuppTimeout
= 30 Seconds
TxPeriod
= 30 Seconds
Guest-Vlan
= 0
This is an example of output from the show dot1x statistics interface fastethernet0/3 command.
Table 2-8 describes the fields in the display.
Switch# show dot1x statistics interface fastethernet0/3
PortStatistics Parameters for Dot1x
-------------------------------------------TxReqId = 15
TxReq = 0
TxTotal = 15
RxStart = 4
RxLogoff = 0
RxRespId = 1
RxResp = 1
RxInvalid = 0
RxLenErr = 0
RxTotal= 6
RxVersion = 1
LastRxSrcMac 00d0.b71b.35de
Table 2-8
show dot1x statistics Field Descriptions
Field
Description
TxReqId
Number of Extensible Authentication Protocol (EAP)-request/identity frames
that have been sent.
TxReq
Number of EAP-request frames (other than request/identity frames) that have
been sent.
TxTotal
Number of Extensible Authentication Protocol over LAN (EAPOL) frames of
any type that have been sent.
RxStart
Number of valid EAPOL-start frames that have been received.
RxLogoff
Number of EAPOL-logoff frames that have been received.
RxRespId
Number of EAP-response/identity frames that have been received.
RxResp
Number of valid EAP-response frames (other than response/identity frames)
that have been received.
RxInvalid
Number of EAPOL frames that have been received and have an unrecognized
frame type.
RxLenErr
Number of EAPOL frames that have been received in which the packet body
length field is invalid.
RxTotal
Number of valid EAPOL frames of any type that have been received.
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show dot1x
Table 2-8
Related Commands
show dot1x statistics Field Descriptions (continued)
Field
Description
RxVersion
Received packets in the IEEE 802.1x Version 1 format.
LastRxSrcMac
Source MAC address carried in the most recently received EAPOL frame.
Command
Description
dot1x
control-direction
Resets the configurable IEEE 802.1x parameters to their default values.
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show env
show env
Use the show env user EXEC command to display fan information for the switch.
show env {all | fan | power} [ | {begin | exclude | include} expression]
Syntax Description
Note
all
Display both fan and temperature environmental status.
fan
Display the switch fan status (only available in privileged EXEC mode).
power
Display the internal power supply status.
| begin
(Optional) Display begins with the line that matches the specified expression.
| exclude
(Optional) Display excludes lines that match the specified expression.
| include
(Optional) Display includes lines that match the specified expression.
expression
Expression in the output to use as a reference point.
Though visible in the command-line help string, the rps keyword is not supported.
Command Modes
User EXEC
Command History
Release
Modification
12.1(13)AY
This command was introduced.
Usage Guidelines
Expressions are case sensitive. For example, if you enter | exclude output, the lines that contain output
do not appear, but the lines that contain Output appear.
Examples
This is an example of output from the show env all command:
Switch> show env all
FAN is OK
Internal POWER supply is FAULTY
This is an example of output from the show env fan command:
Switch# show env fan
FAN 1 is FAULTY
This is an example of output from the show env power command:
Switch> show env power
Internal POWER supply is FAULTY
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show errdisable recovery
show errdisable recovery
Use the show errdisable recovery user EXEC command to display the error-disable recovery timer
information.
show errdisable recovery [ | {begin | exclude | include} expression]
Syntax Description
| begin
(Optional) Display begins with the line that matches the expression.
| exclude
(Optional) Display excludes lines that match the expression.
| include
(Optional) Display includes lines that match the specified expression.
expression
Expression in the output to use as a reference point.
Command Modes
User EXEC
Command History
Release
Modification
12.1(13)AY
This command was introduced.
Usage Guidelines
Expressions are case sensitive. For example, if you enter | exclude output, the lines that contain output
do not appear, but the lines that contain Output appear.
Examples
This is an example of output from the show errdisable recovery command:
Switch> show errdisable recovery
ErrDisable Reason
Timer Status
-----------------------------udld
Disabled
bpduguard
Disabled
security-violatio
Disabled
channel-misconfig
Disabled
vmps
Disabled
pagp-flap
Disabled
dtp-flap
Disabled
link-flap
Disabled
gbic-invalid
Disabled
psecure-violation
Disabled
dhcp-rate-limit
Disabled
unicast-flood
Disabled
loopback
Disabled
Timer interval:300 seconds
Interfaces that will be enabled at the next timeout:
Interface
--------Gi0/1
Errdisable reason
----------------link-flap
Time left(sec)
-------------279
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show errdisable recovery
Note
Related Commands
Though visible in the output, the unicast-flood field is not supported.
Command
Description
errdisable recovery
Configures the recover mechanism variables.
show interfaces trunk
Displays interface status or a list of interfaces in error-disabled state.
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show etherchannel
show etherchannel
Use the show etherchannel user EXEC command to display EtherChannel information for a channel.
show etherchannel [channel-group-number] {detail | load-balance | port | port-channel |
summary} [ | {begin | exclude | include} expression]
Syntax Description
channel-group-number
(Optional) Number of the channel group. The range is 1 to 6.
detail
Display detailed EtherChannel information.
load-balance
Display the load-balance or frame-distribution scheme among ports in the
port channel.
port
Display EtherChannel port information.
port-channel
Display port-channel information.
summary
Display a one-line summary per channel-group.
| begin
(Optional) Display begins with the line that matches the expression.
| exclude
(Optional) Display excludes lines that match the expression.
| include
(Optional) Display includes lines that match the specified expression.
expression
Expression in the output to use as a reference point.
Command Modes
User EXEC
Command History
Release
Modification
12.1(13)AY
This command was introduced.
Usage Guidelines
If you do not specify a channel-group, all channel groups appear.
Expressions are case sensitive. For example, if you enter | exclude output, the lines that contain output
do not appear, but the lines that contain Output appear.
Examples
This is an example of output from the show etherchannel 1 detail command:
Switch> show etherchannel 1 detail
Group state = L2
Ports: 1
Maxports = 8
Port-channels: 1 Max Port-channels = 1
Ports in the group:
------------------Port: Fa0/3
-----------Port state
Channel group
Port-channel
Port index
Flags:
=
=
=
=
Down Not-in-Bndl
1
Mode = Automatic-Sl
null
GC
= 0x00000000
0
Load = 0x00
S - Device is sending Slow hello.
Gcchange = 0
Pseudo port-channel = Po1
C - Device is in Consistent state.
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show etherchannel
A
d
Timers: H
S
-
Device is in Auto mode.
PAgP is down.
Hello timer is running.
Switching timer is running.
P - Device learns on physical port.
Q - Quit timer is running.
I - Interface timer is running.
Local information:
Port
Fa0/3
Flags State
dA
U1/S1
Timers
Hello
Partner PAgP
Interval Count
Priority
1s
0
200
Learning Group
Method Ifindex
Any
0
Age of the port in the current state: 10d:23h:07m:37s
Port-channels in the group:
---------------------Port-channel: Po1
-----------Age of the Port-channel
= 03d:02h:22m:43s
Logical slot/port
= 1/0
Number of ports = 0
GC
= 0x00000000
HotStandBy port = null
Port state
= Port-channel Ag-Not-Inuse
This is an example of output from the show etherchannel 1 summary command:
Switch> show etherchannel 1 summary
Flags: D - down
P - in port-channel
I - stand-alone s - suspended
R - Layer3
S - Layer2
u - unsuitable for bundling
U - port-channel in use
d - default port
Group Port-channel Ports
-----+------------+----------------------------------------------------------1
Po1(SU)
Fa0/1(Pd) Fa0/2(P)
This is an example of output from the show etherchannel 1 port command:
Switch> show etherchannel 1 port
Ports in the group:
------------------Port: Fa0/3
-----------Port state
Channel group
Port-channel
Port index
Flags:
S
A
d
Timers: H
S
-
=
=
=
=
Down Not-in-Bndl
1
Mode = Automatic-Sl
null
GC
= 0x00000000
0
Load = 0x00
Device is sending Slow hello.
Device is in Auto mode.
PAgP is down.
Hello timer is running.
Switching timer is running.
Gcchange = 0
Pseudo port-channel = Po1
C - Device is in Consistent state.
P - Device learns on physical port.
Q - Quit timer is running.
I - Interface timer is running.
Local information:
Port
Fa0/3
Flags State
dA
U1/S1
Timers
Hello
Partner PAgP
Interval Count
Priority
1s
0
200
Learning Group
Method Ifindex
Any
0
Age of the port in the current state: 10d:23h:13m:21s
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show etherchannel
Related Commands
Command
Description
channel-group
Assigns an Ethernet interface to an EtherChannel group.
interface port-channel
Accesses or creates the port channel.
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show file
show file
Use the show file privileged EXEC command to display a list of open file descriptors, file information,
and file system information.
show file {descriptors | information {device:}filename | systems} [ | {begin | exclude |
include} expression]
Syntax Description
descriptors
Display a list of open file descriptors.
information
Display file information.
device:
Device containing the file. Valid devices include the switch flash memory.
filename
Name of file.
systems
Display file system information.
| begin
(Optional) Display begins with the line that matches the specified expression.
| exclude
(Optional) Display excludes lines that match the specified expression.
| include
(Optional) Display includes lines that match the specified expression.
expression
Expression in the output to use as a reference point.
Command Modes
Privileged EXEC
Command History
Release
Modification
12.1(13)AY
This command was introduced.
Usage Guidelines
File descriptors are the internal representations of open files. You can use this command to see if another
user has a file open.
Expressions are case sensitive. For example, if you enter | exclude output, the lines that contain output
do not appear, but the lines that contain Output appear.
Examples
This is an example of output from the show file descriptors command:
Switch# show file descriptors
File Descriptors:
FD Position Open PID Path
0
187392
0001
2 tftp://temp/hampton/c2950g.a
1
184320
030A
2 flash:c2950-i-m.a
Table 2-9 describes the fields in the show file descriptors command output.
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show file
Table 2-9
show file descriptors Field Descriptions
Field
Description
FD
File descriptor. The file descriptor is a small integer used to specify the file once
it has been opened.
Position
Byte offset from the start of the file.
Open
Flags supplied when opening the file.
PID
Process ID of the process that opened the file.
Path
Location of the file.
This is an example of output from the show file information nvram:startup-config command:
Switch# show file information nvram:startup-config
nvram:startup-config:
type is ascii text
Table 2-10 lists the possible file types for the previous example.
Table 2-10
Possible File Types
Field
Description
ascii text
Configuration file or other text file.
coff
Runable image in coff format.
ebcdic
Text generated on an IBM mainframe.
image (a.out)
Runnable image in a.out format.
image (elf)
Runnable image in elf format.
lzw compression
Lzw compressed file.
tar
Text archive file used by the CIP.
This is an example of output from the show file systems command:
Switch# show file systems
File Systems:
*
Size(b)
7741440
7741440
32768
-
Free(b)
433152
433152
25316
-
Type
flash
unknown
nvram
network
opaque
opaque
opaque
opaque
network
network
Flags
rw
rw
rw
rw
rw
rw
ro
ro
rw
rw
Prefixes
flash:
zflash:
nvram:
tftp:
null:
system:
xmodem:
ymodem:
rcp:
ftp:
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show file
For this example, Table 2-11 describes the fields in the show file systems command output. Table 2-12
lists the file system types. Table 2-13 lists the file system flags.
Table 2-11
show file systems Field Descriptions
Field
Description
Size(b)
Amount of memory in the file system, in bytes.
Free(b)
Amount of free memory in the file system, in bytes.
Type
Type of file system.
Flags
Permissions for file system.
Prefixes
Alias for file system.
Table 2-12
File System Types
Field
Description
disk
The file system is for a rotating medium.
flash
The file system is for a flash memory device.
network
The file system is a network file system, such as TFTP, rcp, or FTP.
nvram
The file system is for an NVRAM device.
opaque
The file system is a locally generated pseudo file system (for example, the system)
or a download interface, such as brimux.
rom
The file system is for a ROM or EPROM device.
tty
The file system is for a collection of terminal devices.
unknown
The file system is of unknown type.
Table 2-13
File System Flags
Field
Description
ro
The file system is read-only.
wo
The file system is write-only
rw
The file system is read/write.
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show flowcontrol
show flowcontrol
Use the show flowcontrol user EXEC command to display the flow control status and statistics.
show flowcontrol [interface interface-id | module module-number] [ | {begin | exclude | include}
expression]
Syntax Description
interface interface-id
(Optional) Display the flow control status and statistics for a specific
interface.
module module-number (Optional) Display the flow control status and statistics for all Gigabit
Ethernet interfaces. The only valid module number value is 0.
| begin
(Optional) Display begins with the line that matches the expression.
| exclude
(Optional) Display excludes lines that match the expression.
| include
(Optional) Display includes lines that match the specified expression.
expression
Expression in the output to use as a reference point.
Command Modes
User EXEC
Command History
Release
Modification
12.1(19)EA1
This command was introduced.
Usage Guidelines
Use this command to display the flow control status and statistics on the switch or for a specific
interface.
Use the show flowcontrol command to display information about all the switch interfaces. (Flowcontrol
is supported only on Gigabit Ethernet interfaces.) The output from the show flowcontrol command is
the same as the output from the show flowcontrol module module-number command.
Use the show flowcontrol interface interface-id command to display flow control configuration and
status information about the interfaces on the switch.
Expressions are case sensitive. For example, if you enter | exclude output, the lines that contain output
do not appear, but the lines that contain Output appear.
Examples
This is an example of output from the show flowcontrol command:
Switch> show flowcontrol
Port
Send FlowControl
admin
oper
--------- -------- -------Gi0/1
Unsupp. Unsupp.
Gi0/2
desired off
Receive FlowControl
admin
oper
-------- -------off
off
off
off
RxPause TxPause
------- ------0
0
0
0
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This is an example of output from the show flowcontrol interface interface-id command:
Switch> show flowcontrol gigabitethernet0/2
Port
Send FlowControl Receive FlowControl RxPause TxPause
admin
oper
admin
oper
--------- -------- -------- -------- -------------- ------Gi0/2
desired off
off
off
0
0
Related Commands
Command
Description
flowcontrol
Sets the receive flow-control state for an interface.
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show interfaces
show interfaces
Use the show interfaces privileged EXEC command to display the administrative and operational status
of all interfaces or a specified interface.
show interfaces [interface-id | vlan vlan-id] | [accounting | capabilities [module module-number]
| description | etherchannel | flowcontrol | pruning | stats | status [err-disabled] | switchport
| trunk | transceiver properties] [ | {begin | exclude | include} expression]
Syntax Description
interface-id
(Optional) Valid interfaces include physical ports (including type, slot, and port
number) and port channels. The port-channel range is 1 to 6.
vlan vlan-id
(Optional) VLAN ID. The range is 1 to
accounting
(Optional) Display accounting information on the interface, including active
protocols and input and output packets and octets.
Note
Note
Command Modes
The display shows only packets processed in software; hardware-switched
packets do not appear.
capabilities
[module
module-number]
(Optional) Display the capabilities of the specified interface or all interfaces on the
switch. The module number is always 0. If you enter an interface ID, the module
keyword is not visible.
description
(Optional) Display the administrative status and description set for an interface.
etherchannel
(Optional) Display interface EtherChannel information.
flowcontrol
(Optional) Display interface flowcontrol information.
pruning
(Optional) Display interface trunk VTP pruning information.
stats
(Optional) Display input and output packets by switching path for the interface.
status
[err-disabled]
(Optional) Display the status of the interface, or display interfaces in
error-disabled state.
switchport
(Optional) Display the administrative and operational status of a switching port.
trunk
Display interface trunk information. If you do not specify an interface, information
for only active trunking ports appears.
transceiver
properties
(Optional) Display speed and duplex settings for an interface.
| begin
(Optional) Display begins with the line that matches the expression.
| exclude
(Optional) Display excludes lines that match the expression.
| include
(Optional) Display includes lines that match the specified expression.
expression
Expression in the output to use as a reference point.
Though visible in the command-line help strings, the crb, fair-queue, irb, mac-accounting,
precedence, random-detect, rate-limit, and shape options are not supported.
Privileged EXEC
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Command History
Release
Modification
12.1(13)AY
This command was introduced.
12.1(22)EA1
The transceiver and properties keywords were added.
Usage Guidelines
Expressions are case sensitive. For example, if you enter | exclude output, the lines that contain output
do not appear, but the lines that contain Output appear.
Examples
This is an example of output from the show interfaces accounting command:
Switch# show interfaces accounting
Vlan1
Protocol
Pkts In
IP
17950
ARP
8626
Interface Vlan5 is disabled
Chars In
2351279
552064
Pkts Out
3205
62
Chars Out
411175
3720
Chars In
179218508
5777240
0
1572560
Pkts Out
34383
14307
1408
0
Chars Out
2131700
5722418
145908
0
FastEthernet0/1
Protocol
Spanning Tree
CDP
VTP
DTP
Pkts In
2956958
14301
0
28592
<output truncated>
This is an example of output from the show interfaces capabilities command:
Switch# show interfaces fastethernet0/1 capabilities
FastEthernet0/1
Model:
WS-C2940-8TF-S
Type:
10/100BaseTX
Speed:
10,100,auto
Duplex:
half,full,auto
UDLD:
yes
Trunk encap. type:
802.1Q
Trunk mode:
on,off,desirable,nonegotiate
Channel:
yes
Broadcast suppression: percentage(0-100)
Flowcontrol:
rx-(none),tx-(none)
Fast Start:
yes
CoS rewrite:
yes
ToS rewrite:
yes
Inline power:
no
SPAN:
source/destination
PortSecure:
Yes
Dot1x:
Yes
This is an example of output from the show interfaces command for a specified interface:
Switch# show interfaces fastethernet0/1
FastEthernet0/1 is up, line protocol is down
Hardware is Fast Ethernet, address is 0005.7428.09c1 (bia 0005.7428.09c1)
MTU 1500 bytes, BW 10000 Kbit, DLY 1000 usec,
reliability 255/255, txload 1/255, rxload 1/255
Encapsulation ARPA, loopback not set
Keepalive set (10 sec)
Auto-duplex, Auto-speed
input flow-control is off, output flow-control is off
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Last input never, output 4d21h, output hang never
Last clearing of "show interface" counters never
Input queue:0/75/0/0 (size/max/drops/flushes); Total output drops:0
Queueing strategy:fifo
Output queue :0/40 (size/max)
5 minute input rate 0 bits/sec, 0 packets/sec
5 minute output rate 0 bits/sec, 0 packets/sec
1 packets input, 64 bytes, 0 no buffer
Received 0 broadcasts, 0 runts, 0 giants, 0 throttles
0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored
0 watchdog, 0 multicast, 0 pause input
0 input packets with dribble condition detected
1 packets output, 64 bytes, 0 underruns
0 output errors, 0 collisions, 2 interface resets
0 babbles, 0 late collision, 0 deferred
0 lost carrier, 0 no carrier, 0 PAUSE output
0 output buffer failures, 0 output buffers swapped out
This is an example of output from the show interfaces description command for an interface when the
interface has been described as Connects to Marketing by using the description interface configuration
command.
Switch# show interfaces gigabitethernet0/1 description
Interface Status
Protocol Description
Gi0/1
up
down
Connects to Marketing
This is an example of output from the show interfaces pruning command for an interface when pruning
is enabled in the VTP domain:
Switch# show interfaces fastethernet0/1 pruning
Port
Fa0/1
Vlans pruned for lack of request by neighbor
4,196
Port
Fa0/1
Vlan traffic requested of neighbor
1,4
This is an example of output from the show interfaces stats command:
Switch# show interfaces stats
Vlan1
Switching path
Pkts In
Processor
3224706
Route cache
0
Total
3224706
Interface Vlan5 is disabled
FastEthernet0/1
Switching path
Processor
Route cache
Total
Pkts In
3286423
0
3286423
Chars In
223689126
0
223689126
Pkts Out
3277307
0
3277307
Chars Out
280637322
0
280637322
Chars In
231672787
0
231672787
Pkts Out
179501
0
179501
Chars Out
17431060
0
17431060
This is an example of output from the show interfaces status command. It displays the status of all
interfaces.
Switch# show interfaces status
Port
Fa0/1
Fa0/2
Fa0/3
Fa0/4
Fa0/5
Name
Status
notconnect
notconnect
disabled
connected
notconnect
Vlan
1
1
100
trunk
1
Duplex
auto
auto
auto
a-full
auto
Speed
auto
auto
auto
a-100
auto
Type
10/100BaseTX
10/100BaseTX
10/100BaseTX
10/100BaseTX
10/100BaseTX
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show interfaces
Fa0/6
connected
trunk
a-full
a-100 10/100BaseTX
<output truncated>
This is an example of output from the show interfaces status err-disabled command. It displays the
status of interfaces in error-disabled state.
switch# show interfaces fastethernet0/1 status err-disabled
Port
Fa0/1
Name
Status
Reason
err-disabled psecure-violation
This is an example of output from the show interfaces etherchannel command when port channels are
configured on the switch:
Switch# show interfaces etherchannel
---FastEthernet0/1:
Port state
= Up Mstr In-Bndl
Channel group = 1
Mode = On/FEC
Gcchange = 0
Port-channel = Po1
GC
= 0x00010001
Pseudo port-channel = Po1
Port index
= 0
Load = 0x00
Age of the port in the current state:00d:00h:06m:54s
---Port-channel1:
Age of the Port-channel
= 09d:22h:45m:14s
Logical slot/port
= 1/0
Number of ports = 1
GC
= 0x00010001
HotStandBy port = null
Port state
= Port-channel Ag-Inuse
Ports in the Port-channel:
Index
Load
Port
EC state
------+------+------+-----------0
00
Fa0/1
on
Time since last port bundled:
00d:00h:06m:54s
Fa0/1
This is an example of output from the show interfaces flowcontrol command. Table 2-14 lists the fields
in this display.
Switch# show interfaces flowcontrol
Port
Send FlowControl Receive FlowControl
admin
oper
admin
oper
------------ -------- -------- -------Fa0/1
Unsupp. Unsupp. off
off
Fa0/2
Unsupp. Unsupp. off
off
<output truncated>
Gi0/1 desired off
off
off
0
Table 2-14
RxPause TxPause
------- ------0
0
0
0
0
show interfaces flowcontrol Field Descriptions
Field
Description
Port
Displays the port name.
Send FlowControl
Admin
Displays the administrative (configured) setting for the flow
control send mode.
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Table 2-14
show interfaces flowcontrol Field Descriptions (continued)
Field
Description
Oper
Displays the operational (running) setting for the flow control
send mode.
Receive FlowControl
Admin
Displays the administrative (configured) setting for the flow
control receive mode.
Oper
Displays the operational (running) setting for the flow control
receive mode.
RxPause
Displays the number of pause frames received.
TxPause
Displays the number of pause frames sent.
On
Flow control is enabled.
Off
Flow control is disabled.
Desired
Flow control is enabled if the other end supports it.
Unsupp.
Flow control is not supported.
This is an example of output from the show interfaces switchport command for a single interface.
Table 2-15 describes the fields in the output.
Switch# show interfaces gigabitethernet0/1 switchport
Name: Gi0/1
Switchport:Enabled
Administrative Mode:dynamic desirable
Operational Mode:static access
Administrative Trunking Encapsulation:negotiate
Negotiation of Trunking:On
Access Mode VLAN:1 (default)
Trunking Native Mode VLAN:1 (default)
Voice VLAN:none
Administrative private-vlan host-association:none
Administrative private-vlan mapping:none
Operational private-vlan:none
Trunking VLANs Enabled:ALL
Pruning VLANs Enabled:2-1001
Capture Mode: Disabled
Capture VLANs Allowed:ALL
Protected:true
Unknown unicast blocked:disabled
Unknown multicast blocked:disabled
Voice VLAN:none (Inactive)
Appliance trust:none
Table 2-15
show interfaces switchport Field Descriptions
Field
Description
Name
Displays the port name.
Switchport
Displays the administrative and operational status of the port.
In this output, the port is in switchport mode.
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Table 2-15
show interfaces switchport Field Descriptions (continued)
Field
Description
Administrative Mode
Displays the administrative and operational mode.
Operational Mode
Administrative Trunking
Encapsulation
Displays the administrative and operational encapsulation
method, and whether trunking negotiation is enabled.
Negotiation of Trunking
Access Mode VLAN
Displays the VLAN ID to which the port is configured.
Trunking Native Mode VLAN
Note
Trunking VLANs Enabled
Lists the VLAN ID of the trunk that is in native mode.
Lists the allowed VLANs on the trunk. Lists the active
VLANs on the trunk.
Trunking VLANs Active
Pruning VLANs Enabled
Lists the VLANs that are pruning-eligible.
Administrative private-vlan
host-association >
Administrative private-vlan mapping
Operational private-vlan
Displays the administrative and operational status of the
private VLAN and displays the private-VLAN mapping.
Capture Mode
Captured VLANs Allowed
Note
Private VLANs are not supported on the switch.
Displays the capture mode and the number of captured VLANs
allowed.
Note
Because the switch does not support the capture
feature, the values for these fields do not change.
Protected
Displays whether or not protected port is enabled (True) or
disabled (False) on the interface.
Voice VLAN
Displays the VLAN ID on which voice VLAN is enabled.
Appliance trust
Displays the class of service (CoS) setting of the data packets
of the IP phone.
This is an example of output from the show interfaces trunk command:
Switch# show interfaces trunk
Port
Fa0/4
Fa0/6
Mode
on
on
Encapsulation
802.1q
802.1q
Status
trunking
trunking
Native vlan
1
1
Port
Fa0/4
Fa0/6
Vlans allowed on trunk
1-4094
1-4094
Port
Fa0/4
Fa0/6
Vlans allowed and active in management domain
1-2,51-52
1-2,51-52
Port
Fa0/4
Fa0/6
Vlans in spanning tree forwarding state and not pruned
1
1-2,51-52
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This is an example of output from the show interfaces trunk command for an interface. It displays
trunking information for the interface.
Switch# show interfaces fastethernet0/1 trunk
Port
Fa0/1
Mode
desirable
Encapsulation
802.1q
Status
trunking
Native vlan
1
Port
Fa0/1
Vlans allowed on trunk
1-4094
Port
Fa0/1
Vlans allowed and active in management domain
1,4,196,306
Port
Fa0/1
Vlans in spanning tree forwarding state and not pruned
1,306
This is an example of output from the show interfaces transceiver properties command. If you do not
specify an interface, the output of the command shows the status on all switch ports:
Switch# show interfaces transceiver properties
Name : Fa0/1
Administrative Speed: auto
Administrative Duplex: auto
Administrative Auto-MDIX: N/A
Operational Speed: 100
Operational Duplex: full
Operational Auto-MDIX: N/A
Name : Fa0/2
Administrative Speed: auto
Administrative Duplex: auto
Administrative Auto-MDIX: N/A
Operational Speed: 10
Operational Duplex: full
Operational Auto-MDIX: N/A
Name : Fa0/3
Administrative Speed: auto
Administrative Duplex: auto
Administrative Auto-MDIX: N/A
Operational Speed: 100
Operational Duplex: full
Operational Auto-MDIX: N/A
<output truncated>
This is an example of output from the show interfaces module number transceiver properties
command for a specific interface:
Switch# show interfaces fastethernet0/1 transceiver properties
Name : Fa0/1
Administrative Speed: auto
Administrative Duplex: auto
Administrative Auto-MDIX: N/A
Operational Speed: 100
Operational Duplex: full
Operational Auto-MDIX: N/A
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Related Commands
Command
Description
switchport access
Configures a port as a static-access or dynamic-access port.
switchport protected
Isolates Layer 2 unicast, multicast, and broadcast traffic from other
protected ports on the same switch.
switchport trunk pruning
Configures the VLAN pruning-eligible list for ports in trunking mode.
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show interfaces counters
show interfaces counters
Use the show interfaces counters privileged EXEC command to display various counters for a specific
interface or for all interfaces.
show interfaces [interface-id | vlan vlan-id] counters [errors | etherchannel | trunk] [ | {begin |
exclude | include} expression]
Syntax Description
interface-id
(Optional) ID of the physical interface, including type and slot and port
number.
vlan vlan-id
(Optional) VLAN number of the management VLAN. The range is 1 to 4094.
errors
(Optional) Display error counters.
etherchannel
(Optional) Display etherchannel counters, including octets, broadcast
packets, multicast packets, and unicast packets received and sent.
trunk
(Optional) Display trunk counters.
| begin
(Optional) Display begins with the line that matches the expression.
| exclude
(Optional) Display excludes lines that match the expression.
| include
(Optional) Display includes lines that match the specified expression.
expression
Expression in the output to use as a reference point.
Command Modes
Privileged EXEC
Command History
Release
Modification
12.1(13)AY
This command was introduced.
12.2(22)EA2
The broadcast, multicast, and unicast keywords were removed.
Usage Guidelines
If you do not enter any keywords, all counters for all interfaces are included.
Expressions are case sensitive. For example, if you enter | exclude output, the lines that contain output
do not appear, but the lines that contain Output appear.
Examples
This is an example of output from the show interfaces counters command. It displays all the counters
for the switch. Table 2-16 describes the fields in the output.
Switch# show interfaces counters
Port
InOctets
InUcastPkts
Gi0/1
23324617
10376
Port
Gi0/1
OutOctets
4990607
OutUcastPkts
28079
InMcastPkts
185709
InBcastPkts
126020
OutMcastPkts
21122
OutBcastPkts
10
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Table 2-16
show interfaces counters Field Descriptions
Field
Description
InOctets
Displays the number of bytes received on an interface.
InUcastPkts
Displays the number of unicast packets received on an interface.
InMcastPkts
Displays the number of multicast packets received on an interface.
InBcastPkts
Displays the number of broadcast packets received on the interface.
OutOctets
Displays the number of bytes sent on an interface.
OutUcastPkts
Displays the number of unicast packets sent on an interface.
OutMcastPkts
Displays the number of multicast packets sent on an interface.
OutBcastPkts
Displays the number of broadcast packets sent on an interface.
This is an example of output from the show interfaces counters errors command. It displays the
interface error counters for all interfaces. Table 2-17 describes the fields in the output.
Switch# show interfaces counters errors
Port
Gi0/1
Port
Gi0/1
Table 2-17
Align-Err
0
FCS-Err
0
Single-Col Multi-Col
0
0
Xmit-Err
0
Rcv-Err UnderSize
0
0
Late-Col Excess-Col Carri-Sen
0
0
0
Runts
0
Giants
0
show interfaces counters errors Field Descriptions
Field
Description
Align-Err
Displays the total number of frames that are received on an interface and have
alignment errors.
FCS-Err
Displays the total number of frames that are received on an interface, have a
valid length (in bytes), but do not have the correct FCS1 values.
Xmit-Err
Displays the total number of frames that have errors during transmission.
Rcv-Err
Displays the total number of frames that are received on an interface and have
errors.
Undersize
Displays the total number of frames received that are less than 64 bytes
(including the FCS bits and excluding the frame header) and have either an FCS
or an alignment error.
Single-col
Displays the total number of frames that are successfully sent on an interface
after one collision occurs.
Multi-col
Displays the total number of frames that are successfully sent on an interface
after more than one collision occurs.
Late-col
After a frame is sent, displays the number of times that a collision is detected
on an interface after 512 bit times.
Excess-col
Display the number of frames that could not be sent on an interface because
more than 16 collisions occurs.
Carri-Sen
Displays the number of occurrences in which the interface detects a false carrier
when frames are not sent or received.
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Table 2-17
show interfaces counters errors Field Descriptions (continued)
Field
Description
Runts
Displays the number of frames received on an interface that are smaller than 64
bytes and have an invalid FCS value.
Giants
Displays the number of frames that are larger than the maximum allowed frame
size and have a valid FCS value.
1. FCS = frame check sequence
This is an example of output from the show interfaces counters trunk command. It displays the trunk
counters for all interfaces. Table 2-18 describes the fields in the output.
Switch# show interfaces counters trunk
Port
Gi0/1
TrunkFramesTx
0
Table 2-18
Related Commands
TrunkFramesRx
0
WrongEncap
0
show interfaces counters trunk Field Descriptions
Field
Description
TrunkFrameTx
Displays the number of frames sent on a trunk interface.
TrunkFrameRx
Displays the number of frames received on a trunk interface.
WrongEncap
Displays the number of frames that are received on an interface and have the
incorrect encapsulation type.
Command
Description
show interfaces
Displays interface characteristics.
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show inventory
show inventory
Use the show inventory user EXEC command to display product identification (PID) information for
the hardware.
show inventory [entity-name | raw] [ | {begin | exclude | include} expression]
Syntax Description
entity-name
(Optional) Display the specified entity. For example, enter the interface
(such as gigabitethernet1/0/1) into which a small form-factor pluggable
(SFP) module is installed.
raw
(Optional) Display every entity in the device.
| begin
(Optional) Display begins with the line that matches the expression.
| exclude
(Optional) Display excludes lines that match the expression.
| include
(Optional) Display includes lines that match the specified expression.
expression
Expression in the output to use as a reference point.
Command Modes
User EXEC
Command History
Release
Modification
12.1(22)EA5
This command was introduced.
Usage Guidelines
Note
The command is case sensitive. With no arguments, the show inventory command produces a compact
dump of all identifiable entities that have a product identifier. The compact dump displays the entity
location (slot identity), entity description, and the unique device identifier (UDI) (PID, VID, and SN) of
that entity.
If there is no PID, no output appears when you enter the show inventory command.
Expressions are case sensitive. For example, if you enter | exclude output, the lines that contain output
are not displayed, but the lines that contain Output are displayed.
Examples
This is example output from the show inventory command:
Switch> show inventory
NAME: "sw-1-16-c2940fx", DESCR: "Cisco Catalyst c2940 switch with 8 10/100 BaseTX ports, 1
100BASE-FX SM uplink ports and 1 SFP (Small Form Factor Plugable) Module slot"
PID: WS-C2940-8TF-S
, VID: C0 , SN: FHK0822Y1JD
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show ip dhcp snooping
show ip dhcp snooping
Use the show ip dhcp snooping user EXEC command to display the DHCP snooping configuration.
show ip dhcp snooping
Syntax Description
This command has no arguments or keywords.
Command Modes
User EXEC
Command History
Release
Modification
12.1(22)EA7
This command was introduced.
Usage Guidelines
Examples
Expressions are case sensitive. For example, if you enter | exclude output, the lines that contain output
do not appear, but the lines that contain Output appear.
This is an example of output from the show ip dhcp snooping command:
Switch> show ip dhcp snooping
Switch DHCP snooping is enabled
DHCP snooping is configured on following
40-42
Insertion of option 82 is enabled
Interface
Trusted
-----------------------------FastEthernet0/5
yes
FastEthernet0/7
yes
FastEthernet0/3
no
FastEthernet0/5
yes
FastEthernet0/7
yes
FastEthernet0/5
yes
FastEthernet0/7
yes
Related Commands
VLANs:
Rate limit (pps)
---------------unlimited
unlimited
5000
unlimited
unlimited
unlimited
unlimited
Command
Description
show ip dhcp snooping binding
Displays the DHCP snooping binding information.
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show ip dhcp snooping binding
show ip dhcp snooping binding
Use the show ip dhcp snooping binding user EXEC command to display the DHCP snooping binding
table and configuration information for all interfaces on a switch.
show ip dhcp snooping binding [ip-address] [mac-address] [dynamic] [interface interface-id]
[static] [vlan vlan-id] [ | {begin | exclude | include} expression]
Syntax Description
ip-address
(Optional) Specify the binding entry IP address.
mac-address
(Optional) Specify the binding entry MAC address.
dynamic
(Optional) Specify the dynamic binding entry.
interface interface-id
(Optional) Specify the binding input interface.
static
(Optional) Specify the static binding entry.
vlan vlan-id
(Optional) Specify the binding entry VLAN.
| begin
Display begins with the line that matches the expression.
| exclude
Display excludes lines that match the expression.
| include
Display includes lines that match the specified expression.
expression
Expression in the output to use as a reference point.
Command Modes
User EXEC
Command History
Release
Modification
12.1(22)EA7
This command was introduced.
Usage Guidelines
The show ip dhcp snooping binding command output shows the dynamically configured bindings.
If DHCP snooping is enabled and an interface changes to the down state, the switch does not delete the
manually configured bindings.
Expressions are case sensitive. For example, if you enter | exclude output, the lines that contain output
do not appear, but the lines that contain Output appear.
Examples
This example shows how to display the DHCP snooping binding entries for a switch:
Switch> show ip dhcp snooping binding
MacAddress
IpAddress
Lease(sec)
------------------ --------------- ---------00:30:94:C2:EF:35
41.0.0.51
286
00:D0:B7:1B:35:DE
41.0.0.52
237
00:00:00:00:00:01
40.0.0.46
286
00:00:00:00:00:03
42.0.0.33
286
00:00:00:00:00:02
41.0.0.53
286
Type
------dynamic
dynamic
dynamic
dynamic
dynamic
VLAN
---41
41
40
42
41
Interface
-------------------FastEthernet0/3
FastEthernet0/3
FastEthernet0/8
FastEthernet0/8
FastEthernet0/8
This example shows how to display the DHCP snooping binding entries for a specific IP address:
Switch> show ip dhcp snooping binding 41.0.0.51
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show ip dhcp snooping binding
MacAddress
-----------------00:30:94:C2:EF:35
IpAddress
--------------41.0.0.51
Lease(sec)
---------285
Type
------dynamic
VLAN
---41
Interface
-------------------FastEthernet0/3
This example shows how to display the DHCP snooping binding entries for a specific MAC address:
Switch> show ip dhcp snooping binding 0030.94c2.ef35
MacAddress
IpAddress
Lease(sec) Type
------------------ --------------- ---------- ------00:30:94:C2:EF:35
41.0.0.51
279
dynamic
VLAN
---41
Interface
-------------------FastEthernet0/3
This example shows how to display the DHCP snooping dynamic binding entries on a switch:
Switch> show ip dhcp snooping binding dynamic
MacAddress
IpAddress
Lease(sec)
------------------ --------------- ---------00:30:94:C2:EF:35
41.0.0.51
286
00:D0:B7:1B:35:DE
41.0.0.52
296
00:00:00:00:00:01
40.0.0.46
46
00:00:00:00:00:03
42.0.0.33
46
00:00:00:00:00:02
41.0.0.53
46
Type
------dynamic
dynamic
dynamic
dynamic
dynamic
VLAN
---41
41
40
42
41
Interface
-------------------FastEthernet0/3
FastEthernet0/3
FastEthernet0/8
FastEthernet0/8
FastEthernet0/8
This example shows how to display the DHCP snooping binding entries on an interface:
Switch> show ip dhcp snooping binding interface fastethernet0/3
MacAddress
IpAddress
Lease(sec) Type
VLAN Interface
------------------ --------------- ---------- ------- ---- -------------------00:30:94:C2:EF:35
41.0.0.51
290
dynamic 41
FastEthernet0/3
00:D0:B7:1B:35:DE
41.0.0.52
270
dynamic 41
FastEthernet0/3
This example shows how to display the DHCP snooping binding entries on VLAN 41:
Switch> show ip dhcp snooping binding vlan 41
MacAddress
IpAddress
Lease(sec)
------------------ --------------- ---------00:30:94:C2:EF:35
41.0.0.51
274
00:D0:B7:1B:35:DE
41.0.0.52
165
00:00:00:00:00:02
41.0.0.53
65
Type
------dynamic
dynamic
dynamic
VLAN
---41
41
41
Interface
-------------------FastEthernet0/3
FastEthernet0/3
FastEthernet0/8
Table 2-19 describes the fields in the show ip dhcp snooping binding command output.
Table 2-19
Related Commands
show ip dhcp snooping binding Command Output
Field
Description
MAC Address
Client hardware MAC address
IP Address
Client IP address assigned from the DHCP server
Lease (seconds)
IP address lease time
Type
Binding type
VLAN
VLAN number of the client interface
Interface
Interface that connects to the DHCP client host
Command
Description
show ip dhcp snooping
Displays the DHCP snooping configuration.
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show ip igmp profile
show ip igmp profile
Use the show ip igmp profile privileged EXEC command to view all configured Internet Group
Management Protocol (IGMP) profiles or a specified IGMP profile.
show ip igmp profile [profile number] [ | {begin | exclude | include} expression]
Syntax Description
profile number
(Optional) The IGMP profile number to be displayed. The range is 1 to
4294967295. If no profile number is entered, all IGMP profiles appear.
| begin
(Optional) Display begins with the line that matches the expression.
| exclude
(Optional) Display excludes lines that match the expression.
| include
(Optional) Display includes lines that match the specified expression.
expression
Expression in the output to use as a reference point.
Command Modes
Privileged EXEC
Command History
Release
Modification
12.1(9)EA1
This command was introduced.
Usage Guidelines
Expressions are case sensitive. For example, if you enter | exclude output, the lines that contain output
do not appear, but the lines that contain Output appear.
Examples
These are examples of output from the show ip igmp profile privileged EXEC command, with and
without specifying a profile number. If no profile number is entered, the display includes all profiles
configured on the switch.
Switch# show ip igmp profile 40
IGMP Profile 40
permit
range 233.1.1.1 233.255.255.255
Switch# show ip igmp profile
IGMP Profile 3
range 230.9.9.0 230.9.9.0
IGMP Profile 4
permit
range 229.9.9.0 229.255.255.255
Related Commands
Command
Description
ip igmp profile
Configures the specified IGMP profile number.
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show ip igmp snooping
show ip igmp snooping
Use the show ip igmp snooping user EXEC command to display the Internet Group Management
Protocol (IGMP) snooping configuration of the switch or the VLAN. Use the mrouter keyword to display
the dynamically learned and manually configured multicast router ports.
show ip igmp snooping [group | mrouter | querier] [vlan vlan-id] [ | {begin | exclude | include}
expression]
Syntax Description
group
(Optional) Display information about the IGMP multicast groups, the compatibility
mode, and the ports that are associated with each group.
mrouter
(Optional) Display the IGMP snooping dynamically learned and manually configured
multicast router ports.
querier
(Optional) Display information about the IGMP version that an interface supports.
vlan vlan-id
(Optional) Keyword and variable to specify a VLAN. The range is 1 to 4094. This
keyword is available only in privileged EXEC mode.
| begin
(Optional) Display begins with the line that matches the specified expression.
| exclude
(Optional) Display excludes lines that match the specified expression.
| include
(Optional) Display includes lines that match the specified expression.
expression
Expression in the output to use as a reference point.
Command Modes
User EXEC
Command History
Release
Modification
12.1(13)AY
This command was introduced.
12.1(19)EA1
The group and querier keywords were added.
Usage Guidelines
Use this command to display snooping characteristics for the switch or for a specific VLAN.
You can also use the show mac address-table multicast privileged EXEC command to display entries
in the MAC address table for a VLAN that has IGMP snooping enabled.
When multicast VLAN registration (MVR) is enabled, use the show ip igmp snooping mrouter
command to display the IGMP snooping dynamically learned and manually configured multicast router
ports.
Use the group keyword to display the multicast groups, the compatibility mode, and the ports that are
associated with each group.
Use the show ip igmp snooping querier command to display the IGMP version and IP address of a
detected device that sends IGMP query messages, also called a querier. A subnet can have multiple
multicast routers but has only one IGMP querier. In a subnet running IGMPv2, one of the multicast
routers is elected as the querier. The querier can be a Layer 3 switch. The command output also shows
the VLAN and interface on which the querier was detected. If the querier is a multicast router, the output
shows the Port field as Router.
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show ip igmp snooping
Expressions are case sensitive. For example, if you enter | exclude output, the lines that contain output
do not appear, but the lines that contain Output appear.
Examples
This is an example of output from the show ip igmp snooping command:
Switch> show ip igmp snooping
Global IGMP Snooping configuration:
----------------------------------IGMP snooping
: Enabled
IGMPv3 snooping (minimal) : Enabled
Report suppression
: Enabled
TCN solicit query
: Disabled
TCN flood query count
: 2
Last member query interval : 100
Vlan 1:
-------IGMP snooping
Immediate leave
Multicast router learning mode
Source only learning age timer
CGMP interoperability mode
Last member query interval
Vlan 2:
-------IGMP snooping
Immediate leave
Multicast router learning mode
Source only learning age timer
CGMP interoperability mode
Last member query interval
<output truncated>
:Enabled
:Disabled
:pim-dvmrp
:10
:IGMP_ONLY
:100
:Enabled
:Disabled
:pim-dvmrp
:10
:IGMP_ONLY
:100
This is an example of output from the show ip igmp snooping vlan 1 command:
Switch# show ip igmp snooping vlan 1
Global IGMP Snooping configuration:
----------------------------------IGMP snooping
: Enabled
IGMPv3 snooping (minimal) : Enabled
Report suppression
: Enabled
TCN solicit query
: Disabled
TCN flood query count
: 2
Last member query interval : 100
Vlan 1:
-------IGMP snooping
Immediate leave
Multicast router learning mode
Source only learning age timer
CGMP interoperability mode
Last member query interval
:Enabled
:Disabled
:pim-dvmrp
:10
:IGMP_ONLY
: 100
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show ip igmp snooping
This is an example of output from the show ip igmp snooping mrouter vlan 1 command:
Note
In this example, Fa0/3 is a dynamically learned router port, and Fa0/2 is a configured static router port.
Switch#
Vlan
---1
show ip igmp snooping mrouter vlan 1
ports
----Fa0/2(static), Fa0/3(dynamic)
This is an example of output from the show ip igmp snooping group vlan 1 command:
Switch# show ip igmp snooping group vlan 1
Vlan
Group
Version
Port List
--------------------------------------------------------1
229.2.3.4
v3
fa0/1 fa0/3
1
224.1.1.1
v2
fa0/8
This is an example of output from the show ip igmp snooping querier command:
Switch> show ip igmp snooping querier
Vlan
IP Address
IGMP Version
Port
--------------------------------------------------1
172.20.50.11
v3
fa0/1
2
172.20.40.20
v2
Router
Related Commands
Command
Description
ip igmp snooping
Enables IGMP snooping.
ip igmp snooping
report-suppression
Enables IGMP report suppression.
ip igmp snooping
source-only-learning
Enables IP multicast-source-only learning on the switch.
ip igmp snooping
source-only-learning age-timer
Enables and configures the aging time of the forwarding-table
entries that the switch learns by using the source-only learning
method.
ip igmp snooping vlan vlan-id
Enables IGMP snooping on the VLAN interface.
ip igmp snooping vlan
immediate-leave
Configures IGMP Immediate-Leave processing.
ip igmp snooping vlan mrouter
Configures a Layer 2 port as a multicast router port.
show mac address-table multicast
Displays the Layer 2 multicast entries for a VLAN.
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show lacp
show lacp
Use the show lacp user EXEC command to display Link Aggregation Control Protocol (LACP)
channel-group information.
show lacp {channel-group-number {counters | internal | neighbor} | {counters | internal |
neighbor | sys-id}} [ | {begin | exclude | include} expression]
Syntax Description
channel-group-number
(Optional) Number of the channel group. The range is 1 to 6.
counters
Display traffic information.
internal
Display internal information.
neighbor
Display neighbor information.
sys-id
Display the system identifier that is being used by LACP. The system
identifier is made up of the LACP system priority and a MAC address.
| begin
(Optional) Display begins with the line that matches the expression.
| exclude
(Optional) Display excludes lines that match the expression.
| include
(Optional) Display includes lines that match the specified expression.
expression
Expression in the output to use as a reference point.
Command Modes
User EXEC
Command History
Release
Modification
12.1(13)AY
This command was introduced.
Usage Guidelines
You can enter any show lacp command to display the active port-channel information. To display the
nonactive information, enter the show lacp command with a group number.
Expressions are case sensitive. For example, if you enter | exclude output, the lines that contain output
do not appear, but the lines that contain Output appear.
Examples
This is an example of output from the show lacp counters command:
Switch> show lacp counters
LACPDUs
Marker
Marker Response
LACPDUs
Port
Sent
Recv
Sent
Recv
Sent
Recv
Pkts Err
--------------------------------------------------------------------Channel group:1
Fa0/5
19
10
0
0
0
0
0
Fa0/6
14
6
0
0
0
0
0
Fa0/7
8
7
0
0
0
0
0
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show lacp
This is an example of output from the show lacp 1 internal command:
Switch> show lacp internal
Flags: S - Device is sending Slow LACPDUs F - Device is sending Fast LACPDUs
A - Device is in Active mode
P - Device is in Passive mode
Channel group 1
Port
Fa0/5
Fa0/6
Fa0/7
Flags
SP
SP
SP
LACP port
Priority
32768
32768
32768
State
indep
indep
down
Admin
Key
0x1
0x1
0x1
Oper
Key
0x1
0x1
0x1
Port
Number
0x4
0x5
0x6
Port
State
0x7C
0x7C
0xC
This is an example of output from the show lacp neighbor command:
Switch> show lacp neighbor
Flags: S - Device is sending Slow LACPDUs F - Device is sending Fast LACPDUs
A - Device is in Active mode
P - Device is in Passive mode
Channel group 1 neighbors
Partner's information:
Port
Fa0/5
Partner
System ID
00000,0000.0000.0000
LACP Partner
Port Priority
0
Partner
Port Number
0x0
Partner
Oper Key
0x0
Age
85947s
Partner
Flags
SP
Partner
Port State
0x0
Partner's information:
Port
Fa0/6
Partner
System ID
00000,0000.0000.0000
LACP Partner
Port Priority
0
Partner
Port Number
0x0
Partner
Oper Key
0x0
Age
86056s
Partner
Flags
SP
Partner
Port State
0x0
Partner's information:
Port
Fa0/7
Partner
System ID
00010,0008.a343.b580
LACP Partner
Port Priority
32768
Partner
Port Number
0x6
Partner
Oper Key
0x1
Age
86032s
Partner
Flags
SA
Partner
Port State
0x35
This is an example of output from the show lacp sys-id command:
Switch> show lacp sys-id
32765,0002.4b29.3a00
Related Commands
Command
Description
clear lacp
Clears LACP channel-group information.
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show mac address-table
show mac address-table
Use the show mac address-table user EXEC command to display the MAC address table.
show mac address-table [aging-time | count | dynamic | static] [address hw-addr]
[interface interface-id] [vlan vlan-id] [ | {begin | exclude | include} expression]
Syntax Description
Command Modes
aging-time
(Optional) Display aging time for dynamic addresses for all VLANs.
count
(Optional) Display the count for different kinds of MAC addresses (only
available in privileged EXEC mode).
dynamic
(Optional) Display only the dynamic addresses.
static
(Optional) Display only the static addresses.
address hw-addr
(Optional) Display information for a specific address (only available in
privileged EXEC mode).
interface interface-id
(Optional) Display addresses for a specific interface.
vlan vlan-id
(Optional) Display addresses for a specific VLAN. The range is 1 to 4094.
| begin
(Optional) Display begins with the line that matches the specified
expression.
| exclude
(Optional) Display excludes lines that match the specified expression.
| include
(Optional) Display includes lines that match the specified expression.
expression
Expression in the output to use as a reference point.
User EXEC
The address and count keywords are available only in privileged EXEC mode.
Command History
Usage Guidelines
Release
Modification
12.1(13)AY
This command was introduced.
This command displays the MAC address table for the switch. Specific views can be defined by using
the optional keywords and values. If more than one optional keyword is used, all of the conditions must
be true in order for that entry to appear.
Expressions are case sensitive. For example, if you enter | exclude output, the lines that contain output
do not appear, but the lines that contain Output appear.
Examples
This is an example of output from the show mac address-table command:
Switch> show mac address-table
Dynamic Addresses Count:
9
Secure Addresses (User-defined) Count: 0
Static Addresses (User-defined) Count: 0
System Self Addresses Count:
41
Total MAC addresses:
50
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show mac address-table
Non-static Address Table:
Destination Address Address Type
------------------- -----------0010.0de0.e289
Dynamic
0010.7b00.1540
Dynamic
0010.7b00.1545
Dynamic
0060.5cf4.0076
Dynamic
0060.5cf4.0077
Dynamic
0060.5cf4.1315
Dynamic
0060.70cb.f301
Dynamic
00e0.1e42.9978
Dynamic
00e0.1e9f.3900
Dynamic
VLAN
---1
2
2
1
1
1
1
1
1
Destination Port
-------------------FastEthernet0/1
FastEthernet0/5
FastEthernet0/5
FastEthernet0/1
FastEthernet0/1
FastEthernet0/1
FastEthernet0/1
FastEthernet0/1
FastEthernet0/1
This is an example of output from the show mac address-table static command:
Switch> show mac address-table static
vlan
mac address
type
ports
-----+---------------+--------+--------All 0180.c200.0003 STATIC
CPU
All 0180.c200.0004 STATIC
CPU
All 0180.c200.0005 STATIC
CPU
4 0001.0002.0004 STATIC
Drop
6 0001.0002.0007 STATIC
Drop
This is an example of output from the show mac address-table static interface fastethernet0/2
vlan 1 command:
Switch> show mac address-table static interface fastethernet0/2 vlan 1
vlan
mac address
type
ports
-----+---------------+--------+--------1 abcd.2345.0099 STATIC
Fa0/2
1 abcd.0070.0070 STATIC
Fa0/2
1 abcd.2345.0099 STATIC
Fa0/2
1 abcd.2345.0099 STATIC
Fa0/2
1 00d0.d333.7f34 STATIC
Fa0/2
1 abcd.2345.0099 STATIC
Fa0/2
1 0005.6667.0007 STATIC
Fa0/2
This is an example of output from the show mac address-table count vlan 1 command:
Switch# show mac address-table count vlan 1
MAC Entries for Vlan 1 :
Dynamic Address Count: 1
Static Address (User-defined) Count: 41
Total MAC Addresses In Use:42
Remaining MAC addresses: 8150
This is an example of output from the show mac address-table aging-time command:
Switch> show mac address-table aging-time
Vlan Aging Time
---- ---------1
450
2
300
3
600
300 450
301 450
This is an example of output from the show mac address-table aging-time vlan 1 command:
Switch> show mac address-table aging-time vlan 1
Vlan Aging Time
---- ---------1
450
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show mac address-table
Related Commands
Command
Description
clear mac address-table
dynamic
Deletes from the MAC address table a specific dynamic address, all
dynamic addresses on a particular interface, or all dynamic addresses
on a particular VLAN.
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show mac address-table multicast
show mac address-table multicast
Use the show mac address-table multicast user EXEC command to display the Layer 2 multicast
entries for the switch or for the VLAN.
show mac address-table multicast [vlan vlan-id] [count] [igmp-snooping | user] [ | {begin |
exclude | include} expression]
Note
Syntax Description
The show mac address-table multicast command only shows non-IP multicast addresses. Use the show
ip igmp snooping multicast user EXEC command to display IP multicast addresses.
vlan vlan-id
(Optional) Specify a VLAN. The range is 1 to 4094. (This keyword is only
available in privileged EXEC mode.)
count
(Optional) Display total number of entries for the specified criteria instead of the
actual entries (only available in privileged EXEC mode).
igmp-snooping
(Optional) Display only entries learned through Internet Group Management
Protocol (IGMP) snooping (only available in privileged EXEC mode).
user
(Optional) Display only the user-configured multicast entries (only available in
privileged EXEC mode).
| begin
(Optional) Display begins with the line that matches the specified expression.
| exclude
(Optional) Display excludes lines that match the specified expression.
| include
(Optional) Display includes lines that match the specified expression.
expression
Expression in the output to use as a reference point.
Command Modes
User EXEC
Command History
Release
Modification
12.1(13)AY
This command was introduced.
Usage Guidelines
Expressions are case sensitive. For example, if you enter | exclude output, the lines that contain output
do not appear, but the lines that contain Output appear.
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show mac address-table multicast
Examples
This is an example of output from the show mac address-table multicast vlan 1 command:
Switch# show mac address-table multicast vlan 1
Vlan
---1
1
Mac Address
----------0100.5e00.0128
0100.5e01.1111
Type
---IGMP
USER
Ports
----Fa0/1
Fa0/3, Fa0/4, Fa0/5, Fa0/6
This is an example of output from the show mac address-table multicast count command:
Switch# show mac address-table multicast count
Multicast Mac Entries for all vlans: 10
This is an example of output from the show mac address-table multicast vlan 1 count command:
Switch# show mac address-table multicast vlan 1 count
Multicast Mac Entries for vlan 1: 2
This is an example of output from the show mac address-table multicast vlan 1 user command:
Switch# show mac address-table multicast vlan 1 user
vlan
mac address
type
ports
-----+----------------+-------+--------------------1
0100.5e02.0203
user
Fa0/1,Fa0/2,Fa0/4
This is an example of output from the show mac address-table multicast vlan 1 igmp-snooping count
command:
Switch# show mac address-table multicast vlan 1 igmp-snooping count
Number of igmp-snooping programmed entries : 1
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show mac address-table notification
show mac address-table notification
Use the show mac address-table notification user EXEC command to display parameters for the MAC
notification feature.
show mac address-table notification [interface interface-id] [ | {begin | exclude | include}
expression]
Syntax Description
interface interface-id
(Optional) Specify an interface.
| begin
(Optional) Display begins with the line that matches the specified
expression.
| exclude
(Optional) Display excludes lines that match the specified expression.
| include
(Optional) Display includes lines that match the specified expression.
expression
Expression in the output to use as a reference point.
Command Modes
User EXEC
Command History
Release
Modification
12.1(13)AY
This command was introduced.
Usage Guidelines
Use the show mac address-table notification command without keywords to display parameters for all
interfaces. Use this command with the interface keyword to display parameters for a specific interface.
Expressions are case sensitive. For example, if you enter | exclude output, the lines that contain output
do not appear, but the lines that contain Output appear.
Examples
This is an example of output from the show mac address-table notification command:
Switch> show mac address-table notification
MAC Notification Feature is Disabled on the switch
Related Commands
Command
Description
clear mac address-table notification
Clears the MAC address notification global counters.
mac address-table notification
Enables the MAC notification feature.
snmp trap mac-notification
Enables MAC-notification traps on a port.
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show mls qos interface
show mls qos interface
Use the show mls qos interface user EXEC command to display quality of service (QoS) information
at the interface level.
show mls qos interface [interface-id] [ | {begin | exclude | include} expression]
Syntax Description
Note
interface-id
(Optional) Display QoS information for the specified interface.
| begin
(Optional) Display begins with the line that matches the expression.
| exclude
(Optional) Display excludes lines that match the expression.
| include
(Optional) Display includes lines that match the specified expression.
expression
Expression in the output to use as a reference point.
Though visible in the command-line help strings, the vlan vlan-id option and the policers keyword are
not supported.
Command Modes
User EXEC
Command History
Release
Modification
12.1(13)AY
This command was introduced.
Usage Guidelines
Use the show mls qos interface command without keywords to display parameters for all interfaces.
Use the show mls qos interface interface-id command to display the parameters for a specific interface.
Expressions are case sensitive. For example, if you enter | exclude output, the lines that contain output
do not appear, but the lines that contain Output appear.
Examples
This is an example of output from the show mls qos interface command when the Cisco IP phone is a
trusted device:
Switch> show mls qos interface fastethernet0/1
FastEthernet0/1
trust state:trust cos
trust mode:trust cos
COS override:dis
default COS:0
pass-through:none
trust device:cisco-phone
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show mls qos interface
This is an example of output from the show mls qos interface command when pass-through mode is
configured on an interface:
Switch> show mls qos interface fastethernet0/2
FastEthernet0/2
trust state:not trusted
trust mode:not trusted
COS override:dis
default COS:0
pass-through:dscp
Related Commands
Command
Description
mls qos cos
Defines the default class of service (CoS) value of a port or assigns the
default CoS to all incoming packets on the port.
mls qos trust
Configures the port trust state. Ingress traffic can be trusted and
classification is performed by examining the CoS or DSCP value.
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show monitor
show monitor
Use the show monitor user EXEC command to display Switched Port Analyzer (SPAN) session
information.
show monitor [session {session_number | all | local | range}] [ | {begin | exclude | include}
expression]
Syntax Description
Note
session session_number
(Optional) Specify the session number identified with this SPAN
session.
all
Specify all sessions.
local
Specify local sessions.
range
Specify a range of sessions.
| begin
(Optional) Display begins with the line that matches the expression.
| exclude
(Optional) Display excludes lines that match the expression.
| include
(Optional) Display includes lines that match the specified expression.
expression
Expression in the output to use as a reference point.
Though visible in the command-line help string, the remote keyword is not supported.
Command Modes
User EXEC
Command History
Release
Modification
12.1(13)AY
This command was introduced.
Usage Guidelines
Expressions are case sensitive. For example, if you enter | exclude output, the lines that contain output
do not appear, but the lines that contain Output appear.
Examples
This is an example of output for the show monitor privileged EXEC command for SPAN source
session 1:
Switch# show monitor session 1
Session 1
--------Type:
: Local Session
Source Ports
:
Both:
: Fa0/6
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show monitor
Related Commands
Command
Description
monitor session
Enables SPAN monitoring on a port and configures a port as a source or
destination port.
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show mvr
show mvr
Use the show mvr privileged EXEC command without keywords to display the Multicast VLAN
Registration (MVR) global parameter values, including whether or not MVR is enabled, the MVR
multicast VLAN, the maximum query response time, the number of multicast groups, and the MVR
mode (dynamic or compatible).
show mvr [ | {begin | exclude | include} expression]
Syntax Description
| begin
(Optional) Display begins with the line that matches the expression.
| exclude
(Optional) Display excludes lines that match the expression.
| include
(Optional) Display includes lines that match the specified expression.
expression
Expression in the output to use as a reference point.
Command Modes
Privileged EXEC
Command History
Release
Modification
12.1(13)AY
This command was introduced.
Usage Guidelines
Expressions are case sensitive. For example, if you enter | exclude output, the lines that contain output
do not appear, but the lines that contain Output appear.
Examples
This is an example of output from the show mvr command:
Switch# show mvr
MVR Running: TRUE
MVR multicast vlan: 1
MVR Max Multicast Groups: 256
MVR Current multicast groups: 256
MVR Global query response time: 5 (tenths of sec)
MVR Mode: compatible
In the previous example, the maximum number of multicast groups is 256. The MVR mode is either
compatible (for interoperability with Catalyst 2900 XL and Catalyst 3500 XL switches) or dynamic
(where operation is consistent with Internet Group Management Protocol [IGMP] snooping operation,
and dynamic MVR membership on source ports is supported).
Related Commands
Command
Description
mvr
Enables and configures multicast VLAN registration on the switch.
mvr type
Configures an MVR port as a receiver or a source port.
show mvr interface
Displays the configured MVR interfaces, status of the specified interface, or
all multicast groups to which the interface belongs.
show mvr members
Displays all ports that are members of an MVR multicast group.
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show mvr interface
show mvr interface
Use the show mvr interface privileged EXEC command without keywords to display the Multicast
VLAN Registration (MVR) receiver and source ports. Use the command with keywords to display MVR
parameters for a specific receiver port.
show mvr interface [interface-id [members [vlan vlan-id]] [ | {begin | exclude | include}
expression]
Syntax Description
interface-id
(Optional) Display MVR type, status, and Immediate-Leave setting for the
interface.
members
(Optional) Display all MVR groups to which the specified interface belongs.
vlan vlan-id
(Optional) Display the VLAN to which the receiver port belongs.
| begin
(Optional) Display begins with the line that matches the expression.
| exclude
(Optional) Display excludes lines that match the expression.
| include
(Optional) Display includes lines that match the specified expression.
expression
Expression in the output to use as a reference point.
Command Modes
Privileged EXEC
Command History
Release
Modification
12.1(13)AY
This command was introduced.
Usage Guidelines
If the entered port identification is a non-MVR port or a source port, the command returns an error
message. For receiver ports, it displays the port type, per port status, and Immediate-Leave setting.
Expressions are case sensitive. For example, if you enter | exclude output, the lines that contain output
do not appear, but the lines that contain Output appear.
Examples
This is an example of output from the show mvr interface command:
Switch# show mvr interface
Port
Type
Status
------------Gi0/1 SOURCE
ACTIVE/UP
Immediate Leave
--------------DISABLED
In the previous example, Status is defined as:
•
Active means the port is part of a VLAN.
•
Up/Down means that the port is forwarding/nonforwarding.
•
Inactive means that the port is not part of any VLAN.
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show mvr interface
This is an example of output from the show mvr interface gigabitethernet0/1 command:
Switch# show mvr interface gigabitethernet0/1
Type: RECEIVER Status: ACTIVE Immediate Leave: DISABLED
This is an example of output from the show mvr interface fastethernet0/1 member command:
Switch# show mvr interface fastethernet0/1 member
239.255.0.0
DYNAMIC ACTIVE
239.255.0.1
DYNAMIC ACTIVE
239.255.0.2
DYNAMIC ACTIVE
239.255.0.3
DYNAMIC ACTIVE
239.255.0.4
DYNAMIC ACTIVE
239.255.0.5
DYNAMIC ACTIVE
239.255.0.6
DYNAMIC ACTIVE
239.255.0.7
DYNAMIC ACTIVE
239.255.0.8
DYNAMIC ACTIVE
239.255.0.9
DYNAMIC ACTIVE
Related Commands
Command
Description
mvr
Enables and configures multicast VLAN registration on the switch.
mvr type
Configures an MVR port as a receiver or a source port.
show mvr
Displays the global MVR configuration on the switch.
show mvr members
Displays all receiver ports that are members of an MVR multicast group.
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show mvr members
show mvr members
Use the show mvr members privileged EXEC command to display all receiver and source ports that are
currently members of an IP multicast group.
show mvr members [ip-address] [ | {begin | exclude | include} expression]
Syntax Description
ip-address
(Optional) The IP multicast address. If the address is entered, all receiver and
source ports that are members of the multicast group appear. If no address is
entered, all members of all Multicast VLAN Registration (MVR) groups are listed.
If a group has no members, the group is listed as Inactive.
| begin
(Optional) Display begins with the line that matches the expression.
| exclude
(Optional) Display excludes lines that match the expression.
| include
(Optional) Display includes lines that match the specified expression.
expression
Expression in the output to use as a reference point.
Command Modes
Privileged EXEC
Command History
Release
Modification
12.1(13)AY
This command was introduced.
Usage Guidelines
The show mvr members command applies to receiver and source ports. For MVR compatible mode, all
source ports are members of all multicast groups.
Expressions are case sensitive. For example, if you enter | exclude output, the lines that contain output
do not appear, but the lines that contain Output appear.
Examples
This is an example of output from the show mvr members command:
Switch# show mvr members
MVR Group IP
Status
----------------239.255.0.1
ACTIVE
239.255.0.2
INACTIVE
239.255.0.3
INACTIVE
239.255.0.4
INACTIVE
239.255.0.5
INACTIVE
239.255.0.6
INACTIVE
239.255.0.7
INACTIVE
239.255.0.8
INACTIVE
239.255.0.9
INACTIVE
239.255.0.10
INACTIVE
Members
------Gi0/1(d), Fa0/2(s)
None
None
None
None
None
None
None
None
None
<output truncated>
239.255.0.255
239.255.1.0
INACTIVE
INACTIVE
None
None
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show mvr members
This is an example of output from the show mvr members 239.255.0.2 command. It shows how to view
the members of the IP multicast group 239.255.0.2.
Switch# show mvr member 239.255.0.2
239.255.0.2
ACTIVE
Gi0/1(d), Fa0/2(d)
Related Commands
Command
Description
mvr
Enables and configures multicast VLAN registration on the switch.
mvr type
Configures an MVR port as a receiver or a source port.
show mvr
Displays the global MVR configuration on the switch.
show mvr interface
Displays the configured MVR interfaces, status of the specified interface,
or all multicast groups to which the interface belongs.
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show pagp
show pagp
Use the show pagp user EXEC command to display Port Aggregation Protocol (PAgP) channel-group
information.
show pagp [channel-group-number] {counters | internal | neighbor} [ | {begin | exclude |
include} expression]
Syntax Description
channel-group-number
(Optional) Number of the channel group. The range is 1 to 6.
counters
Display traffic information.
internal
Display internal information.
neighbor
Display neighbor information.
| begin
(Optional) Display begins with the line that matches the expression.
| exclude
(Optional) Display excludes lines that match the expression.
| include
(Optional) Display includes lines that match the specified expression.
expression
Expression in the output to use as a reference point.
Command Modes
User EXEC
Command History
Release
Modification
12.1(13)AY
This command was introduced.
Usage Guidelines
You can enter any show pagp command to display the active port channel information. To display the
nonactive information, enter the show pagp command with a group number.
Expressions are case sensitive. For example, if you enter | exclude output, the lines that contain output
do not appear, but the lines that contain Output appear.
Examples
This is an example of output from the show pagp 1 counters command:
Switch> show pagp 1 counters
Information
Flush
Port
Sent
Recv
Sent
Recv
-------------------------------------Channel group: 1
Fa0/1
45
42
0
0
Fa0/2
45
41
0
0
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show pagp
This is an example of output from the show pagp 1 internal command:
Switch> show pagp 1 internal
Flags: S - Device is sending Slow hello.
A - Device is in Auto mode.
Timers: H - Hello timer is running.
S - Switching timer is running.
C - Device is in Consistent state.
Q - Quit timer is running.
I - Interface timer is running.
Channel group 1
Port
Fa0/1
Fa0/2
Flags State
SC
U6/S7
SC
U6/S7
Timers
H
H
Hello
Interval
30s
30s
Partner PAgP
Count
Priority
1
128
1
128
Learning Group
Method Ifindex
Any
16
Any
16
This is an example of output from the show pagp 1 neighbor command:
Switch> show pagp 1 neighbor
Flags: S - Device is sending Slow hello.
A - Device is in Auto mode.
Channel group 1 neighbors
Partner
Port
Name
Fa0/1
device-p2
Fa0/2
device-p2
Related Commands
C - Device is in Consistent state.
P - Device learns on physical port.
Partner
Device ID
0002.4b29.4600
0002.4b29.4600
Partner
Port
Fa0/1
Fa0/2
Partner
Age Flags
9s SC
24s SC
Group
Cap.
10001
10001
Command
Description
clear pagp
Clears PAgP channel-group information.
pagp learn-method
Sets the source-address learning method of incoming packets received
from an EtherChannel port.
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show parser macro
show parser macro
Use the show parser macro user EXEC command to display the parameters for all configured macros
or for one macro on the switch.
show parser macro [{brief | description [interface interface-id] | name macro-name}] [ | {begin
| exclude | include} expression]
Syntax Description
brief
(Optional) Display the name of each macro.
description [interface
interface-id]
(Optional) Display all macro descriptions or the description of a specific
interface.
name macro-name
(Optional) Display information about a single macro identified by the macro
name.
| begin
(Optional) Display begins with the line that matches the expression.
| exclude
(Optional) Display excludes lines that match the expression.
| include
(Optional) Display includes lines that match the specified expression.
expression
Expression in the output to use as a reference point.
Command Modes
User EXEC
Command History
Release
Modification
12.1(19)EA1
This command was introduced.
Usage Guidelines
Expressions are case sensitive. For example, if you enter | exclude output, the lines that contain output
do not appear, but the lines that contain Output appear.
Examples
This is a partial output example from the show parser macro command. The output for the
Cisco-default macros varies depending on the switch platform and the software image running on the
switch:
Switch# show parser macro
Total number of macros = 6
-------------------------------------------------------------Macro name : cisco-global
Macro type : default global
# Enable dynamic port error recovery for link state
# failures
errdisable recovery cause link-flap
errdisable recovery interval 60
<output truncated>
-------------------------------------------------------------Macro name : cisco-desktop
Macro type : default interface
# macro keywords $AVID
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show parser macro
# Basic interface - Enable data VLAN only
# Recommended value for access vlan (AVID) should not be 1
switchport access vlan $AVID
switchport mode access
<output truncated>
-------------------------------------------------------------Macro name : cisco-phone
Macro type : default interface
# Cisco IP phone + desktop template
# macro keywords $AVID $VVID
# VoIP enabled interface - Enable data VLAN
# and voice VLAN (VVID)
# Recommended value for access vlan (AVID) should not be 1
switchport access vlan $AVID
switchport mode access
<output truncated>
-------------------------------------------------------------Macro name : cisco-switch
Macro type : default interface
# macro keywords $NVID
# Access Uplink to Distribution
# Do not apply to EtherChannel/Port Group
# Define unique Native VLAN on trunk ports
# Recommended value for native vlan (NVID) should not be 1
switchport trunk native vlan $NVID
<output truncated>
-------------------------------------------------------------Macro name : cisco-router
Macro type : default interface
# macro keywords $NVID
# Access Uplink to Distribution
# Define unique Native VLAN on trunk ports
# Recommended value for native vlan (NVID) should not be 1
switchport trunk native vlan $NVID
<output truncated>
-------------------------------------------------------------Macro name : snmp
Macro type : customizable
#enable port security, linkup, and linkdown traps
snmp-server enable traps port-security
snmp-server enable traps linkup
snmp-server enable traps linkdown
#set snmp-server host
snmp-server host ADDRESS
#set SNMP trap notifications precedence
snmp-server ip precedence VALUE
--------------------------------------------------------------
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show parser macro
This is an example of output from the show parser macro name command:
Switch# show parser macro name standard-switch10
Macro name : standard-switch10
Macro type : customizable
macro description standard-switch10
# Trust QoS settings on VOIP packets
auto qos voip trust
# Allow port channels to be automatically formed
channel-protocol pagp
This is an example of output from the show parser macro brief command:
Switch# show parser macro brief
default global
: cisco-global
default interface: cisco-desktop
default interface: cisco-phone
default interface: cisco-switch
default interface: cisco-router
customizable
: snmp
This is an example of output from the show parser description command:
Switch# show parser macro description
Global Macro(s): cisco-global
Interface
Macro Description(s)
-------------------------------------------------------------Fa0/1
standard-switch10
Fa0/2
this is test macro
--------------------------------------------------------------
This is an example of output from the show parser description interface command:
Switch# show parser macro description interface fastethernet0/2
Interface
Macro Description
-------------------------------------------------------------Fa0/2
this is test macro
--------------------------------------------------------------
Related Commands
Command
Description
macro apply
Applies a macro on an interface or applies and traces a macro on an interface.
macro description
Adds a description about the macros that are applied to an interface.
macro global
Applies a macro on a switch or applies and traces a macro on a switch.
macro global
description
Adds a description about the macros that are applied to the switch.
macro name
Creates a macro.
show running-config
Displays the current operating configuration, including defined macros. For
syntax information, select Cisco IOS Configuration Fundamentals
Command Reference, Release 12.1> File Management Commands >
Configuration File Management Commands.
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show port-security
show port-security
Use the show port-security privileged EXEC command to display the port security settings defined for
an interface or for the switch.
show port-security [interface interface-id] [address] [ | {begin | exclude | include} expression]
Syntax Description
interface
interface-id
(Optional) Display the port security settings for the specified interface.
address
(Optional) Display all the secure addresses on all ports.
| begin
(Optional) Display begins with the line that matches the specified expression.
| exclude
(Optional) Display excludes lines that match the specified expression.
| include
(Optional) Display includes lines that match the specified expression.
expression
Expression in the output to use as a reference point.
Command Modes
Privileged EXEC
Command History
Release
Modification
12.1(13)AY
This command was introduced.
Usage Guidelines
If you enter this command without keywords, the output includes the administrative and the operational
status of all secure ports on the switch.
If you enter an interface-id, the show port-security command displays port security settings for the
interface.
If you enter the address keyword, the show port-security address command displays the secure MAC
addresses for all interfaces and the aging information for each secure address.
If you enter an interface-id and the address keyword, the show port-security interface interface-id
address command displays all the MAC addresses for the interface with aging information for each
secure address. You can also use this command to display all the MAC addresses for an interface even
if you have not enabled port security on it.
Expressions are case sensitive. For example, if you enter | exclude output, the lines that contain output
do not appear, but the lines that contain Output appear.
Examples
This is an example of output from the show port-security command:
Switch# show port-security
Secure Port
MaxSecureAddr CurrentAddr SecurityViolation Security
Action
(Count)
(Count)
(Count)
---------------------------------------------------------------------------Fa0/1
11
11
0
Shutdown
Fa0/2
15
5
0
Restrict
Fa0/2
5
4
0
Protect
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show port-security
---------------------------------------------------------------------------Total Addresses in System :21
Max Addresses limit in System :1024
This is an example of output from the show port-security interface command:
Switch# show port-security interface fastethernet0/2
Port Security :Enabled
Port status :SecureUp
Violation mode :Shutdown
Maximum MAC Addresses :11
Total MAC Addresses :11
Configured MAC Addresses :3
Aging time :20 mins
Aging type :Inactivity
SecureStatic address aging :Enabled
Security Violation count :0
This is an example of output from the show port-security address command:
Switch# show port-security address
Secure Mac Address Table
------------------------------------------------------------------Vlan
Mac Address
Type
Ports
Remaining Age
(mins)
--------------------------------1
0001.0001.0001
SecureDynamic
Fa0/1
15 (I)
1
0001.0001.0002
SecureDynamic
Fa0/1
15 (I)
1
0001.0001.1111
SecureConfigured
Fa0/1
16 (I)
1
0001.0001.1112
SecureConfigured
Fa0/1
1
0001.0001.1113
SecureConfigured
Fa0/1
1
0005.0005.0001
SecureConfigured
Fa0/5
23
1
0005.0005.0002
SecureConfigured
Fa0/5
23
1
0005.0005.0003
SecureConfigured
Fa0/5
23
1
0011.0011.0001
SecureConfigured
Fa0/6
25 (I)
1
0011.0011.0002
SecureConfigured
Fa0/7
25 (I)
------------------------------------------------------------------Total Addresses in System :10
Max Addresses limit in System :1024
This is an example of output from the show port-security interface address command:
Switch# show port-security interface fastethernet0/5 address
Secure Mac Address Table
------------------------------------------------------------------Vlan
Mac Address
Type
Ports
Remaining Age
(mins)
--------------------------------1
0005.0005.0001
SecureConfigured
Fa0/5
19 (I)
1
0005.0005.0002
SecureConfigured
Fa0/5
19 (I)
1
0005.0005.0003
SecureConfigured
Fa0/5
19 (I)
------------------------------------------------------------------Total Addresses:3
Related Commands
Command
Description
switchport port-security
Enables port security on a port, restricts the use of the port to a
user-defined group of stations, and configures secure MAC addresses.
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show running-config vlan
show running-config vlan
Use the show running-config vlan privileged EXEC command to display all or a range of
VLAN-related configurations on the switch.
show running-config vlan [vlan-ids] [ | {begin | exclude | include} expression]
Syntax Description
vlan-ids
(Optional) Display configuration information for a single VLAN identified by
VLAN ID number or a range of VLANs separated by a hyphen. The range is 1 to
4094.
| begin
(Optional) Display begins with the line that matches the expression.
| exclude
(Optional) Display excludes lines that match the expression.
| include
(Optional) Display includes lines that match the specified expression.
expression
Expression in the output to use as a reference point.
Command Modes
Privileged EXEC
Command History
Release
Modification
12.1(13)AY
This command was introduced.
Usage Guidelines
Expressions are case sensitive. For example, if you enter | exclude output, the lines that contain output
do not appear, but the lines that contain Output appear.
Examples
This is an example of output from the show running-config vlan command:
Switch# show running-config vlan 900-2005
Building configuration...
Current configuration:
!
vlan 107
!
vlan 120
!
vlan 925
!
vlan 1000
end
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show running-config vlan
Related Commands
Command
Description
show running-config
Displays the running configuration on the switch. For syntax information,
select Cisco IOS Configuration Fundamentals Command Reference for
Release 12.1 > Cisco IOS File Management Commands > Configuration File
Commands.
vlan (global
configuration)
Enters config-vlan mode for creating and editing VLANs. When VLAN
Trunking Protocol (VTP) mode is transparent, you can use this mode to
create extended-range VLANs (VLAN IDs greater than 1005).
vlan database
Enters VLAN configuration mode for creating and editing normal-range
VLANs.
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show setup express
show setup express
Use the show setup express privileged EXEC command to show if Express Setup mode is active on the
switch.
show setup express
Syntax Description
This command has no arguments or keywords.
Defaults
No default is defined.
Command Modes
Privileged EXEC
Command History
Release
Modification
12.1(13)AY
This command was introduced.
Examples
This is an example of output from the show setup express command:
Switch# show setup express
express setup mode is active
Related Commands
Command
Description
setup express
Enables Express Setup mode on the switch.
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show spanning-tree
show spanning-tree
Use the show spanning-tree user EXEC command to display spanning-tree state information.
show spanning-tree [active [detail] | backbonefast | blockedports | bridge | detail [active] |
inconsistentports | interface interface-id | mst | pathcost method | root | summary [totals] |
uplinkfast | vlan vlan-id] [ | {begin | exclude | include} expression]
show spanning-tree vlan vlan-id [active [detail] | blockedports | bridge | detail [active] |
inconsistentports | interface interface-id | root | summary] [ | {begin | exclude | include}
expression
show spanning-tree {vlan vlan-id} bridge [address | detail | forward-time | hello-time | id |
max-age | priority [system-id] | protocol] [ | {begin | exclude | include} expression]
show spanning-tree {vlan vlan-id} root [address | cost | detail | forward-time | hello-time | id |
max-age | port | priority [system-id] [ | {begin | exclude | include} expression]
show spanning-tree interface interface-id [active [detail] | cost | detail [active] | inconsistency |
portfast | priority | rootcost | state] [ | {begin | exclude | include} expression]
show spanning-tree mst [configuration | instance-id] [detail | interface interface-id [detail]]
[ | {begin | exclude | include} expression]
Syntax Description
active [detail]
(Optional) Display spanning-tree information only on active interfaces
(only available in privileged EXEC mode).
backbonefast
(Optional) Display spanning-tree BackboneFast status.
blockedports
(Optional) Display blocked port information (only available in privileged
EXEC mode).
(Optional) Display status and configuration of this switch (optional
bridge [address | detail |
forward-time | hello-time | keywords only available in privileged EXEC mode).
id | max-age | priority
[system-id] | protocol]
detail [active]
(Optional) Display a detailed summary of interface information (active
keyword only available in privileged EXEC mode).
inconsistentports
(Optional) Display inconsistent port information (only available in
privileged EXEC mode).
interface interface-id
[active [detail] | cost |
detail [active] |
inconsistency | portfast |
priority | rootcost | state]
(Optional) Display spanning-tree information for the specified interface
(all options except portfast and state only available in privileged EXEC
mode). Enter each interface separated by a space. Ranges are not
supported. Valid interfaces include physical ports, VLANs, and port
channels. The VLAN range is 1 to 4094. The port-channel range is 1 to 6.
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show spanning-tree
(Optional) Display the multiple spanning-tree (MST) region
configuration and status (all options only available in privileged EXEC
mode).
mst [configuration |
instance-id] [detail |
interface interface-id
[detail]]
Display MST information for an instance, a range of instances separated
by a hyphen, or a series of instances separated by a comma. The range is
0 to 15.
Valid interfaces include physical ports, VLANs, and port channels. The
VLAN range is 1 to 4094. The port-channel range is 1 to 6.
pathcost method
(Optional) Display the default path cost method (only available in
privileged EXEC mode).
root [address | cost | detail (Optional) Display root switch status and configuration (all keywords
| forward-time | hello-time only available in privileged EXEC mode).
| id | max-age | port |
priority [system-id]]
summary [totals]
(Optional) Display a summary of port states or the total lines of the
spanning-tree state section.
uplinkfast
(Optional) Display spanning-tree UplinkFast status.
vlan vlan-id [active
[detail] | backbonefast |
blockedports | bridge
[address | detail |
forward-time | hello-time |
id | max-age | priority
[system-id] | protocol]
(Optional) Display spanning-tree information for a single VLAN
identified by VLAN ID number, a range of VLANs separated by a
hyphen, or a series of VLANs separated by a comma (some keywords
only available in privileged EXEC mode).
| begin
(Optional) Display begins with the line that matches the expression.
| exclude
(Optional) Display excludes lines that match the expression.
| include
(Optional) Display includes lines that match the specified expression.
expression
Expression in the output to use as a reference point.
The VLAN range is 1 to 4094.
Command Modes
User EXEC; indicated keywords available only in privileged EXEC mode
Command History
Release
Modification
12.1(13)AY
This command was introduced.
12.1(20)EA2
The mst keyword and options were added.
Usage Guidelines
If the vlan-id variable is omitted, the command applies to the spanning-tree instance for all VLANs.
Expressions are case sensitive. For example, if you enter | exclude output, the lines that contain output
do not appear, but the lines that contain Output appear.
Examples
This is an example of output from the show spanning-tree active command:
Switch# show spanning-tree active
VLAN0001
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show spanning-tree
Spanning tree enabled protocol ieee
Root ID
Priority
20481
Address
0008.217a.5800
Cost
38
Port
1 (FastEthernet0/1)
Hello Time
2 sec Max Age 20 sec
Bridge ID
Forward Delay 15 sec
Priority
32769 (priority 32768 sys-id-ext 1)
Address
0008.205e.6600
Hello Time
2 sec Max Age 20 sec Forward Delay 15 sec
Aging Time 300
Interface
Role Sts Cost
Prio.Nbr Type
---------------- ---- --- --------- -------- -------------------------------Fa0/1
Root FWD 19
128.1
P2p
This is an example of output from the show spanning-tree detail command:
Switch> show spanning-tree detail
VLAN0001 is executing the ieee compatible Spanning Tree protocol
Bridge Identifier has priority 32768, sysid 1, address 0008.205e.6600
Configured hello time 2, max age 20, forward delay 15
Current root has priority 20481, address 0008.217a.5800
Root port is 1 (FastEthernet0/1), cost of root path is 38
Topology change flag not set, detected flag not set
Number of topology changes 0 last change occurred 3w0d ago
Times: hold 1, topology change 35, notification 2
hello 2, max age 20, forward delay 15
Timers: hello 0, topology change 0, notification 0, aging 300
Port 1 (FastEthernet0/1) of VLAN0001 is forwarding
Port path cost 19, Port priority 128, Port Identifier 128.1.
Designated root has priority 20481, address 0008.217a.5800
Designated bridge has priority 65535, address 0050.2aed.5c80
Designated port id is 128.26, designated path cost 19
Timers: message age 3, forward delay 0, hold 0
Number of transitions to forwarding state: 1
Link type is point-to-point by default
BPDU: sent 0, received 947349
<output truncated>
This is an example of output from the show spanning-tree interface fastethernet0/1 command:
Switch> show spanning-tree interface fastethernet0/1
Vlan
---------------VLAN0001
VLAN0002
VLAN0003
Role
---Root
Desg
Desg
Sts
--FWD
FWD
FWD
Cost
--------19
19
19
Prio.Nbr
-------128.1
128.2
128.2
Type
-------------------------------P2p
P2p
P2p
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show spanning-tree
This is an example of output from the show spanning-tree summary command:
Switch> show spanning-tree summary
Switch is in pvst mode
Root bridge for: none
EtherChannel misconfiguration guard
Extended system ID
is enabled
Portfast
is disabled by
PortFast BPDU Guard is disabled by
Portfast BPDU Filter is disabled by
Loopguard
is disabled by
UplinkFast
is disabled
BackboneFast
is disabled
Pathcost method used is short
is enabled
default
default
default
default
Name
Blocking Listening Learning Forwarding STP Active
---------------------- -------- --------- -------- ---------- ---------VLAN0001
0
0
0
1
1
---------------------- -------- --------- -------- ---------- ---------1 vlan
0
0
0
1
1
<output truncated>
This is an example of output from the show spanning-tree mst configuration command:
Switch# show spanning-tree mst configuration
Name
[region1]
Revision 1
Instance Vlans mapped
-------- --------------------------------------------------------------------0
101-4094
1
1-100
-------------------------------------------------------------------------------
This is an example of output from the show spanning-tree mst interface fastethernet0/1 command:
Switch# show spanning-tree mst interface fastethernet0/1
FastEthernet0/1 of MST00 is designated forwarding
Edge port:no
(default)
port guard :none
Link type:point-to-point (auto)
bpdu filter:disable
Boundary :internal
bpdu guard :disable
Bpdus sent 84122, received 83933
Instance
-------0
1
Role
---Desg
Root
Sts
--FWD
FWD
Cost
--------200000
200000
Prio.Nbr
-------128.1
128.1
(default)
(default)
(default)
Vlans mapped
------------------------------101-4094
1-100
This is an example of output from the show spanning-tree mst 0 command:
Switch# show spanning-tree mst 0
###### MST00
vlans mapped: 101-4094
Bridge
address 0005.7428.1f40 priority 32768 (32768 sysid 0)
Root
address 0001.42e2.cdc6 priority 32768 (32768 sysid 0)
port
Fa0/2
path cost 200038
IST master this switch
Operational hello time 2, forward delay 15, max age 20
Configured hello time 2, forward delay 15, max age 20, max hops 20
Interface
---------------Fa0/1
Fa0/2
Role
---Desg
Root
Sts
--FWD
FWD
Cost
--------200000
200000
Prio.Nbr
-------128.1
128.2
Type
-------------------------------P2p
P2p Bound(PVST)
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show spanning-tree
Related Commands
Command
Description
clear spanning-tree counters
Clears the spanning-tree counters.
clear spanning-tree detected-protocols Restarts the protocol migration process.
spanning-tree backbonefast
Enables the BackboneFast feature.
spanning-tree bpdufilter
Prevents a port from sending or receiving bridge protocol
data units (BPDUs).
spanning-tree bpduguard
Puts a port in the error-disabled state when it receives a
BPDU.
spanning-tree cost
Sets the path cost for spanning-tree calculations.
spanning-tree extend system-id
Enables the extended system ID feature.
spanning-tree guard
Enables the root guard or the loop guard feature for all the
VLANs associated with the selected interface.
spanning-tree link-type
Overrides the default link-type setting for rapid
spanning-tree transitions to the forwarding state.
spanning-tree loopguard default
Prevents alternate or root ports from becoming the
designated port because of a failure that leads to a
unidirectional link.
spanning-tree mst configuration
Enters multiple spanning-tree (MST) configuration mode
through which the MST region configuration occurs.
spanning-tree mst cost
Sets the path cost for MST calculations.
spanning-tree mst forward-time
Sets the forward-delay time for all MST instances.
spanning-tree mst hello-time
Sets the interval between hello BPDUs sent by root switch
configuration messages.
spanning-tree mst max-age
Sets the interval between messages that the spanning tree
receives from the root switch.
spanning-tree mst max-hops
Sets the number of hops in an MST region before the
BPDU is discarded and the information held for a port is
aged.
spanning-tree mst port-priority
Configures an interface priority.
spanning-tree mst priority
Configures the switch priority for the specified
spanning-tree instance.
spanning-tree mst root
Configures the MST root switch priority and timers based
on the network diameter.
spanning-tree port-priority
Configures an interface priority.
spanning-tree portfast (global
configuration)
Globally enables the BPDU filtering or the BPDU guard
feature on Port Fast-enabled ports or enables the Port Fast
feature on all nontrunking ports.
spanning-tree portfast (interface
configuration)
Enables the Port Fast feature on an interface and all its
associated VLANs.
spanning-tree uplinkfast
Accelerates the choice of a new root port when a link or
switch fails or when the spanning tree reconfigures itself.
spanning-tree vlan
Configures spanning tree on a per-VLAN basis.
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show storm-control
show storm-control
Use the show storm-control user EXEC command to display the packet-storm control information. This
command also displays the action that the switch takes when the thresholds are reached.
show storm-control [interface-id] [{broadcast | history | multicast | unicast}] [ | {begin | exclude
| include} expression]
Syntax Description
interface-id
(Optional) Port for which information is to be displayed.
broadcast
(Optional) Display broadcast storm information.
history
(Optional) Display storm history on a per-port basis.
multicast
(Optional) Display multicast storm information.
unicast
(Optional) Display unicast storm information.
| begin
(Optional) Display begins with the line that matches the specified
expression.
| exclude
(Optional) Display excludes lines that match the specified expression.
| include
(Optional) Display includes lines that match the specified expression.
expression
Expression in the output to use as a reference point.
Command Modes
User EXEC
Command History
Release
Modification
12.1(13)AY
This command was introduced.
Usage Guidelines
If the variable interface-id is omitted, the show storm-control command displays storm-control settings
for all ports on the switch.
You can display broadcast, multicast, or unicast packet-storm information by using the corresponding
keyword. When no option is specified, the default is to display broadcast storm-control information.
Expressions are case sensitive. For example, if you enter | exclude output, the lines that contain output
do not appear, but the lines that contain Output appear.
Examples
This is an example of output from the show storm-control broadcast command when the rising and
falling suppression levels are defined as percentages of the total bandwidth:
Switch> show storm-control broadcast
Interface
--------Fa0/1
Fa0/2
Fa0/3
Fa0/4
Filter State
------------<inactive>
<inactive>
<inactive>
Forwarding
Trap State
------------<inactive>
<inactive>
<inactive>
Below rising
Upper
------100.00%
100.00%
100.00%
30.00%
Lower
Current
------- ------100.00%
0.00%
100.00%
0.00%
100.00%
0.00%
20.00% 20.32%
Traps Sent
---------0
0
0
17
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show storm-control
Table 2-20 lists the show storm-control field descriptions.
Table 2-20
show storm-control Field Descriptions
Field
Description
Interface
Displays the ID of the interface.
Filter State
Displays the status of the filter:
•
Blocking—Storm control is enabled, action is filter, and a storm has
occurred.
•
Forwarding—Storm control is enabled, and a storm has not occurred.
•
Inactive—Storm control is disabled.
•
Shutdown—Storm control is enabled, the action is to shut down, and a
storm has occurred.
Note
Trap State
If an interface is disabled by a broadcast, multicast, or unicast storm,
the filter state for all traffic types is shutdown.
Displays the status of the SNMP trap:
•
Above rising—Storm control is enabled, and a storm has occurred.
•
Below rising—Storm control is enabled, and a storm has not occurred.
•
Inactive—The trap option is not enabled.
Upper
Displays the rising suppression level as a percentage of total available
bandwidth.
Lower
Displays the falling suppression level as a percentage of total available
bandwidth.
Current
Displays the bandwidth utilization of a specific traffic type as a percentage
of total available bandwidth. This field is valid only when storm control is
enabled.
Traps Sent
Displays the number traps sent on an interface for a specific traffic type.
This is an example of output from the show storm-control fastethernet0/4 history command, which
displays the ten most recent storm events for an interface:
Switch> show storm-control fastethernet0/4 history
Interface Fa0/4 Storm Event History
Event Type
-----------------Unicast
Broadcast
Multicast
Unicast
Broadcast
Multicast
Unicast
Broadcast
Multicast
Broadcast
Event Start Time
---------------04:58:18
05:01:54
05:01:54
05:01:54
05:05:00
05:05:00
05:06:00
05:09:39
05:09:39
05:11:32
Duration (seconds)
-----------------206
n/a
n/a
108
n/a
n/a
n/a
n/a
n/a
172
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Note
Related Commands
The duration field could be n/a when a storm is still present or when a new storm of a different type
occurs before the current storm ends.
Command
Description
storm-control
Enables broadcast, multicast, or unicast storm control on a port.
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show system mtu
show system mtu
Use the show system mtu privileged EXEC command to display the global maximum packet size or
maximum transmission unit (MTU) set for the switch.
show system mtu [ | {begin | exclude | include} expression]
Syntax Description
| begin
(Optional) Display begins with the line that matches the expression.
| exclude
(Optional) Display excludes lines that match the expression.
| include
(Optional) Display includes lines that match the specified expression.
expression
Expression in the output to use as a reference point.
Command Modes
Privileged EXEC
Command History
Release
Modification
12.1(13)AY
This command was introduced.
Usage Guidelines
Expressions are case sensitive. For example, if you enter | exclude output, the lines that contain output
do not appear, but the lines that contain Output appear.
Examples
This is an example of output from the show system mtu command:
Switch# show system mtu
System MTU size is 1500 bytes
Related Commands
Command
Description
system mtu
Sets the MTU size for the switch.
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show udld
show udld
Use the show udld user EXEC command to display UniDirectional Link Detection (UDLD) status for
all ports or the specified port.
show udld [interface-id] [ | {begin | exclude | include} expression]
Syntax Description
interface-id
(Optional) ID of the interface and port number. Valid interfaces include
physical ports and VLANs. The VLAN range is 1 to 4094.
| begin
(Optional) Display begins with the line that matches the specified
expression.
| exclude
(Optional) Display excludes lines that match the specified expression.
| include
(Optional) Display includes lines that match the specified expression.
expression
Expression in the output to use as a reference point.
Command Modes
User EXEC
Command History
Release
Modification
12.1(13)AY
This command was introduced.
Usage Guidelines
If you do not enter an interface-id, the administrative and the operational UDLD status for all interfaces
appear.
Expressions are case sensitive. For example, if you enter | exclude output, the lines that contain output
do not appear, but the lines that contain Output appear.
Examples
This is an example of output from the show udld gigabitethernet0/1 command. In this example, UDLD
is enabled on both ends of the link, and UDLD detects that the link is bidirectional. Table 2-21 describes
the fields in this example.
Switch> show udld gigabitethernet0/1
Interface gi0/1
--Port enable administrative configuration setting: Follows device default
Port enable operational state: Enabled
Current bidirectional state: Bidirectional
Current operational state: Advertisement - Single Neighbor detected
Message interval: 60
Time out interval: 5
Entry 1
Expiration time: 146
Device ID: 1
Current neighbor state: Bidirectional
Device name: 0050e2826000
Port ID: Gi0/2
Neighbor echo 1 device: SAD03160954
Neighbor echo 1 port: Gi0/1
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show udld
Message interval: 5
CDP Device name: 066527791
Table 2-21
show udld Field Descriptions
Field
Description
Interface
The interface on the local device configured for UDLD.
Port enable administrative
configuration setting
How UDLD is configured on the port. If UDLD is enabled or
disabled, the port enable configuration setting is the same as the
operational enable state. Otherwise, the enable operational setting
depends on the global enable setting.
Port enable operational state
Operational state that shows whether UDLD is actually running on
this port.
Current bidirectional state
The bidirectional state of the link. An unknown state appears if the
link is down or if it is connected to an UDLD-incapable device. A
bidirectional state appears if the link is a normal two-way connection
to a UDLD-capable device. All other values mean miswiring.
Current operational state
The phase of the UDLD state machine. For a normal bidirectional
link, the state machine is usually in the Advertisement phase.
Message interval
How often advertisement messages are sent from the local device.
Measured in seconds.
Time out interval
The time period, in seconds, that UDLD waits for echoes from a
neighbor device during the detection window.
Entry 1
Information from the first cache entry, which contains a copy of echo
information received from the neighbor.
Expiration time
The amount of time in seconds remaining before this cache entry is
aged out.
Device ID
The neighbor device identification.
Current neighbor state
The neighbor’s state. If both the local and neighbor devices are
running UDLD, the neighbor state and the local state is bidirectional.
If the link is down or the neighbor is not UDLD-capable, no cache
entries appear.
Device name
The neighbor MAC address.
Port ID
The neighbor port ID enabled for UDLD.
Neighbor echo 1 device
The MAC address of the neighbors’ neighbor from which the echo
originated.
Neighbor echo 1 port
The port number ID of the neighbor from which the echo originated.
Message interval
The rate, in seconds, at which the neighbor is sending advertisement
messages.
CDP1 device name
CDP name of the device.
1. CDP = Cisco Discovery Protocol
This is an example of output from the show udld interface configuration command when the aggressive
mode is configured:
Switch# show udld gigabitethernet0/1
Interface Gi0/1
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show udld
--Port enable administrative configuration setting:Enabled / in aggressive mode
Port enable operational state:Enabled / in aggressive mode
Current bidirectional state:Unknown
Current operational state:Link down
Message interval:7
Time out interval:5
No neighbor cache information stored
Related Commands
Command
Description
udld
Enables UDLD on all ports on the switch.
udld port
Enables UDLD on a specific port.
udld reset
Resets any interface that was shut down by UDLD.
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show version
show version
Use the show version user EXEC command to display version information for the hardware and
firmware.
show version [ | {begin | exclude | include} expression]
Syntax Description
| begin
(Optional) Display begins with the line that matches the specified
expression.
| exclude
(Optional) Display excludes lines that match the specified expression.
| include
(Optional) Display includes lines that match the specified expression.
expression
Expression in the output to use as a reference point.
Command Modes
User EXEC
Command History
Release
Modification
12.1(13)AY
This command was introduced.
Usage Guidelines
Expressions are case sensitive. For example, if you enter | exclude output, the lines that contain output
do not appear, but the lines that contain Output appear.
Examples
This is an example of output from the show version command:
Note
Though visible in the show version output, the configuration register information is not
supported on the switch.
Switch> show version
Cisco Internetwork Operating System Software
IOS (tm) C2940 Software (C2940-I6Q4L2-M), Version 12.1(13)AY
Copyright (c) 1986-2003 by cisco Systems, Inc.
Compiled Wed 02-Apr-03 09:51 by antonino
Image text-base: 0x80010000, data-base: 0x805B6000
ROM: Bootstrap program is C2940 boot loader
Switch uptime is 6 days, 17 hours, 56 minutes
System returned to ROM by power-on
System image file is "flash:c2940-i6q4l2-mz.121-0.0.9.AY.bin"
cisco WS-C2940-8TT-S (RC32300) processor with 20799K bytes of memory.
Last reset from system-reset
Running Standard Image
8 FastEthernet/IEEE 802.3 interface(s)
1 Gigabit Ethernet/IEEE 802.3 interface(s)
32K bytes of flash-simulated non-volatile configuration memory.
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show version
Base ethernet MAC Address: 00:03:FD:62:91:80
Configuration register is 0xF
<output truncated>
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show vlan
show vlan
Use the show vlan user EXEC command to display the parameters for all configured VLANs or one
VLAN (if the VLAN ID or name is specified) on the switch.
show vlan [brief | id vlan-id | name vlan-name |] [ | {begin | exclude | include} expression]
Syntax Description
Syntax Description
Note
brief
(Optional) Display one line for each VLAN with the VLAN name, status, and its
ports.
id vlan-id
(Optional) Display information about a single VLAN identified by VLAN ID
number or a range of VLANs. For vlan-id, the range is 1 to 4094.
name vlan-name
(Optional) Display information about a single VLAN identified by VLAN name.
The VLAN name is an ASCII string from 1 to 32 characters.
| begin
(Optional) Display begins with the line that matches the expression.
| exclude
(Optional) Display excludes lines that match the expression.
| include
(Optional) Display includes lines that match the specified expression.
expression
Expression in the output to use as a reference point.
Though visible in the command-line help string, the ifindex, private vlan, and remote-span keywords
are not supported.
Command Modes
User EXEC
Command History
Release
Modification
12.1(13)AY
This command was introduced.
Usage Guidelines
Expressions are case sensitive. For example, if you enter | exclude output, the lines that contain output
do not appear, but the lines that contain Output appear.
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show vlan
Examples
This is an example of output from the show vlan command. Table 2-22 describes each field in the
display.
Switch> show vlan
VLAN
---1
2
51
52
100
400
1002
1003
1004
1005
Name
-------------------------------default
VLAN0002
VLAN0051
VLAN0052
VLAN0100
VLAN0400
fddi-default
token-ring-default
fddinet-default
trnet-default
Status
--------active
active
active
active
suspended
suspended
active
active
active
active
Ports
------------------------------Fa0/1, Fa0/2, Fa0/5, Fa0/7
Fa0/3
VLAN Type SAID
MTU
Parent RingNo BridgeNo Stp BrdgMode Trans1 Trans2
---- ----- ---------- ----- ------ ------ -------- ---- -------- ------ -----1
enet 100001
1500 1002
1003
2
enet 100002
1500 0
0
51
enet 100051
1500 0
0
52
enet 100052
1500 0
0
100 enet 100100
1500 0
0
400 enet 100400
1500 0
0
1002 fddi 101002
1500 1
1003
1003 tr
101003
1500 1005
3276
srb
1
1002
1004 fdnet 101004
1500 1
ieee 0
0
1005 trnet 101005
1500 15
ibm 0
0
Remote SPAN VLANs
------------------------------------------------------------------------------
Primary Secondary Type
Ports
------- --------- ----------------- ------------------------------------------
Table 2-22
show vlan Command Output Fields
Field
Description
VLAN
VLAN number.
Name
Name, if configured, of the VLAN.
Status
Status of the VLAN (active or suspend).
Ports
Ports that belong to the VLAN.
Type
Media type of the VLAN.
SAID
Security association ID value for the VLAN.
MTU
Maximum transmission unit size for the VLAN.
Parent
Parent VLAN, if one exists.
RingNo
Ring number for the VLAN, if applicable.
BrdgNo
Bridge number for the VLAN, if applicable.
Stp
Spanning Tree Protocol type used on the VLAN.
BrdgMode
Bridging mode for this VLAN—possible values are source-route bridging
(SRB) and source-route transparent (SRT); the default is SRB.
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show vlan
Table 2-22
show vlan Command Output Fields (continued)
Field
Description
Trans1
Translation bridge 1.
Trans2
Translation bridge 2.
AREHops
Maximum number of hops for All-Routes Explorer frames—possible values
are 1 through 13; the default is 7.
STEHops
Maximum number of hops for Spanning-Tree Explorer frames—possible
values are 1 to 13; the default is 7.
Backup CRF
Status of whether or not the Token Ring concentrator relay function (TrCRF)
is a backup path for traffic.
This is an example of output from the show vlan brief command:
Switch> show vlan brief
VLAN Name
Status
Ports
---- -------------------------------- --------- ------------------------------1
default
active
Fa0/1, Fa0/2, Fa0/3, Fa0/4
Fa0/5, Fa0/6
1002 fddi-default
active
1003 token-ring-default
active
1004 fddinet-default
active
1005 trnet-default
active
This is an example of output from the show vlan id command. The specified VLAN is in the extended
VLAN range.
Switch# show vlan id 2005
VLAN Name
Status
Ports
---- -------------------------------- --------- ------------------------------2005 VLAN 2005
active
Fa0/2
VLAN Type SAID
MTU
Parent RingNo BridgeNo Stp BrdgMode Trans1 Trans2
---- ----- ---------- ----- ------ ------ -------- ---- -------- ------ -----2005 enet 102005
1500 0
0
Related Commands
Command
Description
switchport mode
Configures the VLAN membership mode of a port.
vlan (global
configuration)
Enables config-vlan mode where you can configure VLANs 1 to 4094.
vlan (VLAN
configuration)
Configures VLAN characteristics in the VLAN database. Only available for
normal-range VLANs (VLAN IDs 1 to 1005).
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show vmps
show vmps
Use the show vmps user EXEC command without keywords to display the VLAN Query Protocol (VQP)
version, reconfirmation interval, retry count, VLAN Membership Policy Server (VMPS) IP addresses,
and the current and primary servers, or use the statistics keyword to display client-side statistics.
show vmps [statistics] [ | {begin | exclude | include} expression]
Syntax Description
statistics
(Optional) Display VQP client-side statistics and counters.
| begin
(Optional) Display begins with the line that matches the expression.
| exclude
(Optional) Display excludes lines that match the expression.
| include
(Optional) Display includes lines that match the specified expression.
expression
Expression in the output to use as a reference point.
Command Modes
User EXEC
Command History
Release
Modification
12.1(13)AY
This command was introduced.
Usage Guidelines
Expressions are case sensitive. For example, if you enter | exclude output, the lines that contain output
do not appear, but the lines that contain Output appear.
Examples
This is an example of output from the show vmps command:
Switch> show vmps
VQP Client Status:
-------------------VMPS VQP Version:
1
Reconfirm Interval: 60 min
Server Retry Count: 3
VMPS domain server:
Reconfirmation status
--------------------VMPS Action:
other
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show vmps
This is an example of output from the show vmps statistics command. Table 2-23 describes each field
in the example.
Switch> show vmps statistics
VMPS Client Statistics
---------------------VQP Queries:
0
VQP Responses:
0
VMPS Changes:
0
VQP Shutdowns:
0
VQP Denied:
0
VQP Wrong Domain:
0
VQP Wrong Version:
0
VQP Insufficient Resource: 0
Table 2-23
show vmps statistics Field Descriptions
Field
Description
VQP Queries
Number of queries sent by the client to the VMPS.
VQP Responses
Number of responses sent to the client from the VMPS.
VMPS Changes
Number of times that the VMPS changed from one server to another.
VQP Shutdowns
Number of times the VMPS sent a response to shut down the port. The client
disables the port and removes all dynamic addresses on this port from the
address table. You must administratively re-enable the port to restore
connectivity.
VQP Denied
Number of times the VMPS denied the client request for security reasons.
When the VMPS response denies an address, no frame is forwarded to or
from the workstation with that address. (Broadcast or multicast frames are
delivered to the workstation if the port on the switch has been assigned to a
VLAN.) The client keeps the denied address in the address table as a blocked
address to prevent further queries from being sent to the VMPS for each new
packet received from this workstation. The client ages the address if no new
packets are received from this workstation on this port within the aging time
period.
VQP Wrong Domain
Number of times the management domain in the request does not match the
one for the VMPS. Any previous VLAN assignments of the port are not
changed. This response means that the server and the client have not been
configured with the same VTP management domain.
VQP Wrong Version
Number of times the version field in the query packet contains a value that is
higher than the version supported by the VMPS. The previous VLAN
assignment of the port is not changed. The switches send only VMPS version
1 requests.
VQP Insufficient
Resource
Number of times the VMPS is unable to answer the request because of a
resource availability problem. If the retry limit has not yet been reached, the
client repeats the request with the same server or with the next alternate
server, depending on whether the per-server retry count has been reached.
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show vmps
Related Commands
Command
Description
clear vmps statistics
Clears the statistics maintained by the VQP client.
vmps reconfirm
(global configuration)
Sends VQP queries to reconfirm all dynamic VLAN assignments with the
VMPS.
vmps retry
Configures the per-server retry count for the VQP client.
vmps server
Configures the primary VMPS and up to three secondary servers.
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show vtp
show vtp
Use the show vtp user EXEC command to display general information about the VLAN Trunking
Protocol (VTP) management domain, status, and counters.
show vtp {counters | status} [ | {begin | exclude | include} expression]
Syntax Description
counters
Display the VTP statistics for the switch.
status
Display general information about the VTP management domain status.
| begin
(Optional) Display begins with the line that matches the expression.
| exclude
(Optional) Display excludes lines that match the expression.
| include
(Optional) Display includes lines that match the specified expression.
expression
Expression in the output to use as a reference point.
Command Modes
User EXEC
Command History
Release
Modification
12.1(13)AY
This command was introduced.
Usage Guidelines
Expressions are case sensitive. For example, if you enter | exclude output, the lines that contain output
do not appear, but the lines that contain Output appear.
Examples
This is an example of output from the show vtp counters command. Table 2-24 describes each field in
the display.
Switch> show vtp counters
VTP statistics:
Summary advertisements received
Subset advertisements received
Request advertisements received
Summary advertisements transmitted
Subset advertisements transmitted
Request advertisements transmitted
Number of config revision errors
Number of config digest errors
Number of V1 summary errors
:
:
:
:
:
:
:
:
:
38
0
0
13
3
0
0
0
0
VTP pruning statistics:
Trunk
Join Transmitted Join Received
Summary advts received from
non-pruning-capable device
---------------- ---------------- ---------------- --------------------------Fa0/1
827
824
0
Fa0/2
827
823
0
Fa0/3
827
823
0
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show vtp
Table 2-24
show vtp counters Field Descriptions
Field
Description
Summary advertisements
received
Number of summary advertisements received by this switch on its
trunk ports. Summary advertisements contain the management
domain name, the configuration revision number, the update
timestamp and identity, the authentication checksum, and the
number of subset advertisements to follow.
Subset advertisements received
Number of subset advertisements received by this switch on its
trunk ports. Subset advertisements contain all the information for
one or more VLANs.
Request advertisements received Number of advertisement requests received by this switch on its
trunk ports. Advertisement requests normally request information
on all VLANs. They can also request information on a subset of
VLANs.
Summary advertisements
transmitted
Number of summary advertisements sent by this switch on its trunk
ports. Summary advertisements contain the management domain
name, the configuration revision number, the update timestamp and
identity, the authentication checksum, and the number of subset
advertisements to follow.
Subset advertisements
transmitted
Number of subset advertisements sent by this switch on its trunk
ports. Subset advertisements contain all the information for one or
more VLANs.
Request advertisements
transmitted
Number of advertisement requests sent by this switch on its trunk
ports. Advertisement requests normally request information on all
VLANs. They can also request information on a subset of VLANs.
Number of configuration
revision errors
Number of revision errors.
Whenever you define a new VLAN, delete an existing one, suspend
or resume an existing VLAN, or modify the parameters on an
existing VLAN, the configuration revision number of the switch
increments.
Revision errors increment whenever the switch receives an
advertisement whose revision number matches the revision number
of the switch, but the MD5 digest values do not match. This error
means that the VTP password in the two switches is different or that
the switches have different configurations.
These errors means that the switch is filtering incoming
advertisements, which causes the VTP database to become
unsynchronized across the network.
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show vtp
Table 2-24
show vtp counters Field Descriptions (continued)
Field
Description
Number of configuration digest
errors
Number of MD5 digest errors.
Digest errors increment whenever the MD5 digest in the summary
packet and the MD5 digest of the received advertisement calculated
by the switch do not match. This error usually means that the VTP
password in the two switches is different. To solve this problem,
make sure the VTP password on all switches is the same.
These errors mean that the switch is filtering incoming
advertisements, which causes the VTP database to become
unsynchronized across the network.
Number of V1 summary errors
Number of version 1 errors.
Version 1 summary errors increment whenever a switch in VTP V2
mode receives a VTP version 1 frame. These errors mean that at
least one neighboring switch is either running VTP version 1 or VTP
version 2 with V2-mode disabled. To solve this problem, change the
configuration of the switches in VTP V2-mode to disabled.
Join Transmitted
Number of VTP pruning messages sent on the trunk.
Join Received
Number of VTP pruning messages received on the trunk.
Summary Advts Received from
non-pruning-capable device
Number of VTP summary messages received on the trunk from
devices that do not support pruning.
This is an example of output from the show vtp status command. Table 2-25 describes each field in the
display.
Switch> show vtp status
VTP Version
: 2
Configuration Revision
: 0
Maximum VLANs supported locally : 250
Number of existing VLANs
: 5
VTP Operating Mode
: Server
VTP Domain Name
:
VTP Pruning Mode
: Disabled
VTP V2 Mode
: Disabled
VTP Traps Generation
: Disabled
MD5 digest
: 0xBF 0x86 0x94 0x45 0xFC 0xDF 0xB5 0x70
Configuration last modified by 0.0.0.0 at 0-0-00 00:00:00
Local updater ID is 172.20.135.196 on interface Vl1 (lowest numbered VLAN interface found)
Table 2-25
show vtp status Field Descriptions
Field
Description
VTP Version
Displays the VTP version operating on the switch. By default, the
switch implements version 1 but can be set to version 2.
Configuration Revision
Current configuration revision number on this switch.
Maximum VLANs Supported
Locally
Maximum number of VLANs supported locally.
Number of Existing VLANs
Number of existing VLANs.
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show vtp
Table 2-25
show vtp status Field Descriptions (continued)
Field
Description
VTP Operating Mode
Displays the VTP operating mode, which can be server, client, or
transparent.
Server: a switch in VTP server mode is enabled for VTP and sends
advertisements. You can configure VLANs on it. The switch
guarantees that it can recover all the VLAN information in the
current VTP database from NVRAM after reboot. By default, every
switch is a VTP server.
Note
The switch automatically changes from VTP server mode to
VTP client mode if it detects a failure while writing the
configuration to NVRAM and cannot return to server mode
until the NVRAM is functioning.
Client: a switch in VTP client mode is enabled for VTP, can send
advertisements, but does not have enough nonvolatile storage to
store VLAN configurations. You cannot configure VLANs on it.
When a VTP client starts up, it does not send VTP advertisements
until it receives advertisements to initialize its VLAN database.
Transparent: a switch in VTP transparent mode is disabled for VTP,
does not send or learn from advertisements sent by other devices,
and cannot affect VLAN configurations on other devices in the
network. The switch receives VTP advertisements and forwards
them on all trunk ports except the one on which the advertisement
was received.
VTP Domain Name
Name that identifies the administrative domain for the switch.
VTP Pruning Mode
Displays whether pruning is enabled or disabled. Enabling pruning
on a VTP server enables pruning for the entire management domain.
Pruning restricts flooded traffic to those trunk links that the traffic
must use to access the appropriate network devices.
VTP V2 Mode
Displays if VTP version 2 mode is enabled. By default, all VTP
version 2 switches operate in version 1 mode. Each VTP switch
automatically detects the capabilities of all the other VTP devices.
A network of VTP devices should be configured to version 2 only
if all VTP switches in the network can operate in version 2 mode.
VTP Traps Generation
Displays whether VTP traps are sent to a network management
station.
MD5 Digest
A 16-byte checksum of the VTP configuration.
Configuration Last Modified
Displays the date and time of the last configuration modification.
Displays the IP address of the switch that caused the configuration
change to the database.
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show vtp
Related Commands
Command
Description
clear vtp counters
Clears the VTP and pruning counters.
vtp (global configuration)
Configures the VTP filename, interface name, domain name, and mode.
You can save configuration resulting from this command in the switch
configuration file.
vtp (VLAN configuration)
Configures the VTP domain name, password, pruning, and mode.
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show wrr-queue bandwidth
show wrr-queue bandwidth
Use the show wrr-queue bandwidth user EXEC command to display the weighted round-robin (WRR)
bandwidth allocation for the four class of service (CoS) priority queues.
show wrr-queue bandwidth [ | {begin | exclude | include} expression]
Syntax Description
| begin
(Optional) Display begins with the line that matches the specified
expression.
| exclude
(Optional) Display excludes lines that match the specified expression.
| include
(Optional) Display includes lines that match the specified expression.
expression
Expression in the output to use as a reference point.
Command Modes
User EXEC
Command History
Release
Modification
12.1(13)AY
This command was introduced.
Usage Guidelines
Expressions are case sensitive. For example, if you enter | exclude output, the lines that contain output
do not appear, but the lines that contain Output appear.
Examples
This is an example of output from the show wrr-queue bandwidth command:
Switch> show wrr-queue bandwidth
Related Commands
WRR Queue
:
1
2
3
4
Bandwidth
:
10
20
30
40
Command
Description
show wrr-queue cos-map
Displays the mapping of the CoS to the priority queues.
wrr-queue bandwidth
Assigns WRR weights to the four CoS priority queues.
wrr-queue cos-map
Assigns CoS values to the CoS priority queues.
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show wrr-queue cos-map
show wrr-queue cos-map
Use the show wrr-queue cos-map user EXEC command to display the mapping of the class of service
(CoS) priority queues.
show wrr-queue cos-map [ | {begin | exclude | include} expression]
Syntax Description
| begin
(Optional) Display begins with the line that matches the specified expression.
| exclude
(Optional) Display excludes lines that match the specified expression.
| include
(Optional) Display includes lines that match the specified expression.
expression
Expression in the output to use as a reference point.
Command Modes
User EXEC
Command History
Release
Modification
12.1(13)AY
This command was introduced.
Usage Guidelines
Expressions are case sensitive. For example, if you enter | exclude output, the lines that contain output
do not appear, but the lines that contain Output appear.
Examples
This is an example of output from the show wrr-queue cos-map command:
Switch> show wrr-queue cos-map
CoS Value
Related Commands
:
0
1
2
3
4
5
6
7
Priority Queue :
1
1
2
2
3
3
4
4
Command
Description
show wrr-queue bandwidth
Displays the WRR bandwidth allocation for the four CoS
priority queues.
wrr-queue bandwidth
Assigns weighted round-robin (WRR) weights to the four CoS
priority queues.
wrr-queue cos-map
Assigns CoS values to the CoS priority queues.
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shutdown
shutdown
Use the shutdown interface configuration command to disable a port and to shut down the management
VLAN. Use the no form of this command to enable a disabled port or to activate the management VLAN.
shutdown
no shutdown
Syntax Description
This command has no arguments or keywords.
Command Modes
Interface configuration
Command History
Release
Modification
12.1(13)AY
This command was introduced.
Usage Guidelines
The shutdown interface configuration command for a port causes it to stop forwarding. You can enable
the port with the no shutdown command.
The no shutdown command has no effect if the port is a static-access port assigned to a VLAN that has
been deleted, suspended, or shut down. The port must first be a member of an active VLAN before it can
be re-enabled.
Only one management VLAN interface can be active at a time. The remaining VLANs are shut down.
In the show running-config command, the active management VLAN interface is the one without the
shutdown command displayed.
Examples
This example shows how to disable a port and how to re-enable it:
Switch(config)# interface fastethernet0/1
Switch(config-if)# shutdown
Switch(config-if)# no shutdown
You can verify your settings by entering the show interfaces privileged EXEC command.
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shutdown vlan
shutdown vlan
Use the shutdown vlan global configuration command to shut down (suspend) local traffic on the
specified VLAN. Use the no form of this command to restart local traffic on the VLAN.
shutdown vlan vlan-id
no shutdown vlan vlan-id
Syntax Description
vlan-id
Defaults
No default is defined.
Command Modes
Global configuration
Command History
Release
Modification
12.1(13)AY
This command was introduced.
ID of the VLAN to be locally shut down. The range is 2 to 1001. VLANs defined as
default VLANs under the VLAN Trunking Protocol (VTP), as well as
extended-range VLANs (greater than 1005), cannot be shut down. The default
VLANs are 1 and 1002 to 1005.
Usage Guidelines
The shutdown vlan command does not change the VLAN information in the VTP database. It shuts
down traffic locally, but the switch still advertises VTP information.
Examples
This example shows how to shutdown traffic on VLAN 2:
Switch(config)# shutdown vlan 2
You can verify your setting by entering the show vlan privileged EXEC command.
Related Commands
Command
Description
shutdown
(config-vlan mode)
Shuts down local traffic on the VLAN when in config-VLAN mode (accessed
by the vlan vlan-id global configuration command).
vlan (global
configuration)
Enables config-vlan mode.
vlan database
Enters VLAN configuration mode.
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snmp-server enable traps
snmp-server enable traps
Use the snmp-server enable traps global configuration command to enable the switch to send Simple
Network Management Protocol (SNMP) notification for various trap types to the network management
system (NMS). Use the no form of this command to return to the default setting.
snmp-server enable traps [bridge | c2900 | cluster | config | copy-config | entity | envmon [fan |
shutdown | status | supply | temperature | voltage] | flash | hsrp | mac-notification |
port-security [trap-rate value] | rtr | snmp [authentication | coldstart | linkdown | linkup |
warmstart] | stpx | syslog | vlan-membership | vlancreate | vlandelete | vtp]
no snmp-server enable traps [bridge | c2900 | cluster | config | copy-config | entity | envmon [fan
| shutdown | status | supply | temperature | voltage] | flash | hsrp | mac-notification |
port-security [trap-rate ] | rtr | snmp [authentication | coldstart | linkdown | linkup |
warmstart]| stpx | syslog | vlan-membership | vlancreate | vlandelete | vtp]
Syntax Description
bridge
(Optional) Enable SNMP Spanning Tree Protocol (STP) bridge management
information base (MIB) traps.
c2900
(Optional) Enable SNMP configuration traps.
cluster
(Optional) Enable cluster traps.
config
(Optional) Enable SNMP configuration traps.
copy-config
(Optional) Enable SNMP copy-configuration traps.
entity
(Optional) Enable SNMP entity traps.
envmon
(Optional) Enable environmental monitor (EnvMon) MIB.
fan
(Optional) Enable SNMP EnvMon fan traps.
shutdown
(Optional) Enable SNMP EnvMon monitor shutdown traps.
status
Optional) Enable SNMP EnvMon monitor status change traps.
supply
(Optional) Enable SNMP power supply traps.
temperature
(Optional) Enable SNMP EnvMon temperature traps.
voltage
(Optional) Enable SNMP EnvMon voltage traps.
flash
(Optional) Enable SNMP FLASH notifications.
hsrp
(Optional) Enable Hot Standby Router Protocol (HSRP) traps.
mac-notification
(Optional) Enable MAC address notification traps.
port-security
(Optional) Enable port security traps.
trap-rate value
(Optional) Set the number of traps per second. The range is 0 to 1000.
rtr
(Optional) Enable SNMP Response Time Reporter traps.
snmp
(Optional) Enable SNMP traps.
authentication
(Optional) Enable SNMP authentication traps.
coldstart
(Optional) Enable SNMP coldstart traps.
linkdown
(Optional) Enable SNMP linkdown traps.
linkup
(Optional) Enable SNMP linkup traps.
warmstart
(Optional) Enable SNMP warmstart traps.
stpx
(Optional) Enable SNMP STPX MIB traps.
syslog
(Optional) Enable SNMP syslog traps.
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snmp-server enable traps
Note
vlan-membership
(Optional) Enable SNMP VLAN membership traps.
vlancreate
(Optional) Enable SNMP VLAN-created traps.
vlandelete
(Optional) Enable SNMP VLAN-deleted traps.
vtp
(Optional) Enable VLAN Trunking Protocol (VTP) traps.
Though visible in the command-line help strings, the flash insertion and flash removal keywords are
not supported. The snmp-server enable informs command is not supported. To enable sending of
SNMP inform notifications, use the snmp-server enable traps command combined with the
snmp-server host host-addr informs command..
Defaults
The sending of SNMP traps is disabled.
Command Modes
Global configuration
Command History
Release
Modification
12.1(13)AY
This command was introduced.
Usage Guidelines
Specify the host (NMS) that receives the traps by using the snmp-server host global configuration
command. If no trap types are specified, all trap types are sent.
Use the snmp-server enable traps command to enable sending of traps or informs, when supported.
Note
Informs are not supported in SNMPv1.
To enable more than one type of trap, you must enter a separate snmp-server enable traps command
for each trap type.
Examples
This example shows how to send EnvMon traps to the NMS:
Switch(config)# snmp-server enable traps envmon fan
This example shows how to send VTP traps to the NMS:
Switch(config)# snmp-server enable traps vtp
You can verify your setting by entering the show vtp status privileged EXEC or the show
running-config privileged EXEC command.
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snmp-server enable traps
Related Commands
Command
Description
show running-config
Displays the running configuration on the switch. For syntax information,
select Cisco IOS Configuration Fundamentals Command Reference for
Release 12.1 > Cisco IOS File Management Commands > Configuration
File Commands.
snmp-server host
Specifies the host that receives SNMP traps.
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snmp-server host
snmp-server host
Use the snmp-server host global configuration command to specify the recipient (host) of a Simple
Network Management Protocol (SNMP) notification operation. Use the no form of this command to
remove the specified host.
snmp-server host host-addr [informs | traps] [version {1 | 2c | 3 {auth | noauth}}]
community-string [bridge] [c2900] [cluster] [config] [copy-config] [entity] [envmon] [flash]
[hsrp] [mac-notification] [port-security] [rtr] [snmp] [stpx] [syslog] [tty] [udp-port
port-number] [vlan-membership] [vlancreate] [vlandelete] [vtp]
no snmp-server host host-addr [informs | traps] [version {1 | 2c | 3 {auth | noauth}}]
community-string
Syntax Description
host-addr
Name or Internet address of the host (the targeted recipient).
informs | traps
(Optional) Send SNMP traps or informs to this host.
version {1 | 2c | 3}
(Optional ) Version of SNMP used to send the traps.
These keywords are supported:
1—SNMPv1. This option is not available with informs.
2c—SNMPv2C.
3—SNMPv3. These optional keywords can follow the version 3 keyword:
•
auth (Optional). Enables Message Digest 5 (MD5) and Secure Hash
Algorithm (SHA) packet authentication.
•
community-string
Password-like community string sent with the notification operation.
Though you can set this string by using the snmp-server host command,
we recommend that you define this string by using the snmp-server
community global configuration command before using the snmp-server
host command.
bridge
(Optional) Send SNMP STP bridge MIB traps.
c2900
(Optional) Send SNMP switch traps.
cluster
(Optional) Send cluster member status traps.
config
(Optional) Send SNMP configuration traps.
copy-config
(Optional) Send SNMP copy-configuration traps.
entity
(Optional) Send SNMP entity traps.
envmon
(Optional) Send enviromental monitor (EnvMon) traps.
flash
(Optional) Send SNMP FLASH notifications.
hsrp
(Optional) Send Hot Standby Router Protocol (HSRP) traps.
mac-notification
(Optional) Send MAC notification traps.
port-security
(Optional) Send port security traps.
rtr
(Optional) Send SNMP Response Time Reporter traps.
snmp
(Optional) Send SNMP-type traps.
stpx
(Optional) Send SNMP STPX MIB traps.
syslog
(Optional) Send SNMP syslog traps.
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snmp-server host
Defaults
tty
(Optional) Send TCP connection traps.
udp-port port-number
(Optional) Send notification host’s User Datagram Protocol (UDP) port
number. The range for port-number is 0 to 65535.
vlan-membership
(Optional) Send SNMP VLAN membership traps.
vlancreate
(Optional) Send SNMP VLAN-created traps.
vlandelete
(Optional) Send SNMP VLAN-deleted traps.
vtp
(Optional) Send VLAN Trunking Protocol (VTP) traps.
This command is disabled. No notifications are sent.
If you enter this command with no keywords, the default is to send all trap types to the host. No informs
are sent to this host.
If no version keyword is present, the default is version 1.
If version 3 is selected and no authentication keyword is entered, the default is the noauth
(noAuthNoPriv) security level.
Command Modes
Global configuration
Command History
Release
Modification
12.1(13)AY
This command was introduced.
12.1(20)EA2
The flash keyword was added.
Usage Guidelines
SNMP notifications can be sent as traps or inform requests. Traps are unreliable because the receiver
does not send acknowledgments when it receives traps. The sender cannot determine if the traps were
received. However, an SNMP entity that receives an inform request acknowledges the message with an
SNMP response PDU. If the sender never receives the response, the inform request can be sent again.
Thus, informs are more likely to reach their intended destinations.
However, informs consume more resources in the agent and in the network. Unlike a trap, which is
discarded as soon as it is sent, an inform request must be held in memory until a response is received or
the request times out. Traps are also sent only once, but an inform might be retried several times. The
retries increase traffic and contribute to a higher overhead on the network.
If you do not enter an snmp-server host command, no notifications are sent. To configure the switch to
send SNMP notifications, you must enter at least one snmp-server host command. If you enter the
command with no keywords, all trap types are enabled for the host. To enable multiple hosts, you must
enter a separate snmp-server host command for each host. You can specify multiple notification types
in the command for each host.
When multiple snmp-server host commands are given for the same host and kind of notification (trap
or inform), each succeeding command overwrites the previous command. Only the last snmp-server
host command is in effect. For example, if you enter an snmp-server host inform command for a host
and then enter another snmp-server host inform command for the same host, the second command
replaces the first.
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snmp-server host
The snmp-server host command is used with the snmp-server enable traps global configuration
command. Use the snmp-server enable traps command to specify which SNMP notifications are sent
globally. For a host to receive most notifications, at least one snmp-server enable traps command and
the snmp-server host command for that host must be enabled. Some notification types cannot be
controlled with the snmp-server enable traps command. For example, some notification types are
always enabled. Other notification types are enabled by a different command.
The no snmp-server host command with no keywords disables traps, but not informs, to the host. To
disable informs, use the no snmp-server host informs command.
Examples
This example shows how to configure a unique SNMP community string named comaccess for traps and
prevent SNMP polling access with this string through access list 10:
Switch(config)# snmp-server community comaccess ro 10
Switch(config)# snmp-server host 172.20.2.160 comaccess
Switch(config)# access-list 10 deny any
This example shows how to send the SNMP traps to the host specified by the name myhost.cisco.com.
The community string is defined as comaccess.
Switch(config)# snmp-server enable traps
Switch(config)# snmp-server host myhost.cisco comaccess snmp
This example shows how to enable the switch to send all traps to the host myhost.cisco using the
community string public:
Switch(config)# snmp-server enable traps
Switch(config)# snmp-server host myhost.cisco public
This example shows how to enable the switch to send EnvMon traps to the host myhost.cisco using the
community string public:
Switch(config)# snmp-server host myhost.cisco version 2c public envmon
Related Commands
Command
Description
show running-config
Displays the running configuration on the switch. For syntax
information, select Cisco IOS Configuration Fundamentals
Command Reference for Release 12.1 > Cisco IOS File Management
Commands > Configuration File Commands.
snmp-server enable traps
Enables SNMP notification for various trap types.
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snmp trap mac-notification
snmp trap mac-notification
Use the snmp trap mac-notification interface configuration command to enable the MAC notification
traps on a port. Use the no form of this command to disable the traps and to return the port to default
settings.
snmp trap mac-notification [added | removed]
no snmp trap mac-notification [added | removed]
Syntax Description
added
(Optional) Enable MAC notification traps when a MAC address is added to a port.
removed
(Optional) Enable MAC notification traps when a MAC address is removed from a
port.
Defaults
The Simple Network Management Protocol (SNMP) address-addition and address-removal traps are
disabled.
Command Modes
Interface configuration
Command History
Release
Modification
12.1(13)AY
This command was introduced.
Usage Guidelines
Even though you enable the notification trap for a specific interface by using the snmp trap
mac-notification command, the trap is generated only when you enter the snmp-server enable traps
mac-notification and the mac address-table notification global configuration commands.
Examples
This example shows how to enable an address-addition trap on a port:
Switch(config-if)# snmp trap mac-notification added
This example shows how to enable an address-removal trap on a port:
Switch(config-if)# snmp trap mac-notification removed
You can verify your settings by entering the show mac address-table notification privileged EXEC
command.
Related Commands
Command
Description
clear mac address-table notification
Clears the MAC address notification global counters.
mac address-table notification
Enables the MAC notification feature on a switch.
show mac address-table notification
Displays MAC notification parameters.
snmp-server enable traps
Enables SNMP notification for various trap types.
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spanning-tree backbonefast
spanning-tree backbonefast
Use the spanning-tree backbonefast global configuration command to enable the BackboneFast
feature. Use the no form of this command to return to the default setting.
spanning-tree backbonefast
no spanning-tree backbonefast
Syntax Description
This command has no arguments or keywords.
Defaults
BackboneFast is disabled.
Command Modes
Global configuration
Command History
Release
Modification
12.1(13)AY
This command was introduced.
Usage Guidelines
You can configure the BackboneFast feature for rapid PVST+ or for multiple spanning-tree (MST)
mode, but the feature remains disabled (inactive) until you change the spanning-tree mode to PVST+.
BackboneFast is started when a root port or blocked port on a switch receives inferior bridge protocol
data units (BPDUs) from its designated bridge. An inferior BPDU identifies one switch as both the root
bridge and the designated bridge. When a switch receives an inferior BPDU, it means that a link to which
the switch is not directly connected (an indirect link) has failed (that is, the designated bridge has lost
its connection to the root switch). If there are alternate paths to the root switch, BackboneFast causes the
maximum aging time on the ports on which it received the inferior BPDU to expire and allows a blocked
port to move immediately to the listening state. BackboneFast then transitions the interface to the
forwarding state. For more information, see the software configuration guide for this release.
Enable BackboneFast on all supported switches to allow the detection of indirect link failures and to start
the spanning-tree reconfiguration sooner.
Examples
This example shows how to enable BackboneFast on the switch:
Switch(config)# spanning-tree backbonefast
You can verify your setting by entering the show spanning-tree summary privileged EXEC command.
Related Commands
Command
Description
show spanning-tree summary Displays a summary of the spanning-tree port states.
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spanning-tree bpdufilter
spanning-tree bpdufilter
Use the spanning-tree bpdufilter interface configuration command to prevent a port from sending or
receiving bridge protocol data units (BPDUs). Use the no form of this command to return to the default
setting.
spanning-tree bpdufilter {disable | enable}
no spanning-tree bpdufilter
Syntax Description
disable
Disable BPDU filtering on the specified interface.
enable
Enable BPDU filtering on the specified interface.
Defaults
BPDU filtering is disabled.
Command Modes
Interface configuration
Command History
Release
Modification
12.1(13)AY
This command was introduced.
Usage Guidelines
Caution
You can enable the BPDU filtering feature when the switch is operating in the per-VLAN spanning-tree
plus (PVST+), rapid-PVST+, or in the multiple spanning-tree (MST) mode.
Enabling BPDU filtering on an interface is the same as disabling spanning tree on it and can result in
spanning-tree loops.
You can globally enable BPDU filtering on all Port Fast-enabled ports by using the spanning-tree
portfast bpdufilter default global configuration command.
You can use the spanning-tree bpdufilter interface configuration command to override the setting of
the spanning-tree portfast bpdufilter default global configuration command.
Examples
This example shows how to enable the BPDU filtering feature on a port:
Switch(config)# interface fastethernet0/1
Switch(config-if)# spanning-tree bpdufilter enable
You can verify your setting by entering the show running-config privileged EXEC command.
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Related Commands
Command
Description
show running-config
Displays the current operating configuration. For syntax
information, select Cisco IOS Configuration Fundamentals
Command Reference for Release 12.1 > Cisco IOS File
Management Commands > Configuration File Commands.
spanning-tree portfast (global
configuration)
Globally enables the BPDU filtering or the BPDU guard feature
on Port Fast-enabled ports or enables the Port Fast feature on all
nontrunking ports.
spanning-tree portfast (interface
configuration)
Enables the Port Fast feature on an interface and all its associated
VLANs.
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spanning-tree bpduguard
spanning-tree bpduguard
Use the spanning-tree bpduguard interface configuration command to put a port in the error-disabled
state when it receives a bridge protocol data unit (BPDU). Use the no form of this command to return to
the default setting.
spanning-tree bpduguard {disable | enable}
no spanning-tree bpduguard
Syntax Description
disable
Disable BPDU guard on the specified interface.
enable
Enable BPDU guard on the specified interface.
Defaults
BPDU guard is disabled.
Command Modes
Interface configuration
Command History
Release
Modification
12.1(13)AY
This command was introduced.
Usage Guidelines
The BPDU guard feature provides a secure response to invalid configurations because you must
manually put the port back in service. Use the BPDU guard feature in a service-provider network to
prevent a port from being included in the spanning-tree topology.
You can enable the BPDU guard feature when the switch is operating in the per-VLAN spanning-tree
plus (PVST+), rapid-PVST+, or the multiple spanning-tree (MST) mode.
You can globally enable BPDU guard on all Port Fast-enabled ports by using the spanning-tree portfast
bpduguard default global configuration command.
You can use the spanning-tree bpduguard interface configuration command to override the setting of
the spanning-tree portfast bpduguard default global configuration command.
Examples
This example shows how to enable the BPDU guard feature on a port:
Switch(config)# interface fastethernet0/1
Switch(config-if)# spanning-tree bpduguard enable
You can verify your setting by entering the show running-config privileged EXEC command.
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Related Commands
Command
Description
show running-config
Displays the current operating configuration. For syntax
information, select Cisco IOS Configuration Fundamentals
Command Reference for Release 12.1 > Cisco IOS File
Management Commands > Configuration File Commands.
spanning-tree portfast (global
configuration)
Globally enables the BPDU filtering or the BPDU guard feature
on Port Fast-enabled ports, or enables the Port Fast feature on all
nontrunking ports.
spanning-tree portfast (interface
configuration)
Enables the Port Fast feature on an interface and all its associated
VLANs.
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spanning-tree cost
spanning-tree cost
Use the spanning-tree cost interface configuration command to set the path cost for spanning-tree
calculations. If a loop occurs, spanning tree considers the path cost when selecting an interface to place
in the forwarding state. Use the no form of this command to return to the default setting.
spanning-tree [vlan vlan-id] cost cost
no spanning-tree [vlan vlan-id] cost
Syntax Description
Defaults
vlan vlan-id
(Optional) VLAN range associated with a spanning-tree instance. You can specify
a single VLAN identified by VLAN ID number, a range of VLANs separated by a
hyphen, or a series of VLANs separated by a comma. The range is 1 to 4094.
cost
Path cost can range from 1 to 200000000, with higher values meaning higher costs.
The default path cost is computed from the interface bandwidth setting. These are the IEEE default path
cost values:
•
10 Mbps—100
•
100 Mbps—19
•
155 Mbps—14
•
1000 Mbps—4
•
1 Gbps—4
•
10 Gbps—2
•
Speeds greater than 10 Gbps—1
Command Modes
Interface configuration
Command History
Release
Modification
12.1(13)AY
This command was introduced.
Usage Guidelines
When you configure the cost, higher values represent higher costs.
You can set a cost on a VLAN that does not exist. The setting takes effect when the VLAN exists.
If you configure an interface with both the spanning-tree vlan vlan-id cost cost command and the
spanning-tree cost cost command, the spanning-tree vlan vlan-id cost cost command takes effect.
Examples
This example shows how to set a path cost of 250 on an interface:
Switch(config)# interface fastethernet0/4
Switch(config-if)# spanning-tree cost 250
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spanning-tree cost
This example shows how to set a path cost of 300 for VLANs 10, 12 to 15, and 20:
Switch(config-if)# spanning-tree vlan 10,12-15,20 cost 300
You can verify your settings by entering the show spanning-tree interface interface-id privileged
EXEC command.
Related Commands
Command
Description
show spanning-tree interface
interface-id
Displays spanning-tree information for the specified interface.
spanning-tree port-priority
Configures an interface priority.
spanning-tree vlan priority
Sets the switch priority for the specified spanning-tree instance.
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spanning-tree etherchannel guard misconfig
spanning-tree etherchannel guard misconfig
Use the spanning-tree etherchannel guard misconfig global configuration command to display an
error message when the switch detects a loop that occurred because of an EtherChannel
misconfiguration. Use the no form of this command to disable the feature.
spanning-tree etherchannel guard misconfig
no spanning-tree etherchannel guard misconfig
Syntax Description
This command has no arguments or keywords.
Defaults
EtherChannel guard is enabled on the switch.
Command Modes
Global configuration
Command History
Release
Modification
12.1(13)AY
This command was introduced.
Usage Guidelines
When the switch detects a loop that is caused by an EtherChannel misconfiguration, this error message
appears:
PM-4-ERR_DISABLE: Channel-misconfig error detected on [chars], putting [chars] in
err-disable state.
To determine which switch ports are in the misconfigured EtherChannel, use the show interfaces status
err-disabled privileged EXEC command. To verify the EtherChannel configuration on a remote device,
use the show etherchannel summary privileged EXEC command on the remote device.
When a port is in the error-disabled state because of an EtherChannel misconfiguration, you can bring
it out of this state by entering the errdisable recovery cause channel-misconfig global configuration
command, or you can manually re-enable it by entering the shutdown and no shutdown interface
configuration commands.
Examples
This example shows how to enable the EtherChannel guard misconfiguration feature:
Switch(config)# spanning-tree etherchannel guard misconfig
You can verify your settings by entering the show spanning-tree summary privileged EXEC command.
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Related Commands
Command
Description
errdisable recovery cause
channel-misconfig
Enables the timer to recover from the EtherChannel
misconfiguration error-disable state.
show etherchannel summary
Displays EtherChannel information for a channel as a one-line
summary per channel-group.
show interfaces status
err-disabled
Displays the interfaces in the error-disabled state.
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spanning-tree extend system-id
spanning-tree extend system-id
Use the spanning-tree extend system-id global configuration command to enable the extended system
ID feature.
spanning-tree extend system-id
Note
Though visible in the command-line help strings, the no version of this command is not supported. You
cannot disable the extended system ID feature.
Syntax Description
This command has no arguments or keywords.
Defaults
The extended system ID is enabled.
Command Modes
Global configuration
Command History
Release
Modification
12.1(13)AY
This command was introduced.
Usage Guidelines
Catalyst 2940 switches support the IEEE 802.1t spanning-tree extensions, and some of the bits
previously used for the switch priority are now used for the extended system ID (VLAN identifier for
the per-VLAN spanning-tree plus [PVST+] and for rapid PVST+ or an instance identifier for the
multiple spanning tree [MST]).
The spanning tree uses the extended system ID, the switch priority, and the allocated spanning-tree MAC
address to make the bridge ID unique for each VLAN or multiple spanning-tree instance.
Support for the extended system ID affects how you manually configure the root switch, the secondary
root switch, and the switch priority of a VLAN. For more information, see the “spanning-tree mst root”
and the “spanning-tree vlan” sections.
If your network consists of switches that do not support the extended system ID and switches that do
support it, it is unlikely that the switch with the extended system ID support will become the root switch.
The extended system ID increases the switch priority value every time the VLAN number is greater than
the priority of the connected switches running older software.
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Related Commands
Command
Description
show spanning-tree summary Displays a summary of spanning-tree port states.
spanning-tree mst root
Configures the multiple spanning-tree (MST) root switch priority
and timers based on the network diameter.
spanning-tree vlan priority
Sets the switch priority for the specified spanning-tree instance.
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spanning-tree guard
spanning-tree guard
Use the spanning-tree guard interface configuration command to enable root guard or loop guard on
all the VLANs associated with the selected interface. Root guard restricts which interface is allowed to
be the spanning-tree root port or the path-to-the root for the switch. Loop guard prevents alternate or
root ports from becoming designated ports when a failure creates a unidirectional link. Use the no form
of this command to return to the default setting.
spanning-tree guard {loop | none | root}
no spanning-tree guard
Syntax Description
Defaults
loop
Enable loop guard.
none
Disable root guard or loop guard.
root
Enable root guard.
Root guard is disabled.
Loop guard is configured according to the spanning-tree loopguard default global configuration
command (globally disabled).
Command Modes
Interface configuration
Command History
Release
Modification
12.1(13)AY
This command was introduced.
Usage Guidelines
You can enable root guard or loop guard when the switch is operating in the per-VLAN spanning-tree
plus (PVST+), rapid-PVST+, or the multiple spanning-tree (MST) mode. However, you cannot enable
both PVST+ and MST or both rapid PVST+ and MST at the same time.
When root guard is enabled, if spanning-tree calculations cause a port to be selected as the root port, the
port transitions to the root-inconsistent (blocked) state to prevent the customer’s switch from becoming
the root switch or being in the path to the root. The root port provides the best path from the switch to
the root switch.
When the no spanning-tree guard or the no spanning-tree guard none command is entered, root guard
is disabled for all VLANs on the selected interface. If this interface is in the root-inconsistent (blocked)
state, it automatically transitions to the listening state.
Do not enable root guard on interfaces that will be used by the UplinkFast feature. With UplinkFast, the
backup interfaces (in the blocked state) replace the root port in the case of a failure. However, if root
guard is also enabled, all the backup interfaces used by the UplinkFast feature are placed in the
root-inconsistent state (blocked) and prevented from reaching the forwarding state. The UplinkFast
feature is not available when the switch is operating in rapid-PVST+ or MST mode.
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spanning-tree guard
Loop guard is most effective when it is configured on the entire switched network. When the switch is
operating in PVST+or rapid-PVST+ mode, loop guard prevents alternate and root ports from becoming
designated ports, and spanning tree does not send bridge protocol data units (BPDUs) on root or alternate
ports. When the switch is operating in MST mode, BPDUs are not sent on nonboundary ports only if the
port is blocked by loop guard in all MST instances. On a boundary port, loop guard blocks the port in
all MST instances.
To disable root guard or loop guard, use the spanning-tree guard none interface configuration
command. You cannot enable both root guard and loop guard at the same time.
You can override the setting of the spanning-tree loopguard default global configuration command by
using the spanning-tree guard loop interface configuration command.
Examples
This example shows how to enable root guard on all the VLANs associated with the specified interface:
Switch(config)# interface fastethernet0/1
Switch(config-if)# spanning-tree guard root
This example shows how to enable loop guard on all the VLANs associated with the specified interface:
Switch(config)# interface fastethernet0/1
Switch(config-if)# spanning-tree guard loop
You can verify your settings by entering the show running-config privileged EXEC command.
Related Commands
Command
Description
show running-config
Displays the current operating configuration. For syntax
information, select Cisco IOS Configuration Fundamentals
Command Reference for Release 12.1 > Cisco IOS File
Management Commands > Configuration File Commands.
spanning-tree cost
Sets the path cost for spanning-tree calculations.
spanning-tree loopguard default
Prevents alternate or root ports from becoming designated
ports because of a failure that leads to a unidirectional link.
spanning-tree mst cost
Configures the path cost for MST calculations.
spanning-tree mst port-priority
Configures an interface priority.
spanning-tree mst root
Configures the MST root switch priority and timers based on
the network diameter.
spanning-tree port-priority
Configures an interface priority.
spanning-tree vlan priority
Sets the switch priority for the specified spanning-tree
instance.
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spanning-tree link-type
spanning-tree link-type
Use the spanning-tree link-type interface configuration command to override the default link-type
setting, which is determined by the duplex mode of the port, and to enable rapid spanning-tree transitions
to the forwarding state. Use the no form of this command to return to the default setting.
spanning-tree link-type {point-to-point | shared}
no spanning-tree link-type
Syntax Description
point-to-point
Specify that the link type of a port is point-to-point.
shared
Specify that the link type of a port is shared.
Defaults
The switch derives the link type of a port from the duplex mode. A full-duplex port is considered a
point-to-point link, and a half-duplex port is considered a shared link.
Command Modes
Interface configuration
Command History
Release
Modification
12.1(13)AY
This command was introduced.
Usage Guidelines
You can override the default setting of the link type by using the spanning-tree link-type command;
for example, a half-duplex link can be physically connected point-to-point to a single port on a remote
switch running the Multiple Spanning Tree Protocol (MSTP) or the rapid per-VLAN spanning-tree plus
(rapid-PVST+) protocol and be enabled for rapid transitions.
Examples
This example shows how to specify the link type as shared (regardless of the duplex setting) and to
prevent rapid transitions to the forwarding state:
Switch(config-if)# spanning-tree link-type shared
You can verify your settings by entering the show spanning-tree mst interface interface-id privileged
EXEC command.
Related Commands
Command
Description
show spanning-tree mst interface
interface-id
Displays multiple spanning-tree (MST) information for the
specified interface.
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spanning-tree loopguard default
spanning-tree loopguard default
Use the spanning-tree loopguard default global configuration command to prevent alternate or root
ports from becoming designated ports because of a failure that leads to a unidirectional link. Use the no
form of this command to return to the default setting.
spanning-tree loopguard default
no spanning-tree loopguard default
Syntax Description
This command has no arguments or keywords.
Defaults
Loop guard is disabled.
Command Modes
Global configuration
Command History
Release
Modification
12.1(13)AY
This command was introduced.
Usage Guidelines
You can enable the loop guard feature when the switch is operating in the per-VLAN spanning-tree plus
(PVST+), rapid-PVST+, or the multiple spanning-tree (MST) mode.
Loop guard is most effective when it is configured on the entire switched network. When the switch is
operating in PVST+ or rapid-PVST+ mode, loop guard prevents alternate and root ports from becoming
designated ports, and spanning tree does not send bridge protocol data units (BPDUs) on root or alternate
ports. When the switch is operating in MST mode, BPDUs are not sent on nonboundary ports only if the
port is blocked by loop guard in all MST instances. On a boundary port, loop guard blocks the port in
all MST instances.
Loop guard operates only on ports that are considered point-to-point by the spanning tree.
You can override the setting of the spanning-tree loopguard default global configuration command by
using the spanning-tree guard loop interface configuration command.
Examples
This example shows how to globally enable loop guard:
Switch(config)# spanning-tree loopguard default
You can verify your settings by entering the show running-config privileged EXEC command.
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spanning-tree loopguard default
Related Commands
Command
Description
show running-config
Displays the current operating configuration. For syntax information,
select Cisco IOS Configuration Fundamentals Command Reference
for Release 12.1 > Cisco IOS File Management Commands >
Configuration File Commands.
spanning-tree guard loop
Enables the loop guard feature on all the VLANs associated with the
specified interface.
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spanning-tree mode
spanning-tree mode
Use the spanning-tree mode global configuration command to enable per-VLAN spanning-tree plus
PVST+), rapid PVST+, or multiple spanning tree (MST) on your switch. Use the no form of this
command to return to the default setting.
spanning-tree mode {mst | pvst | rapid-pvst}
no spanning-tree mode
Syntax Description
mst
Enable MST and Rapid Spanning Tree Protocol (RSTP) (based on IEEE 802.1s and
IEEE 802.1w).
pvst
Enable PVST+ (based on IEEE 802.1D).
rapid-pvst
Enable rapid PVST+ (based on IEEE 802.1w).
Defaults
The default mode is PVST+.
Command Modes
Global configuration
Command History
Release
Modification
12.1(13)AY
This command was introduced.
12.1(20)EA2
The mst and rapid-pvst keywords were added.
Usage Guidelines
Caution
The switch supports PVST+, rapid PVST+, and MSTP, but only one version can be active at any time.
All VLANs run PVST+, all VLANs run rapid PVST+, or all VLANs run MSTP.
Changing spanning-tree modes can disrupt traffic because all spanning-tree instances are stopped for the
previous mode and restarted in the new mode.
When you enable the MST mode, RSTP is automatically enabled.
Examples
This example shows to enable MST on the switch:
Switch(config)# spanning-tree mode mst
This example shows to enable rapid PVST+ on the switch:
Switch(config)# spanning-tree mode rapid-pvst
You can verify your setting by entering the show running-config privileged EXEC command.
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Related Commands
Command
Description
show running-config
Displays the current operating configuration. For syntax information,
select Cisco IOS Configuration Fundamentals Command Reference for
Release 12.1 > Cisco IOS File Management Commands > Configuration
File Commands.
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spanning-tree mst configuration
spanning-tree mst configuration
Use the spanning-tree mst configuration global configuration command to enter multiple
spanning-tree (MST) configuration mode through which you configure the MST region. Use the no form
of this command to return to the default settings.
spanning-tree mst configuration
no spanning-tree mst configuration
Syntax Description
This command has no arguments or keywords.
Defaults
The default mapping is that all VLANs are mapped to the common and internal spanning tree (CIST)
instance (instance 0).
The default name is an empty string.
The revision number is 0.
Command Modes
Global configuration
Command History
Release
Modification
12.1(20)EA2
This command was introduced.
Usage Guidelines
Entering the spanning-tree mst configuration command enables the MST configuration mode. These
configuration commands are available:
•
abort: exits the MST region configuration mode without applying configuration changes.
•
exit: exits the MST region configuration mode and applies all configuration changes.
•
instance instance-id vlan vlan-range: maps VLANs to an MST instance. The instance-id range is 1
to 15. The vlan-range range is 1 to 4094. You can specify a single VLAN identified by VLAN ID
number, a range of VLANs separated by a hyphen, or a series of VLANs separated by a comma.
•
name name: sets the configuration name. The name string has a maximum length of 32 characters
and is case sensitive.
•
no: negates the instance, name, and revision commands or sets them to their defaults.
•
private-vlan: Though visible in the command-line help strings, this command is not supported.
•
revision version: sets the configuration revision number. The range is 0 to 65535.
•
show [current | pending]: displays the current or pending MST region configuration.
In MST mode, the switch supports up to 16 MST instances. The number of VLANs that can be mapped
to a particular MST instance is unlimited.
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When you map VLANs to an MST instance, the mapping is incremental, and the VLANs specified in
the command are added to or removed from the VLANs that were previously mapped. To specify a
range, use a hyphen; for example, instance 1 vlan 1-63 maps VLANs 1 to 63 to MST instance 1. To
specify a series, use a comma; for example, instance 1 vlan 10, 20, 30 maps VLANs 10, 20, and 30 to
MST instance 1.
All VLANs that are not explicitly mapped to an MST instance are mapped to the common and internal
spanning tree (CIST) instance (instance 0) and cannot be unmapped from the CIST by using the no form
of the command.
For two or more switches to be in the same MST region, they must have the same VLAN mapping, the
same configuration revision number, and the same name.
Examples
This example shows how to enter MST configuration mode, map VLAN 10 to 20 to MST instance 1,
name the region region1, set the configuration revision to 1, display the pending configuration, apply
the changes, and return to global configuration mode:
Switch# spanning-tree mst configuration
Switch(config-mst)# instance 1 vlan 10-20
Switch(config-mst)# name region1
Switch(config-mst)# revision 1
Switch(config-mst)# show pending
Pending MST configuration
Name
[region1]
Revision 1
Instance Vlans Mapped
-------- --------------------0
1-9,21-4094
1
10-20
------------------------------Switch(config-mst)# exit
Switch(config)#
This example shows how to add VLANs 1 to 100 to the ones already mapped (if any) to instance 2, to
move VLANs 40 to 60 that were previously mapped to instance 2 to the CIST instance, to add VLAN
10 to instance 10, and to remove all the VLANs mapped to instance 2 and map them to the CIST instance:
Switch(config-mst)#
Switch(config-mst)#
Switch(config-mst)#
Switch(config-mst)#
instance 2 vlan 1-100
no instance 2 vlan 40-60
instance 10 vlan 10
no instance 2
You can verify your settings by entering the show pending MST configuration command.
Related Commands
Command
Description
show spanning-tree mst configuration
Displays the MST region configuration.
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spanning-tree mst cost
spanning-tree mst cost
Use the spanning-tree mst cost interface configuration command to set the path cost for multiple
spanning-tree (MST) calculations. If a loop occurs, spanning tree considers the path cost when selecting
an interface to put in the forwarding state. Use the no form of this command to return to the default
setting.
spanning-tree mst instance-id cost cost
no spanning-tree mst instance-id cost
Syntax Description
Defaults
instance-id
Range of spanning-tree instances. You can specify a single instance, a range of
instances separated by a hyphen, or a series of instances separated by a comma. The
range is 0 to 15.
cost
Path cost is 1 to 200000000, with higher values meaning higher costs.
The default path cost is computed from the interface bandwidth setting. These are the IEEE default path
cost values:
•
1000 Mbps—20000
•
100 Mbps—200000
•
10 Mbps—2000000
Command Modes
Interface configuration
Command History
Release
Modification
12.1(20)EA2
This command was introduced.
Usage Guidelines
When you configure the cost, higher values represent higher costs.
Examples
This example shows how to set a path cost of 250 on an interface associated with instances 2 and 4:
Switch(config)# interface fastethernet0/4
Switch(config-if)# spanning-tree mst 2,4 cost 250
You can verify your settings by entering the show spanning-tree mst interface interface-id privileged
EXEC command.
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Related Commands
Command
Description
show spanning-tree mst
interface interface-id
Displays MST information for the specified interface.
spanning-tree mst
port-priority
Configures an interface priority.
spanning-tree mst priority
Configures the switch priority for the specified spanning-tree
instance.
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spanning-tree mst forward-time
spanning-tree mst forward-time
Use the spanning-tree mst forward-time global configuration command to set the forward-delay time
for all multiple spanning-tree (MST) instances. The forwarding time determines how long each of the
listening and learning states last before the interface begins forwarding. Use the no form of this
command to return to the default setting.
spanning-tree mst forward-time seconds
no spanning-tree mst forward-time
Syntax Description
seconds
Defaults
The default is 15 seconds.
Command Modes
Global configuration
Command History
Release
Modification
12.1(20)EA2
This command was introduced.
Length of the listening and learning states. The range is 4 to 30 seconds.
Usage Guidelines
Changing the spanning-tree mst forward-time command affects all spanning-tree instances.
Examples
This example shows how to set the spanning-tree forwarding time to 18 seconds for all MST instances:
Switch(config)# spanning-tree mst forward-time 18
You can verify your settings by entering the show spanning-tree mst privileged EXEC command.
Related Commands
Command
Description
show spanning-tree mst
Displays MST information.
spanning-tree mst hello-time
Sets the interval between hello bridge protocol data units (BPDUs)
sent by root switch configuration messages.
spanning-tree mst max-age
Sets the interval between messages that the spanning tree receives
from the root switch.
spanning-tree mst max-hops
Sets the number of hops in a region before the BPDU is discarded.
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spanning-tree mst hello-time
spanning-tree mst hello-time
Use the spanning-tree mst hello-time global configuration command to set the interval between hello
bridge protocol data units (BPDUs) sent by root switch configuration messages. Use the no form of this
command to return to the default setting.
spanning-tree mst hello-time seconds
no spanning-tree mst hello-time
Syntax Description
seconds
Defaults
The default is 2 seconds.
Command Modes
Global configuration
Command History
Release
Modification
12.1(20)EA2
This command was introduced.
Usage Guidelines
Interval between hello BPDUs sent by root switch configuration messages. The
range is 1 to 10 seconds.
After you set the spanning-tree mst max-age seconds global configuration command, if a switch does
not receive BPDUs from the root switch within the specified interval, the switch recomputes the
spanning-tree topology. The max-age setting must be greater than the hello-time setting.
Changing the spanning-tree mst hello-time command affects all spanning-tree instances.
Examples
This example shows how to set the spanning-tree hello time to 3 seconds for all MST instances:
Switch(config)# spanning-tree mst hello-time 3
You can verify your settings by entering the show spanning-tree mst privileged EXEC command.
Related Commands
Command
Description
show spanning-tree mst
Displays multiple spanning-tree (MST) information.
spanning-tree mst
forward-time
Sets the forward-delay time for all MST instances.
spanning-tree mst max-age
Sets the interval between messages that the spanning tree receives
from the root switch.
spanning-tree mst max-hops
Sets the number of hops in a region before the BPDU is discarded.
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spanning-tree mst max-age
Use the spanning-tree mst max-age global configuration command to set the interval between
messages that the spanning tree receives from the root switch. If a switch does not receive a bridge
protocol data unit (BPDU) message from the root switch within this interval, it recomputes the
spanning-tree topology. Use the no form of this command to return to the default setting.
spanning-tree mst max-age seconds
no spanning-tree mst max-age
Syntax Description
seconds
Defaults
The default is 20 seconds.
Command Modes
Global configuration
Command History
Release
Modification
12.1(20)EA2
This command was introduced.
Usage Guidelines
Interval between messages the spanning tree receives from the root switch. If a switch
does not receive a BPDU message from the root switch within this interval, it
recomputes the spanning-tree topology. The range is 6 to 40 seconds.
After you set the spanning-tree mst max-age seconds global configuration command, if a switch does
not receive BPDUs from the root switch within the specified interval, the switch recomputes the
spanning-tree topology. The max-age setting must be greater than the hello-time setting.
Changing the spanning-tree mst max-age command affects all spanning-tree instances.
Examples
This example shows how to set the spanning-tree max-age to 30 seconds for all MST instances:
Switch(config)# spanning-tree mst max-age 30
You can verify your settings by entering the show spanning-tree mst privileged EXEC command.
Related Commands
Command
Description
show spanning-tree mst
Displays multiple spanning-tree (MST) information.
spanning-tree mst forward-time
Sets the forward-delay time for all MST instances.
spanning-tree mst hello-time
Sets the interval between hello BPDUs sent by root switch
configuration messages.
spanning-tree mst max-hops
Sets the number of hops in a region before the BPDU is
discarded.
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spanning-tree mst max-hops
spanning-tree mst max-hops
Use the spanning-tree mst max-hops global configuration command to set the number of hops in a
region before the bridge protocol data unit (BPDU) is discarded and the information held for a port is
aged. Use the no form of this command to return to the default setting.
spanning-tree mst max-hops hop-count
no spanning-tree mst max-hops
Syntax Description
hop-count
Defaults
The default is 20 hops.
Command Modes
Global configuration
Command History
Release
Modification
12.1(20)EA2
This command was introduced.
Usage Guidelines
Number of hops in a region before the BPDU is discarded. The range is 1 to 40 hops.
The root switch of the instance always sends a BPDU (or M-record) with a cost of 0 and the hop count
set to the maximum value. When a switch receives this BPDU, it decrements the received remaining hop
count by one and propagates the decremented count as the remaining hop count in the generated
M-records. A switch discards the BPDU and ages the information held for the port when the count
reaches 0.
Changing the spanning-tree mst max-hops command affects all spanning-tree instances.
Examples
This example shows how to set the spanning-tree max-hops to 10 for all MST instances:
Switch(config)# spanning-tree mst max-hops 10
You can verify your settings by entering the show spanning-tree mst privileged EXEC command.
Related Commands
Command
Description
show spanning-tree mst
Displays multiple spanning-tree (MST) information.
spanning-tree mst forward-time
Sets the forward-delay time for all MST instances.
spanning-tree mst hello-time
Sets the interval between hello BPDUs sent by root switch
configuration messages.
spanning-tree mst max-age
Sets the interval between messages that the spanning tree
receives from the root switch.
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spanning-tree mst port-priority
spanning-tree mst port-priority
Use the spanning-tree mst port-priority interface configuration command to configure an interface
priority. If a loop occurs, the Multiple Spanning Tree Protocol (MSTP) can determine which interface
to put in the forwarding state. Use the no form of this command to return to the default setting.
spanning-tree mst instance-id port-priority priority
no spanning-tree mst instance-id port-priority
Syntax Description
instance-id
Range of spanning-tree instances. You can specify a single instance, a range of
instances separated by a hyphen, or a series of instances separated by a comma. The
range is 0 to 15.
priority
The range is 0 to 240 in increments of 16 (0, 16, 32, 48, 64, 80, 96, 112, 128, 144,
160, 176, 192, 208, 224, and 240). All other values are rejected. The lower the
number, the higher the priority.
Defaults
The default is 128.
Command Modes
Interface configuration
Command History
Release
Modification
12.1(20)EA2
This command was introduced.
Usage Guidelines
You can assign higher priority values (lower numerical values) to interfaces that you want selected first
and lower priority values (higher numerical values) that you want selected last. If all interfaces have the
same priority value, the MST puts the interface with the lowest interface number in the forwarding state
and blocks other interfaces.
Examples
This example shows how to increase the likelihood that the interface associated with spanning-tree
instance 20 is placed into the forwarding state if a loop occurs:
Switch(config)# interface fastethernet0/2
Switch(config-if)# spanning-tree mst 20 port-priority 0
You can verify your settings by entering the show spanning-tree mst interface interface-id privileged
EXEC command.
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Related Commands
Command
Description
show spanning-tree mst interface
interface-id
Displays MST information for the specified interface.
spanning-tree mst cost
Sets the path cost for MST calculations.
spanning-tree mst priority
Sets the switch priority for the specified spanning-tree
instance.
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spanning-tree mst priority
spanning-tree mst priority
Use the spanning-tree mst priority global configuration command to set the switch priority for the
specified spanning-tree instance. Use the no form of this command to return to the default setting.
spanning-tree mst instance-id priority priority
no spanning-tree mst instance-id priority
Syntax Description
instance-id
Range of spanning-tree instances. You can specify a single instance, a range of
instances separated by a hyphen, or a series of instances separated by a comma. The
range is 0 to 15.
priority
Set the switch priority for the specified spanning-tree instance. This setting affects
the likelihood that the switch is selected as the root switch. A lower value increases
the probability that the switch is selected as the root switch.
The range is 0 to 61440 in increments of 4096 (0, 4096, 8192, 12288, 16384, 20480,
24576, 28672, 32768, 36864, 40960, 45056, 49152, 53248, 57344, and 61440). All
other values are rejected.
Defaults
The default is 32768.
Command Modes
Global configuration
Command History
Release
Modification
12.1(20)EA2
This command was introduced.
Examples
This example shows how to set the spanning-tree priority to 8192 for multiple spanning-tree (MST)
instance 20:
Switch(config)# spanning-tree mst 20 priority 8192
You can verify your settings by entering the show spanning-tree mst instance-id privileged EXEC
command.
Related Commands
Command
Description
show spanning-tree mst instance-id
Displays MST information for the specified interface.
spanning-tree mst cost
Sets the path cost for MST calculations.
spanning-tree mst port-priority
Configures an interface priority.
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spanning-tree mst root
spanning-tree mst root
Use the spanning-tree mst root global configuration command to configure the multiple spanning-tree
(MST) root switch priority and timers based on the network diameter. Use the no form of this command
to return to the default setting.
spanning-tree mst instance-id root {primary | secondary} [diameter net-diameter
[hello-time seconds]]
no spanning-tree mst instance-id root
Syntax Description
Defaults
instance-id
Range of spanning-tree instances. You can specify a single instance, a
range of instances separated by a hyphen, or a series of instances separated
by a comma. The range is 0 to 15.
root primary
Force this switch to be the root switch.
root secondary
Set this switch to be the root switch should the primary root switch fail.
diameter net-diameter
(Optional) Set the maximum number of switches between any two end
stations. The range is 2 to 7. This keyword is available only for MST
instance 0.
hello-time seconds
(Optional) Set the interval between hello bridge protocol data units
(BPDUs) sent by the root switch configuration messages. The range is 1 to 10
seconds. This keyword is available only for MST instance 0.
The primary root switch priority is 24576.
The secondary root switch priority is 28672.
The hello time is 2 seconds.
Command Modes
Global configuration
Command History
Release
Modification
12.1(20)EA2
This command was introduced.
Usage Guidelines
Use the spanning-tree mst instance-id root command used only on backbone switches.
When you enter the spanning-tree mst instance-id root command, the software tries to set a high
enough priority to make this switch the root of the spanning-tree instance. Because of the extended
system ID support, the switch sets the switch priority for the instance to 24576 if this value will cause
this switch to become the root for the specified instance. If any root switch for the specified instance has
a switch priority lower than 24576, the switch sets its own priority to 4096 less than the lowest switch
priority. (4096 is the value of the least-significant bit of a 4-bit switch priority value.)
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spanning-tree mst root
When you enter the spanning-tree mst instance-id root secondary command, because of support for
the extended system ID, the software changes the switch priority from the default value (32768) to
28672. If the root switch fails, this switch becomes the next root switch (if the other switches in the
network use the default switch priority of 32768 and are therefore unlikely to become the root switch).
Examples
This example shows how to configure the switch as the root switch for instance 10 with a network
diameter of 4:
Switch(config)# spanning-tree mst 10 root primary diameter 4
This example shows how to configure the switch as the secondary root switch for instance 10 with a
network diameter of 4:
Switch(config)# spanning-tree mst 10 root secondary diameter 4
You can verify your settings by entering the show spanning-tree mst instance-id privileged EXEC
command.
Related Commands
Command
Description
show spanning-tree mst instance-id
Displays MST information for the specified instance.
spanning-tree mst forward-time
Sets the forward-delay time for all MST instances.
spanning-tree mst hello-time
Sets the interval between hello BPDUs sent by root switch
configuration messages.
spanning-tree mst max-age
Sets the interval between messages that the spanning tree
receives from the root switch.
spanning-tree mst max-hops
Sets the number of hops in a region before the BPDU is
discarded.
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spanning-tree port-priority
spanning-tree port-priority
Use the spanning-tree port-priority interface configuration command to configure an interface
priority. If a loop occurs, spanning tree can determine which interface to put in the forwarding state. Use
the no form of this command to return to the default setting.
spanning-tree [vlan vlan-id] port-priority priority
no spanning-tree [vlan vlan-id] port-priority
Syntax Description
vlan vlan-id
(Optional) VLAN range associated with a spanning-tree instance. You can specify
a single VLAN identified by VLAN ID number, a range of VLANs separated by a
hyphen, or a series of VLANs separated by a comma. The range is 1 to 4094.
priority
The range is 0 to 240 in increments of 16 (0, 16, 32, 48, 64, 80, 96, 112, 128, 144,
160, 176, 192, 208, 224, and 240). All other values are rejected. The lower the
number, the higher the priority.
Defaults
The default is 128.
Command Modes
Interface configuration
Command History
Release
Modification
12.1(13)AY
This command was introduced.
Usage Guidelines
If the variable vlan-id is omitted, the command applies to the spanning-tree instance associated with
VLAN 1.
You can set the priority on a VLAN that has no interfaces assigned to it. The setting takes effect when
you assign the interface to the VLAN.
If you configure an interface with both the spanning-tree vlan vlan-id port-priority priority command
and the spanning-tree port-priority priority command, the spanning-tree vlan vlan-id port-priority
priority command takes effect only on the range of VLANs specified by that command. On the VLANs
that are not specified by the spanning-tree vlan vlan-id port-priority priority command, the
spanning-tree port-priority priority command takes effect.
Examples
This example shows how to increase the likelihood that the specified port will be put in the forwarding
state if a loop occurs:
Switch(config)# interface fastethernet0/2
Switch(config-if)# spanning-tree vlan 20 port-priority 0
You can verify your settings by entering the show spanning-tree interface interface-id privileged
EXEC command.
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spanning-tree port-priority
Related Commands
Command
Description
show spanning-tree interface
interface-id
Displays spanning-tree information for the specified interface.
spanning-tree cost
Sets the path cost for spanning-tree calculations.
spanning-tree vlan priority
Sets the switch priority for the specified spanning-tree instance.
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spanning-tree portfast (global configuration)
spanning-tree portfast (global configuration)
Use the spanning-tree portfast global configuration command to globally enable bridge protocol data
unit (BPDU) filtering on Port Fast-enabled ports, the BPDU guard feature on Port Fast-enabled ports, or
the Port Fast feature on all nontrunking ports. The BPDU filtering feature prevents the switch port from
sending or receiving BPDUs. The BPDU guard feature puts Port Fast-enabled ports that receive BPDUs
in an error-disabled state. Use the no form of this command to return to the default setting.
spanning-tree portfast {bpdufilter default | bpduguard default | default}
no spanning-tree portfast {bpdufilter default | bpduguard default | default}
Syntax Description
bpdufilter default
Globally enable BPDU filtering on Port Fast-enabled ports and prevent the
switch port connected to end stations from sending or receiving BPDUs.
bpduguard default
Globally enable the BPDU guard feature on Port Fast-enabled ports and place
the ports that receive BPDUs in an error-disabled state.
default
Globally enable the Port Fast feature on all nontrunking ports. When the Port
Fast feature is enabled, the port changes directly from a blocking state to a
forwarding state without making the intermediate spanning-tree state
changes.
Defaults
The BPDU filtering, the BPDU guard, and the Port Fast features are disabled on all ports unless they are
individually configured.
Command Modes
Global configuration
Command History
Release
Modification
12.1(13)AY
This command was introduced.
Usage Guidelines
You can enable these features when the switch is operating in the per-VLAN spanning-tree plus
(PVST+), rapid-PVST+, or the multiple spanning-tree (MST) mode.
Use the spanning-tree portfast bpdufilter default global configuration command to globally enable
BPDU filtering on ports that are Port Fast-enabled (the ports are in a Port Fast-operational state). The
ports still send a few BPDUs at link-up before the switch begins to filter outbound BPDUs. You should
globally enable BPDU filtering on a switch so that hosts connected to switch ports do not receive
BPDUs. If a BPDU is received on a Port Fast-enabled port, the port loses its Port Fast-operational status
and BPDU filtering is disabled.
You can override the spanning-tree portfast bpdufilter default global configuration command by
using the spanning-tree bdpufilter interface configuration command.
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Caution
Enabling BPDU filtering on an interface is the same as disabling spanning tree on it and can result in
spanning-tree loops.
Use the spanning-tree portfast bpduguard default global configuration command to globally enable
BPDU guard on ports that are in a Port Fast-operational state. In a valid configuration, Port Fast-enabled
ports do not receive BPDUs. Receiving a BPDU on a Port Fast-enabled port signals an invalid
configuration, such as the connection of an unauthorized device, and the BPDU guard feature puts the
port in the error-disabled state. The BPDU guard feature provides a secure response to invalid
configurations because you must manually put the port back in service. Use the BPDU guard feature in
a service-provider network to prevent an access port from participating in the spanning tree.
You can override the spanning-tree portfast bpduguard default global configuration command by
using the spanning-tree bdpuguard interface configuration command.
Use the spanning-tree portfast default global configuration command to globally enable the Port Fast
feature on all nontrunking ports. Configure Port Fast only on ports that connect to end stations;
otherwise, an accidental topology loop could cause a data packet loop and disrupt switch and network
operation. A Port Fast-enabled port moves directly to the spanning-tree forwarding state when linkup
occurs without waiting for the standard forward-delay time.
You can override the spanning-tree portfast default global configuration command by using the
spanning-tree portfast interface configuration command. You can use the no spanning-tree portfast
default global configuration command to disable Port Fast on all ports unless they are individually
configured with the spanning-tree portfast interface configuration command.
Examples
This example shows how to globally enable the BPDU filtering feature:
Switch(config)# spanning-tree portfast bpdufilter default
This example shows how to globally enable the BPDU guard feature:
Switch(config)# spanning-tree portfast bpduguard default
This example shows how to globally enable the Port Fast feature on all nontrunking ports:
Switch(config)# spanning-tree portfast default
You can verify your settings by entering the show running-config privileged EXEC command.
Related Commands
Command
Description
show running-config
Displays the current operating configuration. For syntax
information, select Cisco IOS Configuration Fundamentals
Command Reference for Release 12.1 > Cisco IOS File
Management Commands > Configuration File Commands.
spanning-tree bpdufilter
Prevents a port from sending or receiving BPDUs.
spanning-tree bpduguard
Puts a port in the error-disabled state when it receives a BPDU.
spanning-tree portfast (interface
configuration)
Enables the Port Fast feature on an interface in all its associated
VLANs.
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spanning-tree portfast (interface configuration)
spanning-tree portfast (interface configuration)
Use the spanning-tree portfast interface configuration command to enable the Port Fast feature on an
interface in all its associated VLANs. When the Port Fast feature is enabled, the interface changes
directly from a blocking state to a forwarding state without making the intermediate spanning-tree state
changes. Use the no form of this command to return to the default setting.
spanning-tree portfast [disable | trunk]
no spanning-tree portfast
Syntax Description
disable
(Optional) Disable the Port Fast feature on the specified interface.
trunk
(Optional) Enable the Port Fast feature on a trunking interface.
Defaults
The Port Fast feature is disabled on all interfaces; however, it is automatically enabled on
dynamic-access ports.
Command Modes
Interface configuration
Command History
Release
Modification
12.1(13)AY
This command was introduced.
Usage Guidelines
Use this feature only on interfaces that connect to end stations; otherwise, an accidental topology loop
could cause a data packet loop and disrupt switch and network operation.
To enable Port Fast on trunk ports, you must use the spanning-tree portfast trunk interface
configuration command. The spanning-tree portfast command is not supported on trunk ports.
You can enable this feature when the switch is operating in the per-VLAN spanning-tree plus (PVST+),
rapid-PVST+, or the multiple spanning-tree (MST) mode.
This feature affects all VLANs on the interface.
A port with the Port Fast feature enabled is moved directly to the spanning-tree forwarding state without
waiting the standard forward-time delay.
You can use the spanning-tree portfast default global configuration command to globally enable the
Port Fast feature on all nontrunking interfaces. However, the spanning-tree portfast interface
configuration command can override the global setting.
If you configure the spanning-tree portfast default global configuration command, you can disable
Port Fast on an interface that is not a trunk interface by using the spanning-tree portfast disable
interface configuration command.
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Examples
This example shows how to enable the Port Fast feature on an interface:
Switch(config)# interface fastethernet0/2
Switch(config-if)# spanning-tree portfast
You can verify your settings by entering the show running-config privileged EXEC command.
Related Commands
Command
Description
show running-config
Displays the current operating configuration. For syntax
information, select Cisco IOS Configuration Fundamentals
Command Reference for Release 12.1 > Cisco IOS File
Management Commands > Configuration File Commands.
spanning-tree bpdufilter
Prevents a port from sending or receiving bridge protocol data units
(BPDUs).
spanning-tree bpduguard
Puts a port in the error-disabled state when it receives a BPDU.
spanning-tree portfast (global
configuration)
Globally enables the BPDU filtering or the BPDU guard feature on
Port Fast-enabled ports or enables the Port Fast feature on all
nontrunking ports.
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spanning-tree uplinkfast
spanning-tree uplinkfast
Use the spanning-tree uplinkfast global configuration command to accelerate the choice of a new root
port when a link or switch fails or when the spanning tree reconfigures itself. Use the no form of this
command to return to the default setting.
spanning-tree uplinkfast [max-update-rate pkts-per-second]
no spanning-tree uplinkfast [max-update-rate]
Syntax Description
max-update-rate pkts-per-second
Defaults
UplinkFast is disabled.
(Optional) The number of packets per second at which update
packets are sent. The range is 0 to 32000.
The update rate is 150 packets per second.
Command Modes
Global configuration
Command History
Release
Modification
12.1(13)AY
This command was introduced.
Usage Guidelines
Use this command only on access switches.
You can configure the UplinkFast feature for rapid PVST+ or for multiple spanning-tree (MST) mode,
but the feature remains disabled (inactive) until you change the spanning-tree mode to PVST+.
When you enable UplinkFast, it is enabled for the entire switch and cannot be enabled for individual
VLANs.
When UplinkFast is enabled, the switch priority of all VLANs is set to 49152. If you change the path
cost to a value less than 3000 and you enable UplinkFast or UplinkFast is already enabled, the path cost
of all interfaces and VLAN trunks is increased by 3000 (if you change the path cost to 3000 or above,
the path cost is not altered). The changes to the switch priority and the path cost reduces the chance that
the switch will become the root switch.
When UplinkFast is disabled, the switch priorities of all VLANs and path costs of all interfaces are set
to default values if you did not modify them from their defaults.
When spanning tree detects that the root port has failed, UplinkFast immediately switches over to an
alternate root port, changing the new root port directly to FORWARDING state. During this time, a
topology change notification is sent.
Do not enable the root guard on interfaces that will be used by the UplinkFast feature. With UplinkFast,
the backup interfaces (in the blocked state) replace the root port in the case of a failure. However, if root
guard is also enabled, all the backup interfaces used by the UplinkFast feature are placed in the
root-inconsistent state (blocked) and prevented from reaching the forwarding state.
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If you set the max-update-rate to 0, station-learning frames are not generated, so the spanning-tree
topology converges more slowly after a loss of connectivity.
Examples
This example shows how to enable UplinkFast:
Switch(config)# spanning-tree uplinkfast
You can verify your setting by entering the show spanning-tree summary privileged EXEC command.
Related Commands
Command
Description
show spanning-tree summary
Displays a summary of the spanning-tree port states.
spanning-tree vlan root primary
Forces this switch to be the root switch.
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spanning-tree vlan
spanning-tree vlan
Use the spanning-tree vlan global configuration command to configure spanning tree on a per-VLAN
basis. Use the no form of this command to return to the default setting.
spanning-tree vlan vlan-id {forward-time seconds | hello-time seconds | max-age seconds |
priority priority | {root {primary | secondary} [diameter net-diameter
[hello-time seconds]]}}
no spanning-tree vlan vlan-id [forward-time | hello-time | max-age | priority | root]
Syntax Description
vlan-id
VLAN range associated with a spanning-tree instance. You can specify a
single VLAN identified by VLAN ID number, a range of VLANs separated
by a hyphen, or a series of VLANs separated by a comma. The range is 1 to
4094.
forward-time seconds
Set the forward-delay time for the specified spanning-tree instance. The
forwarding time determines how long each of the listening and learning
states last before the interface begins forwarding. The range is 4 to 30
seconds.
hello-time seconds
Set the interval between hello bridge protocol data units (BPDUs) sent by
the root switch configuration messages. The range is 1 to 10 seconds.
max-age seconds
Set the interval between messages the spanning tree receives from the root
switch. If a switch does not receive a BPDU message from the root switch
within this interval, it recomputes the spanning-tree topology. The range is
6 to 40 seconds.
priority priority
Set the switch priority for the specified spanning-tree instance. This setting
affects the likelihood that the switch is selected as the root switch. A lower
value increases the probability that the switch is selected as the root switch.
The range is 0 to 61440 in increments of 4096 (4096, 8192, 12288, 16384,
20480, 24576, 28672, 32768, 36864, 40960, 45056, 49152, 53248, 57344,
and 61440). All other values are rejected.
Defaults
root primary
Force this switch to be the root switch.
root secondary
Set this switch to be the root switch should the primary root switch fail.
diameter net-diameter
Set the maximum number of switches between any two end stations. The
range is 2 to 7.
Spanning tree is enabled on all VLANs.
The forward-delay time is 15 seconds.
The hello time is 2 seconds.
The max-age is 20 seconds.
The primary root switch priority is 24576.
The secondary root switch priority is 28672.
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spanning-tree vlan
Command Modes
Global configuration
Command History
Release
Modification
12.1(13)AY
This command was introduced.
Usage Guidelines
Disabling the STP causes the VLAN to stop participating in the spanning-tree topology. Interfaces that
are administratively down remain down. Received BPDUs are forwarded like other multicast frames.
The switch does not detect and prevent loops in a VLAN if STP is disabled for that VLAN.
You can disable the STP on a VLAN that is not currently active and verify the change by using the show
running-config or the show spanning-tree vlan vlan-id privileged EXEC command. The setting takes
effect when the VLAN is activated.
When disabling or re-enabling the STP, you can specify a range of VLANs that you want to disable or
enable.
When the STP is disabled and then enabled, all assigned VLANs continue to be its members. However,
all spanning-tree bridge parameters are returned to their previous settings (the last setting before the
VLAN was disabled).
You can enable spanning-tree options on a VLAN that has no interfaces assigned to it. The setting takes
effect when you assign interfaces to it.
When setting the max-age seconds, if a switch does not receive BPDUs from the root switch within the
specified interval, it recomputes the spanning-tree topology. The max-age setting must be greater than
the hello-time setting.
The spanning-tree vlan vlan-id root command should be used only on backbone switches.
When you enter the spanning-tree vlan vlan-id root command, the software checks the switch priority
of the current root switch for each VLAN. Because of the extended system ID support, the switch sets
the switch priority for the specified VLAN to 24576 if this value will cause this switch to become the
root for the specified VLAN. If any root switch for the specified VLAN has a switch priority lower than
24576, the switch sets its own priority for the specified VLAN to 4096 less than the lowest switch
priority. (4096 is the value of the least-significant bit of a 4-bit switch priority value.)
When you enter the spanning-tree vlan vlan-id root primary command, the switch recalculates the
forward-time, hello-time, max-age, and priority settings. If you previously configured these
parameters, the switch overrides and recalculates them.
When you enter the spanning-tree vlan vlan-id root secondary command, because of support for the
extended system ID, the software changes the switch priority from the default value (32768) to 28672.
If the root switch should fail, this switch becomes the next root switch (if the other switches in the
network use the default switch priority of 32768, and therefore, are unlikely to become the root switch).
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Examples
This example shows how to disable the STP on VLAN 5:
Switch(config)# no spanning-tree vlan 5
You can verify your setting by entering the show spanning-tree privileged EXEC command. In this
instance, VLAN 5 does not appear in the list.
This example shows how to set the spanning-tree forwarding time to 18 seconds for VLANs 20 and 25:
Switch(config)# spanning-tree vlan 20,25 forward-time 18
This example shows how to set the spanning-tree hello-delay time to 3 seconds for VLANs 20 to 24:
Switch(config)# spanning-tree vlan 20-24 hello-time 3
This example shows how to set spanning-tree max-age to 30 seconds for VLAN 20:
Switch(config)# spanning-tree vlan 20 max-age 30
This example shows how to reset the max-age parameter to the default value for spanning-tree
instances 100 and 105 to 108 :
Switch(config)# no spanning-tree vlan 100,105-108 max-age
This example shows how to set the spanning-tree priority to 8192 for VLAN 20:
Switch(config)# spanning-tree vlan 20 priority 8192
This example shows how to configure the switch as the root switch for VLAN 10 with a network
diameter of 4:
Switch(config)# spanning-tree vlan 10 root primary diameter 4
This example shows how to configure the switch as the secondary root switch for VLAN 10 with a
network diameter of 4:
Switch(config)# spanning-tree vlan 10 root secondary diameter 4
You can verify your settings by entering the show spanning-tree vlan vlan-id privileged EXEC
command.
Related Commands
Command
Description
show spanning-tree vlan
Displays spanning-tree information.
spanning-tree cost
Sets the path cost for spanning-tree calculations.
spanning-tree guard
Enables the root guard or the loop guard feature for all the VLANs
associated with the selected interface.
spanning-tree port-priority
Sets an interface priority.
spanning-tree portfast (global Globally enables the BPDU filtering or the BPDU guard feature on
configuration)
Port Fast-enabled ports or enables the Port Fast feature on all
nontrunking ports.
spanning-tree portfast
(interface configuration)
Enables the Port Fast feature on an interface in all its associated
VLANs.
spanning-tree uplinkfast
Enables the UplinkFast feature, which accelerates the choice of a
new root port.
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speed
speed
Use the speed interface configuration command to specify the speed of a port. Use the no form of this
command to return to the default setting.
speed {10 | 100 | 1000 | auto [10 | 100 | 1000]}
no speed
Syntax Description
Defaults
10
Port runs at 10 Mbps.
100
Port runs at 100 Mbps.
1000
Port runs at 1000 Mbps (only valid for Gigabit Ethernet ports).
auto
Port automatically detects whether it should run at 10 or 100 Mbps on Fast
Ethernet ports or at 10, 100, or 1000 Mbps on 10/100/1000 and SFP-module ports.
If you use the 10, 100, or 1000 keywords with the auto keyword, the port only
autonegotiates at the specified speeds.
For Fast Ethernet and 10/100/1000 ports, the default is auto.
For 100BASE-FX ports, the default is 100 Mbps.
For small form-factor pluggable (SFP) ports, the default is 1000 Mbps.
Command Modes
Interface configuration
Command History
Release
Modification
12.1(13)AY
This command was introduced.
12.1(22)EA1
Support for the 10, 100, and 1000 keywords with the auto keyword was
added.
Usage Guidelines
The applicability of this command depends on the switch on which you enter it.
Fast Ethernet ports, except for 100BASE-FX ports, can be configured at 10 or 100 Mbps in half- or
full-duplex mode. The 10/100/1000 ports operate in half- or full-duplex mode at 10 or 100 Mbps and in
full-duplex mode only at 1000 Mbps.
SFP ports only operate at 1000 Mbps, and those with a 1000 BASE-T module installed can only be
configured for full-duplex mode.
If the speed is set to auto, the switch negotiates with the device at the other end of the link for the speed
setting and then forces the speed setting to the negotiated value. The duplex setting remains as
configured on each end of the link, which could result in a duplex setting mismatch. If both the speed
and duplex are set to specific values, autonegotiation is disabled.
If the speed is set to auto and the 10, 100, or 1000 keywords are also used, the port only autonegotiates
at the specified speeds.
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speed
Note
The 100BASE-FX and SFP ports do not support the speed command. These ports operate only at 100
Mbps and in full-duplex mode.
Note
For guidelines on setting the switch speed and duplex parameters, see the “Configuring the Switch
Interfaces” chapter in the switch software configuration guide for this release.
Examples
This example shows how to set a port to 100 Mbps:
Switch(config)# interface fastethernet0/1
Switch(config-if)# speed 100
This example shows how to set a port to autonegotiate the speed:
Switch(config)# interface fastethernet0/1
Switch(config-if)# speed auto
This example shows how to set a port to autonegotiate at only 10 Mbps:
Switch(config)# interface fastethernet0/1
Switch(config-if)# speed auto 10
This example shows how to set a port to autonegotiate at only 10 or 100 Mbps:
Switch(config)# interface fastethernet0/1
Switch(config-if)# speed auto 10 100
You can verify your settings by entering the show interfaces transceiver properties or the
show running-config privileged EXEC command.
Related Commands
Command
Description
duplex
Specifies the duplex mode of operation for switch ports.
show interfaces
Displays the administrative and operational status of all interfaces or a
specified interface.
show running-config
Displays the current operating configuration. For syntax information, select
Cisco IOS Configuration Fundamentals Command Reference for
Release 12.1 > Cisco IOS File Management Commands > Configuration
File Commands.
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storm-control
storm-control
Use the storm-control interface configuration command to enable broadcast, multicast, or unicast storm
control on a port and to specify the action taken when a storm occurs on a port. Use the no form of this
command to disable storm control for broadcast, multicast, or unicast traffic and disable the specified
storm-control action.
storm-control {{{broadcast | multicast | unicast} level {level [level-low]} | action {shutdown |
trap}}
no storm-control {{broadcast | multicast | unicast} level} | action}
Syntax Description
{broadcast | multicast | unicast} Determines the type of packet-storm suppression.
level level [level-low]
action {shutdown | trap}
•
broadcast—Enable broadcast storm control on the port.
•
multicast—Enable multicast storm control on the port.
•
unicast—Enable unicast storm control on the port.
Defines the rising and falling suppression levels.
•
level—Rising suppression level as a percent of total
bandwidth, up to two decimal places. The range is 0 to 100
percent. Block the flooding of storm packets when the value
specified for level is reached.
•
level-low—(Optional) Falling suppression level as a
percent of total bandwidth, up to two decimal places. The
range is 0 to 100. This value must be less than the rising
supression value.
Action taken when a storm occurs on a port. The default action is
to filter traffic and to not send an Simple Network Management
Protocol (SNMP) trap.
The keywords have these meanings:
Defaults
•
shutdown—Disables the port during a storm.
•
trap—Sends an SNMP trap when a storm occurs.
Broadcast, multicast, and unicast storm control are disabled.
The default action is to filter traffic and to not send an SNMP trap.
Command Modes
Interface configuration
Command History
Release
Modification
12.1(13)AY
This command was introduced.
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Usage Guidelines
Use the storm-control command to enable or disable broadcast, multicast, or unicast storm control on
a port. After a port is disabled during a storm, use the no shutdown interface configuration command to
enable the port.
The suppression levels can be entered as a percentage of total bandwidth. A suppression value of
100 percent means that no limit is placed on the specified traffic type. This feature is enabled only when
the rising suppression level is less than 100 percent. If no other storm-control configuration is specified,
the default action is to filter the traffic causing the storm and to send no SNMP trap.
When a storm occurs and the action is to filter traffic, if the falling suppression level is not specified,
the switch blocks all traffic until the traffic rate drops below the rising suppression level. If the falling
suppression level is specified, the switch blocks traffic until the traffic rate drops below this level.
When a multicast or unicast storm occurs and the action is to filter traffic, the switch blocks all traffic
(broadcast, multicast, and unicast traffic) and sends only Spanning Tree Protocol (STP) packets.
When a broadcast storm occurs and the action is to filter traffic, the switch blocks only broadcast traffic.
The trap and shutdown options are independent of each other.
If you configure the action to be taken when a packet storm is detected as shutdown (the port is
error-disabled during a storm), you must use the no shutdown interface configuration command to bring
the interface out of this state. If you do not specify the shutdown action, specify the action as trap (the
switch generates a trap when a storm is detected).
Examples
This example shows how to enable broadcast storm control on a port with a 75.67-percent rising
suppression level:
Switch(config-if)# storm-control broadcast level 75.67
This example shows how to enable multicast storm control on a port with a 87-percent rising suppression
level and a 65-percent falling suppression level:
Switch(config-if)# storm-control multicast level 87 65
This example shows how to enable the shutdown action on a port:
Switch(config-if)# storm-control action shutdown
This example shows how to enable the trap action on a port:
Switch(config-if)# storm-control action trap
This example shows how to disable the shutdown action on a port:
Switch(config-if)# no storm-control action shutdown
You can verify your settings by entering the show storm-control privileged EXEC command.
Related Commands
Command
Description
show storm-control
Displays the packet-storm control information.
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switchport access
switchport access
Use the switchport access interface configuration command to configure a port as a static-access or
dynamic-access port. If the mode is set to access, the port operates as a member of the configured VLAN.
If set to dynamic, the port starts discovery of its VLAN assignment based on the incoming packets it
receives. Use the no form of this command to reset the access mode to the default VLAN for the switch.
switchport access vlan {vlan-id | dynamic}
no switchport access
Syntax Description
Defaults
access vlan
vlan-id
Configure the interface as a static-access port. The range is 1 to 4094.
access vlan
dynamic
Specify that the access mode VLAN is dependent on the VLAN Membership
Policy Server (VMPS) protocol. The port is assigned to a VLAN based on the
source MAC address of a host (or hosts) connected to the port. The switch sends
every new MAC address received to the VMPS server to obtain the VLAN name
to which the dynamic-access port should be assigned. If the port already has a
VLAN assigned and the source has already been approved by the VMPS, the
switch forwards the packet to the VLAN.
All ports are in static-access mode in VLAN 1 if the port is not connected to a device running Dynamic
Trunking Protocol (DTP). The default access VLAN for an access port is VLAN 1.
All ports are dynamic trunk ports.
A dynamic-access port is initially a member of no VLAN and receives its assignment based on the packet
it receives.
Command Modes
Interface configuration
Command History
Release
Modification
12.1(13)AY
This command was introduced.
Usage Guidelines
The no switchport access command resets the access mode VLAN to the appropriate default VLAN for
the device.
The port must be in access mode before the switchport access vlan command can take effect. For more
information, see the switchport mode command.
An access port can be assigned to only one VLAN.
The VMPS server (such as a Catalyst 6000 series switch) must be configured before a port is configured
as dynamic.
These restrictions apply to dynamic-access ports:
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switchport access
•
The software implements the VLAN Query Protocol (VQP) client, which can query a VMPS such
as a Catalyst 6000 series switch. The VMPS server must be configured before a port is configured
as dynamic.
•
Use dynamic-access ports only to connect end stations. Connecting them to switches or routers that
use bridging protocols can cause a loss of connectivity.
•
Configure the network so that Spanning Tree Protocol (STP) does not put the dynamic-access port
in an STP blocking state. The Port Fast feature is automatically enabled on dynamic-access ports.
•
Dynamic-access ports can only be in one VLAN and do not use VLAN tagging.
•
Dynamic-access ports cannot be configured as:
– Members of an EtherChannel port group (dynamic-access ports cannot be grouped with any
other port, including other dynamic ports).
– Source or destination ports in a static address entry.
– Monitor ports.
Examples
This example shows how to assign a port already in access mode to VLAN 2 (instead of the default
VLAN 1):
Switch(config-if)# switchport access vlan 2
You can verify your settings by entering the show interfaces interface-id switchport privileged EXEC
command and examining information in the Administrative Mode and Operational Mode rows.
Related Commands
Command
Description
show interfaces
switchport
Displays the administrative and operational status of a switching
(nonrouting) port, including port blocking and port protection settings.
switchport mode
Configures the VLAN membership mode of a port.
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switchport host
switchport host
Use the switchport host interface configuration command on the switch to optimize a Layer 2 port for a
host connection. The no form of this command has no effect on the system.
switchport host
Syntax Description
This command has no arguments or keywords.
Defaults
The default is for the port to not be optimized for a host connection.
Command Modes
Interface configuration
Command History
Release
Modification
12.1(20)EA1
This command was introduced.
Usage Guidelines
To optimize the port for a host connection, the switchport host command sets the switchport mode to
access, enables spanning-tree Port Fast, and disables channel grouping. Only an end station can accept
this configuration.
Because spanning-tree Port Fast is enabled, you should enter the switchport host command only on
ports that are connected to a single host. Connecting other switches, hubs, concentrators, or bridges to a
fast-start port can cause temporary spanning-tree loops.
Enable the switchport host command to decrease the time to start packet forwarding.
The no switchport host command has no affect. To return an interface to a configuration not optimized
as a host connection, you can manually reconfigure switchport mode, spanning-tree Port Fast, and
channel grouping. You can also use the default interface interface-id global config command to return
the interface to its default state. However, this command also returns other interface configuration to the
default.
Examples
This example shows how to optimize the port configuration for a host connection:
Switch(config-if)# switchport host
switchport mode will be set to access
spanning-tree portfast will be enabled
channel group will be disabled
Switch(config-if)#
You can verify the effects of the command by entering the show interfaces interface-id switchport or
show running-config interface interface-id privileged EXEC command.
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switchport host
Related Commands
Command
Description
show interfaces switchport
Displays the administrative and operational status of a switching
(nonrouting) port, including switchport mode.
show running-config
interface interface-id
Displays the running configuration on the interface.
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switchport mode
switchport mode
Use the switchport mode interface configuration command to configure the VLAN membership mode
of a port. Use the no form of this command to return to the default setting.
switchport mode {access | dynamic {auto | desirable} | trunk}
no switchport mode
Syntax Description
access
Set the port to access mode (either static-access or dynamic-access, depending on the
setting of the switchport access vlan interface configuration command). The port is
set to access unconditionally and operates as a nontrunking, single VLAN interface
that transmits and receives nonencapsulated (nontagged) frames. An access port can
be assigned to only one VLAN.
dynamic auto
Set the interface trunking mode dynamic parameter to auto to specify that the
interface convert the link to a trunk link.
dynamic
desirable
Set the interface trunking mode dynamic parameter to desirable to specify that the
interface actively attempt to convert the link to a trunk link.
trunk
Set the port to trunk unconditionally. The port is a trunking VLAN Layer 2 interface.
The port transmits and receives encapsulated (tagged) frames that identify the VLAN
of origination. A trunk is a point-to-point link between two switches or between a
switch and a router.
Defaults
The default mode is dynamic desirable.
Command Modes
Interface configuration
Command History
Release
Modification
12.1(13)AY
This command was introduced.
Usage Guidelines
Configuration by using the access or trunk keywords takes affect only when you configure the port in
the appropriate mode by using the switchport mode command. The static-access and trunk
configurations are saved, but only one configuration is active at a time.
If you enter access mode, the interface changes into permanent nontrunking mode and negotiates to
convert the link into a nontrunk link even if the neighboring interface does not agree to the change.
If you enter dynamic auto mode, the interface converts the link to a trunk link if the neighboring
interface is set to trunk or desirable mode.
If you enter dynamic desirable mode, the interface becomes a trunk interface if the neighboring
interface is set to trunk, desirable, or auto mode.
If you enter trunk mode, the interface changes into permanent trunking mode and negotiates to convert
the link into a trunk link even if the interface connecting to it does not agree to the change.
The no switchport mode form resets the mode to dynamic desirable.
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switchport mode
Trunk ports cannot coexist on the same switch.
To autonegotiate trunking, the interfaces must be in the same VTP domain. Trunk negotiation is
managed by the Dynamic Trunking Protocol (DTP), which is a point-to-point protocol. However, some
internetworking devices might forward DTP frames improperly, which could cause misconfigurations.
To avoid this, you should configure interfaces connected to devices that do not support DTP to not
forward DTP frames, which turns off DTP.
Examples
•
If you do not intend to trunk across those links, use the switchport mode access interface
configuration command to disable trunking.
•
To enable trunking to a device that does not support DTP, use the switchport mode trunk and
switchport nonegotiate interface configuration commands to cause the interface to become a trunk
but to not generate DTP frames.
This example shows how to configure a port for access mode:
Switch(config-if)# switchport mode access
This example shows how set the interface to dynamic desirable mode:
Switch(config-if)# switchport mode dynamic desirable
This example shows how to configure a port for trunk mode:
Switch(config-if)# switchport mode trunk
You can verify your settings by entering the show interfaces interface-id switchport privileged EXEC
command and examining information in the Administrative Mode and Operational Mode rows.
Related Commands
Command
Description
show interfaces
switchport
Displays the administrative and operational status of a switching (nonrouting)
port, including port blocking and port protection settings.
switchport access
Configures a port as a static-access port.
switchport trunk
Configures the trunk characteristics when an interface is in trunking mode.
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switchport nonegotiate
switchport nonegotiate
Use the switchport nonegotiate interface configuration command to specify that Dynamic Trunking
Protocol (DTP) negotiation packets are not sent on the Layer 2 interface. The switch does not engage in
DTP negotiation on this interface. Use the no form of this command to return to the default setting.
switchport nonegotiate
no switchport nonegotiate
Syntax Description
This command has no arguments or keywords.
Defaults
The default is to use DTP negotiation to determine trunking status.
Command Modes
Interface configuration
Command History
Release
Modification
12.1(13)AY
This command was introduced.
Usage Guidelines
The no form of the switchport nonegotiate command removes nonegotiate status.
This command is valid only when the interface switchport mode is access or trunk (configured by using
the switchport mode access or the switchport mode trunk interface configuration command). This
command returns an error if you attempt to execute it in dynamic (auto or desirable) mode.
Internetworking devices that do not support DTP might forward DTP frames improperly and cause
misconfigurations. To avoid this, you should turn off DTP by using the switchport no negotiate
command to configure the interfaces connected to devices that do not support DTP to not forward DTP
frames.
When you enter the switchport nonegotiate command, DTP negotiation packets are not sent on the
interface. The device does or does not trunk according to the mode parameter given: access or trunk.
Examples
•
If you do not intend to trunk across those links, use the switchport mode access interface
configuration command to disable trunking.
•
To enable trunking ona device that does not support DTP, use the switchport mode trunk and
switchport nonegotiate interface configuration commands to cause the interface to become a trunk
but to not generate DTP frames.
This example shows how to cause an interface to refrain from negotiating trunking mode and to act as a
trunk or access port (depending on the mode set):
Switch(config-if)# switchport nonegotiate
You can verify your setting by entering the show interfaces interface-id switchport privileged EXEC
command.
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switchport nonegotiate
Related Commands
Command
Description
show interfaces switchport
Displays the administrative and operational status of a switching
(nonrouting) port, including port blocking and port protection settings.
switchport mode
Configures the VLAN membership mode of a port.
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switchport port-security
switchport port-security
Use the switchport port-security interface configuration command without keywords to enable port
security on an interface. Use the keywords to configure secure MAC addresses, a maximum number of
secure MAC addresses, or the violation mode. Use the no form of this command to disable port security
or to return to the default settings.
switchport port-security [mac-address mac-address] | [mac-address sticky [mac-address]] |
[maximum value] | [violation {protect | restrict | shutdown}]
no switchport port-security [mac-address mac-address] | [mac-address sticky [mac-address]] |
[maximum value] | [violation {protect | restrict | shutdown}]
Syntax Description
mac-address mac-address
(Optional) Specify a secure MAC address for the port by entering a
48-bit MAC address. You can add additional secure MAC addresses up
to the maximum value configured.
mac-address sticky
[mac-address]
(Optional) Enable the interface for sticky learning by entering only the
mac-address sticky keywords. When sticky learning is enabled, the
interface adds all secure MAC addresses that are dynamically learned
to the running configuration and converts these addresses to sticky
secure MAC addresses.
Specify a sticky secure MAC address by entering the mac-address
sticky mac-address keywords.
Note
Although you can specify a sticky secure MAC address by
entering the mac-address sticky mac-address keywords, we
recommend using the mac-address mac-address interface
configuration command to enter static secure MAC addresses.
maximum value
(Optional) Set the maximum number of secure MAC addresses for the
interface. The range is 1 to 132. The default is 1.
violation
(Optional) Set the security violation mode or the action to be taken if
port security is violated. The default is shutdown.
protect
(Optional) Set the security violation protect mode. When the number of
secure MAC addresses reaches the limit allowed on the port, packets
with unknown source addresses are dropped until you remove a
sufficient number of secure MAC addresses or increase the number of
maximum allowable addresses. You are not notified that a security
violation has occurred.
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Defaults
restrict
(Optional) Set the security violation restrict mode. When the number
of secure MAC addresses reaches the limit allowed on the port, packets
with unknown source addresses are dropped until you remove a
sufficient number of secure MAC addresses or increase the number of
maximum allowable addresses. In this mode, you are notified that a
security violation has occurred. Specifically, an SNMP trap is sent, a
syslog message is logged, and the violation counter increments.
shutdown
(Optional) Set the security violation shutdown mode. In this mode, a
port security violation causes the interface to immediately become
error-disabled and turns off the port LED. It also sends an SNMP trap,
logs a syslog message, and increments the violation counter. When a
secure port is in the error-disabled state, you can bring it out of this
state by entering the errdisable recovery cause psecure-violation
global configuration command, or you can manually re-enable it by
entering the shutdown and no shut down interface configuration
commands.
Port security is disabled.
When port security is enabled, if no keywords are entered, the default maximum number of secure MAC
addresses is 1.
Sticky learning is disabled.
The default violation mode is shutdown.
Command Modes
Interface configuration
Command History
Release
Modification
12.1(13)AY
This command was introduced.
Usage Guidelines
A secure port can have 1 to 132 associated secure addresses. The total number of available secure
addresses on the switch is 1024.
After you have set the maximum number of secure MAC addresses allowed on a port, you can add secure
addresses to the address table by manually configuring them, by allowing the port to dynamically
configure them, or by configuring some MAC addresses and allowing the rest to be dynamically
configured.
You can delete dynamic secure MAC addresses from the address table by entering the clear
port-security dynamic privileged EXEC command.
You can enable sticky learning on an interface by using the switchport port-security mac-address
sticky interface configuration command. When you enter this command, the interface converts all the
dynamic secure MAC addresses, including those that were dynamically learned before sticky learning
was enabled, to sticky secure MAC addresses. It adds all the sticky secure MAC addresses to the running
configuration.
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switchport port-security
You can delete a sticky secure MAC addresses from the address table by using the clear port-security
sticky mac-addr privileged EXEC command. To delete all the sticky addresses on an interface, use the
clear port-security sticky interface-id privileged EXEC command.
If you disable sticky learning, the sticky secure MAC addresses are converted to dynamic secure
addresses and are removed from the running configuration.
If you save the sticky secure MAC addresses in the configuration file, when the switch restarts or the
interface shuts down, the interface does not need to relearn these addresses. If you do not save the
configuration, they are lost.
If you specify restrict or shutdown, use the snmp-server host global configuration command to
configure the Simple Network Management Protocol (SNMP) trap host to receive traps.
It is a security violation when one of these situations occurs:
•
The maximum number of secure MAC addresses have been added to the address table, and a station
whose MAC address is not in the address table attempts to access the interface.
•
An address learned or configured on one secure interface is seen on another secure interface in the
same VLAN.
When a secure port is in the error-disabled state, you can bring it out of this state by entering the
errdisable recovery cause psecure-violation global configuration command, or you can manually
re-enable it by entering the shutdown and no shut down interface configuration commands.
A secure port has these limitations:
Examples
•
Port security can only be configured on static access ports.
•
A secure port cannot be a dynamic port, a dynamic access port or a trunk port.
•
A secure port cannot be a destination port for Switched Port Analyzer (SPAN).
•
A secure port cannot belong to a Fast EtherChannel or Gigabit EtherChannel port group.
•
You cannot configure static secure or sticky secure MAC addresses on a voice VLAN.
•
When you enable port security on an interface that is also configured with a voice VLAN, set the
maximum allowed secure addresses on the port to two. When the port is connected to a Cisco IP
phone, the IP phone requires one MAC address. The Cisco IP phone address is learned on the voice
VLAN, but is not learned on the access VLAN. If you connect a single PC to the Cisco IP phone,
no additional MAC addresses are required. If you connect more than one PC to the Cisco IP phone,
you must configure enough secure addresses to allow one for each PC and one for the phone
•
If any type of port security is enabled on the access VLAN, dynamic port security is automatically
enabled on the voice VLAN.
•
You cannot configure port security on a per-VLAN basis.
•
When a voice VLAN is configured on a secure port that is also configured as a sticky secure port,
all addresses detected on the voice VLAN are learned as dynamic secure addresses while all
addresses detected on the access VLAN (to which the port belongs) are learned as sticky secure
addresses.
•
The switch does not support port security aging of sticky secure MAC addresses.
This example shows how to enable port security:
Switch(config-if)# switchport port-security
This example shows how to set the action that the port takes when an address violation occurs:
Switch(config-if)# switchport port-security violation shutdown
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switchport port-security
This example shows how to set the maximum number of addresses that a port can learn to 20:
Switch(config-if)# switchport port-security maximum 20
This example shows how to enable sticky learning and to enter two sticky secure MAC addresses:
Switch(config-if)# switchport port-security mac-address sticky
Switch(config-if)# switchport port-security mac-address sticky 0000.0000.4141
Switch(config-if)# switchport port-security mac-address sticky 0000.0000.000f
You can verify your settings by entering the show port-security privileged EXEC command.
Related Commands
Command
Description
clear port-security
Deletes from the MAC address table a specific dynamic secure
address or all the dynamic secure addresses on an interface.
clear port-security sticky
Deletes from the MAC address table a specific sticky secure address,
all the sticky secure addresses on an interface, or all the sticky secure
addresses on a switch.
show port-security
Displays the port security settings defined for the port.
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switchport port-security aging
switchport port-security aging
Use the switchport port-security aging interface configuration command to set the aging time and type
for secure address entries or to change the aging behavior for statically configured secure addresses on
a particular port. Use the no form of this command to disable port security aging or to return to the
default settings.
switchport port-security aging {static | time time | type {absolute | inactivity}}
no switchport port-security aging {static | time | type}
Syntax Description
static
Enable aging for statically configured secure addresses on this port.
time time
Specify the aging time for this port. The range is 0 to 1440 minutes. If
the time is 0, aging is disabled for this port.
type {absolute | inactivity}
Sets the type of aging. The keywords have these meanings:
absolute—Set the aging type as absolute aging. All the secure
addresses on this port age out after the time (minutes) specified and are
removed from the secure address list.
inactivity—Set the aging type as inactivity aging. The secure addresses
on this port age out only if there is no data traffic from the secure source
address for the specified time period.
Defaults
The port security aging feature is disabled. The default time is 0 minutes.
The default aging type is absolute.
The default static aging behavior is disabled.
Command Modes
Interface configuration
Command History
Release
Modification
12.1(13)AY
This command was introduced.
Usage Guidelines
To enable secure address aging for a particular port, set the port aging time to a value other than 0.
To allow limited-time access to specific secure MAC addresses, set the aging type as absolute. When
the aging time elapses, the secure addresses are deleted.
To allow continuous access to a limited number of secure addresses, set the aging type as inactivity.
This removes the secure address when it becomes inactive, and other addresses can become secure.
To allow unlimited access to a secure address, configure it as a secure address, and disable aging for the
statically configured secure address by using the no switchport port-security aging static interface
configuration command.
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switchport port-security aging
Examples
This example sets the aging time as 2 hours for absolute aging for all the secure addresses on a port:
Switch(config)# interface fastethernet0/1
Switch(config-if)# switchport port-security aging time 120
This example sets the aging time as 2 minutes for inactivity aging type for configured secure addresses
on a port:
Switch(config)# interface fastethernet0/2
Switch(config-if)# switchport port-security aging time 2
Switch(config-if)# switchport port-security aging type inactivity
Switch(config-if)# switchport port-security aging static
This example shows how to disable aging for configured secure addresses:
Switch(config-if)# no switchport port-security aging static
Related Commands
Command
Description
show port-security
Displays the port security settings defined for the port.
switchport port-security
Enables port security on a port, restricts the use of the port to a
user-defined group of stations, and configures secure MAC addresses.
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switchport priority extend
switchport priority extend
Use the switchport priority extend interface configuration command to set a port priority for the
incoming untagged frames or the priority of frames received by the IP phone connected to the specified
port. Use the no form of this command to return to the default setting.
switchport priority extend {cos value | trust}
no switchport priority extend
Syntax Description
cos value
Set the IP phone port to override the priority received from PC or the attached
device.
The class of service (CoS) range is 0 to 7. Seven is the highest priority. The default
is 0.
trust
Defaults
Set the IP phone port to trust the priority received from PC or the attached device.
The port priority is not set, and the default value for untagged frames received on the port is 0.
The IP phone connected to the port is set to not trust the priority of incoming traffic and overrides the
priority with the CoS value of 0.
Command Modes
Interface configuration
Command History
Release
Modification
12.1(13)AY
This command was introduced.
Usage Guidelines
To instruct the IP Phone to not trust the priority, you can use the no switchport priority extend or the
switchport priority extend cos 0 interface configuration command.
Examples
This example shows how to configure the IP phone connected to the specified port to trust the received
IEEE 802.1p priority:
Switch(config-if)# switchport priority extend trust
You can verify your settings by entering the show interfaces interface-id switchport privileged EXEC
command.
Related Commands
Command
Description
show interfaces
Displays the administrative and operational status of a port or all ports.
switchport voice vlan
Configures the voice VLAN on the port.
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switchport protected
switchport protected
Use the switchport protected interface configuration command to isolate unicast, multicast, and
broadcast traffic at Layer 2 from other protected ports on the same switch. Use the no form of this
command to return to the default setting.
switchport protected
no switchport protected
Syntax Description
This command has no arguments or keywords.
Defaults
No protected port is defined. All ports are nonprotected.
Command Modes
Interface configuration
Command History
Release
Modification
12.1(13)AY
This command was introduced.
Usage Guidelines
The switchport protection feature is local to the switch; communication between protected ports on the
same switch is possible only through a Layer 3 device. To prevent communication between protected
ports on different switches, you must configure the protected ports for unique VLANs on each switch
and configure a trunk link between the switches. A protected port is different from a secure port.
A protected port does not forward any unicast, multicast, or broadcast traffic to any other protected port.
A protected port continues to forward unicast, multicast, and broadcast traffic to unprotected ports and
vice versa.
Port monitoring does not work if both the monitor and monitored ports are protected ports.
Examples
This example shows how to enable a protected port:
Switch(config)# interface fastethernet0/3
Switch(config-if)# switchport protected
You can verify your settings by entering the show interfaces switchport privileged EXEC command.
Related Commands
Command
Description
show interfaces switchport
Displays the administrative and operational staus of a switching port.
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switchport trunk
switchport trunk
Use the switchport trunk interface configuration command to set the trunk characteristics when the
interface is in trunking mode. Use the no form of the command without keywords to reset all of the
trunking characteristics to the defaults. Use the no form with keywords to reset those characteristics to
the defaults.
switchport trunk {{allowed vlan vlan-list} | {native vlan vlan-id} | {pruning vlan vlan-list}}
no switchport trunk {{allowed vlan vlan-list} | {native vlan vlan-id} | {pruning vlan vlan-list}}
Syntax Description
allowed vlan vlan-list
Set the list of allowed VLANs that can receive and send traffic on this
interface in tagged format when in trunking mode. See the following vlan-list
format. The none keyword is not valid. The default is all.
native vlan vlan-id
Set the native VLAN for sending and receiving untagged traffic when the
interface is in IEEE 802.1Q trunking mode. The range is 1 to 4094.
pruning vlan vlan-list
Set the list of VLANs that are enabled for VTP pruning when in trunking
mode. The all keyword is not valid.
The vlan-list format is all | none | [add | remove | except] vlan-atom where:
•
all specifies all VLANs from 1 to 4094. This keyword is not allowed on commands that do not
permit all VLANs in the list to be set at the same time.
•
none means an empty list. This keyword is not allowed on commands that require certain VLANs
to be set or at least one VLAN to be set.
•
add adds the defined list of VLANs to those currently set instead of replacing the list. Valid IDs are
1 to 1005; extended-range VLAN IDs are valid in some cases.
Note
You can add extended-range VLANs to the allowed VLAN list, but not to the
pruning-eligible VLAN list.
Separate nonconsecutive VLAN IDs with a comma; do not enter a space after the comma. Use a
hyphen to designate a range of IDs; do not enter a space before or after the hyphen.
•
remove removes the defined list of VLANs from those currently set instead of replacing the list.
Valid IDs are 2 to 1001; extended-range VLAN IDs are valid in some cases. You cannot remove
VLAN 1 or VLANs 1002 to 1005 from the list.
Note
You can remove extended-range VLANs (VLAN IDs greater than 1005) from the allowed
VLAN list, but you cannot remove them from the pruning-eligible list.
Separate nonconsecutive VLAN IDs with a comma; do not enter a space after the comma. Use a
hyphen to designate a range of IDs; do not enter a space before or after the hyphen.
•
except lists the VLANs that should be calculated by inverting the defined list of VLANs. (VLANs
are added except the ones specified.) Valid IDs are 1 to 1001. Separate nonconsecutive VLAN IDs
with a comma; do not enter a space after the comma. Use a hyphen to designate a range of IDs; do
not enter a space before or after the hyphen.
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switchport trunk
•
vlan-atom is either a single VLAN number from 1 to 4094, a list of nonconsecutive VLANs, or a
continuous range of VLANs described by two VLAN numbers, the lower one first, separated by a
hyphen.
For a list of nonconsecutive VLAN IDs, separate the VLAN IDs with a comma. Do not enter a space
after the comma.
For a continuous range of VLAN IDs, use a hyphen to designate the range. Do not enter a space
before or after the hyphen.
These are examples showing how to specify one or more VLANs:
– Single VLAN—101
– List of nonconsecutive VLANs—10,12,14,16,18
– Continuous range of VLANs—10-15
– List of VLAN continuous ranges—10-15,20-24
– List of nonconsecutive VLANs and VLAN continuous ranges—8,11,20-24,44
Defaults
VLAN 1 is the default native VLAN ID on the port.
The default for all VLAN lists is to include all VLANs.
Command Modes
Interface configuration
Command History
Release
Modification
12.1(13)AY
This command was introduced.
Usage Guidelines
A trunk port cannot be a secure port or a monitor port. However, a static-access port can monitor a
VLAN on a trunk port. The VLAN monitored is the one associated with the static-access port.
Allowed VLAN:
•
The no form of the allowed vlan command resets the list to the default list, which allows all VLANs.
•
You cannot remove VLAN 1 or VLANs 1002 to 1005 from the allowed VLAN list.
Native VLANs:
•
All untagged traffic received on an IEEE 802.1Q trunk port is forwarded with the native VLAN
configured for the port.
•
If a packet has a VLAN ID that is the same as the sending port native VLAN ID, the packet is sent
without a tag; otherwise, the switch sends the packet with a tag.
•
The no form of the native vlan command resets the native mode VLAN to the appropriate default
VLAN for the device.
Trunk Pruning:
•
The pruning-eligible list applies only to trunk ports.
•
Each trunk port has its own eligibility list.
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switchport trunk
Note
Examples
•
If you do not want a VLAN to be pruned, remove it from the pruning-eligible list. VLANs that are
pruning-ineligible receive flooded traffic.
•
VLAN 1, VLANs 1002 to 1005, and extended-range VLANs (VLANs 1006 to 4094) cannot be
pruned.
The switch does not support Inter-Switch Link (ISL) trunking.
This example shows how to configure VLAN 3 as the default port to send all untagged traffic:
Switch(config-if)# switchport trunk native vlan 3
This example shows how to add VLANs 1, 2, 5, and 6 to the allowed list:
Switch(config-if)# switchport trunk allowed vlan add 1,2,5,6
This example shows how to remove VLANs 3 and 10 to 15 from the pruning-eligible list:
Switch(config-if)# switchport trunk pruning vlan remove 3,10-15
You can verify your settings by entering the show interfaces interface-id switchport privileged EXEC
command.
Related Commands
Command
Description
show interfaces switchport
Displays the administrative and operational status of a switching
(nonrouting) port.
switchport mode
Configures the VLAN membership mode of a port.
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switchport voice vlan
switchport voice vlan
Use the switchport voice vlan interface configuration command to configure voice VLAN on the port.
Use the no form of this command to return to the default setting.
switchport voice vlan {vlan-id | dot1p | none | untagged}
no switchport voice vlan
Syntax Description
Defaults
vlan-id
VLAN used for voice traffic. The range is 1 to 4094.
dot1p
The telephone uses priority tagging and uses VLAN 0 (the native VLAN). By
default, the Cisco IP phone forwards the voice traffic with an IEEE 802.1p priority
of 5.
none
The telephone is not instructed through the command-line interface (CLI) about
the voice VLAN. The telephone uses the configuration from the telephone key
pad.
untagged
The telephone does not tag frames and uses VLAN 4095. The default for the
telephone is untagged.
The switch default is not to automatically configure the telephone (none).
The telephone default is not to tag frames.
Command Modes
Interface configuration
Command History
Release
Modification
12.1(13)AY
This command was introduced.
Usage Guidelines
You should configure voice VLAN on access ports.
When you enable port security on an interface that is also configured with a voice VLAN, set the
maximum allowed secure addresses on the port to two. When the port is connected to a Cisco IP phone,
the IP phone requires one MAC address. The Cisco IP phone address is learned on the voice VLAN, but
is not learned on the access VLAN. If you connect a single PC to the Cisco IP phone, no additional MAC
addresses are required. If you connect more than one PC to the Cisco IP phone, you must configure
enough secure addresses to allow one for each PC and one for the phone.
You cannot configure static secure MAC addresses on the voice VLAN.
The Port Fast feature is automatically enabled when voice VLAN is configured. When you disable voice
VLAN, the Port Fast feature is not automatically disabled.
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switchport voice vlan
Examples
This example shows how to configure VLAN 2 as the voice VLAN:
Switch(config-if)# switchport voice vlan 2
You can verify your settings by entering the show interfaces interface-id switchport privileged EXEC
command.
Related Commands
Command
Description
show interfaces interface-id switchport
Displays the administrative and operational status of a
switching (nonrouting) port.
switchport priority extend
Determines how the device connected to the specified port
handles priority traffic received on its incoming port.
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system mtu
system mtu
Use the system mtu global configuration command to set the maximum packet size or maximum
transmission unit (MTU) size for the switch. Use the no form of this command to restore the global MTU
value to its original default value.
system mtu bytes
no system mtu
Syntax Description
bytes
Defaults
The default MTU size is 1500 bytes.
Command Modes
Global configuration
Command History
Release
Modification
12.1(13)AY
This command was introduced.
Usage Guidelines
Packet size in bytes. For valid values, see the “Usage Guidelines” section.
System MTU can only be set to 1500 bytes, the default.
The size of frames that can be received by the switch CPU is limited to 1500 bytes, no matter what value
was entered with the system mtu command. Although frames that are forwarded or routed typically are
not received by the CPU, in some cases packets are sent to the CPU, such as traffic sent to control traffic,
Simple Network Management Protocol (SNMP), Telnet, or routing protocols.
If you enter a value that is outside of the range for the switch, the value is not accepted.
Note
Examples
You cannot set the MTU on a per-interface basis.
This example shows the response when you try to set a switch to an out-of-range number:
Switch(config)# system mtu 2000
^
% Invalid input detected at '^' marker.
You can verify your settings by entering the show system mtu privileged EXEC command.
Related Commands
Command
Description
show system mtu
Displays the maximum packet size set for the switch.
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traceroute mac
traceroute mac
Use the traceroute mac privileged EXEC command to display the Layer 2 path taken by the packets
from the specified source MAC address to the specified destination MAC address.
tracetroute mac [interface interface-id] {source-mac-address} [interface interface-id]
{destination-mac-address} [vlan vlan-id] [detail]
Syntax Description
interface interface-id
(Optional) Specify an interface on the source or destination switch.
source-mac-address
Specify the MAC address of the source switch in hexadecimal format.
destination-mac-address
Specify the MAC address of the destination switch in hexadecimal format.
vlan vlan-id
(Optional) Specify the VLAN on which to trace the Layer 2 path that the
packets take from the source switch to the destination switch. The range is
1 to 4094.
detail
(Optional) Specify that detailed information appears.
Defaults
There is no default.
Command Modes
Privileged EXEC
Command History
Release
Modification
12.1(13)AY
This command was introduced.
Usage Guidelines
For Layer 2 traceroute to functional properly, Cisco Discovery Protocol (CDP) must be enabled on all
the switches in the network. Do not disable CDP.
When the switch detects a device in the Layer 2 path that does not support Layer 2 traceroute, the switch
continues to send Layer 2 trace queries and lets them time out.
The maximum number of hops identified in the path is ten.
Layer 2 traceroute supports only unicast source and destination MAC addresses. If you specify a
multicast source or destination MAC address, the physical path is not identified, and an error message
appears.
The traceroute mac command output shows the Layer 2 path when the specified source and destination
addresses belong to the same VLAN. If you specify source and destination addresses that belong to
different VLANs, the Layer 2 path is not identified, and an error message appears.
If the source or destination MAC address belongs to multiple VLANs, you must specify the VLAN to
which both the source and destination MAC addresses belong. If the VLAN is not specified, the path is
not identified, and an error message appears.
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traceroute mac
The Layer 2 traceroute feature is not supported when multiple devices are attached to one port through
hubs (for example, multiple CDP neighbors are detected on a port). When more than one CDP neighbor
is detected on a port, the Layer 2 path is not identified, and an error message appears.
This feature is not supported in Token Ring VLANs.
Examples
This example shows how to display the Layer 2 path by specifying the source and destination MAC
addresses:
Switch# traceroute mac 0000.0201.0601 0000.0201.0201
Source 0000.0201.0601 found on con6[WS-C2940-8TT-S] (2.2.6.6)
con6 (2.2.6.6) :Fa0/1 => Fa0/3
con5
(2.2.5.5
) :
Fa0/3 => Gi0/1
con1
(2.2.1.1
) :
Gi0/1 => Gi0/2
con2
(2.2.2.2
) :
Gi0/2 => Fa0/1
Destination 0000.0201.0201 found on con2[WS-C3550-24] (2.2.2.2)
Layer 2 trace completed
This example shows how to display the Layer 2 path by using the detail keyword:
Switch# traceroute mac 0000.0201.0601 0000.0201.0201 detail
Source 0000.0201.0601 found on con6[WS-C2940-8TT-S] (2.2.6.6)
con6 / / 2.2.6.6 :
Fa0/1 [auto, auto] => Fa0/3 [auto, auto]
con5 / WS-C2950G-24-EI / 2.2.5.5 :
Fa0/3 [auto, auto] => Gi0/1 [auto, auto]
con1 / WS-C3550-12G / 2.2.1.1 :
Gi0/1 [auto, auto] => Gi0/2 [auto, auto]
con2 / WS-C3550-24 / 2.2.2.2 :
Gi0/2 [auto, auto] => Fa0/1 [auto, auto]
Destination 0000.0201.0201 found on con2[WS-C3550-24] (2.2.2.2)
Layer 2 trace completed.
This example shows how to display the Layer 2 path by specifying the interfaces on the source and
destination switches:
Switch# traceroute mac interface fastethernet0/1 0000.0201.0601 interface fastethernet0/3
0000.0201.0201
Source 0000.0201.0601 found on con6[WS-C2940-8TT-S] (2.2.6.6)
con6
(2.2.6.6) :Fa0/1 => Fa0/3
con5
(2.2.5.5
) :
Fa0/3 => Gi0/1
con1
(2.2.1.1
) :
Gi0/1 => Gi0/2
con2
(2.2.2.2
) :
Gi0/2 => Fa0/1
Destination 0000.0201.0201 found on con2[WS-C3550-24] (2.2.2.2)
Layer 2 trace completed
This example shows the Layer 2 path when the switch is not connected to the source switch:
Switch# traceroute mac 0000.0201.0501 0000.0201.0201 detail
Source not directly connected, tracing source .....
Source 0000.0201.0501 found on con5[WS-C2940-8TT-S] (2.2.5.5)
con5 / WS-C2940-8TT-S / 2.2.5.5 :
Fa0/1 [auto, auto] => Gi0/1 [auto, auto]
con1 / WS-C3550-12G / 2.2.1.1 :
Gi0/1 [auto, auto] => Gi0/2 [auto, auto]
con2 / WS-C3550-24 / 2.2.2.2 :
Gi0/2 [auto, auto] => Fa0/1 [auto, auto]
Destination 0000.0201.0201 found on con2[WS-C3550-24] (2.2.2.2)
Layer 2 trace completed.
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traceroute mac
This example shows the Layer 2 path when the switch cannot find the destination port for the source
MAC address:
Switch# traceroute mac 0000.0011.1111 0000.0201.0201
Error:Source Mac address not found.
Layer2 trace aborted.
This example shows the Layer 2 path when the source and destination devices are in different VLANs:
Switch# traceroute mac 0000.0201.0601 0000.0301.0201
Error:Source and destination macs are on different vlans.
Layer2 trace aborted.
This example shows the Layer 2 path when the destination MAC address is a multicast address:
Switch# traceroute mac 0000.0201.0601 0100.0201.0201
Invalid destination mac address
This example shows the Layer 2 path when source and destination switches belong to multiple VLANs:
Switch# traceroute mac 0000.0201.0601 0000.0201.0201
Error:Mac found on multiple vlans.
Layer2 trace aborted.
Related Commands
Command
Description
traceroute mac ip
Displays the Layer 2 path taken by the packets from the specified source IP
address or hostname to the specified destination IP address or hostname.
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traceroute mac ip
traceroute mac ip
Use the traceroute mac ip privileged EXEC command to display the Layer 2 path taken by the packets
from the specified source IP address or hostname to the specified destination IP address or hostname.
tracetroute mac ip {source-ip-address | source-hostname} {destination-ip-address |
destination-hostname} [detail]
Syntax Description
source-ip-address
Specify the IP address of the source switch as a 32-bit quantity in
dotted-decimal format.
source-hostname
Specify the IP hostname of the source switch.
destination-ip-address
Specify the IP address of the destination switch as a 32-bit quantity in
dotted-decimal format.
destination-hostname
Specify the IP hostname of the destination switch.
detail
(Optional) Specify that detailed information appears.
Defaults
There is no default.
Command Modes
Privileged EXEC
Command History
Release
Modification
12.1(13)AY
This command was introduced.
Usage Guidelines
For Layer 2 traceroute to functional properly, Cisco Discovery Protocol (CDP) must be enabled on all
the switches in the network. Do not disable CDP.
When the switch detects an device in the Layer 2 path that does not support Layer 2 traceroute, the switch
continues to send Layer 2 trace queries and lets them time out.
The maximum number of hops identified in the path is ten.
The traceroute mac ip command output shows the Layer 2 path when the specified source and
destination IP addresses are in the same subnet. When you specify the IP addresses, the switch uses
Address Resolution Protocol (ARP) to associate the IP addresses with the corresponding MAC addresses
and the VLAN IDs.
•
If an ARP entry exists for the specified IP address, the switch uses the associated MAC address and
identifies the physical path.
•
If an ARP entry does not exist, the switch sends an ARP query and tries to resolve the IP address.
The IP addresses must be in the same subnet. If the IP address is not resolved, the path is not
identified, and an error message appears.
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traceroute mac ip
The Layer 2 traceroute feature is not supported when multiple devices are attached to one port through
hubs (for example, multiple CDP neighbors are detected on a port). When more than one CDP neighbor
is detected on a port, the Layer 2 path is not identified, and an error message appears.
This feature is not supported in Token Ring VLANs.
Examples
This example shows how to display the Layer 2 path by specifying the source and destination IP
addresses and by using the detail keyword:
Switch# traceroute mac ip 2.2.66.66 2.2.22.22 detail
Translating IP to mac .....
2.2.66.66 => 0000.0201.0601
2.2.22.22 => 0000.0201.0201
Source 0000.0201.0601 found on con6[WS-C2940-8TT-S] (2.2.6.6)
con6 / WS-C2940-8TT-S / 2.2.6.6 :
Fa0/1 [auto, auto] => Fa0/3 [auto, auto]
con5 / WS-C2950G-24-EI / 2.2.5.5 :
Fa0/3 [auto, auto] => Gi0/1 [auto, auto]
con1 / WS-C3550-12G / 2.2.1.1 :
Gi0/1 [auto, auto] => Gi0/2 [auto, auto]
con2 / WS-C3550-24 / 2.2.2.2 :
Gi0/2 [auto, auto] => Fa0/1 [auto, auto]
Destination 0000.0201.0201 found on con2[WS-C3550-24] (2.2.2.2)
Layer 2 trace completed.
This example shows how to display the Layer 2 path by specifying the source and destination hostnames:
Switch# traceroute mac ip con6 con2
Translating IP to mac .....
2.2.66.66 => 0000.0201.0601
2.2.22.22 => 0000.0201.0201
Source 0000.0201.0601 found on con6
con6 (2.2.6.6) :Fa0/1 => Fa0/3
con5
(2.2.5.5
) :
con1
(2.2.1.1
) :
con2
(2.2.2.2
) :
Destination 0000.0201.0201 found on con2
Layer 2 trace completed
Fa0/3 => Gi0/1
Gi0/1 => Gi0/2
Gi0/2 => Fa0/1
This example shows the Layer 2 path when ARP cannot associate the source IP address with the
corresponding MAC address:
Switch# traceroute mac ip 2.2.66.66 2.2.77.77
Arp failed for destination 2.2.77.77.
Layer2 trace aborted.
Related Commands
Command
Description
traceroute mac
Displays the Layer 2 path taken by the packets from the specified source MAC
address to the specified destination MAC address.
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udld
udld
Use the udld global configuration command to enable aggressive or normal mode in the UniDirectional
Link Detection (UDLD) and to set the configurable message timer. Use the no form of this command to
return to the default settings.
udld {aggressive | enable | message time message-timer-interval}
no udld {aggressive | enable | message time}
Syntax Description
Defaults
aggressive
Enable UDLD in aggressive mode on all fiber-optic interfaces.
enable
Enable UDLD in normal mode on all fiber-optic interfaces.
message time
message-timer-interval
Configure the period of time between UDLD probe messages on ports that
are in the advertisement phase and are determined to be bidirectional. The
range is 7 to 90 seconds.
UDLD is disabled on all fiber-optic interfaces.
The message timer is set at 60 seconds.
Command Modes
Global configuration
Command History
Release
Modification
12.1(13)AY
This command was introduced.
Usage Guidelines
Use the udld global configuration command to enable UDLD only on fiber-optic ports. To enable UDLD
on other interface types, use the udld interface configuration command.
UDLD supports two modes of operation: normal mode (the default) and aggressive mode. In normal
mode, UDLD detects unidirectional links due to misconnected interfaces on fiber-optic connections. In
aggressive mode, UDLD also detects unidirectional links due to one-way traffic on fiber-optic and
twisted-pair links and due to misconnected interfaces on fiber-optic links. For information about normal
and aggressive modes, see the “Understanding UDLD” section in the software configuration guide for
this release.
If you change the message time between probe packets, you are making a trade-off between the detection
speed and the CPU load. By decreasing the time, you can make the detection-response faster but increase
the load on the CPU.
You can use these commands to reset an interface shut down by UDLD:
•
The udld reset privileged EXEC command to reset all interfaces shut down by UDLD
•
The shutdown and no shutdown interface configuration commands
•
The no udld enable global configuration command followed by the udld {aggressive | enable}
global configuration command to re-enable UDLD globally
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udld
Examples
•
The no udld port enable interface configuration command followed by the udld port or udld port
aggressive interface configuration command to re-enable UDLD on the specified interface
•
The errdisable recovery cause udld and errdisable recovery interval interval global
configuration commands to automatically recover from the UDLD error-disabled state
This example shows how to enable UDLD in normal mode on all fiber-optic interfaces:
Switch(config)# udld enable
You can verify your settings by entering the show udld privileged EXEC command.
Related Commands
Command
Description
show running-config
Displays the running configuration on the switch. For syntax information,
select Cisco IOS Configuration Fundamentals Command Reference for
Release 12.1 > Cisco IOS File Management Commands > Configuration
File Commands.
show udld
Displays the UDLD status for all ports or the specified port.
udld port
Enables UDLD on an individual interface or prevents a fiber-optic
interface from being enabled by the udld global configuration command.
udld reset
Resets any interface shut down by UDLD and permits traffic to again pass
through.
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udld port
udld port
Use the udld port interface configuration command to enable UniDirectional Link Detection (UDLD)
on an individual interface or to prevent a fiber-optic interface from being enabled by the udld global
configuration command. Use the no form of this command to return to the udld global configuration
command setting or to disable UDLD if entered for a nonfiber-optic port.
udld port [aggressive]
no udld port [aggressive]
Syntax Description
aggressive
Defaults
On fiber-optic interfaces, UDLD is not enabled, not in aggressive mode, and not disabled. For this
reason, fiber-optic interfaces enable UDLD according to the state of the udld enable or udld aggressive
global configuration command.
(Optional) Enable UDLD in aggressive mode on the specified interface.
On nonfiber-optic interfaces, UDLD is disabled.
Command Modes
Interface configuration
Command History
Release
Modification
12.1(20)EA2
The disable keyword was removed.
12.1(13)AY
This command was introduced.
12.1(19)EA1
The port keyword was added. The enable keyword was removed.
Usage Guidelines
UDLD is supported on fiber- and copper-based Ethernet ports.
A UDLD-capable port cannot detect a unidirectional link if it is connected to a UDLD-incapable port of
another switch.
This setting overrides the global UDLD configuration on the switch.
UDLD supports two modes of operation: normal mode (the default) and aggressive mode. In normal
mode, UDLD detects unidirectional links due to misconnected interfaces on fiber-optic connections. In
aggressive mode, UDLD also detects unidirectional links due to one-way traffic on fiber-optic and
twisted-pair links and due to misconnected interfaces on fiber-optic links. For information about normal
and aggressive modes, see the “Configuring UDLD” chapter in the software configuration guide for this
release.
To enable UDLD in normal mode, use the udld port interface configuration command. To enable UDLD
in aggressive mode, use the udld port aggressive interface configuration command.
Use the no udld port command on fiber-optic ports to return control of UDLD to the udld enable global
configuration command or to disable UDLD on nonfiber-optic ports.
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udld port
Use the udld port aggressive command on fiber-optic ports to override the settings of the udld enable
or udld aggressive global configuration command. Use the no form on fiber-optic ports to remove this
setting and to return control of UDLD enabling to the udld global configuration command or to disable
UDLD on nonfiber-optic ports.
You can use these commands to reset an interface shut down by UDLD:
Examples
•
The udld reset privileged EXEC command to reset all interfaces shut down by UDLD
•
The shutdown and no shutdown interface configuration commands
•
The no udld enable global configuration command followed by the udld {aggressive | enable}
global configuration command to re-enable UDLD globally
•
The no udld port interface configuration command followed by the udld port or udld port
aggressive interface configuration command to re-enable UDLD on the specified interface
•
The errdisable recovery cause udld and errdisable recovery interval interval global
configuration commands to automatically recover from the UDLD error-disabled state
This example shows how to enable UDLD in normal mode on an interface:
Switch(config)# interface fastethernet0/2
Switch(config-if)# udld port
This example shows how to disable UDLD on a fiber-optic interface despite the setting of the udld
global configuration command:
Switch(config)# interface gigabitethernet0/2
Switch(config-if)# no udld port
You can verify your settings by entering the show running-config or show udld privileged EXEC
command.
Related Commands
Command
Description
show running-config
Displays the running configuration on the switch. For syntax information,
select Cisco IOS Configuration Fundamentals Command Reference for
Release 12.1 > Cisco IOS File Management Commands > Configuration
File Commands.
show udld
Displays UDLD status for all ports or the specified port.
udld
Enables UDLD on all fiber-optic ports on the switch.
udld reset
Resets all interfaces shut down by UDLD and permits traffic to again pass
through.
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udld reset
udld reset
Use the udld reset privileged EXEC command to reset all interfaces shut down by UniDirectional Link
Detection (UDLD) and to permit traffic to again pass through. Other features, such as spanning tree, Port
Aggregation Protocol (PAgP), and Dynamic Trunking Protocol (DTP), still have their normal effects, if
enabled.
udld reset
Syntax Description
This command has no arguments or keywords.
Command Modes
Privileged EXEC
Command History
Release
Modification
12.1(13)AY
This command was introduced.
Usage Guidelines
Examples
If the interface configuration is still enabled for UDLD, these ports begin to run UDLD again and might
shut down for the same reason if the problem has not been corrected.
This example shows how to reset all interfaces disabled by UDLD:
Switch# udld reset
1 ports shutdown by UDLD were reset.
You can verify your settings by entering the show udld privileged EXEC command.
Related Commands
Command
Description
show running-config
Displays the running configuration on the switch. For syntax information,
select Cisco IOS Configuration Fundamentals Command Reference for
Release 12.1 > Cisco IOS File Management Commands > Configuration
File Commands.
show udld
Displays UDLD status for all ports or the specified port.
udld
Enables UDLD on all fiber-optic ports on the switch.
udld port
Enables UDLD on an individual interface or prevents a fiber-optic
interface from being enabled by the udld global configuration command.
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vlan (global configuration)
vlan (global configuration)
Use the vlan global configuration command to add a VLAN and enter the config-vlan mode. Use the no
form of this command to delete the VLAN. Configuration information for normal-range VLANs (VLAN
IDs 1 to 1005) is always saved in the VLAN database. When VLAN Trunking Protocol (VTP) mode is
transparent, you can create extended-range VLANs (VLAN IDs greater than 1005), and the VTP mode
and domain name and the VLAN configuration are saved in the switch running configuration file. You
can save these configurations in the switch startup configuration file by entering the copy
running-config startup-config privileged EXEC command.
vlan vlan-id
no vlan vlan-id
Syntax Description
vlan-id
Defaults
This command has no default settings.
Command Modes
Global configuration
Command History
Release
Modification
12.1(13)AY
This command was introduced.
Usage Guidelines
ID of the VLAN to be added and configured. For vlan-id, the range is 1 to 4094. You
can enter a single VLAN ID, a series of VLAN IDs separated by commas, or a range
of VLAN IDs separated by hyphens.
You must use the vlan vlan-id global configuration command to add extended-range VLANs (VLAN
IDs 1006 to 4094). Before configuring VLANs in the extended range, you must use the vtp transparent
global configuration or VLAN configuration command to put the switch in VTP transparent mode.
Extended-range VLANs are not learned by VTP and are not added to the VLAN database, but when VTP
mode is transparent, VTP mode and domain name and all VLAN configurations are saved in the running
configuration, and you can save them in the switch startup configuration file.
When you save the VLAN and VTP configurations in the startup configuration file and reboot the
switch, the configuration is determined in these ways:
•
If both the VLAN database and the configuration file show the VTP mode as transparent and the
VTP domain names match, the VLAN database is ignored. The VTP and VLAN configurations in
the startup configuration file are used. The VLAN database revision number remains unchanged in
the VLAN database.
•
If the VTP mode is server, or if the startup VTP mode or domain names do not match the VLAN
database, the VTP mode and the VLAN configuration for the first 1005 VLANs use the VLAN
database information.
If you try to create an extended-range VLAN when the switch is not in VTP transparent mode, the VLAN
is rejected, and you receive an error message.
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vlan (global configuration)
If you enter an invalid VLAN ID, you receive an error message and do not enter config-vlan mode.
Entering the vlan command with a VLAN ID enables config-vlan mode. When you enter the VLAN ID
of an existing VLAN, you do not create a new VLAN, but you can modify VLAN parameters for that
VLAN. The specified VLANs are added or modified when you exit the config-vlan mode. Only the
shutdown command (for VLANs 1 to 1005) takes effect immediately.
These configuration commands are available in config-vlan mode. The no form of each command
returns the characteristic to its default state.
Note
Although visible in the command-line help string, the remote-span command is not supported.
Note
Although all commands are visible, the only VLAN configuration command supported on
extended-range VLANs is mtu mtu-size. For extended-range VLANs, all other characteristics must
remain at the default state.
•
are are-number: defines the maximum number of all-routes explorer (ARE) hops for this VLAN.
This keyword applies only to TrCRF VLANs. The ARE range is 0 to 13. The default is 7. If no value
is entered, 0 is assumed to be the maximum.
•
backupcrf: specifies the backup CRF mode. This keyword applies only to TrCRF VLANs.
– enable backup CRF mode for this VLAN.
– disable backup CRF mode for this VLAN (the default).
•
bridge {bridge-number | type}: specifies the logical distributed source-routing bridge, the bridge
that interconnects all logical rings having this VLAN as a parent VLAN in FDDI-NET, Token
Ring-NET, and TrBRF VLANs. The bridge number range is 0 to 15. The default bridge number is
0 (no source-routing bridge) for FDDI-NET, TrBRF, and Token Ring-NET VLANs. The type
keyword applies only to TrCRF VLANs and is one of these:
– srb (source-route bridging)
– srt (source-route transparent) bridging VLAN
Note
•
exit: applies changes, increments the VLAN database revision number (VLANs 1 to 1005 only), and
exits config-vlan mode.
•
media: defines the VLAN media type. See Table 2-26 for valid commands and syntax for different
media types.
The switch supports only Ethernet ports. You configure only FDDI and Token Ring media-specific
characteristics for VLAN Trunking Protocol (VTP) global advertisements to other switches. These
VLANs are locally suspended.
– ethernet is Ethernet media type (the default).
– fddi is FDDI media type.
– fd-net is FDDI network entity title (NET) media type.
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vlan (global configuration)
– tokenring is Token Ring media type if the VTP v2 mode is disabled, or TrCRF if the VTP
version 2 (v) mode is enabled.
– tr-net is Token Ring network entity title (NET) media type if the VTP v2 mode is disabled or
TrBRF media type if the VTP v2 mode is enabled.
•
mtu mtu-size: specifies the maximum transmission unit (MTU) (packet size in bytes). The range is
1500 to 18190. The default is 1500 bytes.
•
name vlan-name: names the VLAN with an ASCII string from 1 to 32 characters that must be unique
within the administrative domain. The default is VLANxxxx where xxxx represents four numeric
digits (including leading zeros) equal to the VLAN ID number.
•
no: negates a command or returns it to the default setting.
•
parent parent-vlan-id: specifies the parent VLAN of an existing FDDI, Token Ring, or TrCRF
VLAN. This parameter identifies the TrBRF to which a TrCRF belongs and is required when
defining a TrCRF. The range is 0 to 1005. The default parent VLAN ID is 0 (no parent VLAN) for
FDDI and Token Ring VLANs. For both Token Ring and TrCRF VLANs, the parent VLAN ID must
already exist in the database and be associated with a Token Ring-NET or TrBRF VLAN.
•
ring ring-number: defines the logical ring for an FDDI, Token Ring, or TrCRF VLAN. The range
is 1 to 4095. The default for Token Ring VLANs is 0. For FDDI VLANs, there is no default.
•
said said-value: specifies the security association identifier (SAID) as documented in IEEE 802.10.
The range is 1 to 4294967294 that must be unique within the administrative domain. The default
value is 100000 plus the VLAN ID number.
•
shutdown: shuts down VLAN switching on the VLAN. This command takes effect immediately.
Other commands take effect when you exit config-vlan mode.
•
state: specifies the VLAN state:
– active means the VLAN is operational (the default).
– suspend means the VLAN is suspended. Suspended VLANs do not pass packets.
•
ste ste-number: defines the maximum number of spanning-tree explorer (STE) hops. This keyword
applies only to TrCRF VLANs. The range is 0 to 13. The default is 7.
•
stp type: defines the spanning-tree type for FDDI-NET, Token Ring-NET, or TrBRF VLANs. For
FDDI-NET VLANs, the default STP type is ieee. For Token Ring-NET VLANs, the default STP
type is ibm. For FDDI and Token Ring VLANs, the default is no type specified.
– ieee for IEEE Ethernet STP running source-route transparent (SRT) bridging.
– ibm for IBM STP running source-route bridging (SRB).
– auto for STP running a combination of source-route transparent bridging (IEEE) and
source-route bridging (IBM).
•
tb-vlan1 tb-vlan1-id and tb-vlan2 tb-vlan2-id: specifies the first and second VLAN to which this
VLAN is translationally bridged. Translational VLANs translate FDDI or Token Ring to Ethernet,
for example. The range is 0 to 1005. If no value is specified, 0 (no transitional bridging) is assumed.
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Table 2-26
Valid Commands and Syntax for Different Media Types
Media Type
Valid Syntax
Ethernet
name vlan-name, media ethernet, state {suspend | active}, said said-value, mtu
mtu-size, remote-span, tb-vlan1 tb-vlan1-id, tb-vlan2 tb-vlan2-id
FDDI
name vlan-name, media fddi, state {suspend | active}, said said-value,
mtu mtu-size, ring ring-number, parent parent-vlan-id, tb-vlan1 tb-vlan1-id,
tb-vlan2 tb-vlan2-id
FDDI-NET
name vlan-name, media fd-net, state {suspend | active}, said said-value, mtu
mtu-size, bridge bridge-number, stp type {ieee | ibm | auto}, tb-vlan1 tb-vlan1-id,
tb-vlan2 tb-vlan2-id
If VTP v2 mode is disabled, do not set the stp type to auto.
Token Ring
VTP v1 mode is enabled.
name vlan-name, media tokenring, state {suspend | active}, said said-value,
mtu mtu-size, ring ring-number, parent parent-vlan-id, tb-vlan1 tb-vlan1-id,
tb-vlan2 tb-vlan2-id
Token Ring
concentrator
relay function
(TrCRF)
VTP v2 mode is enabled.
name vlan-name, media tokenring, state {suspend | active}, said said-value,
mtu mtu-size, ring ring-number, parent parent-vlan-id, bridge type {srb | srt},
are are-number, ste ste-number, backupcrf {enable | disable},
tb-vlan1 tb-vlan1-id, tb-vlan2 tb-vlan2-id
Token Ring-NET VTP v1 mode is enabled.
name vlan-name, media tr-net, state {suspend | active}, said said-value,
mtu mtu-size, bridge bridge-number, stp type {ieee | ibm}, tb-vlan1 tb-vlan1-id,
tb-vlan2 tb-vlan2-id
Token Ring
VTP v2 mode is enabled.
bridge relay
name vlan-name, media tr-net, state {suspend | active}, said said-value,
function (TrBRF)
mtu mtu-size, bridge bridge-number, stp type {ieee | ibm | auto},
tb-vlan1 tb-vlan1-id, tb-vlan2 tb-vlan2-id
Table 2-27 describes the rules for configuring VLANs.
Table 2-27
VLAN Configuration Rules
Configuration
Rule
VTP v2 mode is enabled, and you Specify a parent VLAN ID of a TrBRF that already exists in the
are configuring a TrCRF VLAN
database.
media type.
Specify a ring number. Do not leave this field blank.
Specify unique ring numbers when TrCRF VLANs have the same
parent VLAN ID. Only one backup concentrator relay function
(CRF) can be enabled.
VTP v2 mode is enabled, and you Do not specify a backup CRF.
are configuring VLANs other than
TrCRF media type.
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Table 2-27
VLAN Configuration Rules (continued)
Configuration
Rule
VTP v2 mode is enabled, and you Specify a bridge number. Do not leave this field blank.
are configuring a TrBRF VLAN
media type.
VTP v1 mode is enabled.
No VLAN can have an STP type set to auto.
This rule applies to Ethernet, FDDI, FDDI-NET, Token Ring, and
Token Ring-NET VLANs.
Add a VLAN that requires
translational bridging (values are
not set to zero).
The translational bridging VLAN IDs that are used must already
exist in the database.
The translational bridging VLAN IDs that a configuration points
to must also contain a pointer to the original VLAN in one of the
translational bridging parameters (for example, Ethernet points to
FDDI, and FDDI points to Ethernet).
The translational bridging VLAN IDs that a configuration points
to must be different media types than the original VLAN (for
example, Ethernet can point to Token Ring).
If both translational bridging VLAN IDs are configured, these
VLANs must be different media types (for example, Ethernet can
point to FDDI and Token Ring).
Examples
This example shows how to add an Ethernet VLAN with default media characteristics. The default
includes a vlan-name of VLANxxx, where xxxx represents four numeric digits (including leading zeros)
equal to the VLAN ID number. The default media option is ethernet; the state option is active. The
default said-value variable is 100000 plus the VLAN ID; the mtu-size variable is 1500; the stp-type
option is ieee. When you enter the exit config-vlan configuration command, the VLAN is added if it did
not already exist; otherwise, this command does nothing.
This example shows how to create a new VLAN with all default characteristics and enter config-vlan
mode:
Switch(config)# vlan 200
Switch(config-vlan)# exit
Switch(config)#
You can verify your setting by entering the show vlan privileged EXEC command.
Related Commands
Command
Description
show running-config vlan
Displays all or a range of VLAN-related configurations on the switch.
show vlan
Displays the parameters for all configured VLANs or one VLAN (if the
VLAN ID or name is specified) in the administrative domain.
vlan (VLAN configuration) Configures normal-range VLANs in the VLAN database.
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vlan (VLAN configuration)
Use the vlan VLAN configuration command to configure VLAN characteristics for a normal-range
VLAN (VLAN IDs 1 to 1005) in the VLAN database. You access VLAN configuration mode by entering
the vlan database privileged EXEC command. Use the no form of this command without additional
parameters to delete a VLAN. Use the no form with parameters to change its configured characteristics.
vlan vlan-id [are are-number] [backupcrf {enable | disable}] [bridge bridge-number |
type {srb | srt}] [media {ethernet | fddi | fdi-net | tokenring | tr-net}] [mtu mtu-size]
[name vlan-name] [parent parent-vlan-id] [ring ring-number] [said said-value]
[state {suspend | active}] [ste ste-number] [stp type {ieee | ibm | auto}]
[tb-vlan1 tb-vlan1-id] [tb-vlan2 tb-vlan2-id]
no vlan vlan-id [are are-number] [backupcrf {enable | disable}] [bridge bridge-number |
type {srb | srt}] [media {ethernet | fddi | fdi-net | tokenring | tr-net}] [mtu mtu-size]
[name vlan-name] [parent parent-vlan-id] [ring ring-number] [said said-value]
[state {suspend | active}] [ste ste-number] [stp type {ieee | ibm | auto}]
[tb-vlan1 tb-vlan1-id] [tb-vlan2 tb-vlan2-id]
Extended-range VLANs (with VLAN IDs from 1006 to 4094) cannot be added or modified by using
these commands. To add extended-range VLANs, use the vlan (global configuration) command to enter
config-vlan mode.
Note
Syntax Description
The switch supports only Ethernet ports. You configure only FDDI and Token Ring media-specific
characteristics for VLAN Trunking Protocol (VTP) global advertisements to other switches. These
VLANs are locally suspended.
vlan-id
ID of the configured VLAN. The range is 1 to 1005 and must be unique
within the administrative domain. Do not enter leading zeros.
are are-number
(Optional) Specify the maximum number of all-routes explorer (ARE)
hops for this VLAN. This keyword applies only to TrCRF VLANs. The
range is 0 to 13. If no value is entered, 0 is assumed to be the maximum.
backupcrf {enable | disable} (Optional) Specify the backup CRF mode. This keyword applies only
to TrCRF VLANs.
bridge bridge-number |
type {srb | srt}
•
enable backup CRF mode for this VLAN.
•
disable backup CRF mode for this VLAN.
(Optional) Specify the logical distributed source-routing bridge, the
bridge that interconnects all logical rings having this VLAN as a parent
VLAN in FDDI-NET, Token Ring-NET, and TrBRF VLANs.
The bridge number range is 0 to 15.
The type keyword applies only to TrCRF VLANs and is one of these:
•
srb (source-route bridging)
•
srt (source-route transparent) bridging VLAN
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media {ethernet | fddi |
fd-net | tokenring | tr-net}
(Optional) Specify the VLAN media type. Table 2-28 lists the valid
syntax for each media type.
•
ethernet is Ethernet media type (the default).
•
fddi is FDDI media type.
•
fd-net is FDDI network entity title (NET) media type.
•
tokenring is Token Ring media type if the VTP v2 mode is
disabled, or TrCRF if the VTP v2 mode is enabled.
•
tr-net is Token Ring network entity title (NET) media type if the
VTP v2 mode is disabled or TrBRF media type if the VTP v2 mode
is enabled.
mtu mtu-size
(Optional) Specify the maximum transmission unit (MTU) (packet size
in bytes). The range is 1500 to 18190.
name vlan-name
(Optional) Specify the VLAN name, an ASCII string from 1 to 32
characters that must be unique within the administrative domain.
parent parent-vlan-id
(Optional) Specify the parent VLAN of an existing FDDI, Token Ring,
or TrCRF VLAN. This parameter identifies the TrBRF to which a
TrCRF belongs and is required when defining a TrCRF. The range is 0
to 1005.
ring ring-number
(Optional) Specify the logical ring for an FDDI, Token Ring, or TrCRF
VLAN. The range is 1 to 4095.
said said-value
(Optional) Enter the security association identifier (SAID) as
documented in IEEE 802.10. The range is 1 to 4294967294 that must
be unique within the administrative domain.
state {suspend | active}
(Optional) Specify the VLAN state:
•
If active, the VLAN is operational.
•
If suspend, the VLAN is suspended. Suspended VLANs do not
pass packets.
ste ste-number
(Optional) Specify the maximum number of spanning-tree explorer
(STE) hops. This keyword applies only to TrCRF VLANs. The range is
0 to 13.
stp type {ieee | ibm | auto}
(Optional) Specify the spanning-tree type for FDDI-NET, Token
Ring-NET, or TrBRF VLAN.
tb-vlan1 tb-vlan1-id
and tb-vlan2 tb-vlan2-id
•
ieee for IEEE Ethernet STP running source-route transparent
(SRT) bridging.
•
ibm for IBM STP running source-route bridging (SRB).
•
auto for STP running a combination of source-route transparent
bridging (IEEE) and source-route bridging (IBM).
(Optional) Specify the first and second VLAN to which this VLAN is
translationally bridged. Translational VLANs translate FDDI or Token
Ring to Ethernet, for example. The range is 0 to 1005. Zero is assumed
if no value is specified.
Table 2-28 shows the valid syntax options for different media types.
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Table 2-28
Valid Syntax for Different Media Types
Media Type
Valid Syntax
Ethernet
vlan vlan-id [name vlan-name] media ethernet [state {suspend | active}]
[said said-value] [mtu mtu-size] [tb-vlan1 tb-vlan1-id] [tb-vlan2 tb-vlan2-id]
FDDI
vlan vlan-id [name vlan-name] media fddi [state {suspend | active}]
[said said-value] [mtu mtu-size] [ring ring-number] [parent parent-vlan-id]
[tb-vlan1 tb-vlan1-id] [tb-vlan2 tb-vlan2-id]
FDDI-NET
vlan vlan-id [name vlan-name] media fd-net [state {suspend | active}]
[said said-value] [mtu mtu-size] [bridge bridge-number]
[stp type {ieee | ibm | auto}] [tb-vlan1 tb-vlan1-id] [tb-vlan2 tb-vlan2-id]
If VTP v2 mode is disabled, do not set the stp type to auto.
Token Ring
VTP v1 mode is enabled.
vlan vlan-id [name vlan-name] media tokenring [state {suspend | active}]
[said said-value] [mtu mtu-size] [ring ring-number] [parent parent-vlan-id]
[tb-vlan1 tb-vlan1-id] [tb-vlan2 tb-vlan2-id]
Token Ring
concentrator
relay function
(TrCRF)
VTP v2 mode is enabled.
vlan vlan-id [name vlan-name] media tokenring [state {suspend | active}]
[said said-value] [mtu mtu-size] [ring ring-number] [parent parent-vlan-id]
[bridge type {srb | srt}] [are are-number] [ste ste-number]
[backupcrf {enable | disable}] [tb-vlan1 tb-vlan1-id] [tb-vlan2 tb-vlan2-id]
Token Ring-NET VTP v1 mode is enabled.
vlan vlan-id [name vlan-name] media tr-net [state {suspend | active}]
[said said-value] [mtu mtu-size] [bridge bridge-number]
[stp type {ieee | ibm}] [tb-vlan1 tb-vlan1-id] [tb-vlan2 tb-vlan2-id]
Token Ring
VTP v2 mode is enabled.
bridge relay
vlan vlan-id [name vlan-name] media tr-net [state {suspend | active}]
function (TrBRF)
[said said-value] [mtu mtu-size] [bridge bridge-number]
[stp type {ieee | ibm | auto}] [tb-vlan1 tb-vlan1-id] [tb-vlan2 tb-vlan2-id]
Table 2-29 describes the rules for configuring VLANs.
Table 2-29
VLAN Configuration Rules
Configuration
Rule
VTP v2 mode is enabled, and you Specify a parent VLAN ID of a TrBRF that already exists in the
are configuring a TrCRF VLAN
database.
media type.
Specify a ring number. Do not leave this field blank.
Specify unique ring numbers when TrCRF VLANs have the same
parent VLAN ID. Only one backup concentrator relay function
(CRF) can be enabled.
VTP v2 mode is enabled, and you Do not specify a backup CRF.
are configuring VLANs other than
TrCRF media type.
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Table 2-29
VLAN Configuration Rules (continued)
Configuration
Rule
VTP v2 mode is enabled, and you Specify a bridge number. Do not leave this field blank.
are configuring a TrBRF VLAN
media type.
VTP v1 mode is enabled.
No VLAN can have an STP type set to auto.
This rule applies to Ethernet, FDDI, FDDI-NET, Token Ring, and
Token Ring-NET VLANs.
Add a VLAN that requires
translational bridging (values are
not set to zero).
The translational bridging VLAN IDs that are used must already
exist in the database.
The translational bridging VLAN IDs that a configuration points
to must also contain a pointer to the original VLAN in one of the
translational bridging parameters (for example, Ethernet points to
FDDI, and FDDI points to Ethernet).
The translational bridging VLAN IDs that a configuration points
to must be different media types than the original VLAN (for
example, Ethernet can point to Token Ring).
If both translational bridging VLAN IDs are configured, these
VLANs must be different media types (for example, Ethernet can
point to FDDI and Token Ring).
Defaults
The ARE value is 7.
Backup CRF is disabled.
The bridge number is 0 (no source-routing bridge) for FDDI-NET, TrBRF, and Token Ring-NET
VLANs.
The media type is ethernet.
The default mtu size is 1500 bytes.
The vlan-name variable is VLANxxxx, where xxxx represents four numeric digits (including leading
zeros) equal to the VLAN ID number.
The parent VLAN ID is 0 (no parent VLAN) for FDDI and Token Ring VLANs. For TrCRF VLANs,
you must specify a parent VLAN ID. For both Token Ring and TrCRF VLANs, the parent VLAN ID
must already exist in the database and be associated with a Token Ring-NET or TrBRF VLAN.
The ring number for Token Ring VLANs is 0. For FDDI VLANs, there is no default.
The said value is 100000 plus the VLAN ID.
The state is active.
The STE value is 7.
The STP type is ieee for FDDI-NET and ibm for Token Ring-NET VLANs. For FDDI and Token Ring
VLANs, the default is no type specified.
The tb-vlan1-id and tb-vlan2-id variables are zero (no translational bridging).
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Command Modes
VLAN configuration
Command History
Release
Modification
12.1(13)AY
This command was introduced.
Usage Guidelines
Note
You can only use this command mode for configuring normal-range VLANs, that is, VLAN IDs 1 to
1005.
To configure extended-range VLANs (VLAN IDs 1006 to 4094), use the vlan global configuration
command.
VLAN configuration is always saved in the VLAN database. If VTP mode is transparent, it is also saved
in the switch running configuration file, along with the VTP mode and domain name. You can then save
it in the switch startup configuration file by using the copy running-config startup-config privileged
EXEC command.
When you save VLAN and VTP configuration in the startup configuration file and reboot the switch, the
configuration is determined in these ways:
•
If both the VLAN database and the configuration file show the VTP mode as transparent and the
VTP domain names match, the VLAN database is ignored. The VTP and VLAN configurations in
the startup configuration file are used. The VLAN database revision number remains unchanged in
the VLAN database.
•
If the VTP mode is server, or if the startup VTP mode or domain names do not match the VLAN
database, the VTP mode and the VLAN configuration for the first 1005 VLANs use VLAN database
information.
The following are the results of using the no vlan commands:
•
When the no vlan vlan-id form is used, the VLAN is deleted. Deleting VLANs automatically resets
to zero any other parent VLANs and translational bridging parameters that refer to the deleted
VLAN.
•
When the no vlan vlan-id bridge form is used, the VLAN source-routing bridge number returns to
the default (0). The vlan vlan-id bridge command is used only for FDDI-NET and Token Ring-NET
VLANs and is ignored in other VLAN types.
•
When the no vlan vlan-id media form is used, the media type returns to the default (ethernet).
Changing the VLAN media type (including the no form) resets the VLAN MTU to the default MTU
for the type (unless the mtu keyword is also present in the command). It also resets the VLAN parent
and translational bridging VLAN to the default (unless the parent, tb-vlan1, or tb-vlan2 are also
present in the command).
•
When the no vlan vlan-id mtu form is used, the VLAN MTU returns to the default for the applicable
VLAN media type. You can also modify the MTU using the media keyword.
•
When the no vlan vlan-id name vlan-name form is used, the VLAN name returns to the default
name (VLANxxxx, where xxxx represent four numeric digits [including leading zeros] equal to the
VLAN ID number).
•
When the no vlan vlan-id parent form is used, the parent VLAN returns to the default (0). The
parent VLAN resets to the default if the parent VLAN is deleted or if the media keyword changes
the VLAN type or the VLAN type of the parent VLAN.
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Examples
•
When the no vlan vlan-id ring form is used, the VLAN logical ring number returns to the default
(0).
•
When the no vlan vlan-id said form is used, the VLAN SAID returns to the default (100,000 plus
the VLAN ID).
•
When the no vlan vlan-id state form is used, the VLAN state returns to the default (active).
•
When the no vlan vlan-id stp type form is used, the VLAN spanning-tree type returns to the default
(ieee).
•
When the no vlan vlan-id tb-vlan1 or no vlan vlan-id tb-vlan2 form is used, the VLAN
translational bridge VLAN (or VLANs, if applicable) returns to the default (0). Translational bridge
VLANs must be a different VLAN type than the affected VLAN, and if two are specified, the two
must be different VLAN types from each other. A translational bridge VLAN resets to the default
if the translational bridge VLAN is deleted, if the media keyword changes the VLAN type, or if the
media keyword changes the VLAN type of the corresponding translation bridge VLAN.
This example shows how to add an Ethernet VLAN with default media characteristics. The default
includes a vlan-name of VLANxxx, where xxxx represents four numeric digits (including leading zeros)
equal to the VLAN ID number. The default media option is ethernet; the state option is active. The
default said-value variable is 100000 plus the VLAN ID; the mtu-size variable is 1500; the stp-type
option is ieee. When you enter the exit or apply vlan configuration command, the VLAN is added if it
did not already exist; otherwise, this command does nothing.
Switch(vlan)# vlan 2
VLAN 2 added:
Name: VLAN0002
Switch(vlan)# exit
APPLY completed.
Exiting....
This example shows how to modify an existing VLAN by changing its name and MTU size:
Switch(vlan)# no vlan name engineering mtu 1200
You can verify your settings by entering the show vlan privileged EXEC command.
Related Commands
Command
Description
show vlan
Displays the parameters for all configured VLANs or one VLAN (if the VLAN
ID or name is specified) in the administrative domain.
vlan (global
configuration)
Enters config-vlan mode for configuring VLANs.
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vlan database
Use the vlan database privileged EXEC command to enter VLAN configuration mode. From this mode,
you can add, delete, and modify VLAN configurations for normal-range VLANs and globally propagate
these changes by using the VLAN Trunking Protocol (VTP). Configuration information is saved in the
VLAN database.
vlan database
Note
VLAN configuration mode is only valid for VLAN IDs 1 to 1005.
Syntax Description
This command has no arguments or keywords.
Defaults
No default is defined.
Command Modes
Privileged EXEC
Command History
Release
Modification
12.1(13)AY
This command was introduced.
Usage Guidelines
You can use the VLAN database configuration commands to configure VLANs 1 to 1005. To configure
extended-range VLANs (VLAN IDs 1006 to 4094),use the vlan (global configuration) command to
enter config-vlan mode. You can also configure VLAN IDs 1 to 1005 by using the vlan global
configuration command.
To return to the privileged EXEC mode from the VLAN configuration mode, enter the exit command.
Note
This command mode is different from other modes because it is session-oriented. When you add, delete,
or modify VLAN parameters, the changes are not applied until you exit the session by entering the apply
or exit command. When the changes are applied, the VTP configuration version is incremented. You can
also not apply the changes to the VTP database by entering abort.
Once you are in VLAN configuration mode, you can access the VLAN database and make changes by
using these commands:
•
vlan: accesses subcommands to add, delete, or modify values associated with a single VLAN. For
more information, see the vlan (VLAN configuration) command.
•
vtp: accesses subcommands to perform VTP administrative functions. For more information, see the
vtp (VLAN configuration) command.
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When you have modified VLAN or VTP parameters, you can use these editing buffer manipulation
commands:
•
abort: exits the mode without applying the changes. The VLAN configuration that was running
before you entered VLAN configuration mode continues to be used.
•
apply: applies current changes to the VLAN database, increments the database configuration
revision number, propagates it throughout the administrative domain, and remains in VLAN
configuration mode.
Note
You cannot use this command when the switch is in VTP client mode.
•
exit: applies all configuration changes to the VLAN database, increments the database configuration
number, propagates it throughout the administrative domain, and returns to privileged EXEC mode.
•
no: negates a command or set its defaults; valid values are vlan and vtp.
•
reset: abandons proposed changes to the VLAN database, resets the proposed database to the
implemented VLAN database on the switch, and remains in VLAN configuration mode.
•
show: displays VLAN database information.
•
show changes [vlan-id]: displays the differences between the VLAN database on the switch and the
proposed VLAN database for all normal-range VLAN IDs (1 to 1005) or the specified VLAN ID (1
to 1005).
•
show current [vlan-id]: displays the VLAN database on the switch or on a selected VLAN (1 to
1005).
•
show proposed [vlan-id]: displays the proposed VLAN database or a selected VLAN (1 to 1005)
from the proposed database. The proposed VLAN database is not the running configuration until
you use the exit or apply VLAN configuration command.
You can verify that VLAN database changes have been made or aborted by using the show vlan
privileged EXEC command. This output is different from the show VLAN database configuration
command output.
Examples
This example shows how to enter the VLAN configuration mode from the privileged EXEC mode and
to display VLAN database information:
Switch# vlan database
Switch(vlan)# show
Name: default
Media Type: Ethernet
VLAN 802.10 Id: 100001
State: Operational
MTU: 1500
Translational Bridged VLAN: 1002
Translational Bridged VLAN: 1003
Name: VLAN0002
Media Type: Ethernet
VLAN 802.10 Id: 100002
State: Operational
MTU: 1500
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Name: fddi-default
Media Type: FDDI
VLAN 802.10 Id: 101002
State: Operational
MTU: 1500
Bridge Type: SRB
Ring Number: 0
Translational Bridged VLAN: 1
Translational Bridged VLAN: 1003
<output truncated>
This is an example of output from the show changes command:
Switch(vlan)# show changes
DELETED:
Name: VLAN0004
Media Type: Ethernet
VLAN 802.10 Id: 100004
State: Operational
MTU: 1500
DELETED:
Name: VLAN0006
Media Type: Ethernet
VLAN 802.10 Id: 100006
State: Operational
MTU: 1500
MODIFIED:
Current State: Operational
Modified State: Suspended
This example shows how to display the differences between VLAN 7 in the current database and the
proposed database:
Switch(vlan)# show changes 7
MODIFIED:
Current State: Operational
Modified State: Suspended
This is an example of output from the show current 20 command. It displays only VLAN 20 of the
current database:
Switch(vlan)# show current 20
Name: VLAN0020
Media Type: Ethernet
VLAN 802.10 Id: 100020
State: Operational
MTU: 1500
Related Commands
Command
Description
show vlan
Displays the parameters for all configured VLANs in the administrative domain.
shutdown vlan
Shuts down (suspends) local traffic on the specified VLAN.
vlan (global
configuration)
Enters config-vlan mode for configuring VLANs.
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vmps reconfirm (global configuration)
vmps reconfirm (global configuration)
Use the vmps reconfirm global configuration command to change the reconfirmation interval for the
VLAN Query Protocol (VQP) client.
vmps reconfirm interval
Syntax Description
interval
Defaults
The default reconfirmation interval is 60 minutes.
Command Modes
Global configuration
Command History
Release
Modification
12.1(6)EA2
This command was introduced.
Examples
Reconfirmation interval for VQP client queries to the VLAN Membership Policy
Server (VMPS) to reconfirm dynamic VLAN assignments. The range is 1 to 120
minutes.
This example shows how to set the VQP client to reconfirm dynamic VLAN entries every 20 minutes:
Switch(config)# vmps reconfirm 20
You can verify your settings by entering the show vmps privileged EXEC command and examining
information in the Reconfirm Interval row.
Related Commands
Command
Description
show vmps
Displays VQP and VMPS information.
vmps reconfirm (privileged EXEC)
Sends VQP queries to reconfirm all dynamic VLAN
assignments with the VMPS.
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vmps reconfirm (privileged EXEC)
vmps reconfirm (privileged EXEC)
Use the vmps reconfirm privileged EXEC command to immediately send VLAN Query Protocol (VQP)
queries to reconfirm all dynamic VLAN assignments with the VLAN Membership Policy Server
(VMPS).
vmps reconfirm
Syntax Description
This command has no arguments or keywords.
Defaults
No default is defined.
Command Modes
Privileged EXEC
Command History
Release
Modification
12.1(13)AY
This command was introduced.
Examples
This example shows how to send VQP queries to the VMPS:
Switch# vmps reconfirm
You can verify your settings by entering the show vmps privileged EXEC command and examining the
VMPS Action row of the Reconfirmation Status section. The show vmps command shows the result of
the last time the assignments were reconfirmed either as a result of the reconfirmation timer expired or
because the vmps reconfirm command was entered.
Related Commands
Command
Description
show vmps
Displays VQP and VMPS information.
vmps reconfirm (global
configuration)
Changes the reconfirmation interval for the VQP client.
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vmps retry
vmps retry
Use the vmps retry global configuration command to configure the per-server retry count for the VLAN
Query Protocol (VQP) client.
vmps retry count
Syntax Description
count
Defaults
The default retry count is 3.
Command Modes
Global configuration
Command History
Release
Modification
12.1(13)AY
This command was introduced.
Examples
Number of attempts to contact the VLAN Membership Policy Server (VMPS) by the
client before querying the next server in the list. The range is 1 to 10.
This example shows how to set the retry count to 7:
Switch(config)# vmps retry 7
You can verify your settings by entering the show vmps privileged EXEC command and examining
information in the Server Retry Count row.
Related Commands
Command
Description
show vmps
Displays VQP and VMPS information.
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vmps server
vmps server
Use the vmps server global configuration command to configure the primary VLAN Membership
Policy Server (VMPS) and up to three secondary servers. Use the no form of this command to remove
a VMPS server.
vmps server ipaddress [primary]
no vmps server [ipaddress]
Syntax Description
ipaddress
IP address or host name of the primary or secondary VMPS servers. If you specify
a host name, the Domain Name System (DNS) server must be configured.
primary
(Optional) Determines whether primary or secondary VMPS servers are being
configured.
Defaults
No primary or secondary VMPS servers are defined.
Command Modes
Global configuration
Command History
Release
Modification
12.1(13)AY
This command was introduced.
Usage Guidelines
The first server entered is automatically selected as the primary server whether or not the primary
keyword is entered. The first server address can be overridden by using primary in a subsequent
command.
If a member switch in a cluster configuration does not have an IP address, the cluster does not use the
VMPS server configured for that member switch. Instead, the cluster uses the VMPS server on the
command switch, and the command switch proxies the VMPS requests. The VMPS server treats the
cluster as a single switch and uses the IP address of the command switch to respond to requests.
When using the no form without specifying the ipaddress, all configured servers are deleted. If you
delete all servers when dynamic-access ports are present, the switch cannot forward packets from new
sources on these ports because it cannot query the VMPS.
Examples
This example shows how to configure the server with IP address 191.10.49.20 as the primary VMPS
server. The servers with IP addresses 191.10.49.21 and 191.10.49.22 are configured as secondary
servers.
Switch(config)# vmps server 191.10.49.20 primary
Switch(config)# vmps server 191.10.49.21
Switch(config)# vmps server 191.10.49.22
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vmps server
This example shows how to delete the server with IP address 191.10.49.21:
Switch(config)# no vmps server 191.10.49.21
You can verify your settings by entering the show vmps privileged EXEC command and examining
information in the VMPS Domain Server row.
Related Commands
Command
Description
show vmps
Displays VQP and VMPS information.
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vtp (global configuration)
vtp (global configuration)
Use the vtp global configuration command to set or modify the VLAN Trunking Protocol (VTP)
configuration characteristics. Use the no form of this command to remove the settings or to return to the
default settings.
vtp {domain domain-name | file filename | interface name | mode {client | server | transparent}
| password password | pruning | version number}
no vtp {file | interface | mode | password | pruning | version}
Syntax Description
domain domain-name
Specify the VTP domain name, an ASCII string from 1 to 32 characters that
identifies the VTP administrative domain for the switch. The domain name
is case sensitive.
file filename
Specify the Cisco IOS file system file where the VTP VLAN configuration
is stored.
interface name
Specify the name of the interface providing the VTP ID updated for this
device.
mode {client | server |
transparent}
Specify the VTP device mode. The keywords have these meanings:
•
client—Place the switch in VTP client mode. A switch in VTP client
mode is enabled for VTP, and can send advertisements, but does not have
enough nonvolatile storage to store VLAN configurations. You cannot
configure VLANs on the switch. When a VTP client starts up, it does not
send VTP advertisements until it receives advertisements to initialize its
VLAN database.
•
server—Place the switch in VTP server mode. A switch in VTP server
mode is enabled for VTP and sends advertisements. You can configure
VLANs on the switch. The switch can recover all the VLAN information
in the current VTP database from nonvolatile storage after reboot.
•
transparent—Place the switch in VTP transparent mode. A switch in
VTP transparent mode is disabled for VTP, does not send advertisements
or learn from advertisements sent by other devices, and cannot affect
VLAN configurations on other devices in the network. The switch
receives VTP advertisements and forwards them on all trunk ports
except the one on which the advertisement was received.
When VTP mode is transparent, the mode and domain name are saved in
the switch running configuration file, and you can save them in the
switch startup configuration file by entering the copy running-config
startup config privileged EXEC command.
password password
Set the administrative domain password for the generation of the 16-byte
secret value used in MD5 digest calculation to be sent in VTP advertisements
and to validate received VTP advertisements. The password can be an ASCII
string from 1 to 32 characters. The password is case sensitive.
pruning
Enable VTP pruning on the switch.
version number
Set VTP version to version 1 or version 2.
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vtp (global configuration)
Defaults
The default filename is flash:vlan.dat.
The default mode is server mode.
No domain name or password is defined.
No password is configured.
Pruning is disabled.
The default version is version 1.
Command Modes
Global configuration
Command History
Release
Modification
12.1(13)AY
This command was introduced.
Usage Guidelines
When you save VTP mode and domain name and VLAN configurations in the switch startup
configuration file and reboot the switch, the VTP and VLAN configurations are determined by these
conditions:
•
If both the VLAN database and the configuration file show the VTP mode as transparent and the
VTP domain names match, the VLAN database is ignored. The VTP and VLAN configurations in
the startup configuration file are used. The VLAN database revision number remains unchanged in
the VLAN database.
•
If the startup VTP mode is server mode, or the startup VTP mode or domain names do not match the
VLAN database, the VTP mode and VLAN configuration information for the first 1005 VLAN IDs
are determined by VLAN database information, and configuration for VLAN IDs greater than 1005
is determined by the switch configuration file.
The vtp file filename cannot be used to load a new database; it renames only the file in which the existing
database is stored.
Follow these guidelines when configuring a VTP domain name:
•
The switch is in the no-management-domain state until you configure a domain name. While in the
no-management-domain state, the switch does not send any VTP advertisements even if changes
occur to the local VLAN configuration. The switch leaves the no-management-domain state after it
receives the first VTP summary packet on any port that is trunking or after you configure a domain
name by using the vtp domain command. If the switch receives its domain from a summary packet,
it resets its configuration revision number to 0. After the switch leaves the no-management-domain
state, it can not be configured to re-enter it until you clear the NVRAM and reload the software.
•
Domain names are case-sensitive.
•
After you configure a domain name, it cannot be removed. You can only reassign it to a different
domain.
Follow these guidelines when setting VTP mode:
•
The no vtp mode command returns the switch to VTP server mode.
•
The vtp mode server command is the same as no vtp mode except that it does not return an error
if the switch is not in client or transparent mode.
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vtp (global configuration)
•
If the receiving switch is in client mode, the client switch changes its configuration to duplicate the
configuration of the server. If you have switches in client mode, be sure to make all VTP or VLAN
configuration changes on a switch in server mode. If the receiving switch is in server mode or
transparent mode, the switch configuration is not changed.
•
Switches in transparent mode do not participate in VTP. If you make VTP or VLAN configuration
changes on a switch in transparent mode, the changes are not propagated to other switches in the
network.
•
If you change the VTP or VLAN configuration on a switch that is in server mode, that change is
propagated to all the switches in the same VTP domain.
•
The vtp mode transparent command disables VTP from the domain but does not remove the
domain from the switch.
•
The VTP mode must be transparent for you to add extended-range VLANs or for VTP and VLAN
information to be saved in the running configuration file.
•
If extended-range VLANs are configured on the switch and you attempt to set the VTP mode to
server or client, you receive an error message, and the configuration is not allowed.
•
VTP can be set to either server or client mode only when dynamic VLAN creation is disabled.
Follow these guidelines when setting a VTP password:
•
Passwords are case sensitive. Passwords should match on all switches in the same domain.
•
When you use the no vtp password form of the command, the switch returns to the no-password
state.
Follow these guidelines when setting VTP pruning:
•
VTP pruning removes information about each pruning-eligible VLAN from VTP updates if there
are no stations belonging to that VLAN.
•
If you enable pruning on the VTP server, it is enabled for the entire management domain for VLAN
IDs 1 to 1005.
•
Only VLANs in the pruning-eligible list can be pruned.
•
Pruning is supported with VTP version 1 and version 2.
Follow these guidelines when setting the VTP version:
•
Toggling the version 2 (v2) mode state modifies parameters of certain default VLANs.
•
Each VTP switch automatically detects the capabilities of all the other VTP devices. To use version
2, all VTP switches in the network must support version 2; otherwise, you must configure them to
operate in VTP version 1 mode.
•
If all switches in a domain are VTP version 2-capable, you need only to configure version 2 on one
switch; the version number is then propagated to the other version-2 capable switches in the VTP
domain.
•
If you are using VTP in a Token Ring environment, VTP version 2 must be enabled.
•
If you are configuring a Token Ring bridge relay function (TrBRF) or Token Ring concentrator relay
function (TrCRF) VLAN media type, you must use version 2.
•
If you are configuring a Token Ring or Token Ring-NET VLAN media type, you must use version 1.
You cannot save password, pruning, and version configurations in the switch configuration file.
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vtp (global configuration)
Examples
This example shows how to rename the filename for VTP configuration storage to vtpfilename:
Switch(config)# vtp file vtpfilename
This example shows how to clear the device storage filename:
Switch(config)# no vtp file vtpconfig
Clearing device storage filename.
This example shows how to specify the name of the interface providing the VTP updater ID for this
device:
Switch(config)# vtp interface fastethernet
This example shows how to set the administrative domain for the switch:
Switch(config)# vtp domain OurDomainName
This example shows how to place the switch in VTP transparent mode:
Switch(config)# vtp mode transparent
This example shows how to configure the VTP domain password:
Switch(config)# vtp password ThisIsOurDomain’sPassword
This example shows how to enable pruning in the VLAN database:
Switch(config)# vtp pruning
Pruning switched ON
This example shows how to enable version 2 mode in the VLAN database:
Switch(config)# vtp version 2
You can verify your settings by entering the show vtp status privileged EXEC command.
Related Commands
Command
Description
show vtp status
Displays the VTP statistics for the switch and general information about the
VTP management domain status.
vtp (VLAN
configuration)
Configures most VTP characteristics.
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vtp (VLAN configuration)
vtp (VLAN configuration)
Use the vtp VLAN configuration command to configure VLAN Trunking Protocol (VTP)
characteristics. You access VLAN configuration mode by entering the vlan database privileged EXEC
command. Use the no form of this command to return to the default settings, disable the characteristic,
or remove the password.
vtp {domain domain-name | password password | pruning | v2-mode | {server | client |
transparent}}
no vtp {client | password | pruning | transparent | v2-mode}
Note
Syntax Description
VTP configuration in VLAN configuration mode is saved in the VLAN database when applied.
domain domain-name
Set the VTP domain name by entering an ASCII string from 1 to 32
characters that identifies the VTP administrative domain for the switch. The
domain name is case sensitive.
password password
Set the administrative domain password for the generation of the 16-byte
secret value used in MD5 digest calculation to be sent in VTP advertisements
and to validate received VTP advertisements. The password can be an ASCII
string from 1 to 32 characters. The password is case sensitive.
pruning
Enable pruning in the VTP administrative domain. VTP pruning causes
information about each pruning-eligible VLAN to be removed from VTP
updates if there are no stations belonging to that VLAN.
v2-mode
Enable VLAN Trunking Protocol (VTP) version 2 in the administrative
domains.
client
Place the switch in VTP client mode. A switch in VTP client mode is enabled
for VTP, can send advertisements, but does not have enough nonvolatile
storage to store VLAN configurations. You cannot configure VLANs on it.
When a VTP client starts up, it does not send VTP advertisements until it
receives advertisements to initialize its VLAN database.
server
Place the switch in VTP server mode. A switch in VTP server mode is
enabled for VTP and sends advertisements. You can configure VLANs on it.
The switch can recover all the VLAN information in the current VTP
database from nonvolatile storage after reboot.
transparent
Place the switch in VTP transparent mode. A switch in VTP transparent
mode is disabled for VTP, does not send advertisements or learn from
advertisements sent by other devices, and cannot affect VLAN
configurations on other devices in the network. The switch receives VTP
advertisements and forwards them on all trunk ports except the one on which
the advertisement was received.
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vtp (VLAN configuration)
Defaults
The default mode is server mode.
No domain name is defined.
No password is configured.
Pruning is disabled.
VTP version 2 (v2 mode) is disabled.
Command Modes
VLAN configuration
Command History
Release
Modification
12.1(13)AY
This command was introduced.
Usage Guidelines
If VTP mode is transparent, the mode and domain name are saved in the switch running configuration
file, and you can save the configuration in the switch startup configuration file by using the copy
running-config startup-config privileged EXEC command.
Follow these guidelines when setting VTP mode:
•
The no vtp client and no vtp transparent forms of the command return the switch to VTP server
mode.
•
The vtp server command is the same as no vtp client or no vtp transparent except that it does not
return an error if the switch is not in client or transparent mode.
•
If the receiving switch is in client mode, the client switch changes its configuration to duplicate the
configuration of the server. If you have switches in client mode, make sure to make all VTP or
VLAN configuration changes on a switch in server mode. If the receiving switch is in server mode
or transparent mode, the switch configuration is not changed.
•
Switches in transparent mode do not participate in VTP. If you make VTP or VLAN configuration
changes on a switch in transparent mode, the changes are not propagated to other switches in the
network.
•
If you make a change to the VTP or VLAN configuration on a switch in server mode, that change
is propagated to all the switches in the same VTP domain.
•
The vtp transparent command disables VTP from the domain but does not remove the domain from
the switch.
•
The VTP mode must be transparent for you to add extended-range VLANs or for the VTP and the
VLAN configurations to be saved in the running configuration file.
•
If extended-range VLANs are configured on the switch and you attempt to set the VTP mode to
server or client, you receive an error message and the configuration is not allowed.
•
VTP can be set to either server or client mode only when dynamic VLAN creation is disabled.
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vtp (VLAN configuration)
Follow these guidelines when configuring a VTP domain name:
•
The switch is in the no-management-domain state until you configure a domain name. While in the
no-management-domain state, the switch does not send any VTP advertisements even if changes
occur to the local VLAN configuration. The switch leaves the no-management-domain state after
receiving the first VTP summary packet on any port that is currently trunking or after configuring a
domain name using the vtp domain command. If the switch receives its domain from a summary
packet, it resets its configuration revision number to zero. After the switch leaves the
no-management-domain state, it can never be configured to reenter it until you clear the NVRAM
and reload the software.
•
Domain names are case sensitive.
•
After you configure a domain name, it cannot be removed. You can reassign it only to a different
domain.
Follow these guidelines when configuring a VTP password:
•
Passwords are case sensitive. Passwords should match on all switches in the same domain.
•
When the no vtp password form of the command is used, the switch returns to the no-password
state.
Follow these guidelines when enabling VTP pruning:
•
If you enable pruning on the VTP server, it is enabled for the entire management domain.
•
Only VLANs included in the pruning-eligible list can be pruned.
•
Pruning is supported with VTP version 1 and version 2.
Follow these guidelines when enabling VTP version 2 (v2-mode):
Examples
•
Toggling the version (v2-mode) state modifies certain parameters of certain default VLANs.
•
Each VTP switch automatically detects the capabilities of all the other VTP devices. To use VTP
version 2, all VTP switches in the network must support version 2; otherwise, you must configure
them to operate in VTP version 1 (no vtp v2-mode).
•
If all switches in a domain are VTP version 2-capable, you need only to enable VTP version 2 on
one switch; the version number is then propagated to the other version-2 capable switches in the
VTP domain.
•
If you are using VTP in a Token Ring environment or configuring a Token Ring bridge relay
function (TrBRF) or Token Ring concentrator relay function (TrCRF) VLAN media type, you must
enable VTP version 2 (v2-mode).
•
If you are configuring a Token Ring or Token Ring-NET VLAN media type, you must use VTP
version 1.
This example shows how to place the switch in VTP transparent mode:
Switch(vlan)# vtp transparent
Setting device to VTP TRANSPARENT mode.
This example shows how to set the administrative domain for the switch:
Switch(vlan)# vtp domain OurDomainName
Changing VTP domain name from cisco to OurDomainName
This example shows how to configure the VTP domain password:
Switch(vlan)# vtp password private
Setting device VLAN database password to private.
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vtp (VLAN configuration)
This example shows how to enable pruning in the proposed new VLAN database:
Switch(vlan)# vtp pruning
Pruning switched ON
This example shows how to enable V2 mode in the proposed new VLAN database:
Switch(vlan)# vtp v2-mode
V2 mode enabled.
You can verify your settings by entering the show vtp status privileged EXEC command.
Related Commands
Command
Description
show vtp status
Displays the VTP statistics for the switch and general information about the
VTP management domain status.
switchport trunk
pruning
Configures the VLAN pruning-eligible list for ports in trunking mode.
vtp (global
configuration)
Configures the VTP filename, interface, domain-name, and mode.
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wrr-queue bandwidth
wrr-queue bandwidth
Use the wrr-queue bandwidth global configuration command to assign weighted round-robin (WRR)
weights to the four class of service (CoS) priority queues. Use the no form of this command to disable
the WRR scheduler and enable the strict priority scheduler.
wrr-queue bandwidth weight1...weight4
no wrr-queue bandwidth
Syntax Description
weight1...weight4
Defaults
WRR is disabled. The strict priority is the default scheduler.
Command Modes
Global configuration
Command History
Release
Modification
12.1(13)AY
This command was introduced.
Usage Guidelines
The ratio of weight1, weight2, weight3, and weight4 determines the
weights of the WRR scheduler. The range for weight1, weight2, weight3,
and weight4 is 1 to 255.
WRR allows bandwidth sharing at the egress port. This command defines the bandwidths for egress
WRR through scheduling weights.
For more information about strict priority and WRR scheduling, see the “CoS and WRR” section in the
“Configuring QoS” chapter of the software configuration guide for this release.
Examples
This example shows how to assign WRR weights of 10, 20, 30, and 40 to the CoS priority queues 1, 2,
3, and 4:
Switch(config)# wrr-queue bandwidth 10 20 30 40
This example shows how to disable the WRR scheduler and enable the strict priority scheduler:
Switch(config)# no wrr-queue bandwidth
You can verify your settings by entering the show wrr-queue bandwidth privileged EXEC command.
Related Commands
Command
Description
wrr-queue cos-map
Assigns CoS values to the CoS priority queues.
show wrr-queue bandwidth
Displays the WRR bandwidth allocation for the four CoS
priority queues.
show wrr-queue cos-map
Displays the mapping of the CoS to the CoS priority queues.
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wrr-queue cos-map
wrr-queue cos-map
Use the wrr-queue cos-map global configuration command to assign class of service (CoS) values to
the CoS priority queues. Use the no form of this command to return to the default settings.
wrr-queue cos-map quid cos1...cosn
no wrr-queue cos-map [queue-id [cos1 ... cosn]]
Syntax Description
Defaults
quid
The queue id of the CoS priority queue. The range is 1 to 4 where 1 is the
lowest CoS priority queue.
cos1...cosn
The CoS values that are mapped to the queue id.
These are the default CoS values:
CoS Value
CoS Priority Queues
0, 1
1
2, 3
2
4, 5
3
6, 7
4
Command Modes
Global configuration
Command History
Release
Modification
12.1(13)AY
This command was introduced.
Usage Guidelines
CoS assigned at the ingress port is used to select a CoS priority at the egress port.
Examples
This example shows how to map CoS values 0, 1, and 2 to CoS priority queue 1, value 3 to CoS priority
queue 2, values 4 and 5 to CoS priority 3, and values 6 and 7 to CoS priority queue 4:
Switch(config)#
Switch(config)#
Switch(config)#
Switch(config)#
wrr-queue
wrr-queue
wrr-queue
wrr-queue
cos-map
cos-map
cos-map
cos-map
1
2
3
4
0 1 2
3
4 5
6 7
This example shows how to map CoS values 0, 1, 2, and 3 to CoS priority queue 2:
Switch(config)# wrr-queue cos-map 2 0 1 2 3
After entering the wrr-queue cos-map 2 0 1 2 3 command, if all other priority queues use their default
setting, this is the new mapping:
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wrr-queue cos-map
CoS Value
CoS Priority Queue
Not applied
1
0, 1, 2, 3
2
4, 5
3
6, 7
4
In the previous example, CoS priority queue 1 is no longer used because no CoS value is assigned to the
queue.
You can set the CoS values to the default values by entering the no wrr-queue cos-map global
configuration command.
You can verify your settings by entering the show wrr-queue cos-map privileged EXEC command.
Related Commands
Command
Description
wrr-queue bandwidth
Assigns weighted round-robin (WRR) weights to the four CoS
priority queues.
show wrr-queue bandwidth
Displays the WRR bandwidth allocation for the four CoS
priority queues.
show wrr-queue cos-map
Displays the mapping of the CoS to the priority queues.
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A
Catalyst 2940 Switch Debug Commands
This appendix describes the Catalyst 2940-specific debug privileged EXEC commands. These
commands are helpful in diagnosing and resolving internetworking problems and should be used only
with the guidance of Cisco technical support staff.
Caution
Because debugging output is assigned high priority in the CPU process, it can render the system
unusable. For this reason, use the debug commands only to troubleshoot specific problems or during
troubleshooting sessions with Cisco technical support staff. It is best to use the debug commands during
periods of lower network traffic and fewer users. Debugging during these periods decreases the
likelihood that increased debug command processing overhead will affect system use.
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Appendix A
Catalyst 2940 Switch Debug Commands
debug dot1x
debug dot1x
Use the debug dot1x privileged EXEC command to enable debugging of the IEEE 802.1x authentication
feature. Use the no form of this command to disable debugging.
debug dot1x {all | errors | events | packets | registry | state-machine}
no debug dot1x {all | errors | events | packets | registry | state-machine}
Syntax Description
all
Display all IEEE 802.1x authentication debug messages.
errors
Debug IEEE 802.1x error debug messages.
events
Debug IEEE 802.1x event debug messages.
packets
Debug IEEE 802.1x packet debug messages.
registry
Debug registry invocation debug messages.
state-machine
Debug state-machine related-events debug messages.
Defaults
Debugging is disabled.
Command Modes
Privileged EXEC
Command History
Release
Modification
12.1(19)EA1
This command was introduced.
Usage Guidelines
The undebug dot1x command is the same as the no debug dot1x command.
Related Commands
Command
Description
show debugging
Displays information about the types of debugging that are enabled. For
syntax information, select Cisco IOS Configuration Fundamentals
Command Reference for IOS Release 12.1 > Cisco IOS System
Management Commands > Troubleshooting Commands.
show dot1x
Displays IEEE 802.1x statistics, administrative status, and operational status
for the switch or for the specified interface.
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Catalyst 2940 Switch Debug Commands
debug etherchannel
debug etherchannel
Use the debug etherchannel privileged EXEC command to enable debugging of the
EtherChannel/PAgP shim. This shim is the software module that is the interface between the Port
Aggregation Protocol (PAgP) software module and the port manager software module. Use the no form
of this command to disable debugging.
debug etherchannel [all | detail | error | event | idb]
no debug etherchannel [all | detail | error | event | idb]
Syntax Description
Note
all
(Optional) Display all EtherChannel debug messages.
detail
(Optional) Display detailed EtherChannel debug messages.
error
(Optional) Display EtherChannel error debug messages.
event
(Optional) Debug major EtherChannel event debug messages.
idb
(Optional) Debug PAgP interface descriptor block debug messages.
Though visible in the command-line help strings, the linecard keyword is not supported.
Defaults
Debugging is disabled.
Command Modes
Privileged EXEC
Command History
Release
Modification
12.1(13)AY
This command was introduced.
Usage Guidelines
If you do not specify a keyword, all debug messages appear.
The undebug etherchannel command is the same as the no debug etherchannel command.
Related Commands
Command
Description
show debugging
Displays information about the types of debugging that are enabled. For
syntax information, select Cisco IOS Configuration Fundamentals
Command Reference for IOS Release 12.1 > Cisco IOS System
Management Commands > Troubleshooting Commands.
show etherchannel
Displays EtherChannel information for the channel.
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Appendix A
Catalyst 2940 Switch Debug Commands
debug pagp
debug pagp
Use the debug pagp privileged EXEC command to enable debugging of Port Aggregation Protocol
(PAgP) activity. Use the no form of this command to disable debugging.
debug pagp [all | event | fsm | misc | packet]
no debug pagp [all | event | fsm | misc | packet]
Syntax Description
all
(Optional) Display all PAgP debug messages.
event
(Optional) Display PAgP event debug messages.
fsm
(Optional) Display PAgP finite state-machine debug messages.
misc
(Optional) Display miscellaneous PAgP debug messages
packet
(Optional) Display PAgP packet debug messages.
Defaults
Debugging is disabled.
Command Modes
Privileged EXEC
Command History
Release
Modification
12.1(13)AY
This command was introduced.
Usage Guidelines
The undebug pagp command is the same as no debug pagp command.
Related Commands
Command
Description
show debugging
Displays information about the types of debugging that are enabled. For
syntax information, select Cisco IOS Configuration Fundamentals
Command Reference for IOS Release 12.1 > Cisco IOS System
Management Commands > Troubleshooting Commands.
show pagp
Displays PAgP channel-group information.
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Appendix A
Catalyst 2940 Switch Debug Commands
debug pm
debug pm
Use the debug pm privileged EXEC command to enable debugging of port manager (PM) activity. The
port manager is a state machine that controls all the logical and physical interfaces. All features, such as
VLANs, UniDirectional Link Detection (UDLD), and so forth, work with the port manager to provide
switch functions. Use the no form of this command to disable debugging.
debug pm {all | assert | card | cookies | etherchnl | messages | port | registry | sm | span | split |
vlan | vp}
no debug pm {all | assert | card | cookies | etherchnl | messages | port | registry | sm | span | split |
vlan | vp}
Syntax Description
Note
all
Display all PM debug messages.
assert
Display assert debug messages.
card
Display line-card related-events debug messages.
cookies
Display internal PM cookie validation debug messages.
etherchnl
Display EtherChannel related-events debug messages.
messages
Display Host Access Table events debug messages.
port
Display PM debug messages.
registry
Display port related-events debug messages.
sm
Display PM registry invocation debug messages.
span
Display state-machine related-events debug messages.
split
Display spanning-tree related-events debug messages.
vlan
Display split-processor debug messages.
vp
Display VLAN related-events debug messages.
Though visible in the command-line help strings, the scp and pvlan keywords are not supported.
Defaults
Debugging is disabled.
Command Modes
Privileged EXEC
Command History
Release
Modification
12.1(13)AY
This command was introduced.
Usage Guidelines
The undebug pm command is the same as the no debug pm command.
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Appendix A
Catalyst 2940 Switch Debug Commands
debug pm
Related Commands
Command
Description
show debugging
Displays information about the types of debugging that are enabled. For
syntax information, select Cisco IOS Configuration Fundamentals
Command Reference for IOS Release 12.1 > Cisco IOS System
Management Commands > Troubleshooting Commands.
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Appendix A
Catalyst 2940 Switch Debug Commands
debug spanning-tree
debug spanning-tree
Use the debug spanning-tree privileged EXEC command to enable debugging of spanning-tree
activities. Use the no form of this command to disable debugging.
debug spanning-tree {all | backbonefast | bpdu | bpdu-opt | config | etherchannel | events |
exceptions | general | mstp | pvst+ | root | snmp | switch | synchronization | uplinkfast}
no debug spanning-tree {all | backbonefast | bpdu | bpdu-opt | config | etherchannel | events |
exceptions | general | mstp | pvst+ | root | snmp | switch | synchronization | uplinkfast}
Note
Syntax Description
Note
The csuf option is not supported on the switch.
all
Display all spanning-tree debug messages.
backbonefast
Display BackboneFast-event debug messages.
bpdu
Display spanning-tree bridge protocol data unit (BPDU) debug messages.
bpdu-opt
Display optimized BPDU handling debug messages.
config
Display spanning-tree configuration change debug messages.
etherchannel
Display EtherChannel-support debug messages.
events
Display spanning-tree topology event debug messages.
exceptions
Display spanning-tree exception debug messages.
general
Display general spanning-tree activity debug messages.
mstp
Debug Multiple Spanning Tree Protocol events.
pvst+
Display per-VLAN spanning-tree plus (PVST+) event debug messages.
root
Display spanning-tree root-event debug messages.
snmp
Display spanning-tree Simple Network Management Protocol (SNMP)
handling debug messages.
switch
Display switch shim command debug messages. This shim is the software
module that is the interface between the generic Spanning Tree Protocol (STP)
code and the platform-specific code of various switch platforms.
synchronization
Display the spanning-tree synchronization event debug messages.
uplinkfast
Display UplinkFast-event debug messages.
Though visible in the command-line help strings, the csuf/csrt keyword is not supported.
Defaults
Debugging is disabled.
Command Modes
Privileged EXEC
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Appendix A
Catalyst 2940 Switch Debug Commands
debug spanning-tree
Command History
Release
Modification
12.1(13)AY
This command was introduced.
Usage Guidelines
The undebug spanning-tree command is the same as the no debug spanning-tree command.
Related Commands
Command
Description
show debugging
Displays information about the types of debugging that are enabled. For
syntax information, select Cisco IOS Configuration Fundamentals
Command Reference for IOS Release 12.1 > Cisco IOS System
Management Commands > Troubleshooting Commands.
show spanning-tree
Displays spanning-tree state information.
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Catalyst 2940 Switch Debug Commands
debug spanning-tree backbonefast
debug spanning-tree backbonefast
Use the debug spanning-tree backbonefast privileged EXEC command to enable debugging of
spanning-tree BackboneFast events. Use the no form of this command to disable debugging.
debug spanning-tree backbonefast [detail | exceptions]
no debug spanning-tree backbonefast [detail | exceptions]
Syntax Description
detail
(Optional) Display detailed BackboneFast debug messages.
exceptions
(Optional) Display spanning-tree BackboneFast-exception debug messages.
Defaults
Debugging is disabled.
Command Modes
Privileged EXEC
Command History
Release
Modification
12.1(13)AY
This command was introduced.
Usage Guidelines
The undebug spanning-tree backbonefast command is the same as the no debug spanning-tree
backbonefast command.
Related Commands
Command
Description
show debugging
Displays information about the types of debugging that are enabled. For
syntax information, select Cisco IOS Configuration Fundamentals
Command Reference for IOS Release 12.1 > Cisco IOS System
Management Commands > Troubleshooting Commands.
show spanning-tree
Displays spanning-tree state information.
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Appendix A
Catalyst 2940 Switch Debug Commands
debug spanning-tree bpdu
debug spanning-tree bpdu
Use the debug spanning-tree bpdu privileged EXEC command to enable debugging of sent and
received spanning-tree bridge protocol data units (BPDUs). Use the no form of this command to disable
debugging.
debug spanning-tree bpdu [receive | transmit]
no debug spanning-tree bpdu [receive | transmit]
Syntax Description
receive
(Optional) Display the nonoptimized path for received BPDU debug messages.
transmit
(Optional) Display the nonoptimized path for transmitted BPDU debug messages.
Defaults
Debugging is disabled.
Command Modes
Privileged EXEC
Command History
Release
Modification
12.1(13)AY
This command was introduced.
Usage Guidelines
The undebug spanning-tree bpdu command is the same as the no debug spanning-tree bpdu
command.
Related Commands
Command
Description
show debugging
Displays information about the types of debugging that are enabled. For
syntax information, select Cisco IOS Configuration Fundamentals
Command Reference for IOS Release 12.1 > Cisco IOS System
Management Commands > Troubleshooting Commands.
show spanning-tree
Displays spanning-tree state information.
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Appendix A
Catalyst 2940 Switch Debug Commands
debug spanning-tree bpdu-opt
debug spanning-tree bpdu-opt
Use the debug spanning-tree bpdu-opt privileged EXEC command to enable debugging of optimized
spanning-tree bridge protocol data units (BPDUs) handling. Use the no form of this command to disable
debugging.
debug spanning-tree bpdu-opt [detail | packet]
no debug spanning-tree bpdu-opt [detail | packet]
Syntax Description
detail
(Optional) Display detailed optimized BPDU-handling debug messages.
packet
(Optional) Display packet-level optimized BPDU-handling debug messages.
Defaults
Debugging is disabled.
Command Modes
Privileged EXEC
Command History
Release
Modification
12.1(13)AY
This command was introduced.
Usage Guidelines
The undebug spanning-tree bpdu-opt command is the same as the no debug spanning-tree bpdu-opt
command.
Related Commands
Command
Description
show debugging
Displays information about the types of debugging that are enabled. For
syntax information, select Cisco IOS Configuration Fundamentals
Command Reference for IOS Release 12.1 > Cisco IOS System
Management Commands > Troubleshooting Commands.
show spanning-tree
Displays spanning-tree state information.
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Appendix A
Catalyst 2940 Switch Debug Commands
debug spanning-tree mstp
debug spanning-tree mstp
Use the debug spanning-tree mstp privileged EXEC command to enable debugging of the Multiple
Spanning Tree Protocol (MSTP) software. Use the no form of this command to disable debugging.
debug spanning-tree mstp {all | boundary | bpdu-rx | bpdu-tx | errors | flush | init | migration |
pm | proposals | region | roles | sanity_check | sync | tc | timers}
no debug spanning-tree mstp {all | boundary | bpdu-rx | bpdu-tx | errors | flush | init | migration
| pm | proposals | region | roles | sanity_check | sync | tc | timers}
Syntax Description
all
Display all MSTP debug messages.
boundary
Display flag change debug messages at these boundaries:
•
An multiple spanning-tree (MST) region and a single spanning-tree region
running Rapid Spanning Tree Protocol (RSTP)
•
An MST region and a single spanning-tree region running IEEE 802.1D
•
An MST region and another MST region with a different configuration
bpdu-rx
Display received MST bridge protocol data unit (BPDUs) debug messages.
bpdu-tx
Display sent MST BPDU debug messages.
errors
Display MSTP error debug messages.
flush
Display port-flushing mechanism debug messages.
init
Display MSTP data structure initialization debug messages.
migration
Display protocol-migration state-machine debug messages.
pm
Display MSTP port-manager event debug messages.
proposals
Display handshake messages between the designated switch and the root switch
debug messages.
region
Display region synchronization between the switch processor (SP) and the route
processor (RP) debug messages.
roles
Display MSTP role debug messages.
sanity_check
Display received BPDU sanity check debug messages.
sync
Display port synchronization event debug messages.
tc
Display topology change notification event debug messages.
timers
Display MSTP timers for start, stop, and expire event debug messages.
Defaults
Debugging is disabled.
Command Modes
Privileged EXEC
Command History
Release
Modification
12.1(20)EA2
This command was introduced.
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Appendix A
Catalyst 2940 Switch Debug Commands
debug spanning-tree mstp
Usage Guidelines
The undebug spanning-tree mstp command is the same as the no debug spanning-tree mstp
command.
Related Commands
Command
Description
show debugging
Displays information about the types of debugging that are enabled. For
syntax information, select Cisco IOS Configuration Fundamentals
Command Reference for IOS Release 12.1 > Cisco IOS System
Management Commands > Troubleshooting Commands.
show spanning-tree
Displays spanning-tree state information.
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Appendix A
Catalyst 2940 Switch Debug Commands
debug spanning-tree switch
debug spanning-tree switch
Use the debug spanning-tree switch privileged EXEC command to enable debugging of the software
interface between the Spanning Tree Protocol (STP) software module and the port manager software
module. Use the no form of this command to disable debugging.
debug spanning-tree switch {all | errors | general | helper | pm | rx {decode | errors | interrupt
| process} | state | tx [decode]}
no debug spanning-tree switch {all | errors | general | helper | pm | rx {decode | errors |
interrupt | process} | state | tx [decode]}
Syntax Description
all
Display all spanning-tree switch debug messages.
errors
Display debug messages for the interface between the spanning-tree software
module and the port manager software module.
general
Display general event debug messages.
helper
Display spanning-tree helper-task debug messages. Helper tasks handle bulk
spanning-tree updates.
pm
Display port-manager event debug messages.
rx
Display received bridge protocol data unit (BPDU) handling debug messages. The
keywords have these meanings:
•
decode—Display decoded received packets.
•
errors—Display receive error debug messages.
•
interrupt—Display interrupt service request (ISR) debug messages.
•
process—Display process receive BPDU debug messages.
state
Display spanning-tree port state change debug messages.
tx [decode]
Display transmitted BPDU handling debug messages. The keyword has this
meaning:
•
decode—(Optional) Display decoded transmitted packets.
Defaults
Debugging is disabled.
Command Modes
Privileged EXEC
Command History
Release
Modification
12.1(13)AY
This command was introduced.
Usage Guidelines
The undebug spanning-tree switch command is the same as the no debug spanning-tree switch
command.
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Appendix A
Catalyst 2940 Switch Debug Commands
debug spanning-tree switch
Related Commands
Command
Description
show debugging
Displays information about the types of debugging that are enabled. For
syntax information, select Cisco IOS Configuration Fundamentals
Command Reference for IOS Release 12.1 > Cisco IOS System
Management Commands > Troubleshooting Commands.
show spanning-tree
Displays spanning-tree state information.
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Appendix A
Catalyst 2940 Switch Debug Commands
debug spanning-tree uplinkfast
debug spanning-tree uplinkfast
Use the debug spanning-tree uplinkfast privileged EXEC command to enable debugging of
spanning-tree UplinkFast events. Use the no form of this command to disable debugging.
debug spanning-tree uplinkfast [exceptions]
no debug spanning-tree uplinkfast [exceptions]
Syntax Description
exceptions
Defaults
Debugging is disabled.
Command Modes
Privileged EXEC
Command History
Release
Modification
12.1(13)AY
This command was introduced.
(Optional) Display spanning-tree UplinkFast-exception debug messages.
Usage Guidelines
The undebug spanning-tree uplinkfast command is the same as the no debug spanning-tree
uplinkfast command.
Related Commands
Command
Description
show debugging
Displays information about the types of debugging that are enabled. For
syntax information, select Cisco IOS Configuration Fundamentals
Command Reference for IOS Release 12.1 > Cisco IOS System
Management Commands > Troubleshooting Commands.
show spanning-tree
Displays spanning-tree state information.
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Appendix A
Catalyst 2940 Switch Debug Commands
debug switch dhcp
debug switch dhcp
Use the debug switch dhcp privileged EXEC command to enable debugging of DHCP events. Use the
no form of this command to disable debugging.
debug switch dhcp
no debug switch dhcp
Syntax Description
This command has no arguments or keywords.
Defaults
Debugging is disabled.
Command Modes
Privileged EXEC
Command History
Release
Modification
12.1(22)EA7
This command was introduced.
Usage Guidelines
The undebug switch dhcp command is the same as the no debug switch dhcp command.
Related Commands
Command
Description
show ip dhcp snooping
Displays the DHCP snooping configuration.
show ip dhcp snooping binding
Displays the DHCP snooping binding information.
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Appendix A
Catalyst 2940 Switch Debug Commands
debug sw-vlan
debug sw-vlan
Use the debug sw-vlan privileged EXEC command to enable debugging of VLAN manager activities.
Use the no form of this command to disable debugging.
debug sw-vlan {badpmcookies | cfg-vlan {bootup | cli} | events | ifs | management | notification
| packets | registries | vtp}
no debug sw-vlan {badpmcookies | cfg-vlan {bootup | cli} | events | ifs | management |
notification | packets | registries | vtp}
Syntax Description
badpmcookies
Display VLAN manager incidents of bad port manager cookie debug
messages.
cfg-vlan {bootup | cli}
Display config-vlan debug messages. The keywords have these meanings:
events
•
bootup—Display messages when the switch is booting up.
•
cli—Display messages when the command-line interface (CLI) is in
config-vlan mode.
Display VLAN manager event debug messages.
ifs
See the debug sw-vlan ifs command.
management
Display VLAN manager management of internal VLAN debug messages.
notification
See the debug sw-vlan notification command.
packets
Display packet handling and encapsulation process debug messages.
registries
Display VLAN manager registry debug messages.
vtp
See the debug sw-vlan vtp command.
Defaults
Debugging is disabled.
Command Modes
Privileged EXEC
Command History
Release
Modification
12.1(13)AY
This command was introduced.
Usage Guidelines
The undebug sw-vlan command is the same as the no debug sw-vlan command.
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Appendix A
Catalyst 2940 Switch Debug Commands
debug sw-vlan
Related Commands
Command
Description
show debugging
Displays information about the types of debugging that are enabled. For
syntax information, select Cisco IOS Configuration Fundamentals
Command Reference for IOS Release 12.1 > Cisco IOS System
Management Commands > Troubleshooting Commands.
show vlan
Displays the parameters for all configured VLANs or one VLAN (if the
VLAN name or ID is specified) in the administrative domain.
show vtp
Displays general information about VTP management domain, status, and
counters.
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Appendix A
Catalyst 2940 Switch Debug Commands
debug sw-vlan ifs
debug sw-vlan ifs
Use the debug sw-vlan ifs privileged EXEC command to enable debugging of the VLAN manager Cisco
IOS file system (IFS) error tests. Use the no form of this command to disable debugging.
debug sw-vlan ifs {open {read | write} | read {1 | 2 | 3 | 4} | write}
no debug sw-vlan ifs {open {read | write} | read {1 | 2 | 3 | 4} | write}
Syntax Description
open {read | write}
Display VLAN manager IFS file-open operation debug messages. The
keywords have these meanings:
•
read—Display VLAN manager IFS file-read operation debug messages.
•
write—Display VLAN manager IFS file-write operation debug
messages.
read {1 | 2 | 3 | 4}
Display file-read operation debug messages for the specified error test (1, 2,
3, or 4).
write
Display file-write operation debug messages.
Defaults
Debugging is disabled.
Command Modes
Privileged EXEC
Command History
Release
Modification
12.1(13)AY
This command was introduced.
Usage Guidelines
When selecting the file read operation, Operation 1 reads the file header, which contains the header
verification word and the file version number. Operation 2 reads the main body of the file, which
contains most of the domain and VLAN information. Operation 3 reads type length version (TLV)
descriptor structures. Operation 4 reads TLV data.
The undebug sw-vlan ifs command is the same as the no debug sw-vlan ifs command.
Related Commands
Command
Description
show debugging
Displays information about the types of debugging that are enabled. For
syntax information, select Cisco IOS Configuration Fundamentals
Command Reference for IOS Release 12.1 > Cisco IOS System
Management Commands > Troubleshooting Commands.
show vlan
Displays the parameters for all configured VLANs or one VLAN (if the
VLAN name or ID is specified) in the administrative domain.
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Catalyst 2940 Switch Debug Commands
debug sw-vlan notification
debug sw-vlan notification
Use the debug sw-vlan notification privileged EXEC command to enable debugging of the activation
and deactivation of Inter-Link Switch (ISL) VLAN IDs. Use the no form of this command to disable
debugging.
debug sw-vlan notification {accfwdchange | allowedvlancfgchange | fwdchange | linkchange |
modechange | pruningcfgchange | statechange}
no debug sw-vlan notification {accfwdchange | allowedvlancfgchange | fwdchange | linkchange
| modechange | pruningcfgchange | statechange}
Syntax Description
accfwdchange
Display debug messages for VLAN manager notification of aggregated
access interface spanning-tree forward changes.
allowedvlancfgchange
Display debug messages for VLAN manager notification of changes to the
allowed VLAN configuration.
fwdchange
Display debug messages for VLAN manager notification of spanning-tree
forwarding changes.
linkchange
Display debug messages for VLAN manager notification of interface
link-state changes.
modechange
Display debug messages for VLAN manager notification of interface mode
changes.
pruningcfgchange
Display debug messages for VLAN manager notification of changes to the
pruning configuration.
statechange
Display debug messages for VLAN manager notification of interface state
changes.
Defaults
Debugging is disabled.
Command Modes
Privileged EXEC
Command History
Release
Modification
12.1(13)AY
This command was introduced.
Usage Guidelines
The undebug sw-vlan notification command is the same as the no debug sw-vlan notification
command.
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Appendix A
Catalyst 2940 Switch Debug Commands
debug sw-vlan notification
Related Commands
Command
Description
show debugging
Displays information about the types of debugging that are enabled. For
syntax information, select Cisco IOS Configuration Fundamentals
Command Reference for IOS Release 12.1 > Cisco IOS System
Management Commands > Troubleshooting Commands.
show vlan
Displays the parameters for all configured VLANs or one VLAN (if the
VLAN name or ID is specified) in the administrative domain.
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Appendix A
Catalyst 2940 Switch Debug Commands
debug sw-vlan vtp
debug sw-vlan vtp
Use the debug sw-vlan vtp privileged EXEC command to enable debugging of the VLAN Trunking
Protocol (VTP) code. Use the no form of this command to disable debugging.
debug sw-vlan vtp {events | packets | pruning [packets | xmit] | xmit}
no debug sw-vlan vtp {events | packets | pruning [packets | xmit] | xmit}
Syntax Description
events
Display debug messages for general-purpose logic flow and detailed VTP
messages generated by the VTP_LOG_RUNTIME macro in the VTP
code.
packets
Display debug messages for the contents of all incoming VTP packets
that have been passed into the VTP code from the Cisco IOS VTP
platform-dependent layer, except for pruning packets.
pruning [packets | xmit]
Display debug messages generated by the pruning segment of the VTP
code. The keywords have these meanings:
xmit
•
packets—(Optional) Display debug messages for the contents of all
incoming VTP pruning packets that have been passed into the VTP
code from the VTP platform-dependent layer.
•
xmit—(Optional) Display debug messages for the contents of all
outgoing VTP packets that the VTP code requests the Cisco IOS VTP
platform-dependent layer to send.
Display debug messages for the contents of all outgoing VTP packets that
the VTP code requests the VTP platform-dependent layer to send, except
for pruning packets.
Defaults
Debugging is disabled.
Command Modes
Privileged EXEC
Command History
Release
Modification
12.1(13)AY
This command was introduced.
Usage Guidelines
If no further parameters are entered after the pruning keyword, VTP pruning debugging messages
appear. They are generated by the VTP_PRUNING_LOG_NOTICE, VTP_PRUNING_LOG_INFO,
VTP_PRUNING_LOG_DEBUG, VTP_PRUNING_LOG_ALERT, and
VTP_PRUNING_LOG_WARNING macros in the VTP pruning code.
The undebug sw-vlan vtp command is the same as the no debug sw-vlan vtp command.
Catalyst 2940 Switch Command Reference
OL-8606-01
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Appendix A
Catalyst 2940 Switch Debug Commands
debug sw-vlan vtp
Related Commands
Command
Description
show debugging
Displays information about the types of debugging that are enabled. For
syntax information, select Cisco IOS Configuration Fundamentals
Command Reference for IOS Release 12.1 > Cisco IOS System
Management Commands > Troubleshooting Commands.
show vtp
Displays general information about VTP management domain, status, and
counters.
Catalyst 2940 Switch Command Reference
A-24
OL-8606-01
Appendix A
Catalyst 2940 Switch Debug Commands
debug udld
debug udld
Use the debug udld privileged EXEC command to enable debugging of the UniDirectional Link
Detection (UDLD) feature. Use the no form of this command to disable UDLD debugging.
debug udld {events | packets | registries}
no debug udld {events | packets | registries}
Syntax Description
events
Display debug messages for UDLD process events as they occur.
packets
Display debug messages for the UDLD process as it receives packets from the packet
queue and tries to send them at the request of the UDLD protocol code.
registries
Display debug messages for the UDLD process as it processes registry calls from the
UDLD process-dependent module and other feature modules.
Defaults
Debugging is disabled.
Command Modes
Privileged EXEC
Command History
Release
Modification
12.1(13)AY
This command was introduced.
Usage Guidelines
For debug udld events, these debugging messages appear:
•
General UDLD program logic flow
•
State machine state changes
•
Program actions for the set and clear ErrDisable state
•
Neighbor cache additions and deletions
•
Processing of configuration commands
•
Processing of link-up and link-down indications
For debug udld packets, these debugging messages appear:
•
General packet processing program flow on receipt of an incoming packet
•
Indications of the contents of the various pieces of packets received (such as type length versions
[TLVs]) as they are examined by the packet reception code
•
Packet transmission attempts and the outcome
Catalyst 2940 Switch Command Reference
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Appendix A
Catalyst 2940 Switch Debug Commands
debug udld
For debug udld registries, these categories of debugging messages appear:
Related Commands
•
Sub-block creation
•
Fiber-port status changes
•
State change indications from the port manager software
•
MAC address registry calls
Command
Description
show debugging
Displays information about the types of debugging that are enabled. For
syntax information, select Cisco IOS Configuration Fundamentals
Command Reference for IOS Release 12.1 > Cisco IOS System
Management Commands > Troubleshooting Commands.
show udld
Displays UDLD administrative and operational status for all ports or the
specified port.
Catalyst 2940 Switch Command Reference
A-26
OL-8606-01
INDEX
Numerics
C
802.1X Port Based Authentication
caution, description
enabling guest VLAN supplicant
xii
channel-group command
2-48
2-15
channel-protocol command
Cisco SoftPhone, trusting packets sent from
A
2-133
class of service
aaa accounting dot1x command
aaa authentication command
abort command
access ports
See CoS
2-1
clear interface command
2-3
clear lacp command
2-359
apply command
2-20
2-21
clear mac address-table command
2-319
aggregate-port learner
clear pagp command
2-145
archive tar command
2-24
clear spanning-tree counters command
2-5
clear vmps statistics command
2-10
clear vtp counters command
xi
authorization state of controlled port
autonegotiation of duplex mode
2-60
2-67
2-29
2-30
cluster discovery hop-count command
2-32
2-33
cluster holdtime command
B
2-34
cluster management-vlan command
boot host command
cluster member command
2-269
cluster run command
2-13
booting, displaying environment variables
2-157
2-14
adding candidates
BPDU filtering, for spanning tree
2-270, 2-302
binding to HSRP
broadcast suppression level
configuring
displaying
2-313
2-238
2-272, 2-302
2-35
2-36
2-38
clusters
boot private-config-file command
BPDU guard, for spanning tree
2-27
2-28
cluster commander-address command
cluster enable command
BackboneFast, for STP
2-26
clear spanning-tree detected-protocols command
2-7
archive upload-sw command
2-22
2-23
clear port-security command
2-359
archive download-sw command
audience
2-18
building manually
2-36
2-39
2-36
communicating with members by using Telnet
2-150
displaying
candidate switches
member switches
status
2-161
2-163
2-159
Catalyst 2940 Switch Command Reference
OL-8606-01
IN-1
Index
clusters (continued)
debug pagp command
heartbeat messages
debug pm command
duration after which switch declared down
interval between
A-4
2-34
debug spanning-tree backbonefast command
debug spanning-tree bpdu command
2-41
hop-count limit for extended discovery
HSRP standby groups
A-5
debug spanning-tree command
2-39
2-39
debug spanning-tree mstp command
SNMP trap
2-262
debug spanning-tree switch command
cluster timer command
debug switch dhcp command
debug sw-vlan command
1-2
command switch
See clusters
configuration files
debug udld command
delete command
2-14
configuring multiple interfaces
config-vlan mode
description
2-347
summary
1-2
publication
text
2-44
2-71
accepting untrusted packets form edge switch
2-86
displaying
bindings
conventions
2-200
configuration
2-199
enabling
xi
for examples
2-42
DHCP snooping
1-4
entering
A-25
DHCP, error recovery timer
2-80 to 2-81
A-21
A-23
define interface-range command
2-13
configuration files, private
command
A-20
debug sw-vlan vtp command
2-13
A-16
A-18
debug sw-vlan notification command
specifying boot file
A-14
A-17
debug sw-vlan ifs command
loading from a server
A-12
debug spanning-tree uplinkfast command
2-39
2-41
command modes defined
A-11
A-7
redundancy
cluster standby-group command
A-10
debug spanning-tree bpdu-opt command
2-32
A-9
on a VLAN
xii
2-90
trust on an interface
xi
rate limiting
xi
CoS
2-89
2-88
documentation
default value, assigning to incoming packets
incoming value, overriding
2-131
priority queue mapping, displaying
xii
document conventions
2-131
priority queue, assigning values to
related
domain name, VTP
2-375
dot1x auth-fail vlan
2-258
WRR weights, assigning to CoS priority queues
2-366, 2-370
dot1x auth-fail max-attempts
2-259
WRR bandwidth allocation, displaying
xi
2-374
dot1x command
2-49
2-45
dot1x default command
D
debug dot1x command
A-2
debug etherchannel command
A-3
2-47
2-53
dot1x guest-vlan command
2-54
dot1x host-mode command
2-56
dot1x initialize command
2-57
dot1x max-req command
2-58
Catalyst 2940 Switch Command Reference
IN-2
OL-8606-01
Index
dot1x multiple-hosts command
dot1x port-control command
exit command
2-60
dot1x re-authenticate command
2-359
and allowed VLAN list
duplex command
2-331
and pruning-eligible list
2-71
configuring
2-67
dynamic-access ports, configuring
2-32
extended-range VLANs
2-64
2-320
DTP flap, error recovery timer
2-155, 2-232
extended discovery of candidate switches
2-63
dot1x reauthentication command
xii
express setup-related commands
2-62
dot1x re-authentication command
DTP
examples, conventions for
2-59
2-331
2-347
extended system ID for STP
2-315
2-278
Dynamic Host Configuration Protocol (DHCP)
See DHCP snooping
F
Dynamic Trunking Protocol
See DTP
fan information, displaying
file name, VTP
files, deleting
E
2-366
2-44
flowcontrol command
EAP-request/identity frame
receiving
2-58
response time before retransmitting
environment variables, displaying
errdisable recovery command
sending
2-65
2-73
2-73
2-157
errdisable detect cause command
2-69
G
2-71
EtherChannel
global configuration mode
creating port-channel logical interface
debug messages, displaying
A-3 to A-4
H
2-15
heartbeat messages
load-distribution methods
2-148
duration after which switch declared dead
PAgP
interval between
aggregate-port learner
2-145
debug messages, displaying
2-21, 2-23
A-4
learn method
hop-count limit for clusters
loading from a server
2-71
2-32
2-13
host connection, port configuration
2-145
2-317
Hot Standby Router Protocol
2-15
See HSRP
priority of interface for transmitted traffic
Ethernet controller, internal register display
Ethernet statistics, collecting
2-34
host configuration files
2-206, 2-223
error recovery timer
2-34
2-41
holdtime for clusters
clearing channel-group information
displaying
1-2, 1-4
2-79
2-179
LACP, modes
modes
2-73
flow-control packets
maximum number to send
displaying
2-176
2-147
2-166
2-152
Catalyst 2940 Switch Command Reference
OL-8606-01
IN-3
Index
HSRP
interface port-channel command
binding HSRP group to cluster
standby group
interface range command
2-39
interface-range macros
2-39
2-79
2-80
2-42
interfaces
configuring
I
2-67
configuring multiple
IDS, using with SPAN
creating port-channel logical
2-136
IEEE 802.1x commands, authentication methods
IEEE 802.1x violation error recovery
IGMP filters, applying
2-71
setting maximum
2-92
restarting
2-260
2-166
2-82
ip addresses, setting
2-82
See DHCP snooping
2-202
ip dhcp snooping command
IGMP snooping
adding ports statically
configuration, displaying
2-83
ip dhcp snooping information option allow-untrusted
command 2-86
2-108
compatibility mode, displaying
2-203
ip dhcp snooping information option command
2-203
ip dhcp snooping limit rate command
2-96
enabling the configurable-leave timer
IGMP version, displaying
MAC address tables
2-105
2-203
Immediate-Leave processing
2-104
multicast router detection
ip dhcp snooping trust command
2-89
ip dhcp snooping vlan command
2-90
ip igmp filter command
ip igmp profile command
2-203
multicast router ports, displaying
2-203
2-106
2-88
2-92
2-94
ip igmp snooping command
2-97
2-84
2-91
ip igmp max-groups command
2-211
multicast groups, displaying
multicast routers
ip address command
IP DHCP snooping
2-94
per VLAN
2-260
See IDS
2-92
IGMP profiles
enabling
disabling
2-79
Intrusion Detection System
configuring throttling action
displaying
2-3
internal registers, displaying
2-91
IGMP groups
creating
2-80 to 2-81
2-96
ip igmp snooping configurable-leave timer
command 2-105
ip igmp snooping mrouter learn pim v2 command
2-103
ip igmp snooping report-suppression command
report suppression
2-99
source-only-learning
2-101
source-only-learning aging time
2-101
images
2-99
ip igmp snooping source-only-learning age-timer
2-101
ip igmp snooping source-only-learning command
2-101
ip igmp snooping vlan command
2-103
ip igmp snooping vlan immediate-leave command
See software images
ip igmp snooping vlan mrouter command
Immediate-Leave feature, MVR
Immediate-Leave processing
interface command
2-141
2-104
2-77
interface configuration mode
2-97
ip igmp snooping vlan static command
IP multicast addresses
2-104
2-106
2-108
2-138
IP phones, trusting packets sent from
2-133
1-2, 1-4
Catalyst 2940 Switch Command Reference
IN-4
OL-8606-01
Index
ip ssh command
MAC addresses (continued)
2-109
IPv4
1-1
aging time
IPv6
1-1
dynamic
2-208
2-208
IP version 4
1-1
multicast entries
IP version 6
1-1
notification setting
2-211
2-213
number of addresses
per interface
J
per VLAN
secure
jumbo frames
displaying setting
2-241
static
setting switch for
2-336
dynamic
2-115
2-22
displaying
2-208
enabling MAC address notification
LACP
lacp port-priority command
adding
2-111
lacp system-priority command
2-323
displaying
2-113
2-228
static
Layer 2 traceroute
adding
2-340
MAC addresses
2-119
displaying
2-337
line configuration mode
2-208
sticky
1-3, 1-5
configuring manually
Link Aggregation Control Protocol
2-323
enabling sticky learning
See EtherChannel
learning dynamically
link flap
enable error detection for
2-71
load-distribution methods for EtherChannel
loop guard, for spanning tree
2-323
2-148
mac address-table notification command
mac address-table static command
clearing global counters
2-71
2-280, 2-283
configuring
enabling
2-117
2-119
2-22
2-117
2-117
macro description command
2-124
M
macro global command
MAC addresses
macro global description command
and port security
2-115
MAC notification feature
2-79
loopback, error recovery timer
2-323
mac address-table aging-time command
2-69
enable timer to recover from error state
macro name command
2-323
clearing notification global counters
displaying
2-117
secure
See EtherChannel
logical interface
2-208
2-208
deleting
IP addresses
2-208
2-228
aging time
L
2-208
2-22
2-125
2-127
2-128
macros
adding a description
2-124
adding a global description
2-127
Catalyst 2940 Switch Command Reference
OL-8606-01
IN-5
Index
macros (continued)
applying
MSTP (continued)
root switch
2-125
creating
affects of extended system ID
2-128
displaying
hello-time
2-225
interface range
max-age
maximum transmission unit
primary or secondary
switch priority
2-130
member switches
mls qos cos command
mls qos trust command
enabling BPDU guard
2-133
enabling Port Fast
Mode button, and password recovery
monitor session command
2-270, 2-302
2-272, 2-302
2-291
length of listening and learning states
2-135
rapid transition to forwarding
state information display
2-27
configuring size
MST region
aborting changes
2-287
applying changes
2-287
configuration name
2-241
See IGMP snooping
2-287
multicast groups, MVR
2-287
2-139
multicast router detection
2-287
2-97
multicast router learning method
2-234
MST configuration mode
2-336
multicast groups
current or pending display
multicast router ports, configuring
2-287
VLANs-to-instance mapping
configuring
displaying
2-285
restart protocol migration process
enabling
2-27
root port
2-106
2-313
2-238
2-313
multicast VLAN, MVR
2-139
multicast VLAN registration
2-280
preventing from becoming designated
restricting which can be root
2-106
multicast suppression level
2-287
2-289
root guard
2-233
displaying global setting
configuration revision number
loop guard
2-302
MTU
2-282
protocol mode
2-291
2-282
shutting down Port Fast-enabled ports
2-234
interoperability
2-304
2-302, 2-304
forward-delay time
2-153
MSTP
path cost
2-297
enabling BPDU filtering
2-131
2-138
displaying
2-295
2-298
blocking to forwarding state
displaying
2-294
state changes
See clusters
link type
2-293
port priority for selection of
See MTU
mode, MVR
2-292, 2-298
maximum hop count before discarding BPDU
xi
mdix auto command
2-293
interval between hello BPDU messages
2-125
2-125
manual, audience
2-292, 2-298
interval between BDPU messages
2-42
specifying parameter values
tracing
2-278
2-280
2-280
See MVR
multiple hosts on authorized port
2-56
2-280
Catalyst 2940 Switch Command Reference
IN-6
OL-8606-01
Index
Multiple Spanning Tree Protocol
port-based authentication (continued)
See MSTP
auth-fail VLAN
MVR
debug messages, display
configuring
enabling 802.1x
2-138
configuring interfaces
displaying
2-49
guest VLAN
2-142
Immediate Leave feature
source port
2-54
multiple hosts on authorized port
2-141
enabling
2-142
2-141
re-authenticating 802.1x-enabled ports
2-142
mvr vlan group command
2-65
quiet period between failed authentication
exchanges 2-65
2-139
mvr immediate command
mvr type command
2-56
2-64
time between attempts
2-138
mvr group command
2-60
periodic re-authentication
2-142
mvr command
2-60
manual control of authorization state
2-218
receiver port
A-2
2-62
resetting configurable 802.1x parameters
2-144
statistics and status display
2-53
2-172
switch-to-client frame-retransmission number
N
switch-to-client retransmission time
normal-range VLANs
note, description
port-channel load-balance command
2-347, 2-352
Port Fast, for spanning tree
xii
no vlan command
port ranges, defining
2-347, 2-356
2-58
2-65
2-148
2-304
2-42
ports, debug messages, display
A-5
port security
P
aging
displaying
PAgP
enabling
See EtherChannel
pagp learn-method command
pagp port-priority command
password, VTP
2-228
2-323
violation error recovery timer
2-145
port trust states for QoS
2-147
privileged EXEC mode
1-2 to 1-3
2-198
protected ports
displaying
See STP
enabling
2-198
PIM-DVMRP, as multicast router learning method
2-133
2-106
2-192
2-330
pruning, VTP
displaying interface information
enabling
Port Aggregation Protocol
2-187
2-366, 2-370
publications, related
See EtherChannel
xii
PVST+
port-based authentication
802.1x AAA accounting methods
2-14
product identification information, displaying
per-VLAN spanning-tree plus
policy maps, defining the trust states
2-71
2-133
private configuration files
2-366, 2-370
password-recovery mechanism, enabling and
disabling 2-153
PID, displaying
2-327
2-1
See STP
Catalyst 2940 Switch Command Reference
OL-8606-01
IN-7
Index
Q
S
QoS
sending flow-control packets
configuration information, displaying
port trust states
service password-recovery command
2-214
defining the CoS value for an incoming packet
2-131
setup express command
show boot command
2-133
queues
2-157
WRR weights
show cluster command
2-374
trusted boundary for Cisco SoftPhones
trusted boundary for IP phones
querytime, MVR
2-359
show cluster candidates command
2-375
2-133
2-159
show cluster members command
show env command
2-176
show etherchannel command
See STP
show file command
rapid PVST+
show interfaces command
2-150
re-authenticating 802.1x-enabled ports
2-62
2-185
show interfaces counters command
2-195
2-198
show ip dhcp snooping binding command
2-64
time between attempts
receiver port, MVR
show ip dhcp snooping command
2-65
show ip igmp profile command
2-142
receiving flow-control packets
2-73
2-202
2-203
2-206
show mac address-table command
2-71
show mac address-table notification command
2-71
redundancy for cluster switches
reset command
2-39
show mls qos interface command
show monitor command
2-359
show mvr command
restricted VLAN
See dot1x auth-fail VLAN
rmon collection stats command
root guard, for spanning tree
2-208
show mac address-table multicast command
2-177
timer interval
2-200
2-199
show ip igmp snooping command
show lacp command
recovery mechanism
displaying
2-179
2-187
show inventory command
re-authentication
2-177
2-182
show flowcontrol command
See STP
2-170
2-172
show errdisable recovery command
rapid per-VLAN spanning-tree plus
2-152
2-280
2-211
2-213
2-214
2-216
2-218
show mvr interface command
2-219
show mvr members command
2-221
show pagp command
2-166
2-359
show dot1x command
R
causes
2-163
show controller utilization command
show current command
periodic
2-161
show controllers ethernet-controller command
2-133
2-138
rcommand command
2-153
2-155
show changes command
CoS-to-egress-queue map
2-73
2-223
show parser macro command
2-225
show port-security command
2-228
show proposed command
2-359
Catalyst 2940 Switch Command Reference
IN-8
OL-8606-01
Index
show running-config vlan command
sessions (continued)
2-230
start new
show setup express command
2-232
show spanning-tree command
2-233
spanning-tree backbonefast command
show storm-control command
2-238
spanning-tree bpdufilter command
show system mtu command
show udld command
spanning-tree cost command
show vlan command
show vtp command
spanning-tree guard command
2-248
show wrr-queue cos-map command
spanning-tree mode command
2-258
See macros
spanning-tree mst max-age command
spanning-tree mst priority command
2-265
snmp trap mac-notification command
spanning-tree mst root command
2-268
SNMP traps
enabling MAC address notification
2-262
software images
2-262, 2-268
upgrading
2-5
uploading
2-10
spanning-tree port-priority command
speed command
source ports, MVR
2-142
SPAN
2-306
2-308
2-109
static-access ports, configuring
2-245
2-300
2-311
SSH, configuring version
software version, displaying
2-297
spanning-tree portfast (interface configuration)
command 2-304
spanning-tree vlan command
2-5
2-295
2-298
spanning-tree uplinkfast command
2-44
2-294
spanning-tree portfast (global configuration)
command 2-302
2-117
enabling MAC address notification traps
downloading
2-293
spanning-tree mst port-priority command
2-262
2-291
2-292
spanning-tree mst max-hops command
2-265
snmp-server enable traps command
and IDS
2-289
spanning-tree mst hello-time command
enabling the sending of traps
2-287
spanning-tree mst forward-time command
2-261
snmp-server host command
2-283
2-285
spanning-tree mst cost command
Smartports macros
deleting
2-282
spanning-tree mst configuration command
2-259
2-260
SNMP host, specifying
2-278
spanning-tree loopguard default command
show wrr-queue bandwidth command
shutdown vlan command
2-276
2-280
spanning-tree link-type command
2-250
2-253
shutdown command
2-274
spanning-tree extend system-id command
2-247
show vmps command
2-272
spanning-tree etherchannel command
2-245
show vlan command fields
2-269
2-270
spanning-tree bpduguard command
2-241
2-242
show version command
2-135
statistics, Ethernet group
2-152
sticky learning, enabling
2-323
2-315
storm control
2-136
configuring
displaying
broadcast, enabling
2-135
displaying
2-216
unicast, enabling
add interfaces to
displaying
2-238
multicast, enabling
sessions
2-135
2-313
2-313
2-313
storm-control command
2-313
2-216
Catalyst 2940 Switch Command Reference
OL-8606-01
IN-9
Index
STP
state changes (continued)
BackboneFast
shutting down Port Fast-enabled ports
2-269
debug message display
state information display
BackboneFast events
MSTP
VLAN options
A-9
optimized BPDUs handling
spanning-tree activity
switch shim
switching characteristics
A-7
modifying
A-14
switchport host command
2-269
2-315
2-317
switchport mode command
2-276
2-319
switchport nonegotiate command
2-278
2-321
switchport port-security aging command
2-274
protocol mode
2-321
switchport access command
EtherChannel misconfiguration
extended system ID
2-321
returning to interfaces
A-10
A-16
detection of indirect link failures
switchport port-security command
2-285
root port
loop guard
switchport protected command
2-306
switchports, displaying
2-280
preventing from becoming designated
restricting which can be root
root guard
2-280
UplinkFast
2-331
2-334
2-336
2-306
root switch
affects of extended system ID
hello-time
2-187
switchport trunk command
system mtu command
2-280
2-329
2-330
switchport voice vlan command
2-280
2-327
2-323
switchport priority extend command
accelerating choice of new
T
2-278, 2-309
2-308
tar files, creating, listing, and extracting
interval between BDPU messages
2-308
interval between hello BPDU messages
max-age
2-297, 2-308
See SPAN
A-11
transmitted and received BPDUs
path cost
2-233
Switched Port Analyzer
A-12
UplinkFast
2-302
Telnet, using with cluster switches
2-308
2-308
2-150
traceroute, Layer 2
See Layer 2 traceroute
port priority for selection of
primary or secondary
switch priority
2-7
2-300
traceroute mac command
2-308
traceroute mac ip command
2-308
trunk ports, configuring
state changes
enabling BPDU filtering
enabling BPDU guard
2-304
allowed VLANs
2-270, 2-302
native VLANs
2-272, 2-302
2-319
2-302, 2-304
pruning VLANs
2-71
2-308
length of listening and learning states
2-331
2-331
pruning-eligible VLAN list
enabling timer to recover from error state
forward-delay time
2-340
trunks
blocking to forwarding state
enabling Port Fast
2-337
2-332
2-331
trunks, to non-DTP device
trusted boundary for QoS
2-320
2-133
2-308
Catalyst 2940 Switch Command Reference
IN-10
OL-8606-01
Index
VLAN configuration mode (continued)
U
summary
UDLD
1-3
vlan database command
aggressive mode
2-342, 2-344
debug messages, displaying
enabling globally
error recovery timer
See VQP
2-344
VLANs
2-71
adding
2-347, 2-352
debug message display
2-346
ISL
2-242
A-21
VLAN IOS file system error tests
udld command
2-342
udld port command
VLAN manager activity
2-344
udld reset command
VTP
2-346
configuring
A-23
extended-range
2-313
2-313
UniDirectional Link Detection
2-347
displaying
2-208
number of
2-208
media types
See UDLD
normal-range
upgrading software images
user EXEC mode
2-247
MAC addresses
2-238
UplinkFast, for STP
A-20
A-18
displaying configurations
unicast suppression level
enabling
2-347
configuring
2-342, 2-344
resetting shutdown interfaces
displaying
2-347, 2-352
VLAN Query Protocol
2-342
normal mode
status
A-25
2-342
enabling per interface
message timer
VLAN ID range
2-358
2-5
2-350, 2-354
2-347, 2-352
saving the configuration
2-306
shutting down
1-2, 1-3
2-261
SNMP traps for VTP
variables
2-347
2-263, 2-266
2-352
VMPS
V
configuring servers
2-364
reconfirming dynamic VLAN assignments
VLAN
enabling guest VLAN supplicant
2-48
vmps reconfirm (global configuration) command
vlan (global configuration) command
2-347
vmps reconfirm (privileged EXEC) command
vlan (VLAN configuration) command
2-352
vmps retry command
VLAN configuration
rules
2-350, 2-354
saving
2-347, 2-356
VLAN configuration mode
VTP
entering
2-361
2-362
2-363
vmps server command
2-364
voice VLAN
configuring
2-334
setting port priority
2-329
VQP
commands
VLAN
2-362
2-352
2-370
2-358
and dynamic-access ports
2-316
clearing client statistics
2-28
displaying information
2-250
Catalyst 2940 Switch Command Reference
OL-8606-01
IN-11
Index
VQP (continued)
per-server retry count
2-363
reconfirmation interval
2-361
reconfirming dynamic VLAN assignments
2-362
VTP
changing characteristics
2-366
clearing pruning counters
clearing VTP counters
2-29
2-29
configuring
domain name
file name
mode
2-366, 2-370
2-366
2-366, 2-370
password
2-366, 2-370
counters display fields
2-254
displaying information
2-253
enabling
pruning
2-366, 2-370
version 2
mode
pruning
2-366, 2-370
2-366, 2-370
2-366, 2-370
saving the configuration
status display fields
2-347, 2-356
2-255
vtp (global configuration) command
2-366
vtp (VLAN configuration) command
2-370
W
WRR, assigning weights to egress queues
wrr-queue bandwidth command
wrr-queue cos-map command
2-374
2-374
2-375
Catalyst 2940 Switch Command Reference
IN-12
OL-8606-01