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Catalyst 2950 and Catalyst 2955 Switch Command Reference, 12.1(22)EA11 and Later
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Index
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Preface
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Using the Command-Line Interface
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Catalyst 2950 and 2955 Switch Cisco IOS Commands - a through r
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Catalyst 2950 and 2955 Switch Cisco IOS Commands - s
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Catalyst 2950 and 2955 Switch Cisco IOS Catalyst 2950 and 2955 Switch Cisco IOS Commands - t through z \r\n
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Catalyst 2955 Alarm Commands
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Catalyst 2950 and 2955 Switch Boot Loader Commands
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Catalyst 2950 and 2955 Switch Debug Commands
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Feedback
Table Of Contents
Catalyst 2950 and 2955 Cisco IOS Commands
clear controllers ethernet-controller
clear controllers lre link monitor
clear spanning-tree detected-protocols
deny (access-list configuration)
deny (MAC access-list configuration)
ip dhcp snooping information option
ip dhcp snooping information option allow-untrusted
ip igmp snooping mrouter learn pim v2
ip igmp snooping report-suppression
ip igmp snooping source-only-learning
ip igmp snooping vlan immediate-leave
ip igmp snooping vlan last-member-query interval
mac address-table notification
permit (access-list configuration)
permit (MAC access-list configuration)
profile (interface configuration)
profile (sequence configuration)
Catalyst 2950 and 2955 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
Defaults
AAA accounting is disabled.
Command Modes
Global configuration
Command History
Usage Guidelines
This command requires access to a RADIUS server.
Note
We recommend that you enter the dot1x re-authentication interface configuration command before configuring IEEE 802.1x RADIUS accounting on an interface.
Examples
This example shows how to configure IEEE 802.1x accounting:
Switch(config)# aaa new modelSwitch(config)# aaa accounting dot1x default start-stop group radius
Note
Related Commands
Specifies one or more AAA methods for use on interfaces running IEEE 802.1x.
Enables or disables periodic re-authentication.
dot1x timeout reauth-period
Sets the number of seconds between re-authentication attempts.
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
Defaults
No authentication is performed.
Command Modes
Global configuration
Command History
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 modelSwitch(config)# aaa authentication dot1x default group radiusYou can verify your settings by entering the show running-config privileged EXEC command.
Related Commands
access-list (IP extended)
Use the extended version of the access-list global configuration command to configure an extended IP access control list (ACL). Use the no form of this command to remove an extended IP ACL.
access-list access-list-number {deny | permit | remark} protocol {source source-wildcard | host source | any} [operator port] {destination destination-wildcard | host destination | any} [operator port] [dscp dscp-value] [time-range time-range-name]
no access-list access-list-number
This command is available on physical interfaces only if your switch is running the enhanced software image (EI).
Syntax Description
Defaults
The default extended ACL is always terminated by an implicit deny statement for all packets.
Command Modes
Global configuration
Command History
Usage Guidelines
Plan your access conditions carefully. The ACL is always terminated by an implicit deny statement for all packets.
You can use ACLs to control virtual terminal line access by controlling the transmission of packets on an interface.
Extended ACLs support only the TCP and UDP protocols.
Use the show ip access-lists command to display the contents of IP ACLs.
Use the show access-lists command to display the contents of all ACLs.
Note
Examples
This example shows how to configure an extended IP ACL that allows only TCP traffic to the destination IP address 128.88.1.2 with a TCP port number of 25 and how to apply it to an interface:
Switch(config)# access-list 102 permit tcp any host 128.88.1.2 eq 25Switch(config)# interface fastethernet0/8Switch(config-if)# ip access-group 102 inThis is an example of an extended ACL that allows TCP traffic only from two specified networks. The wildcard bits apply to the host portions of the network addresses. Any host with a source address that does not match the ACL statements is denied.
access-list 104 permit tcp 192.5.0.0 0.0.255.255 anyaccess-list 104 permit tcp 128.88.0.0 0.0.255.255 any
Note
You can verify your settings by entering the show ip access-lists or show access-lists privileged EXEC command.
Related Commands
Configures a standard IP ACL.
Controls access to an interface.
Displays ACLs configured on the switch.
Displays IP ACLs configured on the switch.
access-list (IP standard)
Use the standard version of the access-list global configuration command to configure a standard IP access control list (ACL). Use the no form of this command to remove a standard IP ACL.
access-list access-list-number {deny | permit | remark} {source source-wildcard | host source | any}
no access-list access-list-number
This command is available on physical interfaces only if your switch is running the enhanced software image (EI).
Syntax Description
Defaults
The default standard ACL is always terminated by an implicit deny statement for all packets.
Command Modes
Global configuration
Command History
Usage Guidelines
Plan your access conditions carefully. The ACL is always terminated by an implicit deny statement for all packets.
You can use ACLs to control virtual terminal line access by controlling the transmission of packets on an interface.
Use the show ip access-lists command to display the contents of IP ACLs.
Use the show access-lists command to display the contents of all ACLs.
Note
Examples
This example shows how to configure a standard IP ACL that allows only traffic from the host network 128.88.1.10 and how to apply it to an interface:
Switch(config)# access-list 12 permit host 128.88.1.10Switch(config)# interface gigabitethernet0/1Switch(config-if)# ip access-group 12 inThis is an example of an standard ACL that allows traffic only from three specified networks. The wildcard bits apply to the host portions of the network addresses. Any host with a source address that does not match the ACL statements is denied.
access-list 14 permit 192.5.34.0 0.0.0.255access-list 14 permit 128.88.0.0 0.0.0.255access-list 14 permit 36.1.1.0 0.0.0.255
Note
You can verify your settings by entering the show ip access-lists or show access-lists privileged EXEC command.
Related Commands
Configures an extended IP ACL.
Controls access to an interface.
Displays ACLs configured on the switch.
Displays IP ACLs configured on the switch.
archive download-sw
Use the archive download-sw privileged EXEC command to download a new image from a TFTP server to a Catalyst 2950 Long-Reach Ethernet (LRE) 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
This command is available only on the Catalyst 2950 LRE switches.
Syntax Description
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
Command History
Usage Guidelines
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.tarThis 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.tarThis 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.tarRelated Commands
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
Defaults
No default is defined.
Command Modes
Privileged EXEC
Command History
Usage Guidelines
Filenames and directory names are case sensitive.
Image names are case sensitive.
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-configsThis example shows how to display the contents of the saved.tar file that is in flash memory. The contents of the tar file appear on the screen.
Switch # archive tar /table tftp://172.20.136.9/saved.tarLoading saved.tar from 172.20.136.9 (via Vlan1):!info (247 bytes)c2950lre-i6l2q4-mz.121/ (directory)c2950lre-i6l2q4-mz.121/html/ (directory)c2950lre-i6l2q4-mz.121/html/homepage.htm (3990 bytes)!<output truncated>c2950lre-i6l2q4-mz.121/lre-bin/CISCO585-LRE_MC8051boot_01.03.00.bin (688bytes)c2950lre-i6l2q4-mz.121/lre-bin/CISCO585-LRE_vdslsngl_51.00.00.bin (8896bytes)!!c2950lre-i6l2q4-mz.121/pef22824.bin (32768 bytes)!!!!!!!c2950lre-i6l2q4-mz.121/info (247 bytes)info.ver (247 bytes)[OK - 4279808/8559616 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-configsRelated Commands
Downloads a new image to the switch.
Uploads an existing image on the switch to a server.
archive upload-sw
Use the archive upload-sw privileged EXEC command to upload an existing Long-Reach Ethernet (LRE) switch image to a server.
archive upload-sw [/version version_string] destination-url
This command is supported only on Catalyst 2950 LRE switches.
Syntax Description
Defaults
The switch uploads the currently running image from the flash: file system.
Command Modes
Privileged EXEC
Command History
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, LRE binary files, and info.ver. After these files are uploaded, the software creates the tar file.
Image names are case sensitive.
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.tarRelated Commands
Downloads a new image to a Catalyst 2950 LRE switch.
Creates a tar file, lists the files in a tar file, or extracts the files from a tar file.
auto qos voip
Use the auto qos voip interface configuration command to configure automatic quality of service (auto-QoS) for voice over IP (VoIP) within a QoS domain. Use the no form of this command to change the auto-QoS configuration settings to the standard-QoS defaults.
auto qos voip {cisco-phone | cisco-softphone | trust}
no auto qos voip
This command is available only if your switch is running the enhanced software image (EI).
Syntax Description
Defaults
Auto-QoS is disabled on all interfaces.
When auto-QoS is enabled, it uses the ingress packet label to categorize traffic and to configure the egress queues as summarized in Table 2-1.
Table 2-1 Traffic Types, Packet Labels, and Egress Queues
DSCP3
46
24, 26
48
56
34
—
CoS
5
3
6
7
4
—
CoS-to-Queue Map
5
3, 6, 7
4
2
0, 1
Egress Queue
1% WRR4 (queue 4)
70% WRR (queue 3)
20% WRR (queue 2)
20% WRR (queue 2)
10% WRR (queue 1)
1 STP = Spanning Tree Protocol
2 BPDU = bridge protocol data unit
3 DSCP = Differentiated Services Code Point
4 WRR = weighted round robin
Table 2-2 lists the auto-QoS configuration for the egress queues.
Command Modes
Interface configuration
Command History
12.1(12c)EA1
This command was introduced.
12.1(20)EA2
The cisco-softphone keyword was added, and the generated auto-QoS configuration changed.
Usage Guidelines
Use this command to configure the QoS that is appropriate for VoIP traffic within the QoS domain. The QoS domain includes the switch, the interior of the network, and the edge devices that can classify incoming traffic for QoS.
In releases earlier than Cisco IOS Release 12.2(20)EA2, auto-QoS configures the switch only for VoIP with Cisco IP Phones on switch ports.
In Cisco IOS Release 12.2(20)EA2 or later, auto-QoS configures the switch for VoIP with Cisco IP Phones and for VoIP with devices running the Cisco SoftPhone application. These releases support only Cisco IP SoftPhone Version 1.3(3) or later. Connected devices must use Cisco Call Manager Version 4 or later.
To take advantage of the auto-QoS defaults, you should enable auto-QoS before you configure other QoS commands. You can fine-tune the auto-QoS configuration after you enable auto-QoS.
Note
If this is the first port on which you have enabled auto-QoS, the auto-QoS-generated global configuration commands are executed followed by the interface configuration commands. If you enable auto-QoS on another port, only the auto-QoS-generated interface configuration commands for that port are executed.
When you enable the auto-QoS feature on the first interface, these automatic actions occur:
•
•
•
You can enable auto-QoS on static, dynamic-access, voice VLAN access, and trunk ports.
Note
After auto-QoS is enabled, do not modify a policy map or aggregate policer that includes AutoQoS in its name. If you need to modify the policy map or aggregate policer, make a copy of it, and change the copied policy map or policer. To use the new policy map instead of the generated one, remove the generated policy, and apply the new policy map.
To display the QoS configuration that is automatically generated when auto-QoS is enabled, enable debugging before you enable auto-QoS. Use the debug auto qos privileged EXEC command to enable auto-QoS debugging.
To disable auto-QoS on an interface, use the no auto qos voip interface configuration command. When you enter this command, the switch changes the auto-QoS settings to the standard-QoS default settings for that interface.
To disable auto-QoS on the switch and return to the default port trust state (untrusted), follow these steps:
1.
2.
•
•
•
Examples
This example shows how to enable auto-QoS and to trust the QoS labels received in incoming packets when the switch or router connected to a port is a trusted device:
Switch(config)# interface gigabitethernet0/1Switch(config-if)# auto qos voip trustThis example shows how to enable auto-QoS and to trust the QoS labels received in incoming packets when the device connected to a port is detected as a Cisco IP phone:
Switch(config)# interface fastethernet0/1Switch(config-if)# auto qos voip cisco-phoneThis example shows how to display the QoS configuration that is automatically generated when auto-QoS is enabled:
Switch# debug auto qosAutoQoS debugging is onSwitch# configure terminalEnter configuration commands, one per line. End with CNTL/Z.Switch(config)# interface fastethernet0/1Switch(config-if)# auto qos voip cisco-phone00:02:54:wrr-queue bandwidth 10 20 70 100:02:55:no wrr-queue cos-map00:02:55:wrr-queue cos-map 1 0 100:02:56:wrr-queue cos-map 2 2 400:02:57:wrr-queue cos-map 3 3 6 700:02:58:wrr-queue cos-map 4 500:02:59:mls qos map cos-dscp 0 8 16 26 32 46 48 5600:03:00:interface FastEthernet0/100:03:00: mls qos trust device cisco-phone00:03:00: mls qos trust cosSwitch(config-if)# interface fastethernet0/2Switch(config-if)# auto qos voip trust00:03:15:interface FastEthernet0/200:03:15: mls qos trust cosSwitch(config-if)#You can verify your settings by entering the show auto qos interface interface-id privileged EXEC command.
Related Commands
boot buffersize
Use the boot buffersize global configuration command to specify the size of the file system-simulated NVRAM in flash memory. The buffer holds a copy of the configuration file in memory. Use the no form of this command to return to the default setting.
boot buffersize size
no boot buffersize
This command is available only on Catalyst 2950 Long-Reach Ethernet (LRE) switches.
Syntax Description
Defaults
The default is 32 KB.
Command Modes
Global configuration
Command History
Usage Guidelines
The configuration file cannot be larger than the buffer size allocation.
You must reload the switch by using the reload privileged EXEC command for this command to take effect.
This command changes the setting of the CONFIG_BUFSIZE environment variable. For more information, see Appendix B, "Catalyst 2950 and 2955 Switch Boot Loader Commands."
Related Commands
boot config-file
Use the boot config-file global configuration command to specify the filename that the software uses to read and write a nonvolatile copy of the system configuration. Use the no form of this command to return to the default setting.
boot config-file flash:/file-url
no boot config-file
This command is available only on Catalyst 2950 Long-Reach Ethernet (LRE) switches.
Syntax Description
Defaults
The default configuration file is flash:config.text.
Command Modes
Global configuration
Command History
Usage Guidelines
Filenames and directory names are case sensitive.
This command changes the setting of the CONFIG_FILE environment variable. For more information, see Appendix B, "Catalyst 2950 and 2955 Switch Boot Loader Commands."
Related Commands
boot enable-break
Use the boot enable-break global configuration command to enable interrupting the automatic boot process on a Catalyst 2950 Long-Reach Ethernet (LRE) switch. Use the no form of this command to return to the default setting.
boot enable-break
no boot enable-break
This command is available only on Catalyst 2950 LRE switches.
Syntax Description
This command has no arguments or keywords.
Defaults
The automatic start up process cannot be interrupted by pressing the Break key on the console.
Command Modes
Global configuration
Command History
Usage Guidelines
When you enter this command, you can interrupt the automatic boot process by pressing the Break key on the console after the flash file system is initialized.
Note
This command changes the setting of the ENABLE_BREAK environment variable. For more information, see Appendix B, "Catalyst 2950 and 2955 Switch Boot Loader Commands."
Related Commands
boot helper
Use the boot helper global configuration command to dynamically load files during boot loader initialization to extend or to patch the functionality of the boot loader. Use the no form of this command to return to the default setting.
boot helper filesystem:/file-url ...
no boot helper
This command is available only on Catalyst 2950 Long-Reach Ethernet (LRE) switches.
Syntax Description
Defaults
No helper files are loaded.
Command Modes
Global configuration
Command History
Usage Guidelines
Filenames and directory names are case sensitive.
This command changes the setting of the HELPER environment variable. For more information, see Appendix B, "Catalyst 2950 and 2955 Switch Boot Loader Commands."
Related Commands
boot helper-config-file
Use the boot helper-config-file global configuration command to specify the name of the configuration file to be used by the Cisco IOS helper image. If this is not set, the file specified by the CONFIG_FILE environment variable is used by all versions of the software that are loaded. This variable is used only for internal development and testing. Use the no form of this command to return to the default setting.
boot helper-config-file filesystem:/file-url
no boot helper-config file
This command is available only on Catalyst 2950 Long-Reach Ethernet (LRE) switches.
Syntax Description
filesystem:
Alias for a flash file system. Use flash: for the system board flash device.
/file-url
The path (directory) and helper configuration file to load.
Defaults
No helper configuration file is specified.
Command Modes
Global configuration
Command History
Usage Guidelines
Filenames and directory names are case sensitive.
This command changes the setting of the HELPER_CONFIG_FILE environment variable. For more information, see Appendix B, "Catalyst 2950 and 2955 Switch Boot Loader Commands."
Related Commands
boot manual
Use the boot manual global configuration command to enable starting the Catalyst 2950 Long-Reach Ethernet (LRE) switch manually during the next power on cycle. Use the no form of this command to return to the default setting.
boot manual
no boot manual
This command is available only on Catalyst 2950 LRE switches.
Syntax Description
This command has no arguments or keywords.
Defaults
During the next power on cycle, you cannot manually start an LRE switch.
Command Modes
Global configuration
Command History
Usage Guidelines
The next time you restart the system, the switch is in boot loader mode, which is shown by the switch: prompt. To power on the system, use the boot boot loader command, and specify the name of the bootable image.
This command changes the setting of the MANUAL_BOOT environment variable. For more information, see Appendix B, "Catalyst 2950 and 2955 Switch Boot Loader Commands."
Related Commands
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
Defaults
The default configuration file is private-config.text.
Command Modes
Global configuration
Command History
Usage Guidelines
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 pconfigRelated Commands
boot system
Use the boot system global configuration command to specify the software image to load during the next power on cycle. Use the no form of this command to return to the default setting.
boot system filesystem:/file-url ...
no boot system
This command is available only on Catalyst 2950 Long-Reach Ethernet (LRE) switches.
Syntax Description
filesystem:
Alias for a flash file system. Use flash: for the system board flash device.
/file-url
The path (directory) and name of a bootable image. Separate image names with a semicolon.
Defaults
The switch attempts to automatically power on the system by using information in the BOOT environment variable. If this variable is not set, the switch attempts to load and execute the first executable image it can by performing a recursive, depth-first search throughout the flash file system. In a depth-first search of a directory, each encountered subdirectory is completely searched before the switch continues to search in the original directory.
Command Modes
Global configuration
Command History
Usage Guidelines
Filenames and directory names are case sensitive.
If you are using the archive download-sw privileged EXEC command to maintain system images, you do not ever need to use the boot system command. The boot system command is automatically manipulated to load the downloaded image.
This command changes the setting of the BOOT environment variable. For more information, see Appendix B, "Catalyst 2950 and 2955 Switch Boot Loader Commands."
Related Commands
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 onSyntax Description
Defaults
No channel groups are assigned.
There is no default mode.
Command Modes
Interface configuration
Command History
12.1(6)EA2
This command was introduced. It replaced the port group command.
12.1(12c)EA1
The active and passive keywords were added.
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.
Note
Caution
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 gigabitethernet0/1Switch(config-if)# channel-group 1 mode onThis example shows how to set an Etherchannel into PAgP mode:
Switch(config-if)# channel-group 1 mode autoCreating a port-channel interface Port-channel 1This example shows how to set an Etherchannel into LACP mode:
Switch(config-if)# channel-group 1 mode passiveCreating a port-channel interface Port-channel 1You can verify your settings by entering the show etherchannel or show running-config privileged EXEC command.
Related Commands
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
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
This example shows how to set an EtherChannel into PAgP mode:
Switch(config-if)# channel-protocol pagpThis example shows how to set an EtherChannel into LACP mode:
Switch(config-if)# channel-protocol lacpYou can verify your settings by entering the show running-config privileged EXEC command.
Related Commands
class
Use the class policy-map configuration command to define a traffic classification for the policy to act on using the class-map name or access group. Use the no form of this command to delete an existing class map.
class class-map-name [access-group name acl-index-or-name]
no class class-map-name
This command is available only if your switch is running the enhanced software image (EI).
Syntax Description
Defaults
No policy-map class maps are defined.
Command Modes
Policy-map configuration
Command History
Usage Guidelines
Before you use the class command, use the policy-map global configuration command to identify the policy map and to enter policy-map configuration mode. After you specify a policy map, you can configure a policy for new classes or modify a policy for any existing classes in that policy map. You attach the policy map to an interface by using the service-policy interface configuration command; however, you cannot attach one that uses an ACL classification to the egress direction.
The class name that you specify in the policy map ties the characteristics for that class to the class map and its match criteria as configured by using the class-map global configuration command.
The class command performs the same function as the class-map global configuration command. Use the class command when a new classification, which is not shared with any other ports, is needed. Use the class-map command when the map is shared among many ports.
Note
After entering the class command, you enter policy-map class configuration mode. These configuration commands are available:
•
•
•
•
•
To return to policy-map configuration mode, use the exit command. To return to privileged EXEC mode, use the end command.
Note
Examples
This example shows how to create a policy map named policy1. When attached to the ingress port, it matches all the incoming traffic defined in class1 and polices the traffic at an average rate of 1 Mbps and bursts at 131072 bytes. Traffic exceeding the profile is dropped.
Switch(config)# policy-map policy1Switch(config-pmap)# class class1Switch(config-pmap-c)# police 1000000 131072 exceed-action dropSwitch(config-pmap-c)# exitSwitch(config-pmap)#You can verify your settings by entering the show policy-map privileged EXEC command.
Related Commands
class-map
Use the class-map global configuration command to create a class map to be used for matching packets to the class whose name you specify and to enter class-map configuration mode. Use the no form of this command to delete an existing class map and to return to global configuration mode.
class-map class-map-name [match-all]
no class-map class-map-name [match-all]
This command is available only if your switch is running the enhanced software image (EI).
Syntax Description
class-map-name
Name of the class map.
match-all
(Optional) Perform a logical-AND of all matching statements under this class map. All criteria in the class map must be matched.
Defaults
No class maps are defined.
Command Modes
Global configuration
Command History
Usage Guidelines
Use this command to specify the name of the class for which you want to create or modify class-map match criteria and to enter class-map configuration mode. In this mode, you can enter one match command to configure the match criteria for this class.
The class-map command and its subcommands are used to define packet classification and marking as part of a globally named service policy applied on a per-interface basis.
In quality of service (QoS) class-map configuration mode, these configuration commands are available:
•
•
•
Only one match criterion per class map is supported. For example, when defining a class map, only one match command can be entered.
Only one access control list (ACL) can be configured in a class map. The ACL can have multiple access control entries (ACEs).
Note
Note
Examples
This example shows how to configure the class map named class1. class1 has one match criteria, which is a numbered ACL.
Switch(config)# access-list 103 permit tcp any any eq 80Switch(config)# class-map class1Switch(config-cmap)# match access-group 103Switch(config-cmap)# exitYou can verify your settings by entering the show class-map privileged EXEC command.
Related Commands
clear controllers ethernet-controller
Use the clear controllers ethernet-controller privileged EXEC command to clear the Ethernet link transmit and receive statistics for a switch port and for a Long-Reach Ethernet (LRE) customer premises equipment (CPE) device.
clear controllers ethernet-controller interface-id [cpe [port port-id]]
Syntax Description
Defaults
No default is defined.
Command Modes
Privileged EXEC
Command History
Usage Guidelines
The CPE Ethernet link is the connection between the CPE Ethernet port and the remote Ethernet device (such as a PC) connected to it. It is not the link between the switch LRE port and the LRE CPE device.
It takes the switch several seconds to clear the CPE Ethernet ports. The CPE Ethernet ports on CPE devices take longer to clear than all the other port types.
If you enter the clear controllers ethernet-controller privileged EXEC command without specifying an interface-id, the switch clears the Ethernet link statistics for all ports on the switch. If you specify an an interface, the switch clears the Ethernet link statistics for the specified port.
On a Catalyst 2950 LRE switch, if you use the cpe keyword, the switch clears the Ethernet statistics of the LRE chipset and of all these CPE Ethernet ports:
•
•
If you enter the cpe port port-id keywords, the switch clears the Ethernet counters of the specified CPE Ethernet port.
Note
Examples
This example shows how to clear the Ethernet link statistics for an LRE port:
Switch# clear controllers ethernet-controller longreachethernet0/1This example clears the Ethernet statistics for all the CPE Ethernet ports on a Cisco 585 LRE CPE:
Switch# clear controllers ethernet-controller longreachethernet0/1 cpeYou can verify that information was deleted by entering the show controllers ethernet-controller user EXEC command.
Related Commands
Displays per-interface transmit and receive statistics read from the hardware, the interface internal registers, the statistics read from LRE and CPE ports.
clear controllers lre
Use the clear controllers lre user EXEC command to reset an Long-Reach Ethernet (LRE) switch interface or a Cisco LRE customer premises equipment (CPE) device interface.
clear controllers lre {local link | remote [link | micro]} interface-id
This command is available only on Catalyst 2950 LRE switches.
Syntax Description
Defaults
No default is defined.
Command Modes
User EXEC
Command History
Usage Guidelines
Use this command to reset a questionable local or remote interface.
The clear controllers lre remote micro command is not supported on the Cisco 575 LRE CPE and the Cisco 576 LRE 997 CPE devices.
Examples
This example shows how to reset the local LRE interfaces on the switch:
Switch> clear controllers lre local linkThis example shows how to reset the Cisco 575 LRE, Cisco 576 LRE 997 CPE, and the Cisco 585 LRE CPE devices connected to the switch:
Switch> clear controllers lre remote linkThis example shows how to reset the Cisco 585 LRE CPE micro-controller connected to the switch:
Switch> clear controllers lre remote microRelated Commands
clear controllers lre link monitor
Use the clear controllers lre link monitor privileged EXEC command to clear Long-Reach Ethernet (LRE) link monitor data.
clear controllers lre link monitor interface-id
This command is available only on Catalyst 2950 LRE switches.
Syntax Description
Defaults
No default is defined.
Command Modes
Privileged EXEC
Command History
Usage Guidelines
This command clears all collected link monitor data. New entries are added when a new polling cycle starts.
Examples
This example shows how to clear link monitor data on an LRE port:
Switch# clear controllers lre link monitor longreachethernet0/2Related Commands
clear controllers lre log
Use the clear controllers lre log privileged EXEC command to clear the history of link, configuration, and timer events for a specific Long-Reach Ethernet (LRE) port or for all switch LRE ports.
clear controllers lre log [interface-id]
This command is available only on Catalyst 2950 LRE switches.
Syntax Description
Defaults
No default is defined.
Command Modes
Privileged EXEC
Command History
Usage Guidelines
Use the clear controllers lre log command without specifying a switch LRE port to delete the history of events on all LRE ports.
Examples
This example shows how to delete the history of events on an LRE switch port:
Switch# clear controllers lre log longreachethernet0/3You can verify that the information was deleted by entering the show controllers lre log privileged EXEC command.
Related Commands
Sets the LRE logging level.
Displays the history of link, configuration, and timer events for a LRE specific switch port or for all LRE switch ports.
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
Defaults
No default is defined.
Command Modes
Privileged EXEC
Command History
Examples
This example shows how to clear the hardware logic on an interface:
Switch# clear interface gigabitethernet0/1This example shows how to clear the hardware logic on a specific VLAN:
Switch# clear interface vlan 5You can verify that the interface-reset counter for an interface is incremented by entering the show interfaces privileged EXEC command.
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
Defaults
This command has no default setting.
Command Modes
Privileged EXEC
Command History
Examples
This example shows how to clear channel-group information for a specific group:
Switch# clear lacp 4This example shows how to clear channel-group traffic counters:
Switch# clear lacp countersYou can verify that the information was deleted by entering the show lacp privileged EXEC command.
Related Commands
clear lre rate selection
Use the clear lre rate selection privileged EXEC command to reset the current rate selection setting and to restart rate selection for a specific Long-Reach Ethernet (LRE) port or for all switch LRE ports.
clear lre rate selection [lock] [interface-id]
This command is available only on Catalyst 2950 LRE switches.
Syntax Description
lock
(Optional) Rate selection runs on all ports that have rate selection enabled, including ports that are locked.
interface-id
(Optional) ID of an LREs witch port.
Defaults
No default is defined.
Command Modes
Privileged EXEC
Command History
Usage Guidelines
If you enter the lock keyword or specify an interface, the switch runs rate selection on all LRE switch ports that have rate selection enabled, except those ports with locked profiles. If you enter the lock keyword, the switch runs rate selection on all profiles, including those that are locked.
Examples
This example shows how to reset the rate selection setting and to restart rate selection on an LRE port:
Switch# clear lre rate selection longreachethernet0/1This example shows how to rerun rate selection on all ports, including any locked ports:
Switch# clear lre rate selection lockThis example shows how to reset and to restart rate selection on an LRE port, overriding the locked status:
Switch# clear lre rate selection lock longreachethernet0/2Related Commands
Enables rate selection on an LRE specific port
Assigns a rate selection sequence for a specific LRE port.
Assigns a rate selection sequence for the entire LRE switch.
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}
Note
Syntax Description
Defaults
No default is defined.
Command Modes
Privileged EXEC
Command History
Examples
This example shows how to remove a specific dynamic address from the MAC address table:
Switch# clear mac address-table dynamic address 0008.0070.0007You can verify that the information was deleted by entering the show mac address-table privileged EXEC command.
Related Commands
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
Defaults
This command has no default setting.
Command Modes
Privileged EXEC
Command History
Examples
This example shows how to clear channel-group information for a specific group:
Switch# clear pagp 4This example shows how to clear channel-group traffic counters:
Switch# clear pagp countersYou can verify that the information was deleted by entering the show pagp privileged EXEC command.
Related Commands
clear port-security
Use the clear port-security privileged EXEC command to delete from the MAC address table all secure addresses, all configured secure addresses, or a specific or all dynamic or sticky secure address on an interface or on the switch.
clear port-security {all | configured | dynamic | sticky} [address mac-address] | [interface interface-id]
Syntax Description
Defaults
No default is defined.
Command Modes
Privileged EXEC
Command History
12.1(11)EA1
This command was introduced.
12.1(14)EA1
The all and configured keywords were added.
Usage Guidelines
If you enter the clear port-security all privileged EXEC command, the switch removes all secure MAC addresses from the MAC address table.
If you enter the clear port-security configured address mac-address command, the switch removes the specified secure MAC address from the MAC address table.
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 secure addresses from the MAC address table:
Switch# clear port-security allThis example shows how to remove a configured secure address from the MAC address table:
Switch# clear port-security configured address 0008.0070.0007This example shows how to remove all the dynamic secure addresses learned on a specific interface:
Switch# clear port-security dynamic interface fastethernet0/1This example shows how to remove all the sticky secure addresses from the address table:
Switch# clear port-security stickyYou can verify that the information was deleted by entering the show port-security privileged EXEC command.
Related Commands
Displays the port security settings for an interface or for the switch.
Enables port security on an interface.
switchport port-security mac-address mac-address
Configures secure MAC addresses.
switchport port-security maximum value
Configures a maximum number of secure MAC addresses on a secure interface.
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
(Optional) Clear all spanning-tree counters on the specified interface. If interface-id is not specified, spanning-tree counters are cleared for all interfaces.
Defaults
No default is defined.
Command Modes
Privileged EXEC
Command History
Examples
This example shows how to clear spanning-tree counters for all interfaces:
Switch# clear spanning-tree countersRelated Commands
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
Command Modes
Privileged EXEC
Command History
12.1(9)EA1
This command was introduced.
12.1(20)EA2
This command was added to the SI.
Usage Guidelines
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 fastethernet0/1clear 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
Examples
This example shows how to clear VLAN Membership Policy Server (VMPS) statistics:
Switch# clear vmps statisticsYou can verify that the information was deleted by entering the show vmps statistics privileged EXEC command.
Related Commands
show vmps statistics
Displays the VQP version, reconfirmation interval, retry count, VMPS IP addresses, and the current and primary servers.
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
Examples
This example shows how to clear the VTP counters:
Switch# clear vtp countersYou can verify that the information was deleted by entering the show vtp counters privileged EXEC command.
Related Commands
show vtp counters
Displays general information about the VTP management domain, status, and counters.
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
Defaults
The switch is not a member of any cluster.
Command Modes
Global configuration
Command History
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>This example shows how to remove a member from the cluster by using the cluster member console:
Switch# configure terminalEnter configuration commands, one per line. End with CNTL/Z.Switch(config)# no cluster commander-addressYou can verify your settings by entering the show cluster privileged EXEC command.
Related Commands
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
Number of hops from the cluster edge that the command switch limits the discovery of candidates. The range is 1 to 7.
Defaults
The hop count is set to 3.
Command Modes
Global configuration
Command History
Usage Guidelines
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 4You can verify your settings by entering the show cluster privileged EXEC command on the command switch.
Related Commands
Displays the cluster status and a summary of the cluster to which the switch belongs.
Displays a list of candidate switches.
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
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
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 4You can verify your settings by entering the show cluster privileged EXEC command on the command switch.
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
Duration in seconds before a switch (either a command or member switch) declares the other switch down. The range is 1 to 300 seconds.
Defaults
The holdtime is 80 seconds.
Command Modes
Global configuration
Command History
Usage Guidelines
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 3Switch(config)# cluster holdtime 30You can verify your settings by entering the show cluster privileged EXEC command.
Related Commands
Displays the cluster status and a summary of the cluster to which the switch belongs.
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
Defaults
The default management VLAN is VLAN 1.
Command Modes
Global configuration
Command History
Usage Guidelines
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 5You can verify your settings by entering the show interfaces vlan vlan-id privileged EXEC command.
Related Commands
Displays the administrative and operational status of a switching (nonrouting) port.
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
Defaults
A newly enabled command switch has no associated cluster members.
Command Modes
Global configuration
Command History
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.
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 3This 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 00E0.1E00.3333You can verify your settings by entering the show cluster members privileged EXEC command on the command switch.
Related Commands
Displays the cluster status and a summary of the cluster to which the switch belongs.
Displays a list of candidate switches.
Displays information about the cluster members.
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
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 runYou can verify that clustering is disabled by entering the show cluster privileged EXEC command.
Related Commands
Displays the cluster status and a summary of the cluster to which the switch belongs.
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
Name of the HSRP group that is bound to the cluster. The group name is limited to 32 characters.
Defaults
The cluster is not bound to any HSRP group.
Command Modes
Global configuration
Command History
Usage Guidelines
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_hsrpThis 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 existThis 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 switchYou can verify your settings by entering the show cluster privileged EXEC command.
Related Commands
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.
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
Defaults
The interval is 8 seconds.
Command Modes
Global configuration
Command History
Usage Guidelines
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 3Switch(config)# cluster holdtime 30You can verify your settings by entering the show cluster privileged EXEC command.
Related Commands
Displays the cluster status and a summary of the cluster to which the switch belongs.
controller longreachethernet
Use the controller longreachethernet global configuration command to enter the controller configuration mode.
controller longreachethernet ctrlr-number
This command is available only on Catalyst 2950 Long-Reach Ethernet (LRE) switches.
Syntax Description
ctrlr-number
LRE controller number. Controller numbers are device specific. The range is 0 to 2 on a 24-port LRE switch and 0 on an 8-port LRE switch.
Defaults
No default is defined.
Command Modes
Global configuration
Command History
Usage Guidelines
Use this command to enter the controller configuration mode. An LRE controller is the LRE chipset in the switch.
Examples
This example shows how to enter the controller configuration mode for controller 0:
Switch(config)# controller longreachethernet 0Switch(config-controller)#Related Commands
Configures upgrades on either end of an LRE link.
Prevents an upgrade of the local customer premises equipment (CPE) controller and all remote CPE devices connected to it.
cpe duplex
Use the cpe duplex interface configuration command to specify the duplex mode of operation for all customer premises equipment (CPE) ports. Use the no form of this command to return to the default setting.
cpe duplex {{auto | full | half} [port port-id]}
no cpe duplex {{auto | full | half} [port port-id]}
This command is available only on Catalyst 2950 Long-Reach Ethernet (LRE) switches.
Syntax Description
Defaults
The default duplex mode is half.
Command Modes
Interface configuration
Command History
Usage Guidelines
Use the cpe duplex full command to set the duplex mode to full for all the CPE Ethernet ports. Use the auto keyword to set the CPE Ethernet ports to autonegotiate, and use the half keyword to force the duplex mode to half for all the CPE Ethernet ports.
If you do not enter the port keyword, the duplex setting is applied to all the CPE Ethernet ports. If you enter the port port-id keywords, the setting is applied to the specified CPE Ethernet port and overrides any global speed settings.
Use the cpe duplex full port 2 command to set the duplex mode of port 2 on a CPE device to full duplex. If you enter both a switch-wide command, such as the cpe duplex full command, and a port-specific commands, such as the cpe duplex full port 2 command, the switch adds both the configuration file, and the port-specific command takes priority over the switch-wide command.
Examples
This example show how to set the CPE device to autonegotiate:
Switch# configure terminalSwitch(config)# interface longreachethernet0/2Switch(config-if)# cpe duplex autoThis example shows how to set a port on a Cisco 585 LRE CPE to full-duplex mode:
Switch# configure terminalSwitch(config)# interface longreachethernet0/3Switch(config-if)# cpe duplex full port 3This example shows how to restore a port on a Cisco 585 LRE CPE to the default mode of half duplex:
Switch# configure terminalSwitch(config)# interface longreachethernet0/3Switch(config-if)# no cpe duplex full port 3This example shows how the cpe duplex {auto | full | half} port port-id command works with the cpe duplex {auto | full | half} command. Port 1 is set to full duplex, port 2 is set to half duplex, and the remainder of the ports are set to autonegotiate.
Switch# configure terminalSwitch(config)# interface longreachethernet0/4Switch(config-if)# cpe duplex autoSwitch(config-if)# cpe duplex full port 1Switch(config-if)# cpe duplex half port 2After the commands in the previous example are entered, this example shows how to set a port to autonegotiate:
Switch(config-if)# no cpe duplex full port 1Related Commands
Specifies the CPE port speed settings.
show interfaces cpe
Displays CPE Ethernet ports connection, speed, or duplex status.
cpe protected
Use the cpe protected interface configuration command to restrict data traffic to individual ports on Cisco 585 LRE customer premises equipment (CPE) ports. Use the no form of this command to allow different ports on the same CPE device to exchange data directly.
cpe protected [port port-id]
no cpe protected [port port-id]
This command is available only on Catalyst 2950 Long-Reach Ethernet (LRE) switches.
Syntax Description
Defaults
Traffic is not restricted to specific ports.
Command Modes
Interface configuration
Command History
Usage Guidelines
Even though you can protect an LRE interface by using the switchport protected interface configuration command, this command does not protect individual CPE Ethernet ports. Use the cpe protected command to ensure that data traffic from one CPE port is not accessed on any of the other three ports. Use the cpe protected command to restrict CPE traffic, either at the CPE device level or at the individual port level for data security. Use the cpe protected command without specifying a CPE port to protect data for all applicable CPE ports. Use the cpe protected port port-id command to protect a specific CPE Ethernet port.
When using this feature, always specify a minimum of two ports. A single port that is configured as protected has no effect. Data traffic does not flow between two ports that are protected.
Examples
This example show how to protect CPE port 1 on an LRE port:
Switch# configure terminalSwitch(config)# interface longreachethernet0/1Switch(config-if)# cpe protected port 1Related Commands
Shows CPE protected port information.
Isolates unicast, multicast, and broadcast traffic at Layer 2 from other protected ports on the same switch.
cpe shutdown
Use the cpe shutdown interface configuration command to disable one or more customer premises equipment (CPE) ports. Use the no form of this command to enable a port.
cpe shutdown [port port-id]
no cpe shutdown [port port-id]
This command is available only on Catalyst 2950 Long-Reach Ethernet (LRE) switches.
Syntax Description
port port-id
(Optional) CPE Ethernet port identifier. The range is 1 to 4, depending on the CPE device.
Defaults
The CPE ports are enabled.
Command Modes
Interface configuration
Command History
Usage Guidelines
If the port keyword is not specified, the value is applied globally to all the CPE Ethernet ports. If the port keyword is specified, the value is applied to the specific CPE Ethernet port and overrides any global speed settings.
The CPE Ethernet ports can be shut down at the CPE device level and the port level. If you add a configuration at the CPE device level and at the port level, you must enter the no form of the command for both configurations to return the port to the default state.
Examples
This example shows how to disable all ports on the CPE device:
Switch# configure terminalSwitch(config)# interface longreachethernet0/2Switch(config-if)# cpe shutdownThis example shows how to disable port 2 on the CPE device:
Switch# configure terminalSwitch(config)# interface longreachethernet0/2Switch(config-if)# cpe shutdown port 2After the cpe shutdown port 2 command was entered in the previous example, this example shows how to enable all the CPE Ethernet ports that were not shut down. After the no cpe shutdown command is entered, port 2 is still shut down because the cpe shutdown port 2 command was entered in the previous example. Use the no cpe shutdown port 2 command to enable the port 2.
Switch# configure terminalSwitch(config)# interface longreahethernet0/2Switch(config-if)# no cpe shutdownSwitch(config-if)#Related Commands
show interfaces cpe
Displays CPE Ethernet ports connection, speed, or duplex status.
Disables a port.
cpe speed
Use the cpe speed interface configuration command to set the speed of a customer premises equipment (CPE) port. Use the no form of this command to return to the default setting.
cpe speed {{auto | 10 | 100} [port port-id]}
no cpe speed {{auto | 10 | 100} [port port-id]}
This command is available only on Catalyst 2950 Long-Reach Ethernet (LRE) switches.
Syntax Description
Defaults
The default speed is auto.
Command Modes
Interface configuration
Command History
Usage Guidelines
If you do not enter the port keyword, the speed setting is applied globally to all the CPE Ethernet ports. If you enter the port port-id keywords, the setting is applied to the specified CPE Ethernet port and overrides any global speed settings.
Examples
This example shows how to set a port on a CPE to 100 Mbps:
Switch# configure terminalSwitch(config)# interface longreachethernet0/2Switch(config-if)# cpe speed 100 port 1This example shows how to return the default speed setting on all CPE Ethernet ports that were not configured with the cpe speed {10 | 100} port port-id command:
Switch# configure terminalSwitch(config)# interface longreachethernet0/2Switch(config-if)# no cpe speed 100This example shows how to set port 1 to 10 Mbps, port 2 to 100 Mbps, and the remainder of the ports to autonegotiate.
Switch# configure terminalSwitch(config)# interface longreachethernet0/4Switch(config-if)# cpe speed autoSwitch(config-if)# cpe speed 10 port 1Switch(config-if)# cpe speed 100 port 2This example shows how to set port 1 to autonegotiate after the cpe speed 10 command is entered:
Switch(config-if)# no cpe speed 10 portRelated Commands
Sets the port speed for LRE ports.
show interfaces cpe
Displays connection, speed, and duplex settings for CPE Ethernet ports attached to the specified LRE switch port
cpe toggle
Use the cpe toggle interface configuration command to enable the CPE toggle feature. When this feature is enabled, a remote customer premises equipment (CPE) link automatically transitions from down to up if the Long-Reach Ethernet (LRE) link comes up in less than 30 seconds. Use the no form of this command to disable the CPE toggle feature on a specific port or on the switch.
cpe toggle [port cpe-port-id]
no cpe toggle [port cpe-port-id]
This command is available only on Catalyst 2950 Long-Reach Ethernet (LRE) switches.
Syntax Description
Defaults
CPE toggle is enabled on all interfaces.
Command Modes
Interface configuration
Command History
Usage Guidelines
A CPE Ethernet link is the connection between the CPE Ethernet port and the remote Ethernet device (such as a PC) connected to it. It is not the link between the switch LRE port and the LRE CPE device, which is referred to as the LRE link.
CPE toggle cannot be disabled on a Cisco 575 LRE or Cisco 576 LRE 997 CPE link.
You can disable CPE toggle on a link from a Cisco 585 LRE CPE to a remote Ethernet device. You can disable CPE toggle on all interfaces or on a specific interface by using the no cpe toggle [port cpe-port-id] interface configuration command. If CPE toggle is disabled and the LRE link comes up in less than 30 seconds, the CPE link transitions from down to up.
If the port keyword is not specified, this command applies to all Fast Ethernet ports on a CPE device. If the port keyword and a port ID are specified, this command applies to the specific Fast Ethernet port on the CPE and overrides the global configuration.
Examples
This example shows how to disable CPE toggle on a CPE port:
Switch# configure terminalSwitch(config)# interface longreachethernet0/2Switch(config-if)# no cpe toggleRelated Commands
cpe type
Use the cpe type interface configuration command to set the type of customer premises equipment (CPE) port that is connected to a Long-Reach Ethernet (LRE) switch.
cpe type [cisco575-lre | cisco576-lre997 | cisco585-lre | unknown]
This command is available only on Catalyst 2950 LRE switches.
Syntax Description
Defaults
The default CPE type is unknown.
Command Modes
Interface configuration
Command History
12.1(11)YJ
This command was introduced.
12.1(11)YJ4
The cisco576-lre997 keyword was added.
Usage Guidelines
This command can only be used when the port is shut down. If the link is active on a CPE device port, the switch detects the CPE device type and automatically modifies the configuration. You cannot change the CPE device type on active links. For example, if the active CPE device type is cisco575-lre, you cannot change the type to cisco585-lre or unknown.
Examples
This example shows how to set the CPE device type to cisco585-lre while the link is down:
Switch# configure terminalSwitch(config)# interface longreachethernet0/2Switch(config-if)# cpe type cisco585-lreRelated Commands
show interfaces cpe
Displays connection, speed, and duplex settings for CPE Ethernet ports attached to the specified LRE switch port.
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
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:
•
•
Valid values for type and interface:
•
•
•
•
•
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.
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 - 2When you define multiple ranges, you must enter a space before and after the comma (,):
interface range fastethernet0/1 - 2 , gigabitethernet0/1 - 2Examples
This example shows how to create a multiple-interface macro:
Switch(config)# define interface-range macro1 fastethernet0/3 -7 , gigabitethernet0/1Related Commands
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
Command Modes
Privileged EXEC
Command History
12.0(5.2)WC(1)
This command was introduced.
12.1(6)EA2
The /force and /recursive keywords were added.
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:filenameYou can verify that the directory was removed by entering the dir filesystem: privileged EXEC command.
Related Commands
deny (access-list configuration)
Use the deny access-list configuration command to configure conditions for a named or numbered IP access control list (ACL). Use the no form of this command to remove a deny condition from the IP ACL.
Use these commands with standard IP ACLs:
deny {source source-wildcard | host source | any}
no deny {source source-wildcard | host source | any}
Use these commands with extended IP ACLs:
deny protocol {source source-wildcard | host source | any} [operator port] {destination destination-wildcard | host source | any} [operator port] [dscp dscp-value] [time-range time-range-name]
no deny protocol {source source-wildcard | host source | any} [operator port] {destination destination-wildcard | host source | any} [operator port] [dscp dscp-value] [time-range time-range-name]
This command is available on physical interfaces only if your switch is running the enhanced software image (EI).
Syntax Description
Defaults
There are no specific conditions that deny packets in the named or numbered IP ACL.
The default ACL is always terminated by an implicit deny statement for all packets.
Command Modes
Access-list configuration
Command History
Usage Guidelines
Use this command after the ip access-list global configuration command to specify deny conditions for an IP ACL. You can specify a source IP address, destination IP address, IP protocol, TCP port, or UDP port. Specify the TCP and UDP port numbers only if protocol is tcp or udp and operator is eq.
Note
Examples
This example shows how to create an extended IP ACL and to configure deny conditions for it:
Switch(config)# ip access-list extended InternetfilterSwitch(config-ext-nacl)# deny tcp host 190.5.88.10 anySwitch(config-ext-nacl)# deny tcp host 192.1.10.10 anyThis is an example of a standard ACL that sets a deny condition:
Switch(config)# ip access-list standard Acclist1Switch(config-ext-nacl)# deny 192.5.34.0 0.0.0.255Switch(config-ext-nacl)# deny 128.88.10.0 0.0.0.255Switch(config-ext-nacl)# deny 36.1.1.0 0.0.0.255
Note
You can verify your settings by entering the show ip access-lists or the show access-lists privileged EXEC command.
Related Commands
Defines an IP ACL.
Sets conditions for an IP ACL.
Controls access to an interface.
Displays IP ACLs configured on the switch.
Displays ACLs configured on a switch.
deny (MAC access-list configuration)
Use the deny MAC access-list configuration command to prevent Layer 2 traffic from being forwarded if the conditions are matched. Use the no form of this command to remove a deny condition from the MAC named access control list (ACL).
{permit | deny} {any | host src-MAC-addr} {any | host dst-MAC-addr} [aarp | amber | appletalk | dec-spanning | decnet-iv | diagnostic | dsm | etype-6000 | etype-8042 | lat | lavc-sca | mop-console | mop-dump | msdos | mumps | netbios | vines-echo |vines-ip | xns-idp]
no {permit | deny} {any | host src-MAC-addr} {any | host dst-MAC-addr} [aarp | amber | appletalk | dec-spanning | decnet-iv | diagnostic | dsm | etype-6000 | etype-8042 | lat | lavc-sca | mop-console | mop-dump | msdos | mumps | netbios | vines-echo |vines-ip | xns-idp]
This command is available only if your switch is running the enhanced software image (EI).
Syntax Description
Defaults
This command has no defaults. However, the default action for a MAC named ACL is to deny.
Command Modes
MAC access-list configuration
Command History
Usage Guidelines
When an access control entry (ACE) is added to an ACL, an implied deny-any-any condition exists at the end of the list. That is, if there are no matches, the packets are denied. However, before the first ACE is added, the list permits all packets.
These options are not allowed:
•
•
•
Note
Examples
This example shows how to define the MAC named extended ACL to deny NETBIOS traffic from any source to MAC address 00c0.00a0.03fa. Traffic matching this list is denied.
Switch(config-ext-macl)# deny any host 00c0.00a0.03fa netbiosThis example shows how to remove the deny condition from the named MAC extended ACL:
Switch(config-ext-macl)# no deny any host 00c0.00a0.03fa netbiosYou can verify your settings by entering the show access-lists privileged EXEC command.
Related Commands
Creates an ACL based on MAC addresses for non-IP traffic.
Permits Layer 2 traffic to be forwarded if conditions are matched.
Displays ACLs configured on a switch.
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
12.1(14)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-controlThis example shows how to globally enable the optional guest VLAN behavior on a switch:
Switch(config)# dot1x guest-vlan supplicantYou can verify your settings by entering the show dot1x privileged EXEC command.
Related Commands
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
Specify a maximum number of authentication attempts allowed before a port is moved to the restricted VLAN. The range is 1 to 3.
Defaults
The default is 3 attempts.
Command Modes
Interface configuration
Command History
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 terminalEnter configuration commands, one per line. End with CNTL/Z.Switch(config)# interface gigabitethernet0/1Switch(config-if)# dot1x auth-fail max-attempts 2Switch(config-if)# endSwitch(config)# endSwitch#You can verify your settings by entering the show dot1x [interface interface-id] privileged EXEC command.
Related Commands
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.
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
Defaults
No restricted VLAN is configured.
Command Modes
Interface configuration
Command History
Usage Guidelines
You can configure a restricted VLAN on ports configured as follows:
•
•
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:
•
•
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.
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 terminalEnter configuration commands, one per line. End with CNTL/Z.Switch(config)# interface gigabitethernet0/1Switch(config-if)# dot1x auth-fail vlan 40Switch(config-if)# endSwitch(config)# endSwitch#You can verify your configuration by entering the show dot1x [interface interface-id] privileged EXEC command.
Related Commands
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.
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
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 inThese examples show how to enable bidirectional control:
Switch(config-if)# dot1x control-direction bothSwitch(config-if)# no dot1x control-directionYou 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.9275AuthSM State = CONNECTINGBendSM State = IDLEPortStatus = UNAUTHORIZEDIf you enter the dot1x control-direction in interface configuration command to enable unidirectional control, this appears in the show dot1x all command output:
ControlDirection = InIf 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 = In (Disabled due to port settings)Related Commands
show dot1x all [interface interface-id]
Displays control-direction port setting status for the specified interface.
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:
•
•
•
•
•
•
•
•
•
Command Modes
Interface configuration
Command History
12.1(6)EA2
This command was introduced.
12.1(14)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 defaultYou can verify your settings by entering the show dot1x [interface interface-id] privileged EXEC command.
Related Commands
show dot1x [interface interface-id]
Displays IEEE 802.1x status for the specified interface.
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
Defaults
No guest VLAN is configured.
Command Modes
Interface configuration
Command History
12.1(14)EA1
This command was introduced.
12.1(22)EA2
This command was modified to change the default guest VLAN behavior.
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 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.
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 5This 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 3Switch(config-if)# dot1x timeout tx-period 15Switch(config-if)# dot1x guest-vlan 5This 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 supplicantSwitch(config)# interface FastEthernet0/1Switch(config-if)# dot1x guest-vlan 5You can verify your settings by entering the show dot1x [interface interface-id] privileged EXEC command.
Related Commands
Enables the optional guest VLAN supplicant feature.
show dot1x [interface interface-id]
Displays IEEE 802.1x status for the specified interface.
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
12.1(14)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-controlSwitch(config)# interface fastethernet0/1Switch(config-if)# dot1x port-control autoSwitch(config-if)# dot1x host-mode multi-hostYou can verify your settings by entering the show dot1x [interface interface-id] privileged EXEC command.
Related Commands
show dot1x [interface interface-id]
Displays IEEE 802.1x status for the specified interface.
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
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 fastethernet0/1You can verify your settings by entering the show dot1x [interface interface-id] privileged EXEC command.
Related Commands
show dot1x [interface interface-id]
Displays IEEE 802.1x status for the specified interface.
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
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.
Defaults
The default is 2.
Command Modes
Interface configuration
Command History
12.1(6)EA2
This command was introduced.
12.1(14)EA1
This command was changed to the interface configuration mode.
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 5You can verify your settings by entering the show dot1x [interface interface-id] privileged EXEC command.
Related Commands
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.
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
12.1(6)EA2
This command was introduced.
12.1(14)EA1
The dot1x multiple-hosts interface configuration command was replaced by the dot1x host-mode interface configuration command.
Related Commands
Set the IEEE 802.1x host mode on an interface.
Displays IEEE 802.1x statistics, administrative status, and operational status for the switch or for the specified interface.
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
Defaults
The default is force-authorized.
Command Modes
Interface configuration
Command History
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:
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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 fastethernet0/1Switch(config-if)# dot1x port-control autoYou can verify your settings by entering the show dot1x [interface interface-id] privileged EXEC command.
Related Commands
show dot1x [interface interface-id]
Displays IEEE 802.1x status for the specified interface.
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
Defaults
There is no default setting.
Command Modes
Privileged EXEC
Command History
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 fastethernet0/1Related Commands
Displays IEEE 802.1x statistics, administrative status, and operational status for the switch or for the specified interface.
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
12.1(6)EA2
This command was introduced.
12.1(14)EA1
The dot1x reauthentication interface configuration command replaced the dot1x re-authentication global configuration command.
Related Commands
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
12.1(14)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 reauthenticationThis 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 reauthenticationSwitch(config-if)# dot1x timeout reauth-period 4000You can verify your settings by entering the show dot1x [interface interface-id] privileged EXEC command.
Related Commands
Sets the number of seconds between re-authentication attempts.
show dot1x [interface interface-id]
Displays IEEE 802.1x status for the specified interface.
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
Defaults
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
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 reauthenticationSwitch(config-if)# dot1x timeout reauth-period 4000This 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 reauthenticationSwitch(config-if)# dot1x timeout reauth-period serverThis example shows how to set the quiet time on the switch to 30 seconds:
Switch(config-if)# dot1x timeout quiet-period 30This 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 60This 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 25This example shows how to set the switch-to-authentication server retransmission time to 25 seconds:
Switch(config)# dot1x timeout server-timeout 25This example shows how to return to the default re-authorization period:
Switch(config-if)# no dot1x timeout reauth-periodYou can verify your settings by entering the show dot1x [interface interface-id] privileged EXEC command.
Related Commands
Sets the maximum number of times that the switch sends an EAP-request/identity frame before restarting the authentication process.
Enables periodic re-authentication of the client.
show dot1x [interface interface-id]
Displays IEEE 802.1x status for the specified interface.
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
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.
Defaults
For Fast Ethernet and 10/100/1000 ports, the default is auto.
For the default duplex mode of the Gigabit Interface Converter (GBIC)-module ports, see the documentation that came with your GBIC module.
For small, form-factor pluggable (SFP) Gigabit Ethernet ports on Catalyst 2950 LRE switches, the default is auto.
Command Modes
Interface configuration
Command History
Usage Guidelines
Certain ports, such as GBIC module ports, can be configured to be either full duplex or half duplex. The applicability of 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 on Catalyst 2950C-24 switches do not support the duplex interface configuration command. These ports only operate in full-duplex and at 100 Mbps.
You can configure the 10/100/1000 ports on the Catalyst 2950T-24 and Catalyst 2950T-48-SI switches to autonegotiate the duplex mode by using the duplex auto interface configuration command. You can manually set the duplex mode to full by using the duplex full command. The 10/100/1000 ports support the half keyword only when the interface speed is 10 or 100 Mbps.
On Catalyst 2950 Long-Reach Ethernet (LRE) switches, use the duplex command to configure both the MAC and LRE chipsets.
A 10/100/1000 LRE switch port autonegotiates with the device at the other end of the link for the duplex setting and then forces the duplex setting to the negotiated value. A fiber-optic connection (SFP) also autonegotiates with the device at the other end of the link but only accepts a connection at full duplex.
The duplex setting for a SFP Gigabit Ethernet port has a close relationship to the setting for speed. Fiber-optic connections are always forced to 1000 Mbps and full-duplex mode. Copper connections can run at either full- or half-duplex mode for 10 or 100 Mbps but are can only run in full-duplex mode at 1000 Mbps. When you manually set the speed and duplex settings, autonegotiation is disabled, and speed and duplex settings can cause a mismatch.
Note
Examples
This example shows how to set a port to half duplex:
Switch(config)# interface fastethernet0/1Switch(config-if)# duplex halfThis example shows how to set a port to full duplex:
Switch(config)# interface fastethernet0/1Switch(config-if)# duplex fullYou can verify your settings by entering the show interfaces transceiver properties or show running-config privileged EXEC command.
Related Commands
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 | gbic-invalid | link-flap | loopback | pagp-flap | vmps}
no errdisable detect cause {all | dhcp-rate-limit | dtp-flap | gbic-invalid | link-flap | loopback | pagp-flap | vmps}
Syntax Description
Defaults
The default is all, enabled for all causes.
Command Modes
Global configuration
Command History
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.
Examples
This example shows how to enable error disable detection for the link-flap error-disable cause:
Switch(config)# errdisable detect cause link-flapYou can verify your settings by entering the show errdisable detect privileged EXEC command.
Related Commands
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.
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 | gbic-invalid | 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 | gbic-invalid | link-flap | loopback | pagp-flap | psecure-violation | security-violation | udld | vmps}} | {interval interval}
Syntax Description
Note
Defaults
Recovery is disabled for all causes.
The default interval is 300 seconds.
Command Modes
Global configuration
Command History
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 bpduguardThis example shows how to set the timer to 500 seconds:
Switch(config)# errdisable recovery interval 500You can verify your settings by entering the show errdisable recovery privileged EXEC command.
Related Commands
Displays errdisable recovery timer information.
show interfaces status
Displays interface status.
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
Defaults
The defaults for 10/100/1000, GBIC-module ports, and small form-factor pluggable (SFP) -module ports are flowcontrol receive off and flowcontrol send desired.
Command Modes
Interface configuration
Command History
12.0(5.2)WC(1)
This command was introduced.
12.1(6)EA2
The asymmetric and symmetric keywords were replaced with the receive, send, off, on, and desired keywords.
Usage Guidelines
Use the flowcontrol command only on 10/100/1000, GBIC-module ports, and SFP-module ports.
We strongly recommend that you do not configure IEEE 802.3x flowcontrol when quality of service (QoS) is configured on the switch. Before configuring flowcontrol on an interface, make sure to disable QoS on the switch.
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:
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Table 2-3 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.
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 offSwitch(config-if)# flowcontrol send offYou can verify your settings by entering the show interfaces or show flowcontrol privileged EXEC command.
Related Commands
show interfaces flowcontrol
Displays interface input and output flow control settings and status.
Displays flow control settings and status for specified interfaces or all interfaces on the switch.
hw-module slot
Use the hw-module slot privileged EXEC command to perform firmware upgrades on Long-Reach Ethernet (LRE) systems.
hw-module slot module-slot-number upgrade lre [force] [{local ctrlr-unit-number | remote interface-id}]
This command is available only on Catalyst 2950 LRE switches.
Syntax Description
Defaults
No default is defined.
Command Modes
Privileged EXEC
Command History
Usage Guidelines
Use the hw-module slot command to start an LRE upgrade. You can start an LRE upgrade by using one of these methods:
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You can use the force keyword to upgrade an LRE binary on a local LRE controller or a remote LRE CPE device, even though the device is already running the version of the desired LRE binary. The default behavior is to not upgrade LRE binaries that are already up to date.
During an upgrade, users on the LRE links being upgraded experience a temporary disruption of Ethernet connectivity. All LRE local and remote upgrades run concurrently and take 3 to 6 minutes to complete.
The command-line interface (CLI) is available while an LRE upgrade is in progress.
Once started, an LRE upgrade can only be stopped by physically changing the remote CPE device or by reloading the software on the Ethernet switch.
In most cases, configuration for upgrades is not necessary.
Examples
This example shows how to start a system-wide LRE upgrade:
Switch# hw-module slot 0 upgrade lreYou are about to start an LRE upgrade on all LRE interfaces.Users on LRE links being upgraded will experience a temporarydisruption of Ethernet connectivity.Start LRE upgrade ? [yes]:Starting remote upgrade on CPE Lo0/1.Starting remote upgrade on CPE Lo0/2Starting remote upgrade on CPE Lo0/3Starting remote upgrade on CPE Lo0/4Starting remote upgrade on CPE Lo0/5Starting remote upgrade on CPE Lo0/6Starting remote upgrade on CPE Lo0/7Starting remote upgrade on CPE Lo0/8Starting upgrade on local controller LongReachEthernet 0Starting remote upgrade on CPE Lo0/9<output truncated>Starting remote upgrade on CPE Lo0/23Starting remote upgrade on CPE Lo0/24Starting upgrade on local controller LongReachEthernet 2This example shows how to start an LRE upgrade on a single LRE controller in a switch. Specifying the interface-id as longreachethernet 0 causes an LRE upgrade to run on controller 0 in the switch.
Switch# hw-module slot 0 upgrade lre local longreachethernet 0You are about to start an LRE upgrade on local controller LongReachEthernet 0.Users on LRE links being upgraded will experience a temporarydisruption of Ethernet connectivity.Start LRE upgrade ? [yes]:Starting Upgrade on local controller LongReachEthernet 0This example shows how to start an LRE upgrade on a single CPE device. Specifying the interface-id as longreachethernet 0 causes an LRE upgrade to run on the CPE device connected to the LRE port 1.
Switch# hw-module slot 0 upgrade lre remote longreachethernet0/1You are about to start an LRE upgrade on CPE Lo0/1.Users on LRE links being upgraded will experience a temporarydisruption of Ethernet connectivity.Start LRE upgrade ? [yes]:Starting remote upgrade on CPE Lo0/1This example shows what happens when you attempt to update current firmware without using the force option:
Switch# hw-module slot 0 upgrade lre remote longreachethernet0/1You are about to start an LRE upgrade on CPE Lo0/1.Users on LRE links being upgraded will experience a temporarydisruption of Ethernet connectivity.Start LRE upgrade ? [yes]:No upgrade required on CPE Lo0/1This example shows how to use the force option when you attempt to update current firmware on a CPE:
Switch# hw-module slot 0 upgrade lre force remote longreachethernet0/1You are about to start an LRE upgrade on CPE Lo0/1.Users on LRE links being upgraded will experience a temporarydisruption of Ethernet connectivity.Start LRE upgrade ? [yes]:Starting remote upgrade on CPE Lo0/1Switch#Related Commands
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
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 fastethernet0/2Switch(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 terminalSwitch(config)# interface vlan 3Switch(config-if)# ip address 172.20.128.176 255.255.255.0Switch(config-if)# no shutdownSwitch(config-if)# exitYou can verify your settings by entering the show interfaces and show interfaces vlan vlan-id privileged EXEC commands.
Related Commands
Displays the administrative and operational status of a switching (nonrouting) port.
Disables a port and shuts down the management VLAN.
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
Defaults
No port-channel logical interfaces are defined.
Command Modes
Global configuration
Command History
Usage Guidelines
Only one port channel in a channel group is allowed.
Follow these guidelines when you use the interface port-channel command:
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Examples
This example shows how to create a port-channel interface with a port-channel number of 5:
Switch(config)# interface port-channel 5You can verify your settings by entering the show running-config or show etherchannel channel-group-number detail privileged EXEC command.
Related Commands
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
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:
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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, all Long-Reach Ethernet (LRE) ports, or all VLANs.
These are the valid values for port-range type and interface:
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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 - 2When you define multiple ranges, you must enter a space before and after the comma (,):
interface range fastethernet0/3 - 7 , gigabitethernet0/1You 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
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 - 2Switch(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 - 2Switch(config)# interface range macro macro1Switch(config-if-range)#Related Commands
interleave
Use the interleave interface configuration command to set the interleave block size on the Long-Reach Ethernet (LRE) interfaces. Use the no form of this command to return to the default setting.
interleave {downstream value | upstream value}
no interleave {downstream value | upstream value}
This command is available only on Catalyst 2950 LRE switches.
Syntax Description
Defaults
The default is 0 for low latency (LL) profiles and 16 for non-LL profiles.
Command Modes
Interface configuration
Command History
Usage Guidelines
The interleave delay is applicable only when the non-LL profiles are used. Existing LL profiles are supported.
Different ports with the same profile can have different interleave settings.
A lower value of interleave block size indicates less tolerance to noise and causes a lower latency of frame transmission. For example, lower values of interleave block size can be used for voice applications. A higher value of interleave block size indicates higher tolerance to noise and causes higher latency in the frame transmission. For example, higher values of interleave block size can be used for data applications.
If a lower latency of frame transmission is required, you can use a lower interleave value but you will have less tolerance to noise.
For information on configuring the interleave delay, see the switch software configuration guide for this release.
Examples
This example shows how to specify an interleave value of 2 for both upstream and downstream ends of the link:
Switch(config-if)# interleave upstream 2 downstream 2You can verify your settings by entering the show controllers lre status interleave privileged EXEC command.
Related Commands
show controllers lre status interleave
Displays the interleave block size values on the LRE interfaces.
ip access-group
Use the ip access-group interface configuration command to control access to an interface. Use the no form of this command to remove an access group from an interface.
ip access-group {access-list-number | name} in
no ip access-group {access-list-number | name} in
This command is available on physical interfaces only if your switch is running the enhanced software image (EI).
Syntax Description
access-list-number
Number of the IP access control list (ACL). The range is 1 to 199 and 1300 to 2699.
name
Name of an IP ACL, specified in the ip access-list command.
Defaults
No ACL is applied to the interface.
Command Modes
Interface configuration
Command History
Usage Guidelines
You can apply IP ACLs only to ingress interfaces. If a MAC access group is already defined for an interface, you cannot apply this command to the interface.
The ACLs can be standard or extended.
For standard ACLs, after receiving a packet, the switch checks the packet source address. If the source address matches a defined address in the ACL and the list permits the address, the switch forwards the packet.
For extended ACLs, after receiving the packet, the switch checks the match conditions in the ACL. If the conditions are matched, the switch forwards the packet.
If the specified ACL does not exist, the switch forwards all packets.
IP access groups can be separated on Layer 2 and Layer 3 interfaces.
Note
Examples
This example shows how to apply a numbered ACL to an interface:
Switch(config)# interface fastethernet0/1Switch(config-if)# ip access-group 101 inYou can verify your settings by entering the show access-lists or show ip access-lists privileged EXEC command.
Related Commands
ip access-list
Use the ip access-list global configuration command to create an IP access control list (ACL) to be used for matching packets to an ACL whose name or number you specify and to enter access-list configuration mode. Use the no form of this command to delete an existing IP ACL and to return to global configuration mode.
ip access-list {extended | standard} {access-list-number | name}
no ip access-list {extended | standard} {access-list-number | name}
This command is available on physical interfaces only if your switch is running the enhanced software image (EI).
Syntax Description
Defaults
No named or numbered IP ACLs are defined.
Command Modes
Global configuration
Command History
Usage Guidelines
Use this command to enter access-list configuration mode and to specify the name or number of the IP ACL for which you want to create or modify ACL match criteria. In this mode, you must enter the permit and deny commands to configure the permit and deny access conditions for this list.
Use the ip access-list command and its subcommands to define packet classification and marking as part of a globally-named service policy applied on a per-interface basis or as an IP access group applied on a per-interface basis.
Specifying standard or extended with the ip access-list command determines the prompt that you get when you enter access-list configuration mode.
Note
Examples
This example shows how to configure a standard ACL named Internetfilter1:
Switch(config)# ip access-list standard Internetfilter1Switch(config-std-nacl)# permit 192.5.34.0 0.0.0.255Switch(config-std-nacl)# permit 192.5.32.0 0.0.0.255Switch(config-std-nacl)# exitThis example shows how to configure an extended ACL named Internetfilter2:
Switch(config)# ip access-list extended Internetfilter2Switch(config-ext-nacl)# permit any 128.8.10.0 0.0.0.255 eq 80Switch(config-ext-nacl)# permit any 128.5.8.0 0.0.0.255 eq 80Switch(config-ext-nacl)# exit
Note
You can verify your settings by entering the show access-lists or show ip access-lists privileged EXEC command.
Related Commands
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
Defaults
No IP address is defined for the switch.
Command Modes
Interface configuration
Command History
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 1Switch(config-if)# ip address 172.20.128.2 255.255.255.0You can verify your settings by entering the show running-config privileged EXEC command.
Related Commands
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
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 snoopingYou can verify your settings by entering the show ip dhcp snooping privileged EXEC command.
Related Commands
Enables DHCP snooping on a VLAN.
Displays the DHCP snooping configuration.
Displays the DHCP snooping binding information.
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
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 optionYou can verify your settings by entering the show ip dhcp snooping privileged EXEC command.
Related Commands
Displays the DHCP snooping configuration.
Displays the DHCP snooping binding information.
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
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
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-untrustedYou can verify your settings by entering the show ip dhcp snooping privileged EXEC command.
Related Commands
Displays the DHCP snooping configuration.
Displays the DHCP snooping binding information.
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
Defaults
DHCP snooping rate limiting is disabled.
Command Modes
Interface configuration
Command History
Usage Guidelines
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 150You can verify your settings by entering the show ip dhcp snooping privileged EXEC command.
Related Commands
Configures the recover mechanism.
Displays the DHCP snooping configuration.
Displays the DHCP snooping binding information.
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
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 trustYou can verify your settings by entering the show ip dhcp snooping privileged EXEC command.
Related Commands
Displays the DHCP snooping configuration.
Displays the DHCP snooping binding information.
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
Defaults
DHCP snooping is disabled on all VLANs.
Command Modes
Global configuration
Command History
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 10You can verify your settings by entering the show ip dhcp snooping privileged EXEC command.
Related Commands
Displays the DHCP snooping configuration.
Displays the DHCP snooping binding information.
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
Defaults
No IGMP filters are applied.
Command Modes
Interface configuration
Command History
Usage Guidelines
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 fastethernet0/1Switch(config-if)# ip igmp filter 22You can verify your setting by using the show running-config interface interface-id privileged EXEC command.
Related Commands
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
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
12.1(9)EA1
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:
•
•
•
Examples
This example shows how to limit to 25 the number of IGMP groups that an interface can join:
Switch(config)# interface fastethernet0/1Switch(config-if)# ip igmp max-groups 25This 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 gigabitethernet0/1Switch(config-if)# ip igmp max-groups action replaceYou can verify your setting by using the show running-config interface interface-id privileged EXEC command.
Related Commands
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
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
Usage Guidelines
When you are in IGMP profile configuration mode, you can create the profile by using these commands:
•
•
•
•
•
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 terminalSwitch(config)# ip igmp profile 40Switch(config-igmp-profile)# permitSwitch(config-igmp-profile)# range 233.1.1.1 233.255.255.255You can verify your settings by using the show ip igmp profile privileged EXEC command.
Related Commands
Applies the IGMP profile to the specified interface.
Displays the characteristics of all IGMP profiles or the specified IGMP profile number.
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
This command has no arguments or keywords.
Note
Defaults
IGMP snooping is globally enabled.
Command Modes
Global configuration
Command History
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 snoopingTo verify your settings, enter the show ip igmp snooping privileged EXEC command.
Related Commands
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
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-learningSwitch(config)# no ip igmp snooping mrouter learn pim v2You can verify your settings by entering the show running-config | include mrouter learn pim v2 privileged EXEC command.
Related Commands
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
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-suppressionThis example shows how to enable report suppression:
Switch(config)# ip igmp snooping report-suppressionYou can verify your settings by entering the show ip igmp snooping privileged EXEC command.
Related Commands
Globally enables IGMP snooping. IGMP snooping must be globally enabled in order to be enabled on a VLAN.
Displays the IGMP snooping configuration of the switch or the VLAN.
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
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
Usage Guidelines
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.
Note
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.
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-learningThis example shows how to enable source-only learning:
Switch(config)# ip igmp snooping source-only-learningThis example shows how to set the aging time as 1200 seconds (20 minutes):
Switch(config)# ip igmp snooping source-only-learning age-timer 1200This example shows how to disable aging of the forward-table entries:
Switch(config)# ip igmp snooping source-only-learning age-timer 0You can verify your settings by entering the show running-config | include source-only-learning privileged EXEC command.
Related Commands
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
Defaults
IGMP snooping is enabled when each VLAN is created.
Command Modes
Global configuration
Command History
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 2This example shows how to disable IGMP snooping on VLAN 2:
Switch(config)# no ip igmp snooping vlan 2You can verify your settings by entering the show ip igmp snooping vlan privileged EXEC command.
Related Commands
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
Defaults
IGMP Immediate-Leave processing is disabled.
Command Modes
Global configuration
Command History
Usage Guidelines
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-leaveThis example shows how to disable IGMP Immediate-Leave processing on VLAN 1:
Switch(config)# no ip igmp snooping vlan 1 immediate-leaveYou can verify your settings by entering the show ip igmp snooping vlan privileged EXEC command.
Related Commands
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 Description
vlan-id
VLAN ID value. The range is 1 to 4094.
time
Interval time out in seconds. The range is 100 to 5000 milliseconds.
t
Defaults
The default timeout setting is 100 milliseconds.
Command History
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 timeTo verify your settings, enter the show ip igmp snooping privileged EXEC command.
Related Commands
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
Defaults
The default learning method is pim-dvmrp.
Command Modes
Global configuration
Command History
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 fastethernet0/1This example shows how to specify the multicast router learning method as CGMP:
Switch(config)# no ip igmp snooping vlan 1 mrouter learn cgmpYou can verify your settings by entering the show ip igmp snooping mrouter privileged EXEC command.
Related Commands
Globally enables Internet Group Management Protocol (IGMP) snooping.
Enables IGMP snooping on the VLAN interface.
Configures IGMP Immediate-Leave processing.
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.
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
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 fastethernet0/1Configuring port FastEthernet 0/1 on group 0100.5e02.0203You can verify your settings by entering the show mac address-table multicast privileged EXEC command.
Related Commands
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
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 2You can verify your settings by entering the show ip ssh or show ssh privileged EXEC command.
Related Commands
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
Defaults
The default priority value is 32768.
Command Modes
Interface configuration
Command History
Usage Guidelines
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
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.
Examples
This example shows set the port priority for LACP:
Switch(config)# lacp port-priority 32764You can verify your settings by entering the show etherchannel privileged EXEC command.
Related Commands
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
Defaults
The default priority value is 32768.
Command Modes
Global configuration
Command History
Usage Guidelines
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 32764You can verify your settings by entering the show lacp sys-id privileged EXEC command.
Related Commands
link monitor
Use the link monitor interface configuration command to enable Long-Reach Ethernet (LRE) link monitoring on a port. Use the no form of this command to disable LRE link monitoring on a port.
link monitor
no link monitor
This command is available only on Catalyst 2950 LRE switches.
Syntax Description
This command has no arguments or keywords.
Defaults
LRE monitoring is enabled.
Command Modes
Interface configuration
Command History
Usage Guidelines
If the link is shut down, link monitor data is not collected.
Examples
This example shows how to enable LRE link monitoring on an LRE port:
Switch# configure terminalSwitch(config)# interface longreachethernet0/1Switch(config-if)# link monitorRelated Commands
link monitor logging
Use the link monitor logging interface configuration command to enable Long-Reach Ethernet (LRE) link monitoring event logging. Use the no form of this command to disable LRE link monitor logging.
link monitor logging
no link monitor logging
This command is available only on Catalyst 2950 LRE switches.
Syntax Description
This command has no arguments or keywords.
Defaults
LRE link monitoring event logging is disabled.
Command Modes
Interface configuration
Command History
Usage Guidelines
Events are logged in the system log when a configured threshold is crossed.
Examples
This example shows how to enable LRE link monitoring logging on an LRE port:
Switch# configure terminalSwitch(config)# interface longreachethernet0/2Switch(config-if)# link monitor loggingRelated Commands
link monitor threshold rserr
Use the link monitor threshold rserr interface configuration command to establish threshold values for Reed-Solomon errors. Use the no form of this command to return to the default setting.
link monitor threshold rserr {downstream value | upstream value}
no link monitor threshold rserr {downstream value | upstream value}
This command is available only on Catalyst 2950 Long-Reach Ethernet (LRE) switches.
Syntax Description
Defaults
The default is 1000 errors per second.
Command Modes
Interface configuration
Command History
Usage Guidelines
To compute threshold values, calculate the number of frames that can be sent for a particular bandwidth based on the LRE profile. Use the show controller lre status profile privileged EXEC command to determine the downstream and upstream data rates. Divide the downstream data rate by the length of an LRE frame (216 bytes) multiplied by 8 (8 bits per byte).
For example, a link is running LRE-10, which has a downstream data rate of 12.5 Mbps.
((12500000)/(261*8))=5986If you configure the downstream Reed-Solomon error threshold to 5986, an alarm counter increments when the threshold is exceeded.
Examples
This example shows how to configure a threshold for Reed-Solomon errors at 4000 errors per second downstream and 3000 errors per second upstream:
Switch# configure terminalSwitch(config)# interface longreachethernet0/1Switch(config-if)# link monitor threshold rserr downstream 4000Switch(config-if)# link monitor threshold rserr upstream 3000Related Commands
link monitor threshold snr
Use the link monitor threshold snr interface configuration command to establish threshold values for signal-to-noise ratio (SNR) errors. Use the no form of this command to return to the default setting.
link monitor threshold snr {downstream value | upstream value}
no link monitor threshold snr {downstream value | upstream value}
This command is available only on Catalyst 2950 Long-Reach Ethernet (LRE) switches.
Syntax Description
Defaults
The default is 2 dB.
Command Modes
Interface configuration
Command History
Usage Guidelines
The default theoretical SNR value added to the threshold value is compared to the value in the LRE chipset.
Examples
This example shows how to configure the SNR threshold as 6 dB downstream and 4 dB upstream:
Switch# configure terminalSwitch(config)# interface longreachethernet0/1Switch(config-if)# link monitor threshold snr downstream 6Switch(config-if)# link monitor threshold snr upstream 4Related Commands
local duplex
Use the local duplex interface configuration command to specify the duplex mode of operation for a Long-Reach Ethernet (LRE) port. Use the no form of this command to return to the default setting.
local duplex {full | half}
no local duplex
This command is available only on Catalyst 2950 LRE switches.
Syntax Description
Defaults
The default is half.
Command Modes
Interface configuration
Command History
Usage Guidelines
This command only sets the duplex mode on an LRE port. To set the duplex mode on a customer premises equipment (CPE) Ethernet link, use the cpe duplex interface configuration command; to set the duplex mode of the Gigabit Ethernet ports, use the duplex interface configuration command.
Examples
This example shows how to set LRE port 1 to full duplex:
Switch(config)# interface longreachethernet0/1Switch(config-if)# local duplex fullYou can verify your settings by entering the show running-config privileged EXEC command.
Related Commands
local speed
Use the local speed interface configuration command to specify the speed of a Long-Reach Ethernet (LRE) interface. Use the no form of this command to return to the default setting.
local speed {10 | 100}
no local speed
This command is available only on Catalyst 2950 LRE switches.
Syntax Description
Defaults
The default is 100 Mbps.
Command Modes
Interface configuration
Command History
Usage Guidelines
This command sets the speed only on an LRE link. To set the speed on a customer premises equipment (CPE) Ethernet link, use the cpe speed interface configuration command. To set the speed of the Gigabit Ethernet ports, use the speed interface configuration command.
Examples
This example shows how to set LRE port 1 to 100 Mbps:
Switch(config)# interface longreachehernet1/1Switch(config-if)# local speed 100You can verify your settings by entering the show running-config privileged EXEC command.
Related Commands
logging lre
Use the logging lre interface configuration command to specify the mode in which to log Long-Reach Ethernet (LRE) events. Use the no form of this command to disable logging of events.
logging lre {event | extended | normal}
no logging lre {event | extended | normal}
This command is available only on Catalyst 2950 LRE switches.
Syntax Description
event
Log events only.
extended
Log events and all possible parameters.
normal
Log events and some typical parameters.
Defaults
The default is normal.
Command Modes
Interface configuration
Command History
Usage Guidelines
This command is not needed for normal operation of the switch. However, it can be used as a diagnostic tool to analyze switch activity.
The maximum number of events that can be logged on a per-port basis is 50. The log overwrites itself when it is full.
Examples
This example shows how to set logging for events:
Switch (config)# interface longreachethernet0/1Switch(config-if)# logging lre eventRelated Commands
lre profile
Use the lre profile global configuration command to assign a Long-Reach Ethernet (LRE) profile to all switch LRE ports. Use the no form of this command to remove the profile.
lre profile profile-name
no lre profile profile-name
This command is available only on Catalyst 2950 LRE switches.
Syntax Description
Defaults
The default for the Catalyst 2950ST-8 LRE and 2950ST-24 LRE switches is LRE-10. The default for the Catalyst 2950ST-24 LRE 997 switch is LRE-6.
Command Modes
Global configuration
Command History
Usage Guidelines
Unless you assign a profile, the switch uses the default global profile. The LRE-10 profile allows the upstream and downstream transmission rate on the LRE link to be 12.5 Mbps. The LRE-6 profile allows the upstream and downstream transmission rate on the LRE link to be 6.25 Mbps. Profiles assigned at the port level have priority over profiles assigned at the global level.
When assigning profiles to LRE ports, keep these considerations in mind:
•
•
•
Examples
This example shows how to specify the LRE-8 profile on a Catalyst 2950ST-8 LRE or 2950ST-24 LRE switch:
Switch# configure terminalSwitch(config)# lre profile lre-8You can verify your settings by entering the show controllers lre profile details privileged EXEC command.
Related Commands
Adds an LRE profile to a rate selection sequence.
Displays LRE profile information.
lre rate selection sequence
Use the lre rate selection sequence global configuration command to assign the rate selection sequence for the entire switch. Use the no form of the command to delete the assigned sequence.
lre rate selection sequence sequence-name
no lre rate selection sequence sequence-name
This command is available only on Catalyst 2950 Long-Reach Ethernet (LRE) switches.
Syntax Description
Command Modes
Global configuration
Command History
Usage Guidelines
This command applies a sequence to all ports that have rate selection enabled. The command is rejected if the sequence is not configured with a profile.
When rate selection is enabled, profiles and sequences follow a predefined priority scheme that determines the rate for a port or for the entire switch. In general, sequences have priority over standalone profiles, and port configurations have priority over global configurations. These are the priority levels with rate selection enabled, from highest to lowest:
1.
2.
3.
4.
For further details on profiles, sequences, and their priority scheme, see the switch software configuration guide for this release.
Examples
This example shows how to specify the sequence named lre-seq-upstream:
Switch# configure terminalSwitch(config)# lre rate selection sequence lre-seq-upstreamRelated Commands
lre sequence
Use the lre sequence global configuration command to define a new sequence and to enter sequence configuration mode. Use the no form of this command to delete a user-configured sequence.
lre sequence sequence-name
no lre sequence sequence-name
This command is available only on Catalyst 2950 Long-Reach Ethernet (LRE) switches.
Syntax Description
Defaults
No default is defined.
Command Modes
Global configuration
Command History
Usage Guidelines
This command creates a new sequence when the sequence name specified in the command does not match any of the existing configured sequences. When the sequence name specified in the command matches a configured sequence, a new sequence is not created.
The profiles can be edited from the sequence configuration mode. However, the system-defined sequences cannot be edited. If the sequence specified in this command is a system-defined sequence, the command is rejected. An error message appears if the sequence name matches the name of a system-defined sequence. Use the exit command to return to global configuration mode.
Examples
This example shows how to specify the a user-defined sequence called myseq:
Switch# configure terminalSwitch(config)# lre sequence myseqSwitch(config-seq)#This example shows how to create a user-defined sequence called corpseq, with two profiles in that sequence:
Switch# configure terminalSwitch(config)# lre sequence corpseqSwitch(config-seq)# profile lre-15-5Switch(config-seq)# profile lre-15-3Switch(config-seq)# exitSwitch(config)#This example shows the error message that appears when you try to edit a system-defined sequence:
Switch(config)# lre sequence lre-seq-complete-reachError:Sequence LRE-SEQ-COMPLETE-REACH is a system defined sequence. Cannot edit this sequenceSwitch>(config)#This example shows how to delete a user-defined sequence:
Switch# configure terminalSwitch(config)# no lre sequence myseqSwitch(config-seq)# exitSwitch(config)#Related Commands
Assigns sequences globally.
Adds a profile to a sequence.
Adds a profile to a sequence.
lre syslog
Use the lre syslog global configuration command to enable a Long-Reach Ethernet (LRE) switch to send the switch debugging messages to the LRE logging process and to the system message logging process. Use the no form of this command to disable the syslog export feature.
lre syslog
no lre syslog
This command is available only on Catalyst 2950 LRE switches.
Syntax Description
This command has no arguments or keywords.
Defaults
The syslog export feature is disabled.
Command Modes
Global configuration
Command History
Usage Guidelines
Before enabling the syslog export feature, follow these guidelines:
•
•
In software releases earlier than Cisco IOS Release 12.1(14)EA1, the switch sends information only to the LRE logging process. To display the LRE events, use the show controllers lre log privileged EXEC command.
For more information, see the "Configuring LRE" chapter in the software configuration guide for this release.
Examples
This example shows how to enable the syslog export feature:
Switch(config)# lre syslogRelated Commands
Displays the history of link, configuration, and timer events for a specific port or for all LRE switch ports.
lre upbo
Use the lre upbo global configuration command to configure the reference TX power level on the Long-Reach Ethernet (LRE) customer premises equipment (CPE) device. Use the no form of this command to return t to the default setting.
lre upbo {noise-model | offset value}
no lre upbo {noise-model | offset value}
This command is available only on Catalyst 2950 LRE switches.
Syntax Description
noise-model
Specify the noise model. See Table 2-4 in the "Usage Guidelines" section for the supported values. Values are not case sensitive.
offset value
Specify the offset value. The range is 300 to 800.
The offset value is calculated with reference to -140 decibels referenced to 1 milliwatt per hertz (dBm/Hz). For example, if you require a reference power spectral density (PSD) of -95.0 dBm/Hz, you need to enter an offset of 45.0 (-95.0 - [-140] = 45.0).
Note
Defaults
The default is the ETSI-E noise model.
Command Modes
Global configuration
Command History
Usage Guidelines
The upstream power back-off mechanism allows for normalization of the upstream receive power levels by requiring the CPE devices on shorter lines to transmit at a lower power level than the CPEs on longer lines. You can change the upstream power back-off values by either selecting a standard noise model or by setting an offset value for the default reference PSD.
Note
Table 2-4 shows the supported values for the noise models:
You can use the offset values to adjust the CPE transmit reference PSD relative to the default reference of -140 dBm/Hz. Only reference PSD values greater than -140 dBm/Hz are supported. A zero value for the offset corresponds to a reference PSD of -140 dBm/Hz.
The smallest offset is 30 dBm/Hz and the corresponding value is 300.
Caution
When you enter the lre upbo command, all LRE links are reset to the up state.
Before configuring the reference TX power level, follow these guidelines:
•
•
Examples
This example shows how to set the noise model to ETSI-A:
Switch# configure terminalSwitch(config)# lre upbo etsi-aThis example shows how to set the offset value to 450 (45.0 dB):
Switch# configure terminalSwitch(config)# lre upbo offset 450Related Commands
Displays information about the LRE CPE devices connected to an LRE switch.
Displays the LRE line status parameters.
lre upgrade default family
Use the lre upgrade default family global configuration command to define a map between a Long-Reach Ethernet (LRE) device and an LRE binary. Use the no form of this command to return to the default setting.
lre upgrade default family device-family {model model {revision revision | binary LRE binary} | binary LRE binary}
no lre upgrade default family device-family {model model {revision revision | binary LRE binary} | binary LRE binary}
This command is available only on Catalyst 2950 LRE switches.
Syntax Description
Defaults
No default is defined. The system selects the binary file.
Command Modes
Global configuration
Command History
12.1(11)YJ
This command was introduced.
12.1(11)YJ4
The cisco576-lre997 value was added.
Usage Guidelines
Use the lre upgrade default family device-family binary configuration command to override the default behavior for upgrading LRE firmware. Use this command when you want to upgrade all CPE devices or local controllers of a given family to an LRE binary version.
Note
Examples
This example shows how to configure all CISCO585-LRE CPE devices to upgrade with the LRE binary file CISCO-585-LRE_vdslsngl_51.00.00:
Switch(config)# lre upgrade default family cisco585-lre binary cisco585-lre_vdslsngl_51.00.00.binRelated Commands
mac access-group
Use the mac access-group interface configuration command to apply a named extended MAC access control list (ACL) to an interface. Use the no form of this command to remove a MAC ACL from an interface.
mac access-group name in
no mac access-group name in
This command is available only if your switch is running the enhanced software image (EI).
Syntax Description
Defaults
No MAC ACL is applied to the interface.
Command Modes
Interface configuration
Command History
Usage Guidelines
You can apply MAC ACLs only to ingress interfaces. If an IP access group is already defined for an interface, you cannot apply this command to the interface.
After receiving the packet, the switch checks the match conditions in the ACL. If the conditions are matched, the switch forwards the packet.
If the specified ACL does not exist, the switch forwards all packets.
Note
Examples
This example shows how to apply a MAC extended ACL named macacl2 to an interface:
Switch(config)# interface fastethernet0/1Switch(config-if)# mac access-group macacl2 inYou can verify your settings by entering the show mac access-group privileged EXEC command.
Related Commands
{deny (MAC access-list configuration) | permit (MAC access-list configuration)}
Configures a MAC ACL.
Displays the ACLs configured on the switch.
Displays the MAC ACLs configured on the switch.
mac access-list extended
Use the mac access-list extended global configuration command to create an access control list (ACL) based on MAC addresses. Using this command changes the mode to extended MAC access-list configuration mode. Use the no form of this command to return to the default setting.
mac access-list extended name
no mac access-list extended name
This command is available only if your switch is running the enhanced software image (EI).
Syntax Description
Defaults
No MAC ACLs are created.
Command Modes
Global configuration
Command History
Usage Guidelines
MAC-named extended ACLs are used with the mac access-group interface configuration command and class maps.
Note
Examples
This example shows how to enter extended MAC access-list configuration mode and to create a MAC extended ACL named mac1:
Switch(config)# mac access-list extended mac1Switch(config-ext-macl)#This example shows how to delete the MAC extended ACL named mac1:
Switch(config)# no mac access-list extended mac1You can verify your settings by entering the show access-lists privileged EXEC command.
Related Commands
Creates a class map to be used for matching packets to the class whose name you specify and to enter class-map configuration mode.
{deny (MAC access-list configuration) | permit (MAC access-list configuration)}
Configures a MAC ACL.
Applies a MAC ACL to an interface.
Displays the ACLs configured on the switch.
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]
Note
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
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 200This example shows how to disable aging in VLAN 1.
Switch(config)# mac address-table aging-time 0This 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 450You can verify your settings by entering the show mac address-table privileged EXEC command.
Related Commands
Deletes dynamic entries from the 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.
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]
Note
Syntax Description
Defaults
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
12.1(6)EA2
This command was introduced.
12.1(11)EA1
The mac-address-table notification command was replaced by the mac address-table notification command.
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 notificationThis example shows how to set the notification-trap interval to 60 seconds:
Switch(config)# mac address-table notification interval 60This example shows how to set the number of entries in the history table to 32:
Switch(config)# mac address-table notification history-size 32You can verify your settings by entering the show mac address-table notification privileged EXEC command.
Related Commands
clear mac address-table notification
Clears the MAC address notification global counters.
Displays the MAC address notification settings for all interfaces or the specified interface.
Sends the SNMP MAC notification traps when the mac-notification keyword is appended.
Enables the SNMP MAC notification trap on a specific interface.
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]
Note
Syntax Description
Defaults
None configured.
Command Modes
Global configuration
Command History
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.
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 fastethernet0/2This 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 gigabitethernet0/1You can verify your settings by entering the show mac address-table privileged EXEC command.
Related Commands
Deletes entries from the MAC address table.
Sets the length of time that a dynamic entry remains in the MAC address table after the entry is used or updated.
Displays the MAC address table.
show mac address-table static
Displays static MAC address table entries only.
mac address-table static drop
Use the mac address-table static drop global configuration command to enable unicast MAC address filtering and to configure the switch to drop traffic with a specific source or destination MAC address. Use the no form of this command to return to the default setting.
mac address-table static mac-addr vlan vlan-id drop
no mac address-table static mac-addr vlan vlan-id
Syntax Description
Defaults
Unicast MAC address filtering is disabled. The switch does not drop traffic for specific source or destination MAC addresses.
Command Modes
Global configuration
Command History
Usage Guidelines
Follow these guidelines when using this feature:
•
•
For example, if you enter the mac address-table static mac-addr vlan vlan-id interface interface-id global configuration command followed by the mac address-table static mac-addr vlan vlan-id drop command, the switch drops packets with the specified MAC address as a source or destination.
If you enter the mac address-table static mac-addr vlan vlan-id drop global configuration command followed by the mac address-table static mac-addr vlan vlan-id interface interface-id command, the switch adds the MAC address as a static address.
Examples
This example shows how to enable unicast MAC address filtering and to configure the switch to drop packets that have a source or destination address of c2f3.220a.12f4. When a packet is received in VLAN 4 with this MAC address as its source or destination, the packet is dropped.
Switch(config)# mac address-table static c2f3.220a.12f4 vlan 4 dropThis example shows how to disable unicast MAC address filtering:
Switch(config)# no mac address-table static c2f3.220a.12f4 vlan 4You can verify your setting by entering the show mac address-table static privileged EXEC command.
Related Commands
show mac address-table static
Displays only static MAC address table entries.
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
Defaults
This command has no default setting.
Command Modes
Interface configuration
Command History
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.
Follow these guidelines when you apply a Cisco-default Smartports macro on an interface:
•
•
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 duplexTo 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 duplexApplying 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-desktopMacro type : default# Basic interface - Enable data VLAN only# Recommended value for access vlan (AVID) should not be 1switchport access vlan $AVIDswitchport mode access# Enable port security limiting port to a single# MAC address -- that of desktopswitchport port-securityswitchport port-security maximum 1# Ensure port-security age is greater than one minute# and use inactivity timerswitchport port-security violation restrictswitchport port-security aging time 2switchport port-security aging type inactivity# Configure port as an edge network portspanning-tree portfastspanning-tree bpduguard enable--------------------------------------------------------------Switch#Switch# configure terminalSwitch(config)# interface fastethernet0/4Switch(config-if)# macro apply cisco-desktop $AVID 25Related Commands
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
Defaults
This command has no default setting.
Command Modes
Interface configuration
Command History
Usage Guidelines
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 settingsYou can verify your settings by entering the show parser macro description privileged EXEC command.
Related Commands
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
Defaults
This command has no default setting.
Command Modes
Global configuration
Command History
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:
•
•
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 snmpMacro name : snmpMacro type : customizable#enable port security, linkup, and linkdown trapssnmp-server enable traps port-securitysnmp-server enable traps linkupsnmp-server enable traps linkdown#set snmp-server hostsnmp-server host ADDRESS#set SNMP trap notifications precedencesnmp-server ip precedence VALUE--------------------------------------------------Switch(config)# macro global apply snmp ADDRESS test-server VALUE 7To 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 7Applying 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
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
Defaults
This command has no default setting.
Command Modes
Global configuration
Command History
Usage Guidelines
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 enabledYou can verify your settings by entering the show parser macro description privileged EXEC command.
Related Commands
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
Defaults
This command has no default setting.
Command Modes
Global configuration
Command History
12.1(19)EA1
This command was introduced.
12.1(20)EA2
The help string # macro keywords was added.
Usage Guidelines
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.
Examples
This example shows how to create a macro that defines the duplex mode and speed:
Switch(config)# macro name duplexEnter macro commands one per line. End with the character `@'.duplex fullspeed auto@This example shows how create a macro with # macro keywords:
Switch(config)# macro name testswitchport access vlan $VLANIDswitchport 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 fa1/1Switch(config-if)# macro apply test ?WORD keyword to replace with a value e.g $VLANID,$MAX<cr>Switch(config-if)# macro apply test $VLANID ?WORD Value of first keyword to replaceSwitch(config-if)# macro apply test $VLANID 2WORD 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 replaceRelated Commands
margin
Use the margin interface configuration command to specify the margin value used to determine link quality during Long-Reach Ethernet (LRE) rate selection. Use the no form of this command to return to the default setting.
margin {downstream value | upstream value}
no margin {downstream value | upstream value}
This command is available only on Catalyst 2950 LRE switches.
Syntax Description
downstream value
Value at the remote end of the link. The range is 0 to 10 decibels (dB).
upstream value
Value at the local end of the link. The range is 0 to 10 dB.
Defaults
The default is 0 dB.
Command Modes
Interface configuration
Command History
Usage Guidelines
When rate selection is running, the signal-to-noise ratio (SNR) shows the link quality. The switch does not provide any internal mechanism to ensure link quality. There can be different requirements for link quality, depending on the required bit-error rate and the noise level of the environment. A noisier environment would require a higher SNR in order to provide a stable link. A lower bit-error rate would require a higher SNR. Typically a 6-dB margin provides an error rate of 10-21 bits.
To provide link stability, you should add a margin to the required SNR. You can configure your margins to an amount that is appropriate for the noise level of your environment. Increasing the margin requirement can cause the system to choose a lower profile, which would in turn translate to a lower rate but with a longer reach.
The switch does not guarantee any margins after a link is activated. Margins are only guaranteed when the link is established. When a link is activated, if the SNR requirements do not match the configured margin level, the link is not established.
Downstream means the remote end of the link and upstream the local end. The link has to satisfy both the local and remote margin requirements. If either one is not met, the link is advertised as down. This command has no significance if rate selection is not running on this interface.
Note
For more information about link stability and margins, see the software configuration guide for this release.
Examples
This example shows how to specify a margin of 2 dB for both upstream and downstream. If the SNR is 2 dB above the theoretical minimum for the chosen profile when the link is established, the link is classified as down and the next profile in the sequence is attempted.
Switch(config-if)# margin upstream 2 downstream 2This example shows show to specify a margin of 1 dB for downstream:
Switch(config-if)# margin downstream 1Related Commands
Assigns a rate selection sequence for the entire switch.
Enables rate selection on a specific port.
Assigns a rate selection sequence for a specific port.
match
Use the match class-map configuration command to define the match criteria to classify traffic. Use the no form of this command to remove the match criteria.
match {access-group acl-index | access-group name acl-name | ip dscp dscp-list}
no match {access-group acl-index | access-group name acl-name | ip dscp}
This command is available only if your switch is running the enhanced software image (EI).
Syntax Description
Defaults
No match criteria are defined.
Command Modes
Class-map configuration
Command History
Usage Guidelines
Use the match command to specify which fields in the incoming packets are examined to classify the packets. Only IP access groups, MAC access groups, and classification based on DSCP values are supported.
Only one match command per class map is supported.
Note
Examples
This example shows how to classify traffic on an interface by using the access group named acl2:
Switch(config)# class-map class2Switch(config-cmap)# match access-group name acl2Switch(config-cmap)# exitYou can verify your settings by entering the show class-map privileged EXEC command.
Related Commands
media-type
Use the media-type interface configuration command to enable or disable fiber-optic or copper connections on a Long-Reach Ethernet (LRE) switch. You can also manually set the port to select a small form-factor pluggable (SFP) module connector or an RJ-45 connector. Use the no form of this command to return to the default setting.
media-type {auto-select | rj45 | sfp}
no media-type {auto-select | rj45 | sfp}
This command is available only on Catalyst 2950 LRE switches.
Syntax Description
Defaults
The default is SFP module preferred.
Command Modes
Interface configuration
Command History
Usage Guidelines
If an LRE switch detects an SFP connector in the switch, whether or not a fiber-optic connector is connected to that connector, it attempts to establish a link by using the SFP module as the media type. This preference of a fiber-optic connection over a copper connection is called SFP-module preferred. To physically connect both fiber-optic and copper connections and to override the SFP-module-preferred setting, use the auto-select keyword, or manually configure the port by using the rj45 or sfp keyword.
Examples
This example shows how to force the connection to a copper RJ-45 connection:
Switch# configure terminalSwitch(config)# interface gigabitethernet0/1Switch(config-if)# media-type rj45You can verify your settings by using the show interfaces media or media interface-id privileged EXEC command.
Related Commands
show interfaces cpe
Shows the status or resolution of the link.
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
The default CoS value for a port is 0.
CoS override is disabled.
Command Modes
Interface configuration
Command History
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.
Examples
This example shows how to configure the default port CoS to 4:
Switch(config)# interface gigabitethernet0/1Switch(config-if)# mls qos trust cosSwitch(config-if)# mls qos cos 4This example shows how to assign all the packets entering a port to the default port CoS value of 4:
Switch(config)# interface gigabitethernet0/1Switch(config-if)# mls qos cos 4Switch(config-if)# mls qos cos overrideYou can verify your settings by entering the show mls qos interface privileged EXEC command.
Related Commands
Defines the CoS-to-DSCP map or the DSCP-to-CoS map.
Configures the port trust state.
Displays quality of service (QoS) information.
mls qos map
Use the mls qos map global configuration command to define the class of service (CoS)-to-Differentiated Services Code Point (DSCP) map or DSCP-to-CoS map. Use the no form of this command to return to the default map.
mls qos map {cos-dscp dscp1...dscp8 | dscp-cos dscp-list to cos}
no mls qos map {cos-dscp | dscp-cos}
This command is available only if your switch is running the enhanced software image (EI).
Syntax Description
Defaults
Table 2-5 shows the default CoS-to-DSCP map:
Table 2-6 shows the default DSCP-to-CoS map:
Table 2-6 Default DSCP-to-CoS Map
0
0
8, 10
1
16, 18
2
24, 26
3
32, 34
4
40, 46
5
48
6
56
7
Command Modes
Global configuration
Command History
Usage Guidelines
All the maps are globally defined. You apply all maps to all ports.
If you enter the mls qos trust cos command, the default CoS-to-DSCP map is applied.
If you enter the mls qos trust dscp command, the default DSCP-to-CoS map is applied.
After a default map is applied, you can define the CoS-to-DSCP or DSCP-to-CoS map by entering consecutive mls qos map commands.
The supported DSCP values are 0, 8, 10, 16, 18, 24, 26, 32, 34, 40, 46, 48, and 56. If the mls qos trust dscp command is entered and a packet with an untrusted DSCP value is at an ingress port, the packet CoS value is set to 0.
Note
Examples
This example shows how to define the DSCP-to-CoS map. DSCP values 16, 18, 24, and 26 are mapped to CoS 1. DSCP values 0, 8, and 10 are mapped to CoS 0.
Switch# configure terminalSwitch(config)# mls qos map dscp-cos 16 18 24 26 to 1Switch(config)# mls qos map dscp-cos 0 8 10 to 0This example shows how to define the CoS-to-DSCP map. CoS values 0 to 7 are mapped to DSCP values 8, 8, 8, 8, 24, 32, 56, and 56.
Switch# configure terminalSwitch(config)# mls qos map cos-dscp 8 8 8 8 24 32 56 56You can verify your settings by entering the show mls qos maps privileged EXEC command.
Related Commands
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 | dscp]
no mls qos trust [cos [pass-through dscp] | device cisco-phone | dscp]
Syntax Description
Defaults
The port is not trusted.
Pass-through mode is disabled.
Trusted boundary is disabled.
If no keyword is specified and the switch is running the EI, the default is dscp.
Command Modes
Interface configuration
Command History
12.1(6)EA2
This command was introduced.
12.1(11)EA1
The device cisco-phone and pass-through dscp keywords were added.
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.
When a port is configured with trust DSCP and the incoming packet is a tagged non-IP packet, the CoS value for the packet is set to 0, and the DSCP-to-CoS map is not applied. For an untagged non-IP packet, the default port CoS value is used.
If DSCP is trusted, the DSCP field of the IP packet is not modified. However, it is still possible that the CoS value of the packet is modified (according to the DSCP-to-CoS map).
If CoS is trusted, the CoS of the packet is not modified, but DSCP can be modified (according to the CoS-to-DSCP map) if it is an IP packet.
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.
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.
In software releases earlier than Cisco IOS Release 12.1(11)EA1, the switch is in pass-through mode. It uses the CoS value of incoming packets without modifying the DSCP value and sends the packets from one of the four egress queues. You cannot enable or disable pass-through mode if your switch is running a software release earlier than Cisco IOS Release 12.1(11)EA1.
In Cisco IOS Release 12.1(11)EA1 or later, pass-through mode is disabled by default. 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 on a switch running Cisco IOS Release 12.1(11)EA1 or later 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.
Note
Examples
This example shows how to configure a port to be a DSCP-trusted port:
Switch(config)# interface gigabitethernet0/1Switch(config-if)# mls qos trust dscpThis example shows how to specify that the Cisco IP phone is a trusted device:
Switch(config)# interface fastethernet0/1Switch(config-if)# mls qos trust device cisco-phoneThis 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 fastethernet0/1Switch(config-if)# mls qos trust cos pass-through dscpYou can verify your settings by entering the show mls qos interface privileged EXEC command.
Related Commands
monitor session
Use the monitor session global configuration command to start a new Switched Port Analyzer (SPAN) or Remote SPAN (RSPAN) session. Use the no form of this command to remove the SPAN or the RSPAN session or to remove source or destination interfaces from the SPAN or RSPAN session.
monitor session session_number {destination {interface interface-id [, | -] [encapsulation {dot1q}] [ingress vlan vlan id] | remote vlan vlan-id reflector-port interface-id} | {source {interface interface-id [, | -] [both | rx | tx] | remote vlan vlan-id}}
no monitor session session_number {destination {interface interface-id [, | -] [encapsulation {dot1q}] [ingress vlan vlan id] | remote vlan vlan-id reflector-port interface-id} | {source {interface interface-id [, | -] [both | rx
