Table Of Contents
access-list hardware program nonblocking
clear l2protocol-tunnel counters
clear spanning-tree detected-protocols
ip dhcp snooping information option
ip dhcp snooping information option format snmp-ifindex
ip igmp snooping report-suppression
ip igmp snooping source-only-learning age-timer
ip vrf (interface configuration)
mac address-table notification
match (access-map configuration)
match (class-map configuration)
Cisco IOS Commands
aaa authentication dot1x
Use the aaa authentication dot1x global configuration command to specify one or more authentication, authorization, and accounting (AAA) methods for use on interfaces running IEEE 802.1X. Use the no form of this command to disable authentication.
aaa authentication dot1x {default} method1 [method2...]
no aaa authentication dot1x {default}
Syntax Description
Defaults
No authentication is performed.
Command Modes
Global configuration
Command History
Usage Guidelines
The method argument identifies the list of methods that the authentication algorithm tries in the given sequence to validate the password provided by the client. The only method that is truly 802.1X-compliant is the group radius method, in which the client data is validated against a RADIUS authentication server. The remaining methods enable AAA to authenticate the client by using locally configured data. For example, the local and local-case methods use the username and password that are saved in the Cisco IOS configuration file. The enable and line methods use the enable and line passwords for authentication.
If you specify group radius, you must configure the RADIUS server by entering the radius-server host global configuration command.
If you are not using a RADIUS server, you can use the local or local-case methods, which access the local username database to perform authentication. By specifying the enable or line methods, you can supply the clients with a password to provide access to the switch.
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 authentication list for 802.1X. This authentication first tries to contact a RADIUS server. If this action returns an error, the user is allowed access with no authentication.
Switch(config)# aaa new-modelSwitch(config)# aaa authentication dot1x default group radius noneYou can verify your settings by entering the show running-config privileged EXEC command.
Related Commands
access-list hardware program nonblocking
Use the access-list hardware program nonblocking global configuration command to cause the system to continue to forward frames even while a new security access-control list (ACL) configuration is being programmed into the hardware. Use the no form of this command to return to the default behavior, where traffic is blocked on affected interfaces when changes are made to the security ACL configuration while the hardware is updated with the new configuration.
access-list hardware program nonblocking
no access-list hardware program nonblocking
Syntax Description
This command has no arguments or keywords.
Defaults
Traffic is blocked on affected interfaces while a new ACL configuration is loaded into hardware.
Command Modes
Global configuration
Command History
Usage Guidelines
By default, when changes are made to the configuration of security ACLs, the system completely blocks traffic on the affected ports or VLANs while it is updating the hardware to the new configuration. This includes any changes that affect the ternary content addressable memory (TCAM), including applying an ACL to an interface or making changes to VLAN maps or ACLs that are used for security features. This prevents the possibility of forwarding frames that should have been dropped because a partially loaded configuration permitted a frame that the complete configuration would have blocked.
You can use the access-list hardware program nonblocking command to set the system to continue to forward frames while a new security ACL configuration is being programmed into the hardware. Enabling this setting might cause less disruption to traffic that should be allowed while the hardware is being updated, but might also temporarily allow some traffic that would be denied when the new configuration is completely loaded.
Examples
This example shows how to set the system to continue forwarding frames while a new security ACL configuration is being programmed into hardware:
Switch (config)# access-list hardware program nonblockingYou can verify your setting by entering the show running-config | include access-list hardware privileged EXEC command.
Related Commands
access-list {deny | permit}
Configures a standard numbered ACL. For syntax information, select Cisco IOS IP and IP Routing Command Reference for IOS
Release 12.1 > IP Addressing and Services > IP Services Commands.action (access map configuration)
Defines or modifies the action for the VLAN access map entry.
ip access-group
Applies an IP access list to a Layer 2 or Layer 3 interface.
ip access-list
Configures a named access list. For syntax information, select Cisco IOS IP and IP Routing Command Reference for IOS Release 12.1 > IP Addressing and Services > IP Services Commands.
Applies a MAC access list to a Layer 2 interface.
Defines the match conditions for a VLAN map.
show running-config | include access-list hardware
Displays the current operating configuration. For syntax information, select Cisco IOS Configuration Fundamentals Command Reference for Release 12.1 > Cisco IOS File Management Commands > Configuration File Commands.
Creates a VLAN access map or enters access-map configuration mode.
Applies a VLAN map to one or more VLANs.
action
Use the action access map configuration command to set the action for the VLAN access map entry. Use the no form of this command to set the action to the default value, which is to forward.
action {drop | forward}
no action
Syntax Description
drop
Drop the packet when the specified conditions are matched.
forward
Forward the packet when the specified conditions are matched.
Defaults
The default action is to forward packets.
Command Modes
Access-map configuration
Command History
Usage Guidelines
You enter access-map configuration mode by using the vlan access-map global configuration command.
If the action is drop, you should define the access map, including configuring any access control list (ACL) names in match clauses, before applying the map to a VLAN, or all packets could be dropped.
In access map configuration mode, use the match access map configuration command to define the match conditions for a VLAN map. Use the action command to set the action that occurs when a packet matches the conditions.
The drop and forward parameters are not used in the no form of the command.
Examples
This example shows how to identify and apply a VLAN access map vmap4 to VLANs 5 and 6 that causes the VLAN to forward an IP packet if the packet matches the conditions defined in access list al2:
Switch(config)# vlan access-map vmap4Switch(config-access-map)# match ip address al2Switch(config-access-map)# action forwardSwitch(config-access-map)# exitSwitch(config)# vlan filter vmap4 vlan-list 5-6You can verify your settings by entering the show vlan access-map privileged EXEC command.
Related Commands
archive download-sw
Use the archive download-sw privileged EXEC command to download a new image to the switch and overwrite or keep the existing image.
archive download-sw {/force-reload | /imageonly | /leave-old-sw | /no-set-boot | /overwrite | /reload | /safe} source-url
Syntax Description
Defaults
The current software image is not overwritten with the downloaded image.
Both the software image and HTML 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 HTML files for the existing image if the existing image is being removed or replaced. Only the Cisco IOS image (without the HTML 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" section.
If you leave the existing software in place before downloading the new image, an error results if the existing software will prevent 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 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 /image-only 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, list files in a tar file, or 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
None
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 172.20.10.30:
Switch# archive tar /create tftp:172.20.10.30/saved.tar flash:/new-configsThis example shows how to display the contents of the c3550-tv0-m.tar file that is in Flash memory. The contents of the tar file appear on the screen:
Switch# archive tar /table flash:c3550-tv0-m.tarinfo (219 bytes)c3550-tv0-mz-121/ (directory)c3550-tv0-mz-121/html/ (directory)c3550-tv0-mz-121/html/foo.html (0 bytes)c3550-tv0-mz-121/vegas-tv0-mz-121.bin (610856 bytes)c3550-tv0-mz-121/info (219 bytes)info.ver (219 bytes)This example shows how to display only the c3550-tv0-mz-121/html directory and its contents:
Switch# archive tar /table flash:c3550-tv0-m.tar c3550-tv0-mz-121/htmlc3550-tv0-mz-121/html/ (directory)c3550-tv0-mz-121/html/foo.html (0 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 switch image to a server.
archive upload-sw [/version version_string] destination-url
Syntax Description
Defaults
Uploads the currently running image from the flash: file system.
Command Modes
Privileged EXEC
Command History
Usage Guidelines
The upload feature is available only if the HTML files associated with the Cluster Management Suite (CMS) have been installed with the existing image.
The files are uploaded in this sequence: info, the Cisco IOS image, the HTML 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 the 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 automatically configure 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 | trust}
no auto qos voip
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 class of service (CoS) packet labels and to configure the egress queues as summarized in Table 2-1.
Table 2-1 Traffic Types, Ingress Packet Labels, Assigned Packet Labels, and Egress Queues
Ingress DSCP3
46
26
-
-
-
Ingress CoS
5
3
6
7
-
DiffServ
EF
AF31
-
-
-
Assigned DSCP
46
26
48
56
0
Assigned CoS
5
3
6
7
0
CoS-to-Queue Map
5
3, 6, 7
0, 1, 2, 4
Egress Queue
Expedite queue
80% WRR4
20% WRR
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
Usage Guidelines
Use this command to configure the QoS 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.
Use the cisco-phone keyword on ports at the edge of the network that are connected to Cisco IP phones. The switch detects the telephone through the Cisco Discovery Protocol (CDP) and trusts the QoS labels in packets received from the telephone.
Use the trust keyword on ports connected to the interior of the network. Because it is assumed that traffic has already been classified by other edge devices, the QoS labels in these packets are trusted.
When you enable the auto-QoS feature on the first interface, these automatic actions occur:
•
QoS is globally enabled (mls qos global configuration command).
•
•
You can enable auto-QoS on static, dynamic-access, voice VLAN access, and trunk ports.
To display the QoS configuration that is automatically generated when auto-QoS is enabled, enable debugging before you enable auto-QoS. Use the debug autoqos 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 enables standard QoS and changes the auto-QoS settings to the standard-QoS default settings for that interface.
To disable auto-QoS on the switch, use the no mls qos global configuration command. When you enter this command, the switch disables QoS on all interfaces and enables pass-through mode.
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 Gigabit Ethernet interface 0/1 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 Fast Ethernet interface 0/1 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 autoqosAutoQoS debugging is onSwitch# configure terminalEnter configuration commands, one per line. End with CNTL/Z.Switch(config)# interface fastethernet0/1Switch(config-if)# auto qos voip trustSwitch(config-if)#4d22h:mls qos map cos-dscp 0 8 16 26 32 46 48 564d22h:mls qos min-reserve 5 1704d22h:mls qos min-reserve 6 104d22h:mls qos min-reserve 7 654d22h:mls qos min-reserve 8 264d22h:mls qos4d22h:interface FastEthernet0/14d22h: mls qos trust cos4d22h: wrr-queue bandwidth 20 1 80 04d22h: wrr-queue min-reserve 1 54d22h: wrr-queue min-reserve 2 64d22h: wrr-queue min-reserve 3 74d22h: wrr-queue min-reserve 4 84d22h: no wrr-queue cos-map4d22h: wrr-queue cos-map 1 0 1 2 44d22h: wrr-queue cos-map 3 3 6 74d22h: wrr-queue cos-map 4 54d22h: priority-queue outSwitchconfig-if)# interface gigabitethernet0/1Switch(config-if)# auto qos voip cisco-phoneSwitch(config-if)#4d22h:interface GigabitEthernet0/14d22h: mls qos trust device cisco-phone4d22h: mls qos trust cos4d22h: wrr-queue bandwidth 20 1 80 04d22h: wrr-queue queue-limit 80 1 20 14d22h: no wrr-queue cos-map4d22h: wrr-queue cos-map 1 0 1 2 44d22h: wrr-queue cos-map 3 3 6 74d22h: wrr-queue cos-map 4 54d22h: priority-queue outSwitch(config-if)#You can verify your settings by entering the show auto qos interface interface-id privileged EXEC command.
Related Commands
Enables debugging of the auto-QoS feature.
mls qos map {cos-dscp dscp1 ... dscp8 | dscp-cos dscp-list to cos}
Defines the CoS-to-DSCP map or the DSCP-to-CoS map.
Configures the port trust state.
Displays auto-QoS information.
Displays global QoS configuration information.
Displays QoS information at the interface level.
Displays QoS mapping information.
boot boothlpr
Use the boot boothlpr global configuration command to load a special Cisco IOS image, which when loaded into memory, can load a second Cisco IOS image into memory and launch it. This variable is used only for internal development and testing. Use the no form of this command to return to the default setting.
boot boothlpr filesystem:/file-url
no boot boothlpr
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 helper image.
Defaults
No helper image is loaded.
Command Modes
Global configuration
Command History
Usage Guidelines
Filenames and directory names are case sensitive.
This command changes the setting of the BOOTHLPR environment variable. For more information, see "Boot Loader Commands."
Related Commands
boot buffersize
Use the boot buffersize global configuration command to specify the size of the file system-simulated nonvolatile RAM (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
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 "Boot Loader Commands."
Related Commands
boot config-file
Use the boot config-file global configuration command to specify the filename that Cisco IOS 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
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 "Boot Loader Commands."
Related Commands
boot enable-break
Use the boot enable-break global configuration command to enable interrupting the automatic boot process. Use the no form of this command to return to the default setting.
boot enable-break
no boot enable-break
Syntax Description
This command has no arguments or keywords.
Defaults
Disabled. The automatic boot 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 "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 patch the functionality of the boot loader. Use the no form of this command to return to the default.
boot helper filesystem:/file-url ...
no boot helper
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 "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 Cisco IOS 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
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 "Boot Loader Commands."
Related Commands
boot manual
Use the boot manual global configuration command to enable manually booting the switch during the next boot cycle. Use the no form of this command to return to the default setting.
boot manual
no boot manual
Syntax Description
This command has no arguments or keywords.
Defaults
Manual booting is disabled.
Command Modes
Global configuration
Command History
Usage Guidelines
The next time you reboot the system, the switch is in boot loader mode, which is shown by the switch: prompt. To boot 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 "Boot Loader Commands."
Related Commands
boot private-config-file
Use the boot private-config-file global configuration command to specify the filename that Cisco IOS 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 Cisco IOS 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 to be pconfig:
Switch(config)# boot private-config-file pconfigRelated Commands
boot system
Use the boot system global configuration command to specify the Cisco IOS image to load during the next boot cycle. Use the no form of this command to return to the default setting.
boot system filesystem:/file-url ...
no boot system
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 boot 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 continuing the 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 never 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 "Boot Loader Commands."
Related Commands
channel-group
Use the channel-group interface configuration command to assign an Ethernet interface to an EtherChannel group. Use the no form of this command to remove an Ethernet interface from an EtherChannel group.
channel-group channel-group-number mode {auto [non-silent] | desirable [non-silent] | on | active | passive}
no channel-group
Syntax Description
Defaults
No channel groups are assigned.
No mode is configured.
Command Modes
Interface configuration
Command History
12.1(4)EA1
This command was first introduced.
12.1(12c)EA1
The active and passive keywords were added.
Usage Guidelines
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, if it is not already created.
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.
For Layer 2 EtherChannels, you must configure the channel-group interface configuration command, which automatically creates the port-channel logical interface. You cannot put Layer 2 interfaces into a manually created port-channel interface.
You create Layer 3 port channels by using the interface port-channel command. You must manually configure the port-channel logical interface before putting the interface into the channel group.
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).
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. A 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.
With the on mode, a usable PAgP EtherChannel exists only when a port group in on mode is connected to another port group in on mode.
Caution
Note
Before enabling 802.1X on a port, you must first remove it from the EtherChannel. If you try to enable 802.1X on an EtherChannel or on an active port in an EtherChannel, an error message appears, and 802.1X is not enabled. If you enable 802.1X on a not-yet active port of an EtherChannel, the port does not join the EtherChannel.
Do not configure a secure port as part of an EtherChannel.
Caution
Examples
This example shows how to assign Gigabit Ethernet interfaces 0/4 and 0/5 as static-access ports in VLAN 10 to channel 5 with the PAgP mode desirable:
Switch# configure terminalSwitch(config)# interface range gigabitethernet0/4 -5Switch(config-if-range)# switchport mode accessSwitch(config-if-range)# switchport access vlan 10Switch(config-if-range)# channel-group 5 mode desirableSwitch(config-if-range)# endThis 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 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. Use the no form of this command to delete an existing class map.
class class-map-name
no class class-map-name
Syntax Description
Note
Defaults
No policy map class-maps are defined.
Command Modes
Policy-map configuration
Command History
Usage Guidelines
Use the policy-map global configuration command to identify the policy map and to enter policy-map configuration mode before you use the class command. 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.
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.
After you enter the class command, the switch enters policy-map class configuration mode, and 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.
Examples
This example shows how to create a policy map called policy1. When attached to the ingress direction, it matches all the incoming traffic defined in class1, sets the IP DSCP to 10, and polices the traffic at an average rate of 1 Mbps and for 20 KB bursts. Traffic exceeding the profile is marked down to a DSCP value obtained from the policed-DSCP map and then sent.
Switch(config)# policy-map policy1Switch(config-pmap)# class class1Switch(config-pmap-c)# set ip dscp 10Switch(config-pmap-c)# police 1000000 20000 exceed-action policed-dscp-transmitSwitch(config-pmap-c)# exitYou 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 return to global configuration mode.
class-map [match-all | match-any] class-map-name
no class-map [match-all | match-any] class-map-name
Syntax Description
Defaults
No class maps are defined.
When neither the match-all or match-any keyword is specified, the default is match-all.
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.
The class-map command and its subcommands are used to define packet classification, marking, and aggregate policing as part of a globally named service policy applied on a per-interface basis.
After you are in quality of service (QoS) class-map configuration mode, these configuration commands are available:
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A class-map with this name already existsTo define packet classification on a physical-port basis, only one match command per class map is supported. In this situation, the match-all and match-any keywords are equivalent.
To define packet classification on a per-port per-VLAN basis, you must use the match-all keyword with the class-map global configuration command. You also must enter the match vlan vlan-list and the match class-map class-map-name class-map configuration commands. For more information, see the "match (class-map configuration)" section.
Only one access control list (ACL) can be configured in a class map. The ACL can have multiple access control entries (ACEs).
Examples
This example shows how to configure the class map called class1. class1 has one match criterion, which is an access list called 103.
Switch(config)# access-list 103 permit any any dscp 10Switch(config)# class-map class1Switch(config-cmap)# match access-group 103Switch(config-cmap)# exitThis example shows how to delete the class map class1:
Switch(config)# no class-map class1This example shows how to configure a class map called dscp_class whose match criterion is to match IP DSCP 9. A second class map, called vlan_class, matches traffic on VLANs 10, 20 to 30, and 40 to class map dscp_class:
Switch(config)# class-map match-any dscp_classSwitch(config-cmap)# match ip dscp 9Switch(config-cmap)# exitSwitch(config)# class-map match-all vlan_classSwitch(config-cmap)# match vlan 10 20-30 40Switch(config-cmap)# match class-map dscp_classSwitch(config-cmap)# exitYou can verify your settings by entering the show class-map privileged EXEC command.
Related Commands
Defines the match criteria to classify traffic.
Creates or modifies a policy map that can be attached to multiple interfaces to specify a service policy.
Displays QoS class maps.
clear lacp
Use the clear lacp privileged EXEC command to clear Link Aggregration Control Protocol (LACP) channel-group counters.
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 l2protocol-tunnel counters
Use the clear l2protocol-tunnel counters privileged EXEC command to clear the protocol counters in protocol tunnel ports.
clear l2protocol-tunnel counters [interface-id]
Syntax Description
Defaults
This command has no defaults.
Command Modes
Privileged EXEC
Command History
Usage Guidelines
Use this command to clear protocol tunnel counters on the switch or on the specified interface.
Examples
This example shows how to clear Layer 2 protocol tunnel counters for Gigabit Ethernet interface 0/3:
Switch # clear l2protocol-tunnel counters gigabitethernet0/3Related Commands
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
Command Modes
Privileged EXEC
Command History
Examples
This example shows how to remove a specific MAC address from the dynamic address table:
Switch# clear mac address-table dynamic address 0008.0070.0007You can verify that 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 10This example shows how to clear channel-group traffic filters:
Switch# clear pagp countersYou can verify that 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 dynamic or sticky secure address on an interface.
clear port-security {all | configured | dynamic | sticky} [address mac-addr [vlan vlan-id]] | [interface interface-id]
Syntax Description
Defaults
No default is defined.
Command Modes
Privileged EXEC
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-addr vlan vlan-id command, the switch removes the specified secure MAC address from the specified VLAN.
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.
Command History
12.1(11)EA1
This command was first introduced.
12.1(14)EA1
The all, configured, and vlan keywords were added.
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 gigabitethernet0/1This 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.
clear setup express
Use the clear setup express privileged EXEC command to exit Express Setup mode without saving the current configuration.
clear setup express
Syntax Description
This command has no arguments or keywords.
Defaults
No default is defined.
Command Modes
Privileged EXEC
Command History
Usage Guidelines
You can use the clear setup express privileged EXEC command to exit Express Setup mode. For example, if you activate Express Setup and then decide to connect to the switch through the console port instead of through an Ethernet port, enter the clear setup express command. The switch exits Express Setup mode. The IP address 10.0.0.1 is no longer valid on the switch, and your connection using this IP address is ended.
This command is available only when the switch is in Express Setup mode.
Examples
This example shows how to exit Express Setup mode:
Switch# clear setup expressYou can verify that the switch has exited Express Setup mode by entering the show express setup privileged EXEC command.
Related Commands
Enables Express Setup mode on the switch.
Displays if Express Setup mode is active on the switch.
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
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 802.1D switches. If a rapid-PVST+ switch or an MSTP switch receives a legacy 802.1D configuration bridge protocol data unit (BPDU) with the protocol version set to 0, it sends only 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 MSTP mode if it no longer receives 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 Fast Ethernet interface 0/1:
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 information was deleted by entering the show vmps statistics privileged EXEC command.
Related Commands
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 information was deleted by entering the show vtp counters privileged EXEC command.
Related Commands
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. Use the no form of this command from the member switch console 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 console 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 partial sample output 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
Displays the cluster status and a summary of the cluster to which the switch belongs.
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 from 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 hop count limit to 4. This command is executed on the command switch.
Switch(config)# cluster discovery hop-count 4You can verify your setting 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.
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 to optionally assign a member number to it. Use the no form of this command to remove all members and to 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 the switch 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 cluster 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 setting 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.
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 set the duration to the default value.
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 from 1 to 300 seconds.
Defaults
The default 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 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 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 member
Use the cluster member global configuration command on the command switch to add candidates 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 candidate 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 that is 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 outside-interface
Use the cluster outside-interface global configuration command to configure the outside interface for cluster Network Address Translation (NAT) so that a member without an IP address can communicate with devices outside the cluster. Use the no form of this command to return to the default setting.
cluster outside-interface interface-id
no cluster outside-interface
Syntax Description
interface-id
Interface to serve as the outside interface. Valid interfaces include physical interfaces, port-channels, or VLANs. The port-channel range is 1 to 64. The VLAN range is 1 to 4094.
Defaults
The default outside interface is automatically selected by the command switch.
Command Modes
Global configuration
Command History
Usage Guidelines
Enter this command only on the command switch. If you enter this command on a member switch, an error message appears.
Examples
This example shows how to set the outside interface to VLAN 1:
Switch(config)# cluster outside-interface vlan 1You can verify your setting by entering the show running-config privileged EXEC command.
Related Commands
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
Syntax Description
This command has no arguments or keywords.
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 is incapable of becoming 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 is incapable of becoming 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 your setting 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 cluster to an existing Hot Standby Router Protocol (HSRP). Entering the routing-redundancy keyword enables the same HSRP group to be used for command-switch redundancy and routing redundancy. Use the no form of this command to return to the default setting.
cluster standby-group HSRP-group-name [routing-redundancy]
no cluster standby-group
Syntax Description
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 cluster-HSRP capable members. Each member switch stores the binding information in its nonvolatile RAM (NVRAM).
The HSRP group name must be a valid standby group; otherwise, the command exits with an error.
The same group name should be used on all members of the HSRP standby group that is to be bound to the cluster. The same HSRP group name should also be used 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 for the cluster commander and the members.)
Examples
This example shows how to bind the HSRP group named my_hsrp to the cluster. This command is executed on the command switch.
Switch(config)# cluster standby-group my_hsrpThis example shows how to use the same HSRP group named my_hsrp for routing redundancy and cluster redundancy.
Switch(config)# cluster standby-group my_hsrp routing-redundancyThis example shows the error message when this command is executed 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 executed on a member switch:
Switch(config)# cluster standby-group my_hsrp routing-redundancy%ERROR: This command runs on a cluster command switchYou can verify your settings by entering the show cluster privileged EXEC command. The output shows whether redundancy is enabled in the cluster.
Related Commands
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 set the interval to the default value.
cluster timer interval-in-secs
no cluster timer
Syntax Description
interval-in-secs
Interval in seconds between heartbeat messages. The range is from 1 to 300 seconds.
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.
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:
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Valid values for type and interface:
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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 slot/number (where slot is always 0 for the Catalyst 3550 switch), and the range can be entered as one of the following:
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You can also enter multiple ranges.
When you define a range, you must enter a space before and after the hyphen (-), for example, gigabitethernet0/1 - 2
When you define multiple ranges, you must enter a space before and after the comma (,), for example, fastethernet0/3 - 7 , gigabitethernet0/1 - 2
Examples
This example shows how to create a multiple-interface macro:
Switch(config)# define interface-range macro1 gigabitethernet 0/1 -2 , gigabitethernet 0/5Related 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
Usage Guidelines
If you use the /force keyword, you are prompted 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, refer to the Cisco IOS Command Reference for Release 12.1.
Examples
This example shows how to remove the directory that contains the old software image after a successful download of a new image:
Switch# delete /force /recursive flash:/old-imageYou can verify that the directory was removed by entering the dir filesystem: privileged EXEC command.
Related Commands
deny
Use the deny MAC access list configuration command to prevent non-IP traffic from being forwarded if the conditions are matched. Use the no form of this command to remove a deny condition from the named MAC access list.
{deny | permit} {any | host src-MAC-addr | src-MAC-addr mask} {any | host dst-MAC-addr | dst-MAC-addr mask} [type mask | aarp | amber | cos cos | dec-spanning | decnet-iv | diagnostic | dsm | etype-6000 | etype-8042 | lat | lavc-sca | lsap lsap mask |mop-console | mop-dump | msdos | mumps | netbios | vines-echo | vines-ip | xns-idp]
no {deny | permit} {any | host src-MAC-addr | src-MAC-addr mask} {any | host dst-MAC-addr | dst-MAC-addr mask} [type mask | aarp | amber | cos cos | dec-spanning | decnet-iv | diagnostic | dsm | etype-6000 | etype-8042 | lat | lavc-sca | lsap lsap mask | mop-console | mop-dump | msdos | mumps | netbios | vines-echo | vines-ip | xns-idp]
Note
Syntax Description
To filter IPX traffic, you use the type mask or lsap lsap mask keywords, depending on the type of IPX encapsulation being used. Filter criteria for IPX encapsulation types as specified in Novell terminology and Cisco IOS terminology are listed in Table 2-3.
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
You enter MAC-access list configuration mode by using the mac access-list extended global configuration command.
If you use the host keyword, you cannot enter an address mask; if you do not use the host keyword, you must enter an address mask.
When an access control entry (ACE) is added to an access control list, 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.
Note
Examples
This example shows how to define the named MAC extended access list 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 netbios.This example shows how to remove the deny condition from the named MAC extended access list:
Switch(config-ext-macl)# no deny any 00c0.00a0.03fa 0000.0000.0000 netbios.This example denies all packets with Ethertype 0x4321:
Switch(config-ext-macl)# deny any any 0x4321 0You can verify your settings by entering the show access-lists privileged EXEC command.
Related Commands
dot1x default
Use the dot1x default interface configuration command to reset the configurable 802.1X parameters to their default values.
dot1x default
Syntax Description
This command has no arguments or keywords.
Defaults
These are the default values:
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Command Modes
Interface configuration
Command History
12.1(8)EA1
This command was first introduced.
12.1(14)EA1
This command was changed to the interface configuration mode.
Examples
This example shows how to reset the configurable 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 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 802.1X guest VLAN. 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
Usage Guidelines
When you configure a guest VLAN, clients that are not 802.1X-capable are put into the guest VLAN when the server does not receive a response to its Extensible Authentication Protocol over LAN (EAPOL) request/identity frame. Clients that are 802.1X-capable but fail authentication are not granted access to the network.
Guest VLANs are supported on 802.1X ports in single-host mode and multiple-hosts mode.
Any VLAN can be configured as an 802.1X guest VLAN except RSPAN VLANs, voice VLANs, or internal routed ports.
Examples
This example shows how to specify VLAN 5 as an 802.1X guest VLAN:
Switch(config-if)# dot1x guest-vlan 5You can verify your settings by entering the show dot1x [interface interface-id] privileged EXEC command.
Related Commands
show dot1x [interface interface-id]
Displays 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 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 first introduced. It replaces the dot1x multiple-hosts interface configuration command.
Usage Guidelines
You can use this command to limit an 802.1X-enabled port to a single client or to attach multiple clients to an 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 802.1X globally, enable 802.1X on Fast Ethernet interface 0/1, 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 802.1X status for the specified interface.
dot1x initialize
Use the dot1x initialize privileged EXEC command to manually return an 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 Fast Ethernet interface 0/1 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 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)-request/identity frame (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-request/identity frame before restarting the authentication process. The range is 1 to 10.
Defaults
The default is 2.
Command Modes
Interface configuration
Command History
12.1(8)EA1
This command was first 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-request/identity 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 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 802.1X-authorized port.
Command History
Related Commands
Set the 802.1X host mode on an interface.
Displays 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 802.1X globally on the switch by using the dot1x system-auth-control global configuration command before enabling 802.1X on a specific interface.
The 802.1X protocol is supported on both Layer 2 static-access ports and Layer 3 routed ports.
You can use the auto keyword only if the port is not configured as one of these:
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To disable 802.1X globally on the switch, use the no dot1x system-auth-control global configuration command. To disable 802.1X on a specific interface, use the no dot1x port-control interface configuration command.
Examples
This example shows how to enable 802.1X on Fast Ethernet interface 0/1:
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 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 all 802.1X-enabled ports or the specified 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 Fast Ethernet interface 0/1:
Switch# dot1x re-authenticate interface fastethernet0/1Related Commands
Displays 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
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 first 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 802.1X status for the specified interface.
dot1x system-auth-control
Use the dot1x system-auth-control global configuration command to enable 802.1X globally. Use the no form of this command to return to the default setting.
dot1x system-auth-control
no dot1x system-auth-control
Syntax Description
This command has no arguments or keywords.
Defaults
802.1X is disabled.
Command Modes
Global configuration
Command History
Usage Guidelines
You must enable authentication, authorization, and accounting (AAA) and specify the authentication method list before enabling 802.1X globally. A method list describes the sequence and authentication methods to be queried to authenticate a user.
Examples
This example shows how to enable 802.1X globally on a switch:
Switch(config)# dot1x system-auth-controlYou can verify your settings by entering the show dot1x privileged EXEC command.
Related Commands
Displays 802.1X statistics, administrative status, and operational status for the switch or for the specified interface.
dot1x timeout
Use the dot1x timeout interface configuration command to set the 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-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 smaller number 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 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 802.1X status for the specified interface.
duplex
Use the duplex interface configuration command to specify the duplex mode of operation for Fast Ethernet and Gigabit Ethernet ports. Use the no form of this command to return the port to its default value.
duplex {auto | full | half}
no duplex
Note
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
The default is auto.
Command Modes
Interface configuration
Command History
Usage Guidelines
Certain ports can be configured to be either full duplex or half duplex. Applicability of this command depends on the device to which the switch is attached.
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.
For Gigabit Ethernet ports, setting the port to auto has the same effect as specifying full if the attached device does not autonegotiate the duplex parameter.
You cannot configure duplex mode on GBIC interfaces.
If both ends of the line support autonegotiation, we highly recommend using the default autonegotiation settings. If one interface supports autonegotiation and the other end does not, configure duplex and speed on both interfaces; do use the auto setting on the supported side.
If the speed is set to auto, the switch negotiates with the device at the other end of the link for the speed setting and then forces the speed setting to the negotiated value. The duplex setting remains as configured on each end of the link, which could result in a duplex setting mismatch.
If both the speed and duplex are set to specific values, autonegotiation is disabled.
Caution
Note
Examples
This example shows how to configure an interface for full duplex operation:
Switch(config)# interface gigabitethernet0/1Switch(config-if)# duplex fullYou can verify your setting by entering the show interfaces privileged EXEC command.
Related Commands
Displays the interface settings on the switch.
Sets the speed on a 10/100/1000 Mbps interface.
errdisable detect cause
Use the errdisable detect cause global configuration command to enable error disable detection for a specific cause or all causes. Use the no form of this command to disable the error disable detection feature.
errdisable detect cause {all | dhcp-rate-limit | dtp-flap | gbic-invalid | l2ptguard | link-flap | loopback | pagp-flap}
no errdisable detect cause {all | dhcp-rate-limit | dtp-flap | gbic-invalid | l2ptguard | link-flap | loopback | pagp-flap}
Syntax Description
Defaults
Detection is enabled for all causes.
Command Modes
Global configuration
Command History
Usage Guidelines
A cause (dhcp-rate-limit, dtp-flap, gbic-invalid, l2ptguard, link-flap, loopback, and pagp-flap) 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 set a recovery mechanism for the cause by entering the errdisable recovery global configuration command for the cause, the interface is brought out of the error-disabled state and allowed to retry the operation when all causes have timed out. If you do not set a recovery mechanism, 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 setting by entering the show errdisable detect privileged EXEC command.
Related Commands
Displays errdisable detection information.
show interfaces status err-disabled
Displays interface status or a list of interfaces in the 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 | l2ptguard | 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 | l2ptguard | link-flap | loopback | pagp-flap | psecure-violation | security-violation | udld | vmps}} | {interval interval}
Syntax Description
Defaults
Recovery is disabled for all causes.
The default recovery interval is 300 seconds.
Command Modes
Global configuration
Command History
Usage Guidelines
A cause (bpduguard, dhcp-rate-limit, dtp-flap, gbic-invalid, l2ptguard, link-flap, loopback, pagp-flap, psecure-violation, security-violation, udld, vmps) 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 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 err-disabled
Displays interface status or a list of interfaces in error-disabled state.
flowcontrol
Use the flowcontrol interface configuration command to set the receive or send flow-control value for an 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 Gigabit Ethernet interfaces are flowcontrol receive off and flowcontrol send desired. The defaults for Fast Ethernet interfaces are flowcontrol receive off and flowcontrol send off.
Command Modes
Interface configuration
Command History
Usage Guidelines
You must not configure both IEEE 802.3X flowcontrol and quality of service (QoS) on a switch. Before configuring flowcontrol on an interface, use the no mls qos global configuration command to disable QoS on the switch.
Note that when used with receive, the on and desired keywords have the same result.
Note
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 2-4 shows the flow control results on local and remote ports for a combination of settings. The table assumes that receive desired has the same results as using the receive on keywords. Because 10/100 Mbps ports cannot send pause frames, only the last two rows (send off) apply to these ports.
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 privileged EXEC command.
Related Commands
Displays the interface settings on the switch, including input and output flow control.
interface port-channel
Use the interface port-channel global configuration command to access or create the port-channel logical interface for Layer 3 routed 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
For Layer 2 EtherChannels, you must configure the channel-group interface configuration command, which automatically creates the port-channel logical interface. You cannot put Layer 2 interfaces into a manually created port-channel interface.
You create Layer 3 port channels by using the interface port-channel command. You must manually configure the port-channel logical interface before putting the interface into the channel group.
Only one port channel in a channel group is allowed.
Caution
Caution
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 setting by entering the show running-config privileged EXEC 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
When you enter interface range configuration mode, all interface parameters you enter are attributed to all interfaces within the range.
For VLANs, you can use the interface range command only on existing VLAN switch virtual interfaces (SVIs). To display VLAN SVIs, enter the show running-config privileged EXEC command. VLANs not displayed cannot be used in the interface range command. The commands entered under interface range command are applied to all existing VLAN SVIs in the range.
All configuration changes made to an interface range are saved to nonvolatile RAM (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, or all VLANs.
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 Catalyst 3550 switch), and you can enter the range in one of these ways:
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When you define a range, you must enter a space between the first entry and the hyphen (-):
interface range gigabitethernet0/1 -2, gigabitethernet0/4 -5When you define multiple ranges, you must enter a space before and after the comma (,):
interface range fastethernet0/3 - 7 , gigabitethernet0/1 - 2You cannot specify both a macro and an interface range in the same command.
A single interface can also be specified in port-range (this would make the command 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 to apply commands to two ports:
Switch(config)# interface range gigabitethernet0/1 - 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 macro1 until you delete it.
Switch(config)# define interface-range macro1 gigabitethernet0/1 - 2Switch(config)# interface range macro macro1Switch(config-if-range)#Related Commands
interface vlan
Use the interface vlan global configuration command to create or access a dynamic switch virtual interface (SVI) and to enter interface configuration mode. Use the no form of this command to delete an SVI.
interface vlan vlan-id
no interface vlan vlan-id
Syntax Description
Defaults
The default VLAN interface is VLAN 1.
Command Modes
Global configuration
Command History
Usage Guidelines
You cannot delete the VLAN 1 interface.
SVIs are created the first time you enter the interface vlan vlan-id command for a particular vlan. The vlan-id corresponds to the VLAN-tag associated with data frames on an ISL or 802.1Q encapsulated trunk or the VLAN ID configured for an access port.
Note
If you delete an SVI by entering the no interface vlan vlan-id command, the deleted interface is no longer visible in the output from the show interfaces privileged EXEC command.
You can reinstate a deleted SVI by entering the interface vlan vlan-id command for the deleted interface. The interface comes back up, but much of the previous configuration will be gone.
The number of routed ports and SVIs that you can configure is not limited by software; however, the interrelationship between this number and the number of other features being configured might have an impact on CPU utilization due to hardware limitations. You can use the sdm prefer global configuration command to reallocate system hardware resources based on templates and feature tables. For the Catalyst 3550 Gigabit Ethernet switches, the tables are based on 16 routed interfaces (SVIs and routed ports. For switches with mainly Fast Ethernet ports, the tables are based on 8 routed interfaces. For more information, see the sdm prefer command.
Examples
This example shows how to create a new SVI with VLAN ID 23 and enter interface configuration mode:
Switch(config)# interface vlan 23Switch(config-if)#You can verify your setting by entering the show interfaces and show interfaces vlan vlan-id privileged EXEC commands.
Related Commands
show interfaces vlan vlan-id
Displays the administrative and operational status of all interfaces or the specified VLAN.
ip access-group
Use the ip access-group interface configuration command to control access to a Layer 2 or Layer 3 interface. Use the no form of this command to remove all access groups or the specified access group from the interface.
ip access-group {access-list-number | name} {in | out}
no ip access-group [access-list-number | name] {in | out}
Syntax Description
Defaults
No access list is applied to the interface.
Command Modes
Interface configuration
Command History
Usage Guidelines
You can apply named or numbered standard or extended access lists to an interface. To define an access list by name, use the ip access-list global configuration command. To define a numbered access list, use the access list global configuration command. You can used numbered standard access lists ranging from 1 to 99 and 1300 to 1999 or extended access lists ranging from 100 to 199 and 2000 to 2699.
You can use this command to apply an access list to a Layer 2 or Layer 3 interface. However, note these limitations for Layer 2 interfaces (port ACLs):
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You can apply IP ACLs to both outbound or inbound Layer 3 interfaces.
A Layer 2 interface can have only one IP ACL applied (in the inbound direction). A Layer 3 interface can have one IP ACL applied in each direction.
You cannot apply an IP ACL to a Layer 3 interface on a switch that has a Layer 2 interface with an applied IP ACL or MAC ACL, and you cannot apply a VLAN map to any of the switch VLANs.
You cannot apply an IP ACL or MAC ACL to a Layer 2 interface on a switch that has an input Layer 3 ACL or a VLAN map applied to it.
For standard inbound access lists, after the switch receives a packet, it checks the source address of the packet against the access list. IP extended access lists can optionally check other fields in the packet, such as the destination IP address, protocol type, or port numbers. If the access list permits the packet, the switch continues to process the packet. If the access list denies the packet, the switch discards the packet. If the access list has been applied to a Layer 3 interface, discarding a packet (by default) causes the generation of an Internet Control Message Protocol (ICMP) Host Unreachable message. ICMP Host Unreachable messages are not generated for packets discarded on a Layer 2 interface.
For standard outbound access lists, after receiving a packet and sending it to a controlled interface, the switch checks the packet against the access list. If the access list permits the packet, the switch sends the packet. If the access list denies the packet, the switch discards the packet and, by default, generates an ICMP Host Unreachable message.
If the specified access list does not exist, all packets are passed.
Examples
This example shows how to apply IP access list 101 to inbound packets on Fast Ethernet interface 1:
Switch(config)# interface fastethernet0/1Switch(config-if)# ip access-group 101 inYou can verify your settings by entering the show ip interface, 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 the Layer 2 switch or an IP address for each switch virtual interface (SVI) or routed port on the Layer 3 switch. Use the no form of this command to remove an IP address or to disable IP processing.
ip address ip-address subnet-mask [secondary]
no ip address [ip-address subnet-mask] [secondary]
Syntax Description
Defaults
No IP address is defined.
Command Modes
Interface configuration
Command History
Usage Guidelines
If you remove the switch IP address through a Telnet session, your connection to the switch is lost.
Hosts can determine subnet masks by sending an Internet Control Message Protocol (ICMP) Mask Request message. Routers respond to this request with an ICMP Mask Reply message.
You can disable IP processing on a particular interface by removing its IP address with the no ip address command. If the switch detects another host using one of its IP addresses, it sends an error message to the console.
You can use the optional keyword secondary to specify an unlimited number of secondary addresses. Secondary addresses are treated like primary addresses, except the system never generates datagrams other than routing updates with secondary source addresses. IP broadcasts and ARP requests are handled properly, as are interface routes in the IP routing table.
Note
When you are routing Open Shortest Path First (OSPF), ensure that all secondary addresses of an interface fall into the same OSPF area as the primary addresses.
If your switch receives its IP address from a Bootstrap Protocol (BOOTP) or Dynamic Host Configuration Protocol (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.
A Layer 3 switch can have an IP address assigned to each routed port and SVI. The number of routed ports and SVIs that you can configure is not limited by software; however, the interrelationship between this number and the number of other features being configured might have an impact on CPU utilization due to hardware limitations. You can use the sdm prefer global configuration command to reallocate system hardware resources based on templates and feature tables. For the Catalyst 3550 Gigabit Ethernet switches, the tables are based on 16 routed interfaces (SVIs and routed ports. For switches with mainly Fast Ethernet ports, the tables are based on 8 routed interfaces. For more information, see the sdm prefer command.
Examples
This example shows how to configure the IP address for the Layer 2 switch on a subnetted network:
Switch(config)# interface vlan 1Switch(config-if)# ip address 172.20.128.2 255.255.255.0This example shows how to configure the IP address for a port on the Layer 3 switch:
Switch(config)# ip multicast-routingSwitch(config)# interface gigabitethernet0/1Switch(config-if)# no switchportSwitch(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 enable Dynamic Host Configuration Protocol (DHCP) snooping globally. 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.
In Cisco IOS Release 12.1(19)EA1, the implementation for the option-82 subscriber identification changed from the previous release. The new option-82 format uses a different circuit ID and remote ID suboption, vlan-mod-port. The previous version uses the snmp-ifindex circuit ID and remote ID suboption.
If you have option 82 configured on the switch and you upgrade to Cisco IOS Release 12.1(19)EA1 or later, the option-82 configuration is not affected. However, when you enable DHCP snooping globally on the switch by using the ip dhcp snooping global configuration command, the previous option-82 configuration is suspended, and the new option-82 format is applied. When you disable DHCP snooping on the switch, the previous option-82 configuration is re-enabled.
To provide for backward compatibility, you can select the previous option-82 format by using the ip dhcp snooping information option format snmp-ifindex global configuration command when you enable DHCP snooping. When DHCP snooping is enabled globally, option-82 information (in the selected format) is inserted only on snooped VLANs.
To use the previous version of option 82 without enabling DHCP snooping, see the software configuration guide for more information.
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 Dynamic Host Configuration Protocol (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 or snmp-ifindex, 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 the 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.
In Cisco IOS Release 12.1(19)EA1, the implementation for the option-82 subscriber identification changed from the previous release. The new option-82 format uses a different circuit ID and remote ID suboption, vlan-mod-port. The previous version uses the snmp-ifindex circuit ID and remote ID suboption.
You can select the previous option-82 format by using the ip dhcp snooping information option format snmp-ifindex global configuration command. When DHCP snooping is enabled globally, option-82 information (in the selected format) is only inserted on snooped VLANs.
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 format snmp-ifindex
Use the ip dhcp snooping information option format snmp-ifindex global configuration command to select the snmp-ifindex alternative option-82 data format. Use the no form of this command to use the vlan-mod-port option-82 data format.
ip dhcp snooping information option format snmp-ifindex
no ip dhcp snooping information option format snmp-ifindex
Syntax Description
This command has no arguments or keywords.
Defaults
DHCP option-82 data insertion uses the vlan-mod-port format.
Command Modes
Global configuration
Command History
Usage Guidelines
If you have option 82 configured on the switch and you upgrade to Cisco IOS Release 12.1(19)EA1 or later, the option 82 configuration is not affected. However, when you enable Dynamic Host Configuration Protocol (DHCP) snooping globally on the switch by using the ip dhcp snooping global configuration command, the relay agent information option configuration is disabled. This happens regardless of whether snooping is enabled on any VLANs. To provide for backward compatibility when using option 82 with DHCP snooping, you can select the previous option-82 format by using the ip dhcp snooping information option format snmp-ifindex global configuration command.
You can configure some switches in the network to continue using the previous option 82 format, and configure DHCP snooping on other switches in the network.
Option-82 information is only inserted on snooped VLANs.
Examples
This example shows how to enable DHCP option 82 data insertion in the snmp-ifindex format:
Switch(config)# ip dhcp snooping information option format snmp-ifindexYou 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 Dynamic Host Configuration Protocol (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 Dynamic Host Configuration Protocol (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 as trusted ports that are connected to a DHCP server or to other switches or routers. Configure as untrusted ports that are connected to DHCP clients.
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 Dynamic Host Configuration Protocol (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 fastethernet0/12Switch(config-if)# ip igmp filter 22You can verify your setting by using the show running-config privileged EXEC command and by specifying an interface.
Switch# show running-config interface fastethernet0/12Building configuration...Current configuration : 124 bytes!interface FastEthernet0/12no ip addressshutdownsnmp trap link-statusip igmp filter 22endRelated 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(8)EA1
This command was first 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 routed ports, switch virtual interfaces (SVIs), or ports that belong to an EtherChannel group.
Follow these guidelines when configuring the IGMP throttling action:
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•
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Examples
This example shows how to limit to 25 the number of IGMP groups that an interface can join.
Switch(config)# interface fastethernet0/12Switch(config-if)# ip igmp max-groups 25This example shows how to configure the switch to delete a random IGMP group in the forwarding table and to add an entry for the IGMP group 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 privileged EXEC command and by specifying an interface.
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:
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•
•
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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 # config 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 on the switch or to enable it on the interface. Use the command with keywords to enable and configure IGMP snooping on a VLAN interface. Use the no form of this command to disable IGMP snooping or to reset the parameters to the default setting.
ip igmp snooping
