U and V Commands

udld (Ethernet)

To enable and configure the Unidirectional Link Detection (UDLD) protocol on an Ethernet interface, use the udld command. To disable UDLD, use the no form of this command.

udld { aggressive | disable | enable }

no udld { aggressive | disable | enable }

Syntax Description

aggressive

Enables UDLD in aggressive mode on the interface.

disable

Disables UDLD on the interface.

enable

Enables UDLD in normal mode on the interface.

Command Default

None

Command Modes

Interface configuration mode

Command History

Release

Modification

4.0(1a)N1(1)

This command was introduced.

Usage Guidelines

You can configure normal or aggressive UDLD modes for an Ethernet interface. Before you can enable a UDLD mode for an interface, you must make sure that UDLD is enabled on the switch. UDLD must also be enabled on the other linked interface and its device.

To use the normal UDLD mode on a link, you must configure one of the ports for normal mode and configure the port on the other end for the normal or aggressive mode. To use the aggressive UDLD mode, you must configure both ends of the link for aggressive mode.

Examples

This example shows how to enable the normal UDLD mode for an Ethernet port: 

switch# configure terminal
switch(config)# interface ethernet 1/1
switch(config-if)# udld enable

This example shows how to enable the aggressive UDLD mode for an Ethernet port: 

switch(config-if)# udld aggressive

This example shows how to disable UDLD for an Ethernet port: 

switch(config-if)# udld disable

Related Commands

Command

Description

show udld

Displays the administrative and operational UDLD status.

vpc domain

To create a virtual port-channel (vPC) domain, use the vpc domain command. To remove a vPC domain, use the no form of this command.

vpc domain domain-id

no vpc domain domain-id

Syntax Description

domain-id

Domain ID for the vPC . The range of numbers is from 1 to 1000. You must use unique vPC IDs for each vPC within a single virtual device context (VDC).

Command Default

None

Command Modes

Any command
mode


network-admin

Command History

Release

Modification

5.2(1)N1(1)

This command was introduced.

Usage Guidelines

You must enable the vPC feature before you can create a vPC domain.

You put all vPC interfaces, including the vPC peer link, on both of the vPC peer devices into the identical vPC domain. You must have unique vPC domain numbers within each VDC. Once you create a vPC domain, the system automatically creates a vPC system MAC address that is unique to that vPC.

You also use this command to enter the vpc-domain command mode in order to configure vPC parameters.

This command does not require a license.

Examples

This example shows how to create a vPC domain:

 switch#
config
t switch(config)#
vpc domain
5 switch(config-vpc-domain)#

This example shows how to enter the vpc-domain command mode to configure an existing vPC domain:

 switch#
config
t switch(config)#
vpc domain
5 switch(config-vpc-domain)#

Related Commands

Command

Description

show vpc brief

Displays information about vPCs. If the feature is not enabled, the system displays an error when you enter this command.

vpc orphan-port suspend

To suspend a nonvirtual port channel (vPC) port when the peer link of a vPC secondary goes down, use the vpc orphan-port suspend command. To resume the non-vPC port, use the no form of this command.

vpc orphan-port suspend

no vpc orphan-port suspend

Syntax Description

This command has no arguments or keywords.

Command Default

None

Command Modes

Interface configuration mode.

Command History

Release

Modification

5.0(3)N2(1)

This command was introduced.

Usage Guidelines

A non-vPC port, also known as an orphaned port, is a port that is not part of a vPC.

Examples

This example shows how to suspend an orphan port: 

switch(config)# interface ethernet 1/20
switch(config-if)# vpc orphan-port suspend
switch(config-if)#

Related Commands

Command

Description

show vpc brief

Displays brief information about the vPCs.

show vpc orphan-ports

Displays information about orphan ports.