U Commands

udld

To configure the interfaces to use a Unidirectional Link Detection (UDLD) mode, use the udld command.

udld {enable | disable}

Syntax Description

disable

Disables the UDLD mode for fiber interfaces.

enable

Enables the normal UDLD mode for nonfiber interfaces.

Command Default

By default, UDLD is disabled for the 48-port, 10/100/1000-Ethernet module ports.

By default, UDLD is enabled for the 32-port, 10-Gigabit Ethernet module ports.

Command Modes

Interface configuration mode

Command History

Release

Modification

4.0

This command was introduced.

Usage Guidelines

Before you can enable a UDLD mode for specified interfaces, you must make sure that UDLD is already enabled globally on the device. Use the feature udld command to enable UDLD globally.

Use the udld command to enable or disable UDLD separately on specified interfaces . This action enables UDLD in normal mode. Enter the udld aggressive command to enable the aggressive mode on UDLD-enabled interfaces.

This command does not require a license.

Examples

This example shows how to enable the normal UDLD mode for Ethernet port 3/1:

switch# configure terminal
switch(config)# feature udld
switch(config)# interface ethernet 3/1
switch(config-if)# udld enable

This example shows how to disable UDLD for Ethernet port 3/1:

switch# configure terminal
switch(config)# interface ethernet 3/1
switch(config-if-range)# udld disable

udld aggressive

To configure the interfaces for aggressive Unidirectional Link Detection (UDLD) mode, use the udld aggressive command.

udld aggressive

Syntax Description

This command has no arguments or keywords.

Command Default

None

Command Modes

Interface configuration mode

Global configuration mode

Command History

Release

Modification

4.0

This command was introduced.

Usage Guidelines

Before you can enable the aggressive UDLD mode for an interface, you must make sure that UDLD is already enabled globally on the device and on the specified interfaces.

Use the udld aggressive command to configure the ports to use a UDLD mode:

  • To enable fiber interfaces for the aggressive mode, enter the udld aggressive command in the global command mode and all the fiber interfaces will be in aggressive UDLD mode.

  • To enable the copper interfaces for the aggressive, you must enter the udld aggressive command in the interface mode, specifying each interface you want in aggressive UDLD mode.

To use the aggressive UDLD mode, you must configure the interfaces on both ends of the link for the aggressive UDLD mode.

This command does not require a license.

Examples

This example shows how to enable fiber interfaces for the aggressive UDLD mode:

switch# configure terminal
switch(config)# udld aggressive

This example shows how to enable the aggressive UDLD mode for the copper Ethernet interface 3/1:

switch# configure terminal
switch(config)# interface ethernet 3/1
switch(config-if)# udld aggressive

udld message-time

To set the Unidirectional Link Detection (UDLD) message interval timer, use the udld message-time command.

udld message-time seconds

Syntax Description

seconds

Number of seconds that you want between sending UDLD messages. The range is from 7 to 90 seconds.

Command Default

15 seconds

Command Modes

Global configuration mode

Command History

Release

Modification

4.0

This command was introduced.

Usage Guidelines

Before you can set the UDLD message timer, you must make sure that UDLD is already enabled globally on the device. Use the feature udld command to globally enable UDLD.

This command does not require a license.

Examples

This example shows how to configure UDLD interval to 30 seconds:

switch# configure terminal
switch(config)# udld message-time 30

udld reset

To reset the interfaces that Unidirectional Link Detection (UDLD) has shut down and return them to the UP condition, use the udld reset command.

udld reset

Syntax Description

This command has no arguments or keywords.

Command Default

None

Command Modes

Global configuration mode

Command History

Release

Modification

4.0

This command was introduced.

Usage Guidelines

This command does not require a license.

Examples

This example shows how to reset those interfaces that UDLD has shut down:

switch# configure terminal
switch(config)# udld reset

uni-directional link-fault

To configure what action is taken on an interface when a link-fault notification is received from the remote Ethernet OAM peer, use the uni-directional link-fault command in Ethernet OAM action configuration mode or interface Ethernet OAM actionconfiguration mode. To remove the configuration, use the no form of this command.

uni-directional link-fault {disable | efd | error-disable-interface | log}

nouni-directional link-fault {disable | efd | error-disable-interface | log}

Syntax Description

disable

Performs no action on the interface when a link-fault notification is received.

efd

Puts the line protocol into the down state for an interface when a link-fault notification is received.

error-disable-interface

Puts the interface into the error-disable state when a link-fault notification is received.

log

(Interface Ethernet OAM action configuration only) Creates a syslog entry when a link-fault notification is received. This action is available in Interface Ethernet OAM action configuration mode to override the profile setting and log the event for the interface when it occurs.

Command Default

The default action is to create a syslog entry.

Command Modes

Ethernet OAM action configuration (config-eoam-action)

Interface Ethernet OAM action configuration (config-if-eoam-action)

Command History

Release Modification
7.3(0)D1(1)

This command was introduced.

Usage Guidelines

This command does not require a license.

Examples

The following example shows how to configure that no action is performed on the interface when a link-fault notification is received:

switch# configure terminal
switch(config)# ethernet oam profile Profile_1
switch(config-eoam)# action
switch(config-eoam-action)# uni-directional link-fault disable

The following example shows how to configure putting the interface into the line-protocol-down state when a link-fault notification is received:

switch# configure terminal
switch(config)# ethernet oam profile Profile_1
switch(config-eoam)# action
switch(config-eoam-action)# uni-directional link-fault efd

The following example shows how to configure that the interface is put into the error-disable state when a link-fault notification is received:

switch# configure terminal
switch(config)# ethernet oam profile Profile_1
switch(config-eoam)# action
switch(config-eoam-action)# uni-directional link-fault error-disable-interface

The following example shows how to configure that a syslog is created when a link-fault notification is received:

switch# configure terminal
switch(config)# interface ethernet 2/1
switch(config-if)# ethernet oam
switch(config-if-eoam)# action
switch(config-if-eoam-action)# uni-directional link-fault log