UDLD configuration commands

Syntax:

Switch(config)# link-keepalive mode [verify-then-forward | forward-then-verify]

This command configures the link-keepalive mode.

Link-keepalive provides two modes of operation; verify-then-forward and forward-then-verify.

When using the verify-then-forward mode, the port is in a blocking state until the link configured for UDLD establishes bidirectional communication. When using the forward-then-verify mode, the port forwards the data then verifies the status of the link-in state.

When a unidirectional state is detected, the port is moved to a blocked state.

When a bidirectional state is detected, the data is forwarded without interruption.

Syntax:

Switch(config)# link-keepalive mode verify-then-forward

Keeps the port in a logically blocked state until the link configured for UDLD has been successfully established in bi-directional communication.

Syntax:

Switch(config)# link-keepalive mode forward-then-verify

Forwards the data then verifies the status of the link. If a unidirectional state is detected, the port is then moved to a blocked state.

Syntax:

Switch(config)# link-keepalive interval <deciseconds>

Configure the interval for link-keepalive. The link-keepalive interval is the time between sending two UDLD packets. The time interval is entered in deciseconds (1/10 sec). The default keepalive interval is 50 deciseconds.

Example:

A value of 10 is 1 sec., 11 is 1.1 sec.

Syntax:

Switch(config)# link-keepalive retries <number>

Maximum number of sending attempts for UDLD packets before declaring the link as faulty.

Default keepalive attempt is 4.