Enabling UDLD (CLI)
UDLD is enabled on a per-port basis.
Example:
To enable UDLD on port a1, enter:
switch(config)#interface al link-keepalive
To enable the feature on a trunk group, enter
the appropriate port range. For example:
switch(config)#interface al-a4 link-keepalive
NOTE:
When at least one port is UDLD-enabled, the switch will forward out UDLD packets that arrive on non-UDLD-configured ports out of all other non-UDLDconfigured ports in the same vlan. That is, UDLD control packets will “pass through” a port that is not configured for UDLD. However, UDLD packets will be dropped on any blocked ports that are not configured for UDLD.