Configuring UDLD
When configuring UDLD, keep the following considerations
in mind:
UDLD is configured on a per-port basis and must be enabled at both ends of the link. See the note below for a list of switches that support UDLD.
To configure UDLD on a trunk group, you must configure the feature on each port of the group individually. Configuring UDLD on a trunk group's primary port enables the feature on that port only.
Dynamic trunking is not supported. If you want to configure a trunk group that contains ports on which UDLD is enabled, you must remove the UDLD configuration from the ports. After you create the trunk group, you can re-add the UDLD configuration.