How To Configure Udld Protocol; Enabling Udld Protocol - Cisco NCS 4200 Series Configuration Manual

How to Configure UDLD Protocol

aggressive mode, the link is considered unidirectional, and the interface is shut down. If UDLD in normal
mode is in the advertisement or in the detection phase and all the neighbor cache entries are aged out, UDLD
restarts the link-up sequence to resynchronize with any potentially out-of-sync neighbors. If you enable
aggressive mode when all the neighbors of a port have aged out either in the advertisement or in the detection
phase, UDLD restarts the link-up sequence to resynchronize with any potentially out-of-sync neighbor. UDLD
shuts down the port if, after the fast train of messages, the link state is still undetermined.
How to Configure UDLD Protocol

Enabling UDLD Protocol

SUMMARY STEPS
1. enable
2. configure terminal
3. udld {enable|aggressive}
4. end
DETAILED STEPS
Command or Action
Step 1 enable
Example:
Router> enable
Step 2 configure terminal
Example:
Router# configure terminal
Step 3 udld {enable|aggressive}
Example:
Router(config)# udld enable
Step 4
end
Example:
Router# end
LAN Switching Configuration Guide, Cisco IOS XE Everest 16.6.1 (Cisco NCS 4200 Series)
4
UniDirectional Link Detection (UDLD) Protocol
Purpose
Enables privileged EXEC mode.
Enter your password if prompted.
Enters global configuration mode.
Enables UDLD protocol on the router.
Returns to privileged EXEC mode.