Configuring UDLD

  1. Enable UDLD on a physical interface with the command udld.
  2. For most deployments, the default values for the following settings do not need to be changed. If your deployment requires different settings, change the default values with the indicated command:
    UDLD setting Default value Command to change it
    Packet transmission delay interval. 7000 ms udld interval
    Operating mode. Interconnect with HPE PVOS/Brocade/Foundry switches in forward-then-verify mode. udld mode
    Retry count. 4 udld retries
  3. Review UDLD configuration settings with the command show udld.


This example creates the following configuration:

  • Enables UDLD on interface 1/1/1.
  • Sets the UDLD mode to rfc5171 aggressive.
  • Sets the UDLD interval to 1000.
  • Sets the UDLD retries to 3.
switch(config)# interface 1/1/1
switch(config-if)# mode rfc5171 aggressive
switch(config-if)# interval 10000
switch(config-if)# retries 3
switch(config-if)# udld
switch(config-if)# quit
switch(config)# show udld interface 1/1/1
Interface 1/1/1
 Config: enabled
 State: active
 Substate: bidirectional
 Link: unblock
 Version: rfc5171
 Mode: aggressive
 Interval: 10000 milliseconds
 Retries: 3
 Tx: 0 packets
 Rx: 0 packets, 0 discarded packets, 0 dropped packets
 Port transitions: 0