BFD session not created

Use the show run command to make sure that the interface is not administratively shutdown. If shutdown is configured, remove this configuration with the no shutdown command.

Use the show interface command to make sure that the interface is up.

 

Check if minimum BFD configuration exists for the respective client. Client list includes static route, RIP, OSPF, BGP, ISIS. For configuration refer BFD command reference guide.

 

Check if BFD is administratively down. If BFD is admin-down, session will show state as Admin-Down for 1 minute and then session information is deleted. No session will be seen after that.

 

The next hop for which BFD is enabled should be reachable. For example in OSPF, OSPF neighbor adjacency should be formed for BFD session to be created to monitor the neighbor next hop. This applies to all clients.

 

If configuration is as expected, then enable BFD debug logs and check if packets are received, transmitted for that session. To turn on logging, enter the debug bfd all command

BFD session down

Check the diagnostic reason which can be Neighbor Signaled Down (Remote admin Down) or Control Detect Expiry (non-receipt of hello packets from neighbor for detect multiplier time).