Why BGP flaps upon a commit on change in BGP import rule.
12335
Created On 07/04/22 09:33 AM - Last Modified 10/22/24 05:55 AM
Question
Why BGP flaps upon committing a configuration change in BGP import rule?
Environment
Post a commit after a change in BGP import rule, BGP neighborship flaps:
2021/03/18 13:20:38 info general general 0 CommitAll job enqueued. Enqueue time=2021/03/18 13:20:38. JobId=12. User: Panorama-admin. Type: Full
2021/03/18 13:21:04 high routing VR-1 routed- 0 BGP peer session left established state.peer name: XXXXX, peer IP: x.x.x.x.
Answer
In the routed logs, it can be seen that the reason for BGP flap was lack of support of route refresh capability on the peer:
mp routed.log 2021-03-18 13:21:04 Import policy has been changed for a peer session which does not support route refresh messages. The session will be restarted.
If route refresh capacity is not supported by the peer, BGP sessions gets restarted/flapped.
Additional Information
https://datatracker.ietf.org/doc/html/rfc2918