Hello everyone,
Now I’d like to share with you BGP peer tracking.
In a network where BFD is unsuitable to be deployed, you can configure BGP Peer Tracking on the local device to implement fast network convergence by rapidly detecting the unreachable state of the peer.
A proper value of delay-time can ensure network stability when a peer is detected unreachable.
1. If delay-time is set to 0, BGP immediately tears down the connection between the local device and its peer after the peer is detected unreachable.
2. If IGP route flapping occurs and delay-time for an IBGP peer is set to 0, the peer relationship between the local device and the peer alternates between Up and Down. Therefore, delay-time for an IBGP peer should be set to a value greater than the actual IGP route convergence time.
3. When BGP neighbors successfully perform the GR negotiation, the master/slave switchover occurs on the BGP neighbors, to prevent the failure of GR, delay-time should be set to a value greater than GR convergence time. If delay-time is set to be smaller than the GR convergence time, the connection between the local device and the BGP peer will be torn down, which leads to the failure of GR.
The peer tracking command enables BGP Peer Tracking. That is, you can configure BGP to fast detect the unreachable state of a peer and re-establish the connection between the local device and the peer.
This is what I want to share with you today, thank you!