ospfv3 bfd block

Usage Scenario

Either a link fault or topology change on a network will cause routes to be re-calculated within an area. As such, speeding up the convergence of a routing protocol is critical to improving the network performance.

As link faults are inevitable, rapidly detecting these faults and notifying routing protocols is an effective way to quickly mitigate them. This includes associating BFD with a routing protocol to speed up convergence of the routing protocol once a link fault occurs.

Prerequisites

BFD has been enabled on the interface.

Implementation Procedure

The receive-interval is negotiated by the local and peer ends by comparing the values of the local min-rx-interval and the peer min-tx-interval. If the local end fails to receive a BFD packet from the neighbor within an interval of receive-interval * multiplier-value, the local end considers the neighbor Down.

Configuration Impact

If global BFD is not enabled, BFD can be enabled on an interface. The BFD session, however, cannot be set up after BFD is enabled on the interface. If the parameters of a BFD session are set but the ospfv3 bfd enable command is not run, the BFD session cannot be set up.

The BFD configuration on an interface takes precedence over that in a process. If BFD is enabled on an interface, a BFD session is established according to the BFD parameters set on the interface.

Follow-up Procedure

Run the display ospfv3 bfd session command to view the information about neighbors enabled with BFD.

Precautions

After BFD is enabled, a device sets up BFD sessions with only adjacencies.

The ospfv3 bfd enable command and ospfv3 bfd block commandare mutually exclusive in function, and the later configuration overwrites the previous one.

NOTE:

After BFD is disabled from an interface using the undo ospfv3 bfd enable command, the parameters for setting up BFD sessions remain on this interface but no longer take effect.