Configuring the BFD Protocol for IS-IS

The isis bfd-liveness-detection command configures the Bidirectional Forwarding Detection (BFD) protocol for IS-IS. The BFD protocol uses control packets and shorter detection time limits to more rapidly detect failures in a network. Also, because they are adjustable, you can modify the BDF timers for more or less aggressive failure detection.

When you issue the isis bfd-liveness-detection command on an IS-IS peer, the peer establishes BFD liveness detection with all BFD-enabled IS-IS peers. When the local peer receives an update from a remote IS-IS peer—if BFD is enabled and if the session is not already present—the local peer attempts to create a BFD session to the remote peer.

Each adjacent pair of peers negotiates an acceptable transmit interval for BFD packets. The negotiated value can be different on each peer. Each peer then calculates a BFD liveness detection interval. When a peer does not receive a BFD packet within the detection interval, it declares the BFD session to be down and purges all routes learned from the remote peer.

Note: Before the router can use the isis bfd-liveness-detection command, you must specify a BFD license key. To view an already configured license, use the show license bfd command.

For general information about configuring and monitoring the BFD protocol, see JunosE IP Services Configuration Guide.

isis bfd-liveness-detection