On a network that runs high-rate data services, BFD for RIP can be configured to quickly detect and respond to network faults.
Before configuring BFD for RIP, complete the following tasks:
Assigning an IP address to each interface to ensure reachability between neighboring nodes at the network layer
Generally, RIP uses timers to receive and send Update messages to maintain neighbor relationships. If a RIP device does not receive an Update message from a neighbor after the Age timer expires, the RIP device will announce that this neighbor goes Down. The default value of the Age timer is 180s. If a link fault occurs, RIP can detect this fault after 180s. If high-rate data services are deployed on a network, a great deal of data will be lost during the aging time.
BFD provides millisecond-level fault detection. It can rapidly detect faults in protected links or nodes and report them to RIP. This speeds up RIP processes' response to network topology changes and achieves rapid RIP route convergence.
In BFD for RIP, BFD session establishment is triggered by RIP. When establishing a neighbor relationship, RIP will send detection parameters of the neighbor to BFD. Then, a BFD session will be established based on these detection parameters. If a link fault occurs, the local RIP process will receive a neighbor unreachable message within seconds. Then, the local RIP device will delete routing entries in which the neighbor relationship is Down and use the backup path to transmit messages.