(Optional) Configuring BFD for a Specified Interface

Procedure

1. Run system-view

   The system view is displayed.

2. Run interface interface-type interface-number

   The interface view is displayed.

3. Run ospfv3 bfd enable [ instance instance-id ]

   BFD is enabled on the interface to establish a BFD session.

   When BFD is configured globally and the neighbor status is Full, OSPFv3 establishes BFD sessions on all the neighbors in the process using default BFD parameters.

   You can run the ospfv3 bfd { min-transmit-interval min-transmit-value | min-receive-interval min-receive-value | detect-multiplier detect-multiplier-value | frr-binding } ^* [ instance instance-id ] } command to set parameters for BFD sessions.

   

   • The BFD configured on an interface takes precedence over that configured in a process. Specifically, if BFD is enabled on an interface, BFD parameters on the interface are used to establish BFD sessions.

   • If the parameters of a BFD session are set but the ospfv3 bfd enable command is not run, BFD cannot be enabled.

   You can skip this step. The default interval at which BFD packets are transmitted and the default detection multiplier are recommended.

   The parameters are configured based on the network status and network reliability requirements. A short interval at which BFD packets are transmitted can be configured for a link that has a higher requirement for reliability. A long interval at which BFD packets are transmitted can be configured for a link that has a lower requirement for reliability.

   

   • Actual interval at which BFD packets are transmitted on the local router = Max { configured interval min-transmit-value at which BFD packets are transmitted on the local router, configured interval min-receive-value at which BFD packets are received on the peer router }
   • Actual interval at which BFD packets are received on the local router = Max { configured interval min-transmit-value at which BFD packets are transmitted on the peer router, configured interval min-receive-value at which BFD packets are received on the local router }
   • Actual time for detecting BFD packets = Actual interval at which BFD packets are received on the local router x Configured detection multiplier detect-multiplier-value on the peer router

   For example:

   • On the local router, the configured interval at which BFD packets are transmitted is 200 ms; the configured interval at which BFD packets are received is 300 ms; the detection multiplier is 4.
   • On the peer router, the configured interval at which BFD packets are transmitted is 100 ms; the interval at which BFD packets are received is 600 ms; the detection multiplier is 5.

   Then:

   • On the local router, the actual interval at which BFD packets are transmitted is 600 ms calculated by using the formula max {200 ms, 600 ms}; the interval at which BFD packets are received is 300 ms calculated by using the formula max {100 ms, 300 ms}; the detection period is 1500 ms calculated by multiplying 300 ms by 5.
   • On the peer router, the actual interval at which BFD packets are transmitted is 300 ms calculated by using the formula max {100 ms, 300 ms}, the actual interval at which BFD packets are received is 600 ms calculated by using the formula max {200 ms, 600 ms}, and the detection period is 2400 ms calculated by multiplying 600 ms by 4.

4. (Optional) Run ospfv3 bfd incr-cost { cost | max-reachable }

   The OSPFv3 interface is enabled to adjust the cost based on BFD.

   The interface-specific BFD-associated cost value has a higher priority than the process-specific BFD-associated cost value.

5. Run commit

   The configuration is committed.