Configuring BFD for OSPF

Procedure

1. Run system-view

   The system view is displayed.

2. Run ospf [ process-id ]

   The OSPF view is displayed.

3. Run bfd all-interfaces enable

   BFD for OSPF is enabled, and BFD sessions are established.

   If all the interfaces in a single process are configured with BFD and their neighbor relationships are in the Full state, OSPF establishes BFD sessions on all the interfaces in the process.

4. (Optional) run bfd all-interfaces { min-rx-interval receive-interval | min-tx-interval transmit-interval | detect-multiplier multiplier-value } ^*

   Parameters are set for the BFD sessions.

   • The parameter min-rx-interval receive-interval specifies the expected minimum interval for receiving BFD packets from the neighbor.
   • The parameter min-tx-interval transmit-interval specifies the minimum interval for sending BFD packets to the neighbor.
   • The parameter detect-multiplier multiplier-value specifies the local detection multiplier.
   

   Default values of receive-interval, transmit-interval, and multiplier-value are recommended.

   Configure parameters based on the network status and network reliability requirements. A short interval between BFD packet transmissions can be configured if high network reliability is required.

   

   • Actual interval between BFD packet transmissions on the local switch = Max {value of transmit-interval configured on the local switch, value of receive-interval configured on the neighboring switch }
   • Actual interval between BFD packet receipts on the local switch = Max {value of transmit-interval configured on the neighboring switch, value of receive-interval configured on the local switch }
   • Actual BFD packet detection period on the local switch = Actual interval between BFD packet receipts on the local switch x Value of multiplier-value configured on the neighboring switch

   For example, if:

   • On the local switch, the configured interval between BFD packet transmissions is 200 ms; the configured interval between BFD packet receipts is 300 ms; the detection multiplier is 4.
   • On the neighboring switch, the configured interval between BFD packet transmissions is 100 ms; the configured interval between BFD packet receipts is 600 ms; the detection multiplier is 5.

   Then:

   • On the local switch, the actual interval between BFD packet transmissions is 600 ms calculated by using the formula: max {200 ms, 600 ms}; the interval between BFD packet receipts is 300 ms calculated by using the formula: max {100 ms, 300 ms}; the detection period is 1500 ms calculated by using the formula: 300 ms x 5.
   • On the neighboring switch, the actual interval between BFD packet transmissions is 300 ms calculated by using the formula: max {100 ms, 300 ms}; the actual interval between BFD packet receipts is 600 ms calculated by using the formula: max {200 ms, 600 ms}; the detection period is 2400 ms calculated by using the formula: 600 ms x 4.