BFD Session Cannot Become Up

Procedure

1. Run the display current-configuration configuration bfd command to check whether the local and remote discriminators at both ends match.

   • If the local and remote discriminators at both ends match, go to step 2.

   • If the local and remote discriminators at both ends do not match, run the discriminator command to correctly configure local and remote discriminators, and then run the display bfd session all command to check whether the BFD session is Up.

     • If the value of the State field is Up, the BFD session has been established.

     • If the value of the State field is not Up, go to step 2.

2. Run the display current-configuration configuration bfd command to check whether the BFD detection time is longer than the delay before the BFD session becomes Up.

   Detection time = Received Detect Multi of the remote system x Max (Local RMRI, Received DMTI)

   Detect Multi is the local detection multiplier, which is set by using the detect-multiplier command. The Required Min Rx Interval (RMRI) is the minimum interval for receiving BFD packets, which is set by using the min-rx-interval command. The Desired Min Tx Interval (DMTI) is the minimum interval for sending BFD packets, which is set by using the min-tx-interval command.

   The link delay can be obtained using the ping or tracert mechanism.

   If the BFD detection time is shorter than the delay before the BFD session becomes Up, run the detect-multiplier, min-rx-interval, and min-tx-interval commands to increase the BFD detection time to be longer than the delay.