Configuring BFD for PWs

Context

You must configure or delete BFD for PWs on the two PEs of a PW simultaneously; otherwise, the PW status on the two PEs may be different. Perform the following operations on the two PEs of the PW to be detected.

Procedure

Run system-view
The system view is displayed.
Run bfd cfg-name bind pw interface interface-type interface-number [ secondary ]
BFD for PWs is configured.

The outbound interface interface interface-type interface-number bound to a BFD session is the AC interface where a PW resides.

To detect a secondary PW, specify secondary.
Configure BFD discriminators.
- Run discriminator local discr-value
  
  The local discriminator is set.
- Run discriminator remote discr-value
  
  The remote discriminator is set.
The local discriminator at the local end must be the same as the remote discriminator at the peer end, and the remote discriminator at the local end must be the same as the local discriminator at the peer end.
Run commit
The configuration is committed.

When the PW status is Down, a BFD session can be set up but cannot go Up.
- The local and remote BFD discriminators cannot be modified once being configured. To modify the local or remote BFD discriminator, run the undo bfd bfd-name command in the system view to delete the configuration of BFD for PWs, and then reconfigure the local or remote BFD discriminator.
- After the PW is deleted, the related BFD session and configuration are deleted.
(Optional) Set the encapsulation type for BFD CV packets to be sent to remote peers.
1. Run quit
  Return to the system view.
2. Run mpls l2vpn
  The MPLS L2VPN view is displayed.
3. Run either of the following commands:
  - To set the encapsulation type to 0x04 for BFD CV packets to be sent to all remote peers, run the mpls l2vpn vccv bfd-cv-negotiation fault-detection-only command.
  - To set the encapsulation type 0x08 for BFD CV packets to be sent to all remote peers, run the undo mpls l2vpn vccv bfd-cv-negotiation fault-detection-only command.
  - To set the encapsulation type to 0x04 for BFD CV packets to be sent to a specified remote peer, run the mpls l2vpn vccv bfd-cv-negotiation fault-detection-only peer peer-address enable command.
  - To set the encapsulation type to 0x08 for BFD CV packets to be sent to a specified remote peer, run the mpls l2vpn vccv bfd-cv-negotiation fault-detection-only peer peer-address disable command.
  - To restore the global encapsulation type of BFD CV packets to be sent to a specified remote peer, run the undo mpls l2vpn vccv bfd-cv-negotiation fault-detection-only peer peer-address command.