If only signaling is used to detect PW faults, PWs are slow to become aware of faults. BFD for PW is often used to quickly detect PW faults.
Generally, BFD for PW only needs to be configured for the primary PW. When BFD for PW detects a fault on the primary PW, BFD for PW immediately triggers an active/standby PW switchover.
Do as follows on the UPE devices:
The system view is displayed.
BFD is enabled globally and the BFD view is displayed.
Return to the system view.
On the UPE configured with a VSI, run bfd cfg-name bind pw vsi vsi-name peer peer-address [ vc-id vc-id ] [ remote-peer remote-peer-address pw-ttl { auto-calculate | ttl-number } ]
BFD for PW is configured to detect VSI PW faults.
Run discriminator local discr-value
A local BFD session discriminator is configured.
Run discriminator remote discr-value
A remote BFD session discriminator is configured.
The local BFD session discriminator on one end must be the remote BFD session discriminator on the other end.
The configuration is committed.
If the status of a PW is Down, the BFD session can be established but cannot go Up.
Note that you must configure or cancel BFD for PW on both ends of a PW. Otherwise, the PW status on both ends may be inconsistent.
Return to the system view.
The system is enabled to send BFD for VSI-PW packets to the protocol stack for processing.