Configuring a Policy for Triggering Dynamic BFD for LDP LSPs

A BFD session can be created to monitor an LDP LSP only after a policy for triggering dynamic BFD is configured.

A policy can be enforced to establish a session of dynamic BFD for LDP LSP in either of the following modes:

Host mode: applies when all host addresses are used to establish a BFD session. You can specify nexthop and outgoing-interface to define LSPs that support a BFD session.
FEC list mode: applies when only some host addresses are used to establish a BFD session. You can use the fec-list command to specify host addresses.

Perform the following steps on the ingress of an LSP to be monitored:

Run system-view
The system view is displayed.
(Optional) To use a FEC list, perform the following operations:
1. Run fec-list list-name
  A FEC list is created, and the FEC list view is displayed.
2. Run fec-node fec-node-address [ nexthop nexthop-address | outgoing-interface interface-type interface-number ] ^*
  A FEC node is added to the FEC list.
3. Run quit
  Return to the system view.
Run mpls
The MPLS view is displayed.
Run mpls bfd-trigger { host [ nexthop next-hop-address | outgoing-interface interface-type interface-number ] ^* | fec-list list-name } [ option-tlv ]
The policy for establishing a session of dynamic BFD for LDP LSP is configured.

After the command is run, the BFD session starts to be created.
(Optional) Run mpls bfd-option-tlv ip-prefix ip-prefix-name
An IP prefix list is configured to trigger the establishment of LDP BFD sessions working in compatible mode so that a Huawei device communicates with a specified range of non-Huawei devices.

If the mpls bfd-trigger command has been run to configure the BFD compatible mode globally, the mpls bfd-option-tlv ip-prefix command does not take effect after being run.
Run commit
The configuration is committed.