Configuration of S-BFD on SR-TE LSPs

For PCC-initiated or PCC-controlled LSPs, the head end of an S-BFD session is configured under the SR-TE LSP context, the SR-TE primary path context, or the SR-TE secondary path context by using the following commands:

config>router>mpls>lsp lsp-name sr-te>bfd
config>router>mpls>lsp lsp-name sr-te>primary>bfd
config>router>mpls>lsp lsp-name sr-te>secondary>bfd

The remote discriminator value is determined by passing the to address of the LSP to BFD, which then matches it to a mapping table of peer IP addresses to reflector remote discriminators. If there is no match for the to address of the LSP, a BFD session is not established on the LSP or path.

Note: A remote peer IP address-to-discriminator mapping must exist prior to bringing an LSP administratively up.

The referenced BFD template must specify parameters that are consistent with an S-BFD session; for example, the endpoint type must be np.

S-BFD can be configured at the LSP level, as follows:

configure>router>mpls>lsp <name> sr-te
      bfd
        [no] bfd-enable
        [no] bfd-template
        [no] failure-action
        [no] wait-for-up-timer <seconds>
        exit

When S-BFD is configured at the LSP level, separate S-BFD sessions with the same configuration are enabled on all primary, secondary, and standby paths of the LSP.

Alternatively, S-BFD can be configured on the primary path or secondary path of the LSP, as follows:

configure>router>mpls>lsp <name> sr-te
   primary <name>
      bfd
        [no] bfd-enable
        [no] bfd-template <name>
        [no] wait-for-up-timer <seconds>
        exit

configure>router>mpls>lsp <name> sr-te
   secondary <name>
      bfd
        [no] bfd-enable
        [no] bfd-template <name>
        [no] wait-for-up-timer <seconds>
        exit
      standby

The wait-for-up-timer command only applies if the configured failure action is failover-or-down. For more information, see Support for BFD Failure Action with SR-TE LSPs.