For PCC-initiated or PCC-controlled LSPs, it is possible to configure an S-BFD session under the SR-TE LSP context, the primary path context, and the SR-TE secondary path by using the config>router>mpls>lsp, config>router>mpls >lsp>primary, and config>router>mpls>lsp>secondary commands.
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, that are created by the centralized configuration under the IGP (refer to the 7450 ESS, 7750 SR, 7950 XRS, and VSR OAM and Diagnostics Guide). If there is no match to the ‟to” address of the LSP, then a BFD session is not established on the LSP or path.
The referenced BFD template must specify parameters consistent with an S-BFD session. For example, the endpoint type is cpm-np for platforms supporting a CPM P-chip, otherwise a CLI error is generated. The same BFD template can be used for both S-BFD and any other type of BFD session requested by MPLS.
If S-BFD is configured at the LSP level, then sessions are created on all paths of the LSP.
config>router>mpls>lsp <name> sr-te
bfd
[no] bfd-enable
[no] bfd-template
[no] wait-for-up-timer <seconds>
exit
S-BFD can alternatively be configured on the primary or a specific secondary path of the LSP, as follows:
config>router>mpls>lsp <name> sr-te
primary <name>
bfd
[no] bfd-enable
[no] bfd-template <name>
[no] wait-for-up-timer <seconds>
exit
config>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 is only applicable if failure action is failover-or-down. For more information, see Support for BFD Failure Action with SR-TE LSPs.
For PCE-initiated LSPs and SR-TE auto LSPs, S-BFD session parameters are specified in the LSP template. The ‟to” address that is used for determining the remote discriminator is derived from the far end address of the auto LSP or PCE-initiated LSP.
config>router>mpls
lsp-template <name> pce-init-p2p-sr-te <default | 1...4294967295>
bfd
[no] bfd-enable
[no] bfd-template
[no] wait-for-up-timer <seconds>
config>router>mpls
lsp-template <name> mesh-sr-te <1...4294967295>
bfd
[no] bfd-enable
[no] bfd-template
[no] wait-for-up-timer <seconds>
config>router>mpls
lsp-template <name> p2p-sr-te <1...4294967295>
bfd
[no] bfd-enable
[no] bfd-template
[no] wait-for-up-timer <seconds>