BFD for SR LSP can be configured to detect faults of SR LSPs.
Segment Routing-MPLS Best Effort (SR-MPLS BE) refers to the use of an IGP to compute an optimal SR LSP based on the shortest path first algorithm. An SR LSP is a label forwarding path that is established using SR and guides data packet forwarding through a prefix or node SID.
BFD for SR-MPLS BE is used to detect SR LSP connectivity. If BFD for SR-MPLS BE detects a fault on the primary SR LSP, an application such as VPN FRR rapidly switches traffic, which minimizes the impact on services.
Before configuring BFD for SR-MPLS BE, complete the following tasks:
Configure an IS-IS SR-MPLS BE tunnel or configure an OSPF SR-MPLS BE tunnel.
Set each LSR ID using the mpls lsr-id lsr-id command. Ensure that the route to the local lsr-id is reachable.
The system view is displayed.
The BFD view is displayed.
The egress is enabled to create a BFD session passively.
The egress has to receive an LSP ping request carrying a BFD TLV before creating a BFD session.
Return to the system view.
The Segment Routing view is displayed.
BFD is enabled for SR LSPs.
If effect-sr-lsp is specified and BFD goes down, the SR LSPs are withdrawn.
BFD parameters are set for SR LSPs.
The configuration is committed.
After successfully configuring BFD for SR-MPLS BE, run the display segment-routing bfd tunnel session [ prefix ip-address { mask | mask-length } ] command to check information about the BFD session that monitors SR LSPs.