Usage Scenario
In a VPNv6 over SRv6 scenario, to enable BGP to exchange IPv6 route information with the specified IPv6 peer in the BGP-VPNv6 address family view, run the peer enable command. To enable a device to exchange IPv6 prefix SIDs with a specified IPv6 peer, run the peer prefix-sid command.
In a VPNv6 over SRv6 scenario where BFD is used to monitor a locator's reachability, if the primary path fails, BFD goes down, triggering auto FRR to perform path switching. However, if locator routes are summarized by a P device between PEs, the remote PE can learn only the locator route obtained after routes from the local PE are summarized. Since BFD detection on the remote PE depends on the peer IPv6 address (locator address of the local PE) bound to the BFD session, BFD fails in this case and auto FRR cannot be triggered to perform path switching. To resolve this problem, specify the advertise-srv6-locator parameter when you run the
peer prefix-sid command on the local PE so that the BGP routes that the local PE advertises to the remote PE carry the locator length information. The remote PE uses the SRv6 SID and locator length information carried in the received routes to calculate the local PE's locator. In this way, the peer IPv6 address bound to the BFD session on the remote PE matches the IPv6 address of the local PE's locator, allowing BFD to take effect. In this case, if the primary path fails, auto FRR is triggered to perform path switching.