Migrating to SR-MPLS

The migration is facilitated by extending the SR-MPLS configuration to the LDP routers and removing the LDP configuration. In production networks, migrating to sr-prefer should be carried out during a planned window as a precaution.

Configuration

The remaining routers not operating under SR-MPLS are P4, P8, and PE5. Extend the configuration of SR-MPLS to these routers as outlined here:

In this context, the x variable represents the IDs of the nodes, as outlined in the preceding chapter. Specifically, x equals 4 for P4, 5 for PE5, and 8 for P8:

router isis IGP
address-family ipv4 unicast
  segment-routing mpls sr-prefer
!
interface Loopback0
  address-family ipv4 unicast
   prefix-sid index x

Furthermore, deactivate LDP on those routers, as well as on P3 and P7:

router isis IGP
address-family ipv4 unicast
  no mpls ldp auto-config

At the end of this step, the network topology is now running SR-MPLS...