MPLS domain separation

By removing LDP from routers PE1, P2, and P6, these routers are exclusively placed in the SR-MPLS domain. The routers P4, P8, and PE5 remain exclusively in the LDP domain. The routers P3 and P7 become the border routers, as they continue to run both SR-MPLS and LDP. This completes the separation of the network into two distinct MPLS domains: SR-MPLS and LDP.

The necessary configuration to achieve this will be shown now.

Configuration

The following configuration disables LDP label distribution on the routers.

PE1, P2, and P6

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

For ease of understanding and clarity, removing LDP from the IS-IS context is sufficient for the router to cease LDP functionality, as it will no longer distribute labels for IS-IS routing.

The LDP-based labeled forwarding would cease to function, as confirmed next.

Verification

The following steps confirm the absence of LDP labels and...