Implementing and Operating Cisco Service Provider Network Core Technologies (SPCOR) — Question 103

The network-engineering team of a service provider is integrating several recently acquired networks into a more scalable common Unified MPLS architecture.
The new network architecture will support end-to-end VPNv4 and VPNv6 services with these requirements:
✑ The IGP of the core layer is IS-IS in Area 0.
✑ The IGP of the aggregation layers is OSPF in Area 0.
✑ The LDP protocol is used to distribute label bindings within each IGP domain.
Which task must the network engineer perform when implementing this new architecture?

Answer options

• A. Configure a BGP session between the ABR routers of each IGP domain to exchange VPNv4 or VPNv6 prefixes.
• B. Configure mutual redistribution of each IGP domain's loopback prefix to provide end-to-end LDP LSP.
• C. Configure the ABR in each IGP domain to preserve next-hop information on all VPNv4 and VPNv6 prefixes advertised by the PE.
• D. Configure BGP-LU between ABR routers of each IGP domain to carry MPLS label information in NLRI.

Correct answer: D

Explanation

The correct answer is D because BGP-LU allows the exchange of MPLS label information between different IGP domains, which is crucial for maintaining label-switched paths. Option A is incorrect as it does not specifically address label distribution. Option B is not suitable since mutual redistribution does not directly relate to label distribution for MPLS. Option C is also wrong because preserving next-hop information does not ensure proper label distribution for MPLS.