Implementing and Operating Cisco Service Provider Network Core Technologies (SPCOR) — Question 180

An engineering team must implement Unified MPLS to scale an MPLS network. Devices in the core layer use different IGPs, so the team decided to split the network into different areas. The team plans to keep the MPLS services as they are and introduce greater scalability. Which additional action must the engineers take to implement the Unified MPLS?

Answer options

• A. Redistribute the IGP prefixes from one IGP into the other routers to ensure end-to-end LSPs.
• B. Configure the ABR routers as route reflectors that redistribute IGP into BGP.
• C. Redistribute the IGP prefixes into another IGP to ensure end-to-end LSPs.
• D. Move the IGP prefixes into IS-IS as the loopback prefixes of the PE routers to distribute the prefixes to other routers to create end-to-end LSPs.

Correct answer: B

Explanation

The correct answer is B because configuring ABR routers as route reflectors allows for proper redistribution of IGP routes into BGP, which is essential for maintaining connectivity in a Unified MPLS setup. Option A is incorrect since simply redistributing IGP prefixes does not guarantee the necessary scalability and integration with BGP. Option C is misleading as it suggests redistributing IGP prefixes into another IGP, which does not align with Unified MPLS principles. Option D, while mentioning IS-IS, does not address the requirement for BGP integration necessary for Unified MPLS.