Implementing Cisco Enterprise Advanced Routing and Services (ENARSI) — Question 21

Which statement about MPLS LDP router ID is true?

Answer options

• A. If not configured, the operational physical interface is chosen as the router ID even if a loopback is configured.
• B. The loopback with the highest IP address is selected as the router ID.
• C. The MPLS LDP router ID must match the IGP router ID.
• D. The force keyword changes the router ID to the specified address without causing any impact.

Correct answer: B

Explanation

The correct answer is B because the MPLS LDP router ID is determined by selecting the loopback interface with the highest IP address when available. Option A is incorrect as the loopback takes precedence over the physical interface. Option C is false since the MPLS LDP router ID does not have to match the IGP router ID. Option D is misleading because while the force keyword can change the router ID, it might cause disruptions.