Implementing Cisco Enterprise Advanced Routing and Services (ENARSI) — Question 536

What is a MPLS PHP label operation?

Answer options

• A. Downstream node signals to remove the label.
• B. It uses implicit-NULL for traffic congestion from source to destination forwarding.
• C. PE removes the outer label before sending to the P router.
• D. It improves P router performance by not performing multiple label lookup.

Correct answer: A

Explanation

The correct answer A describes that in the MPLS PHP operation, the downstream node informs the previous node to remove the label, which is vital for efficient routing. Option B is incorrect as it refers to traffic congestion handling rather than label operations. Option C incorrectly describes the label removal process, which occurs at the downstream node, not the PE. Option D, while true in improving performance, does not define the specific PHP label operation.