Implementing and Operating Cisco Enterprise Network Core Technologies (ENCOR) — Question 1052

What is the role of the RP in PIM sparse mode?

Answer options

• A. The RP maintains default aging timeouts for all multicast streams requested by the receivers.
• B. The RP acts as a control-plane node only and does not receive or forward multicast packets.
• C. The RP is the multicast router that is the root of the PIM-SM shared multicast distribution tree.
• D. The RP responds to the PIM join messages with the source of a requested multicast group.

Correct answer: C

Explanation

The correct answer is C because the RP is indeed the multicast router that forms the root of the shared multicast distribution tree in PIM-SM. Option A is incorrect as the RP does not maintain aging timeouts; Option B is misleading since while the RP primarily operates at the control plane, it does play a role in multicast routing. Option D is incorrect because the RP does not directly respond with the source of a group, but rather facilitates the join process.