Implementing and Operating Cisco Data Center Core Technologies (DCCOR) — Question 218

A content delivery network sends video traffic to a multicast distribution device where the receiver requests the traffic from the multicast distribution device through an IGMP join message. When the traffic reaches the multicast distribution device from a CDN, the switching network populates the multicast routing table in the group (S,G), and the multicast distribution device sends the required traffic back to the receiver.

Which feature is used to send back the traffic from the streamer to the receiver in the group (S,G)?

Answer options

• A. RP
• B. Source Specific Multicast
• C. Reverse Path Forwarding
• D. IGMP

Correct answer: B

Explanation

The correct answer is Source Specific Multicast (SSM), which allows for efficient one-to-many streaming by specifying a source address along with the multicast group. RP (Rendezvous Point) is used in PIM-SM for multicast group management, Reverse Path Forwarding is a technique that ensures packets are routed correctly but does not itself send traffic, and IGMP is a protocol used for host membership management in multicast groups, but it does not handle the actual traffic flow.