300-320 Question #496: Real Exam Question with Answer & Explanation

The correct answer is A: IGMP snooping. IGMP snooping enables a Layer 2 switch to listen to IGMP Join and Leave messages exchanged between hosts and the multicast router. By building a per-port multicast group membership table, the switch forwards multicast streams only to ports that have interested receivers, rather t

Question

Multicast PIM-Sparse mode sends traffic overload. Which feature can reduce the multicast traffic in the access layer?

Options

AIGMP snooping
BFilter at Boundaries
CPIM Dense-Mode
DMSDP

Explanation

IGMP snooping enables a Layer 2 switch to listen to IGMP Join and Leave messages exchanged between hosts and the multicast router. By building a per-port multicast group membership table, the switch forwards multicast streams only to ports that have interested receivers, rather than flooding multicast traffic out all ports. This directly reduces unnecessary multicast traffic at the access layer. Filtering at boundaries (B) controls inter-domain multicast propagation, not intra-segment flooding. PIM Dense Mode (C) floods multicast traffic everywhere and prunes it back - it would make overload worse, not better. MSDP (D) is used for inter-domain Rendezvous Point (RP) peering between PIM-SM domains, which is unrelated to access-layer traffic reduction.

Community Discussion

No community discussion yet for this question.

Full 300-320 Practice