Which IGMP version allows a host to indicate that they only want to receive traffic from a specific source within a multicast group?
- IGMPv2
- IGMPv3
- IGMPv1
- IGMPv4
Explanation: IGMP Version 3 added support for "source filtering," a feature that enables a multicast receiver host to signal to a router which multicast groups it wants to join and the specific sources from which it expects to receive that traffic. This is also known as source-specific multicast (SSM) capability. By using this membership information, Cisco IOS Software can forward traffic only from the sources explicitly requested by the receivers.
In contrast, earlier versions do not have this capability:
- IGMPv1 uses a basic query-response model for reporting group membership.
- IGMPv2 improves on version 1 by adding group-specific queries and a leave-group message to reduce latency, but it still lacks source-specific filtering.
Related exam: Modules 8 – 13: Checkpoint Exam: Network Routing Answers (CCNP ENCOR v9)
