STD 100

The Internet Group Management Protocol (IGMP) is the protocol used by IPv4 systems to report their IP multicast group memberships to neighboring multicast routers. Version 3 of IGMP (IGMPv3) adds support for source filtering, that is, the ability for a system to report interest in receiving packets only from specific source addresses, or from all but specific source addresses, sent to a particular multicast address. That information may be used by multicast routing protocols to avoid delivering multicast packets from specific sources to networks where there are no interested receivers. This document specifies IGMPv3. It is a revised version of RFC 3376 that includes clarifications and fixes for errata, and it is backward compatible with RFC 3376. This document updates RFC 2236 and obsoletes RFC 3376.