Internet Group Management Protocol

Internet Group Multicast Protocol (IGMP) is used to manage IP Multicast sessions. Like ICMP, IGMP is implemented as part of the IP software, but runs as a higher level protocol in that IGMP datagrams are encapsulated within the IP datagram's payload. IGMP is now in it's second revision as a protocol.

Routers use IGMP to manage multicasting. The IGMP messages are used to learn which hosts are part of which multicast groups. Hosts use IGMP to subscribe to and leave from multicast groups.

• IGMP Messages
• IGMP Message Format
• IGMP Operation

IGMP STANDARDS

• RFC 1112 - Host Extensions for IP Multicasting, Appendix I
• RFC 2236 - Internet Group Management Protocol, v2

 

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