The Internet Group Management Protocol (IGMP) is an internal protocol within the Internet
Protocol (IP) suite. The IP suite manages multicast traffic by using switches, routers, and hosts
that support IGMP. Enabling IGMP allows the ports to detect IGMP queries and report packets,
and manage IP multicast traffic through the switch. IGMP has three fundamental types of
messages, shown below:
Message Description
Query A message sent from the queries (IGMP router or switch) asking for a response
from each host belonging to the multicast group.
Report A message sent by a host to the queries to indicate that the host wants to be or
already is a member of a given group cited in the report message.
Leave Group A message sent by a host to the queries to indicate that the host is no longer a
member of a specific multicast group.
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