Message types

The multicast group running IGMP uses three message types to communicate:

• Query:

  A message sent from the querier (multicast router or switch) asking for a response from each host belonging to the multicast group. If no multicast router supporting IGMP is present, then the switch assumes this function to elicit group membership information from the hosts on the network. (To disable the querier, use the CLI IGMP configuration MIB. See "Configuring the querier function" in CLI: Configuring and displaying IGMP)

• Report (join):

  A message sent by a host to the querier indicating that the host wants to be or is a member of a given group in the report message.

• Leave group:

  A message sent by a host to the querier indicating that the host has ceased to be a member of a specific multicast group.