The name for the TCP/IP protocol IGMP can stand either for Internet Group Management Protocol or Internet Group Multicast Protocol. It is used for sending exact same packets of data to multiple nodes. Unlike broadcasting, the group of recipients can be defined. Although most of data is sent on P2P basis in the network, IGMP is providing multicasting that uses P2MP method.
IGMP protocol is used by routers to determine which nodes should receive the data. Those nodes are using same protocol for managing multicast groups.
