IGMP Internet Group Management Protocol
This is the protocol used by network hosts to express the desire to join or leave a particular multicast group. For example, in an IPTV scenario, a subscriber changing channel will leave one multicast group and join a different multicast group. IGMP is typically found operating over the last hop in the IP network, between the host device and the router that device is connected to. In the multicast network, PIM is used to allow multicast routers to join and leave multicast groups, as and when they are required to forward or stop forwarding multicast traffic to a particular recipient.
