multicast routing

igmp internet group managemtn protocol 0 used by clients and router sto know which interfaces tha hae ulticast V 1 2 and 3 .

v1 clients join and 60 secs is aksed, v2 clients send leave message. v3 can choose more.

protocol independent multicast - trouts multicast traffic between rottuters and forms a multicast distribution tree

pIM-dm periodic flood and purnd behafour, hurts network performance.

pim-sm - uses a shared distribution tree and learns the shortest tree path SPT