IP Multicast (3)
PIM - Protocol Independent Multicast (routing protocol from Cisco, Bay Networks). PIM is used by multicast routers to determine which other multicast routers should receive multicast packets; dense-mode: transmits packets to all LANs unless it receives instruction to the contrary; sparse-mode: transmits packets to LANs which have made "join" request
DVMPR - Distance Vector Multicast Routing Protocol (Cisco, Bay, 3Com) more complicated than RIP
MOSPF - Multicast Open Shortest Path First (3Com) - multicast routing