Conclusion

Here we describe the principles and operation of the main multicast routing protocols used in IP multicast networks to build distribution trees between sources and receivers in a given multicast group.

Among this set of protocols, PIM-SM is currently the most widely used multicast routing protocol within a multicast domain. The PIM-BIDIR protocol is still very little deployed, while PIM-SSM is becoming increasingly important and common as IGMPv3/MLDv2 group subscription protocols become available in end devices. The only deployments of the PIM-DM protocol are in small networks, while the DVMRP protocol is now only used to interoperate with existing deployments.

MSDP is the most widely deployed protocol today for inter-domain multicast routing between PIM-SM domains, but it only works for IPv4 traffic, while BGMP is a complete inter-domain...