Multicast routing protocol

A multicast routing protocol is one type of service provider and that functions as a client within the framework of the router architecture. This routing protocol manages group membership and controls the path that multicast data take over the network. The routing architecture is designed to be extended by such router client type of modules.

Multicast routing is in charge of deciding and propagating information needed to forward multicast packets outside in local area network among multiple interconnected multicast routers over the network. Multicast routing protocol which is used for graphs while in multicast routing protocol is used for a tree. 

Multicast routing protocol includes protocol independent multicast(PIM), Multicast open shortest path first(MOSPF), and Distance vector multicast routing protocol(DVMRP). The internet group management protocol(IGMP) is a special multicast protocol that acts as an intermediary between host and routers.

Protocol dependent multicast is commonly used now. It has two flavors:
  • MOSPF: Multicast open shortest path first
  • CBT: Core-based tree
  • PIM: protocol independent multicast
Protocol independent multicast is commonly used now. It has two flavors:
  • PIM type dense mode -  This mode uses source-based trees. It is used in dense environments such as LAN.
  • PIM type sparse mode - This mode uses shared trees. It is used in a sparse environment such as WAN.