Dell PowerConnect M6220 User's Guide - Page 653

Configuring IP Multicast 12 Overview This chapter describes how to configure multicast features on the PowerConnect M6220/M6348/M8024. Multicast protocols are used to deliver Multicast packets from one source to multi receivers. They facilitate better bandwidth utilization, less host and router processing, making them ideal for usage in applications like video or audio conferencing, Whiteboard tools, stock distribution tickers etc. Multicast applications send one copy of a packet, and address it to a group of receivers (Multicast Group Address) rather than to a single receiver (unicast address). Multicast depends on the network to forward the packets to only those networks and hosts that need to receive them. Multicast capable/enabled routers forward multicast packets based on the routes in the Multicast Routing Information Base (MRIB). These routes are created in the MRIB during the process of building multicast distribution trees by the Multicast Protocols running on the router. Different IP Multicast routing protocols use different techniques to construct these multicast distribution trees. If Multicast traffic is to be routed through a part of a network that does not support multicasting (routers which are not multicast capable) then the multicast packets are encapsulated in an IP datagram and sent as a unicast packet. When the multicast router at the remote end of the tunnel receives the packet, the router strips off the IP encapsulation and forwards the packet as an IP Multicast packet. This process of encapsulating multicast packets in IP is called tunneling. To display the IP Multicast menu page, click IP Multicast in the tree view. The IP Multicast menu page contains links to the following features: • Multicast • Multicast Listener Discovery • Distance Vector Multicast Routing Protocol • Internet Group Management Protocol • Protocol Independent Multicast-Dense Mode • Protocol Independent Multicast-Sparse Mode Configuring IP Multicast 651