PIM Dense Mode
Protocol-Independent Multicast - Dense Mode (PIM-DM) is a multicast
routing protocol. PIM dense-mode is a flood and prune-based protocol. Convergence is based on
the downstream routers' response for the traffic received. The downstream router in turn
floods the traffic to its own downstream interfaces. Each router sends prune to the interface
on which it received the traffic under the following conditions:
- Traffic was not received on RPF interface towards the source.
- The PIM router is a leaf router, and there are no IGMP/MLD members.
- All the downstream PIM routers have pruned the stream, and there are no IGMP/MLD
A feature called PIM-DM state refresh creates two PIM-DM operating modes, which are described
in the following sections:
For additional information on PIM-DM, see RFC 3973,
Protocol Independent Multicast - Dense Mode (PIM-DM): Protocol Specification.