Dense-mode PIM
Efficient for networks with extensive multicast deployment and usage, or in a LAN/Campus environment
- assumes everybody is interested to multicast packets (like DVMRP)
Initial flooding (broadcast) of packets; path optimization follows
- all hosts in a LAN define a single forwarder
- deletes non-RPF neighbors (pruning)
- note: if a prune message is lost (it’s UDP after all!), the whole network suffers from unneeded data flow
- builds source-rooted trees using RPF
Easy to understand and configure
- watch for frequent floods (prune expiration time = 3 min.)