In case of multicast routing, I encountered source based tree and shared cost based tree.What is the difference between source based tree and shared core based tree? In which case they are used? what is reverse path forwading and how is it used?
Source-based tree: A non-shared multicast distribution tree (forwarding/replication state on intermediate routers) is built for every SOURCE,GROUP pair. Source-based tree is unidirectional.
Shared tree: A per-group multicast distribution tree is built on routers, shared by all group's senders and receivers. The shared tree might be bidirectional.