PIM should be configured only on the first and the last hop routers in

the multicast tree.

PIM is a multicast

routing protocol that makes packet-forwarding decisions independent of the

unicast IP routing protocol that is running in the

PIM sparse mode is most useful when there are few senders, many

receivers, and the volume of multicast traffic is high.

Three of the

forwarding modes for PIM are PIM dense mode (PIM-DM), PIM sparse mode (PIMSM),

and PIM sparse-dense mode.

PIM should be configured on the device that hosts the source of the

muticast traffic.