Multicast PIM sparse mode

Protocol Independent Multicast (PIM) is a multicast routing protocol that operates in several modes. In sparse mode, multicast traffic is not forwarded on any router interface until a downstream router requests that it be forwarded.

In other words, no multicast traffic is initially sent until it is requested.

Unlike dense mode, sparse mode requires the role of a Multicast PIM sparse mode Rendezvous Point (RP).