PIM Modes of Operation

PIM operates in two basic modes: sparse mode and dense mode. In addition, PIM can operate in sparse-dense mode, with some multicast groups configured as dense mode (flood-and-prune, (S,G) state) and others configured as sparse mode (explicit join to rendezvous point (RP), (*, G) state).

PIM drafts also establish a mode known as PIM source-specific mode, or PIM SSM. In PIM SSM there is only one specific source for the content of a multicast group within a given domain.