Understanding PIM Sparse-Dense Mode

Sparse-dense mode, as the name implies, allows the interface to operate on a per-group basis in either sparse or dense mode. A group specified as dense is not mapped to an RP. Instead, data packets destined for that group are forwarded by means of PIM dense-mode rules. A group specified as sparse is mapped to an RP, and data packets are forwarded by means of PIM sparse-mode rules.

For information about PIM sparse-mode and PIM dense-mode rules, see Understanding PIM Sparse Mode and Understanding PIM Dense Mode.