Enabling PIM6 SM Snooping
Use IPv6 PIM-Sparse Mode (PIM6 SM) snooping only in topologies where multiple PIM sparse routers connect through a device. PIM6 SM snooping does not work on a PIM dense mode router which does not send join messages and traffic to PIM dense ports is stopped. A PIM6 SM snooping-enabled device displays a warning if it receives PIM dense join or prune messages.
The PIM6 SM traffic snooping feature assumes that the network has routers that are running PIM6 SM.