This article is more of a reminder to me on some of the finer points of multicast show commands.
1) #sh ip mroute - in the output of this cmd the neighbor stated in the RPF field is the upstream router to the multicast source
2) #sh ip mroute summary - displays active multicast groups
3) #sh ip pim interface count - The H parameter identifies the IP-Multicast, MLS-enabled interfaces
4) #sh ip pim int s0/0 - displays the IP of the next hop router, number of PIM neighbors discovered, PIM mode
5) IGMPv3, receivers signal membership to a multicast host group in either Exclude or Include mode