[nznog] IGMP test tools

Hi all, I'm looking for some linux test tools that I can run that will send IGMP join commands and that will respond to IGMP queries (to keep the group alive), that I can use to prove or disprove a sparse mode pim configuration. There's such a blatent lack of matches for anything like this on google that I wonder if I'm overlooking some basic utility that is already included with most distros or is built into the kernel, but I can't come up with anything on that front either. Using a Cisco router or switch as a multicast group member is a possibility, but I'd rather use linux hosts if I can do so.