I'm facing some issues with IGMP, but unfortunately know next to nothing about it. The extent of my knowledge is that adding and removing various iterations of 'ip igmp snooping' globally or per VLAN sometimes results in a working config :-)
We have several 2960s that feed small streaming networks, with one or more VOD or other streaming video server. Those servers have various test clips, video sent by customers for troubleshooting, etc. We just got in a big satellite dish that has feeds for several channels, and I'm trying to reliably get the video from it.
Behind the receivers for the dish is a 48 port 2960. Someone added a crossconnect from that switch to one of the streaming networks. It looked like traffic from the streaming network was flooding onto the satellite distribution switch... Wireshark showed a lot of stuff with source addresses that I recognized as being on that streaming network. I thought that, with IGMP, you had to specifically "join" a "channel", so I'm not sure why this happened. All of that traffic seemed to bring the satellite switch to it's knees... no hosts on it could ping each other, and we could not play any video signals with VLC on a laptop connected directly to that switch.
Once I removed that crossconnect, things improved. One laptop with VLC was able to play Animal Planet HD, but it was extremely choppy... horrible pixelation, short "freezes", etc.
I connected another laptop, and if I start to play Animal Planet HD, I can see 8.9 Mb/s of traffic coming in, but it just sits on one frame. I cannot play any other channels. After a few minutes, VLC bombs out and wants to send it's useless error report off into the ether.
I realize I'm not giving a lot of useful info here, but I have no idea what else could be pertinent. I can find my way around IOS, but I know nothing about multicast. I could use any suggestions on how to correctly set up a Cisco switch for multicast, or any pointers to material that might help.