Problems Receiving a Multicast stream - How to Debug?

Question

Through my university I've got a multicast stream that I can watch (using VPN). I try to watch it using vlc,

vlc udp://@233.121.29.1:1234

but nothing happens. When I try to double click to start it from the playlist, vlc says "main stream error: cannot pre fill buffer" so it seems like I can't connect to it properly. My router has multicast enabled, or at least it says so...

I've tried stopping iptables with

/etc/init.d/iptables stop

but that didn't help. Maybe it shouldn't either, I'm quite new to this stuff.

Is there any way I can do some debugging to figure out what's wrong?

Btw, I'm running Fedora 13

Answer 1

Multicast packets won't traverse subnets by default so if your VPN Connection IP is not the same subnet as the stream then that could be the problem. You should talk to the university network administrator they'll be able to give you more information.