Hmmm thought I replied, but 'taint here.
I'm using Suse 9.0 (soon 9.1).
I don't think it's the switch(es) unless is packet size related, which I'll try. If I do a ping -b 192.168.255.255, I get answers back from hosts all over the network, so I know broadcast is propagating. (I have two netgear gigabit switches and a noname 16 port between the linux host and some of the others that answered.)
It's probably also worth writing a multicast ping tester, to rule out the network.
I'm still thinking there is something about the riot code or the configuration that is wrong. Are there any other ideas what to try?
thanks,
-dB