recv() fails, tcp dump says i'm receiving isakmp packets
 

I am calling recv() and getting zero bites back. I know the data is there and I know it is valid because I can get it just fine from a windows box. When I run tcp dump it says something to the effect of:

192.168.20.222.8500 > 224.100.6.200.8500 isakmp: phase 2/others? #251[c]


This is existing, generic udp data from a system which I wish to receive on a linux box. I tried it on Red Hat and Suse, both said essentially the same thing.

I suspect that the IP stack is preventing me from getting data back from recv() because it thinks it's an authentication packet, when actually it isn't. These are isolated systems so just ignoring all isakmp would sute me just fine, does anyone know how to do that?


Thanks,
Rowland