> However, in any case when I run the compiled nfq_test, the program > seems to do nothing after setting the packet copy mode. So it seems > to me as if it is perpetually waiting for a packet to be sent over the > netlink, but one never arrives, no matter how much network traffic I > have. > > Am I missing some vital piece of setup? When I run nfq_test, there > are two netfilter modules loaded. Should there be more? Do they need > to be configured somehow? Is this the expected behavior? > > I have tested this both on my ubuntu install and on a friend's debian, > both machines exhibit the same behavior. Any help is certainly > appreciated. It is amazing what a good night's sleep does to improve your ability to read and comprehend. I was, of course, forgetting to setup an iptable rule to queue packets, so now I can proceed.