problem with dns on local network

[Micha Feigin <michf@post.tau.ac.il>]

I installed dnsmasq to supply dns to my local network. Lately (I'm not sure if
its since I installed snort or not, although uninstalling doesn't seem to help)
the dns service seems to come and go intermittently. The same sites that don't
work from the local computers work perfectly well on the server, so it's either
dnsmasq that is not functioning properly, or something is blocking dns on the
server.

Any ideas on what may be causing the problem, how to find out and how to solve
it?

Thanks