"Ian Douglas" alug@the-zub.demon.co.uk writes:
But if I use ping to discover the IP Address of www.alug.org.uk and then type it (http://199.254.168.73) into the browser the PHP4Hosting.com homepage appears rather than the ALUG webpage I was expecting. This confuses me, but is probably simply an unrelated point.
Yes, it is unrelated, and will occur even when DNS is working fine.
If I rename the ~/.mozilla directory a second time and restart Mozilla, but this time create a new user profile, rather than importing my Netscape one, the problem still exists.
I think the next step is to determine if Mozilla is even sending any DNS queries. As root, this command:
tcpdump -n port 53
will report any DNS packets appearing on your ethernet.
Do a ping with this running first; you'll see the kind of thing that ought to be happening (there ought to be a request and a response).
Then try to visit a website through Mozilla and see what you see. Paste it all into another message to this list if you have trouble interperting it.
That said if Mozilla has randomly decided to stop doing DNS lookups I'm not sure what you can do about it, other than possibly reinstalling Mozilla.