On my home network I connect to a Kubuntu box, which is connected via a second network card to the router.
I decided to upgrade the Kubuntu to 10.10 and have most things working now, with one anoying exception.
Firefox on the Kubuntu box can not access Google and some other sites, but it can access lots of others. A machine on the network seems to be able to access anything.
The K-box can definitely access the web for things like upgrades.
I have a feeling my firewall rc.firewall) is dropping replies to the K-box if they originated from there (not however if they originated from the LAN).
Any clues as to what might be wrong and which files it might be worth checking to find out more.