I use Comcast as My ISP, Firefox for my Browser, and a Netgear WNDR3700 v3 router to access the internet through Comcast. I use several Linux Distrebutions and window 7. Everytime I change to a different OS I get the following error.
Firefox can’t find the server at (some Url).
If you are unable to load any pages, check your computer’s network connection.
If your computer or network is protected by a firewall or proxy, make sure that Firefox is permitted to access the Web.
After all but Pulling my hair out, changing Modems and router I finally fixed the problem by changing the DNS servers from Auto to manual and putting in Pri: 220.127.116.11 Sec 18.104.22.168 This has solved the problem for me. I suspect that comcast’s DNS servers are partly at fault. Perhaps they get overloaded and can’t handle the load. It is not firefox. Its not the router because firefox can access it. Perhaps Comcast needs to use a different DNS Server as the present one has created intermittent problems for me until I changed the DNS Servers in the router. Maybe it is a configuration issue. If anyone has any thoughts please leave a comment.