I have a Fedora 11 system. Recently after reconfiguring my network, the system can't access port 80 on systems that need a DNS query. Here is what I know:
I can access port 80 on systems by IP number, either using Firefox or telnet <ip-number> 80.
Trying to access systems that need a DNS lookup fails in Firefox and also by telnet <name> 80. Even though I can resolve the ip address with the host command, telnet says that the DNS lookup failed. In Firefox, the failure occurs even in a newly created profile.
Name lookups by themselves work just fine. I can say host www.google.com
and get back good numbers. When I put those numbers into Firefox, I get back the google web page but content that comes from other servers is not present.
The problem occurs both when I am connected to the router directly with a cable or with a wireless interface.
Other network services work. I can do a yum update by ftp or skype.
Other systems on my network do not have this problem.
The firewall has been disabled.
The same problem is evident in a newly created account on the system.
When I boot that system with the RIP rescue disk I do not have the problem.
As far as I can tell, I have eliminated problems in the firewall, the router, network connection, the firefox profile, the actual system hardware, or any user specific settings. What other system global characteristics could be causing this problem?