Context: small academic cluster of SL5.8 machines, x86_64. Recently, some of the machines on the cluster stopped being able to access the outside internet. Machines can still update via ftp, yum, nslookup, and ping, but http requests beyond the local cluster seem to be universally denied. I've never encountered a problem like this before (and it is probably my own fault, as I am a self-taught sys-admin), but I'm wondering if anyone else has seen a similar problem.
Bonus points if you can tell me where in /etc or /var I should look to find the offending config file. regards, NTM
