Server randomly stops responding

[Jayock]

I am running an FC7 server setup using the Perfect server guide, and running ISPConfig. The server randomly stops responding to all requests except for telnet, which always goes through. This happens fairly frequently with dovecot, apache, and SSH. Restarting the services will typically bring them back to life, but not always. They go back down again, and I repeat while I try to figure out the permanent solutions. Nothing in the system logs seems to be showing me any solutions. Any ideas where to start looking from here?

Im wondering if it might be a PAM issue, or PHP scripts on my website (which worked perfectly on a debian server before migrating here).

Thanks,
Justin

[falko]

Just a shot in the dark: is SELinux enabled?

[Jayock]

Nope, its off. The ISPConfig firewall is the only firewall too. Ive tried turning that on and off, no difference.

Had a large outage this afternoon. About an hour long, Restarting services, and even the entire server did nothing. Pings OK, but nothing else works, ssh, ftp, http, bind, you name it.

Very perplexing.

[Jayock]

Oddly enough ive noticed that while on the local network, ping times go from 1ms to 27-47ms when the server isn't responding, but only on the primary IP. It doesn't ever slow down on the secondary IP (on eth0:1)

munin doesnt show any excessive loads on anything that should be causing this (and the server is 2x Quad core Xeon 8gb ram, Gig-E) So is it possible that a service is causing the eth0 address to respond slowly, but not the eth0:1? Or is it a network issue. The server always gets all services outbound, just never inbound. Ive already replaced the switch, since i had a second lying around, just to narrow it down.

Any ideas with this new Info?

[falko]

Can you disable the firewall for testing purposes? Does it then happen again?

[Jayock]

Ive already tried. It does not seem to be the firewall.