djc225 — 2012-06-08T09:13:33-04:00 — #1
I seem to randomly receive "page cannot load, cannot connect to server" errors for sites on one of my servers. when this happens, it seems to only happen on certain IPs or IP ranges at a time. I say this because while I'll get the error from my home laptop I'll be able to access the site fine from my work computer or from an offsite VPS.
DNS records should already be fully propagated as these records were updated months ago.
I have no idea how to diagnose what's going on. Is there a tool in cpanel or outside on the web that can help me figure out what's going on?
amishwebmaster — 2012-06-08T14:10:08-04:00 — #2
I would suggest taking a read through your error log directly after it happens. You will be able to confirm the IP addresses accessing the server and kinda get a feel for whats going on. Definitely keep an eye on the Apache error's if your running it given the error page your seeing.
doug_g — 2012-06-09T17:08:29-04:00 — #3
command-line tools like dig, traceroute, ping can help identify if you have a problem outside your system. I usually start with ping to the domain name and see if it works, if not dig to get the domain site ip address then ping the ip. If you're getting packet loss traceroute can sometimes help you identify some external router problem somewhere, but there's not you can do about an external problem except wait for a while & hope it goes away.
And as mentioned check all your log files for clues.