This issue has be stumped beyond belief. I've got a website, located on CentOS, offered from Apache. We have an SSL certificate installed, however the behavior is available for that SSL along with the non-SSL side (i removed out my .htaccess file to make certain it had not been leading to the problem).
When someone attempts to access the website from outdoors our network (where we host our very own DNS servers), they obtain a connection timed out error. Basically upload personal files (transformed or otherwise) towards the site, it is visible towards the outdoors for a while of your time, about a few minutes approximately. I can tell the website fine from the inside our very own network anytime, and taking advantage of our very own DNS servers. I'm also able to view it from your own network using Google's DNS servers (22.214.171.124 and 126.96.36.199). The access_log and error_log files do not show the demands that fail, just the demands which are effective.
I've no clue what is leading to this, or where else to search for clues. I understand I've not given many details (configs, etc), but I'm not sure what information could be relevant. Any ideas? I am reluctant to connect to the website because it is an unlaunched client's site, but when it's important, I'm able to either PM it or publish it.