Thread:Project:Support desk/Cannot access mediawiki from outside of firewall/reply

"It just hangs while trying to connect" Are you sure its hanging and not just giving you an empty blank page? (Empty blank page = php fatal error).

Could be that its trying to redirect users to what it thinks the server url should be. Look in your LocalSettings.php file, and see if you have a  entry there. Try deleting the line (If wgServer is not in LocalSettings.php, then mediawiki tries to auto-detect it on each request. See manual:$wgServer for details.)