Question : can't connect to Linux webserver from outside the network

We have a problem that we have trying to solve for weeks. We are moving our web services from a Windows box to a Linux box. It works fine inside the network but not outside or through the VPN connection. Can't connect to it or ping it, but it can ping out to anything. We have the ports forwarded and have even tried a couple different firewalls. We did test it hooked directly to outside IP and it works fine, but not when it has to go through our network. It isn't an option to have it outside the network because it has to access other data inside the network. Any help would be appreciated. I would also like to add that on occasion it will connect usually after a rebooting the server for a bit, but once in awhile it will for no apparent reason, but not for long.

Answer : can't connect to Linux webserver from outside the network

So it is magically working, and I think it was an issue with our switch, or the goblins in our office, either way, it seems that it wasn't the server.