We have an Ubuntu 10.04 LAMP server running on site (Apache is on port 80). It is running fine through the LAN, but I cannot access it using its external IP address through the Netopia 3000 Series modem by which it is connected to the internet. I have tried using what Netopia calls "Pinholes" (Port Forwarding) to make the server accessible, but a telnet to the external address just gives me "connect to address x.x.x.x: Operation timed out." I have also tried enabling "Services" and "IP Passthrough" on the router, but it gives the same result as above.
How can I enable the server to be accessed through its external IP address? Because it connects fine locally, it would seem to be a problem with the Netopia router.
Update: Booting the server in GUI mode instead of text mode solved the problem instantly. Any ideas why?