Well, kind of both
Your internal network is probably something like 192.168.x.y. This is a non-routable IP address which means that it will not be available from the internet. So in your internal network you'll want to access the server by it's local IP - again, likely to be something like 192.168.something.something. Your router will provide NAT - network address translation from the outside address to the inside address. From your office or outside of your home you'll access the server via the
external IP you've been given. But the Listen address will be your local IP.
[ April 12, 2006: Message edited by: Scott Dunbar ]