So you do have a router on site and it is owned and configured by your ISP. If it connects to a switch onsite it sounds like you are using NAT from the router with internal IPs being private (192.168.c 10.a 172.16.b). Server 2003 includes ICF as XP does but if you can serve the LAN http OK and your router port forwards to the same interface - it should work. My guess would be that your port forwarding isn't set up correctly, try doing a tracert or pathping from external to your web server and see what the last hop says. What about FTP and SMTP are they on and can you connect? You can also try telnetting in to your external ip and see if that returns a banner from the router or the server - depends on what ports you have forwarded. You could always post a link to what should be your websites and we can look from here.