We recently put a new 2003 webserver on line. To make a smooth transition, we just unplugged the old webserver (also 2003) and plugged the new one in, giving the new server the same IP address as the old server, so we wouldn't have to make any DNS changes. It worked like a charm! Everyone loved the new style and content. This was on Friday around noon.
On Saturday, the site was no longer accessible from the outside, but it was still available from inside. The mail server and terminal server remained available from outside. I unplugged the new server, and plugged the old one back in, and the old one worked fine. I tried plugging the new one back in, but it still wouldn't work. Finally, we tried disabling, then re-enabling the NIC, and were once again able to access from the outside.
I didn't build either one of the webservers, and I haven't had much experience with 2003 servers, I have been going through settings on both servers to try to find what could possibly make the server stop accepting traffic from the outside, but start again after a reboot. Any ideas?