My Windows Server 2003 has two NICs, one for LAN and the other for dedicated Internet access. Suddenly, the Internet connection stopped working. It can ping itself and the hosts on the LAN. However, it can't ping any Internet address or its own DNS. Both NICs are set to static IPs and IP routing is enabled.
Sometimes, if I disconnect the Internet NIC's Ethernet cable and reconnect it, I can briefly access the Internet, but it disconnects shortly afterwards. If I connect the same Ethernet cable into another machine and set the IP and gateway correctly I'm able to normally connect to the Internet.
The Server was working with the same configuration before and no alterations were made. I've tried restarting the server and the routing service to no avail.
UPDATE: I connected the Ethernet cable into another machine, configured it and Internet access was normal. After that, I reconnected the cable into the Windows server, but this time, no problem happened. The Internet access is normal and it is routing traffic to/from its hosts. What could have caused the sudden loss of connection on the first time?