Hello community,
I'm trouble shooting a network/server/local domain for a SOHO client. It was having problems last week and the router was replaced and configured, which solved the problem, allowing all functionality to be restored. Today, however, I was called back because Remote Desktop Connection is no longer allowing connections from outside the LAN. RDC works perfectly from the LAN. This server isn't allowing Remote Desktop Connections from outside the LAN as of yesterday, though it had been fine for the last week since it was configured. The server is an old Windows Server 2003 System.
The modem has a local IP of 10.1.10.1, forwarding TCP/UDP on Port 3389 to the router, which has a static local IP of 10.1.10.12. The router has its own static local IP as the default gateway for the LAN of 192.168.1.1 (I'm not sure if it is normal for the router to have one IP for the LAN and another for its point-to-point connection with the modem, but that's the way it was set up and was working to begin with). The static IP for the server is 192.168.1.3. Let's pretend the public IP for the server is a.b.c.d. The public IP has not changed since the RDC was properly configured last week.
All internet connectivity for all devices on the the LAN is perfectly good. The test clients were all getting good internet connectivity, as well. Remote Desktop Access is enabled. Terminal Services are allowed for the appropriate domain users, but the client can't even get to the login screen, anyway.
Like I mentioned, port forwarding is set on the modem for TCP/UDP on port 3389 to 10.1.10.12. Port forwarding is set on the router for TCP/UDP on port 3389 to 192.168.1.3. Firewalls on the modem, router, and Windows Server are all disabled for the test (although the usual configuration is just exceptions for port 3389 for TCP/UDP for RDC).
From any client used outside the LAN, attempting to connect to RDC to IP Address a.b.c.d results in a typical error:
Remote Desktop can't connect to the remote computer for one of three reasons:
1) Remote access to the server is not enabled
2) The remote computer is off
3) The remote computer is not available on the network
Make sure the computer is turned on and connected to the network, and that remote access is enabled.
... Well, access is enabled, the server is on, and the server is getting on to the net just fine... The NIC and other hardware seems fine (I'm a professional computer tech, though I don't claim to know even close to everything. There doesn't seem to be any hardware failure. Link lights and devices are all doing what they are supposed to do. RDC is the only thing not working, and it stopped working after allegedly "no one used anything for three days" and "no one touched or changed anything at all". Working perfectly fine last week). The network drives are all being picked up by the LAN devices just fine. Pinging every which way works fine.
What am I missing here? I'm not that knowledgeable with networks yet, studying for my Net+, CCNA, MCSA to take it in a couple months. I'm really at a loss here. I'm going back to the job site in the morning to troubleshoot it, so I can provide more details at that time.
Any help would be greatly, GREATLY appreciated!
