Windows 7 custom RDP port?

[Unseen]

I tried to change the default remote desktop port from 3389 to some other 4 digit number.

I did this via regedit

1. HKEY_LOCAL_MACHINE
2. SYSTEM
3. CurrentControlSet
4. Control
5. Terminal Server
6. WinStations
7. RDP-Tcp

I setup that port correctly as a port forwarder in my router. The original 3389 was working fine. However, the new 4 digit one is not strange enough (port forwarder is 'ok' according to one of those port forwarder checking sites). I tried to RDP from one network to my IP (confirmed correct) like this:

myipaddress:1234

1234 = being the actual port number I set up.

Of course, I do already have RDP enabled on both W7 laptops.

What could be the cause of the invalid connection? It was working fine on 3389 by for extra security measures, I changed it to something else.

I did restart the laptop as well.

I tried a handful of different port numbers, for some strange reason they all show as 'closed'

Using this tool to check:
Open Port Check Tool - Test Port Forwarding on Your Router

I have a D-Link DIR-655

 

[ChatGPT]

When you're changing the default Remote Desktop Protocol (RDP) port from 3389 to a different 4-digit number, you need to ensure that the changes are correctly made in the Windows Registry and also in your router settings. Here are some steps and things to check to troubleshoot the issue of the connection being invalid:

Steps to Troubleshoot:​

1. Registry Configuration:
   • Verify that you updated the port number in the Registry correctly. Check under HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Terminal Server\WinStations\RDP-Tcp for the PortNumber value.
   []Firewall Settings:
   • Ensure that the new port number is allowed through the Windows Firewall or any third-party firewall software you might have installed. Create a rule to allow inbound traffic on the new port.
   []Router Configuration:
   • Double-check that the port forwarding rule in your D-Link DIR-655 router is correctly configured to forward incoming traffic on the new port to the local IP address of the Windows 7 laptop where RDP is running.
   []Testing the Connection:
   • Use a different device on the same local network to test the RDP connection internally by specifying the local IP address of the Windows 7 laptop with the new port number. This can help confirm if the issue is with the port forwarding or the RDP configuration.
   []External Connection Test:
   • Test the connection externally using a different network. You can use an online port checking tool to verify if the port is open and reachable from an outside network. Make sure to test from a separate network, not the same one where your Windows 7 laptops are located.
   []Troubleshooting Port Forwarding:
   • If the port keeps showing as closed, reassess the port forwarding setup on your router. Ensure the external port (the one you set up) forwards to the internal port correctly.
   []Router Firmware Update:
   • Consider updating the firmware of your D-Link DIR-655 router to ensure that there are no known issues with port forwarding functionality.

     Additional Tips:​

     • Recheck Port Number: Ensure there are no typos in the port number configuration both in the registry and router settings.
     • Service Restart: After making changes, restart the Remote Desktop service on your Windows laptop to apply the changes.
     • Dynamic DNS: If you have a dynamic IP address, consider using a dynamic DNS service to map a domain name to your changing external IP address.
     By going through these troubleshooting steps, you should be able to identify and resolve the issue with your RDP connection on the new port number. If the issue persists, consider undoing the port change temporarily to ensure that the RDP connection works as expected on the default port 3389.