What port should I open to allow remote desktop?
Solution 1:
Remote Desktop requires TCP port 3389 to be open.
It is possible to change the port used by the terminal server (or PC which is accessed), see this Microsoft support article: "How to change the listening port for Remote Desktop"
Solution 2:
In addition to opening port 3389 for UDP and TCP, I had to go edit the windows firewall rule and set Edge traversal to allow. Like this:
Solution 3:
If you don't want to use 3389 externally, open a different port externally, but point it to 3389 on the IP address of the machine you want RDC on. This is helpful for routing many systems with RDC. It's also nice because it won't require any registry edits.
Solution 4:
The only exception to the previous answer (3389) is when using Small Business Server through Remote Web Workplace.
In this case the server NAT's the connection between you and server port 80 (HTTP) or 443 (HTTPS), and then to the internal computer; so only 80/443 is required.
Solution 5:
What ports should I open for remote desktop - Answer: None.
Opening RDC to the Internet is a BAD IDEA. Port scanners will pick up an open 3389 pretty quickly and try to break your logon.
https://www.grc.com/port_3389.htm