Which Port for RDP?

The default port used for Remote Desktop Protocol (RDP) connections is TCP port 3389.

Understanding RDP and Port 3389

Remote Desktop Protocol (RDP) is a Microsoft proprietary protocol that allows users to connect remotely to another computer. This enables control and management of the remote system as if you were physically present. By default, RDP communications occur over TCP port 3389.

Why is TCP Port 3389 Important?

• Standard Communication Channel: Port 3389 serves as the standard communication channel for RDP connections.
• Firewall Configuration: Firewalls typically need to have rules allowing traffic on port 3389 for successful RDP connections.
• Security Considerations: While it is the standard port, using a different port is a common practice to enhance security through obscurity.
• Network Address Translation (NAT): In networks using NAT, port forwarding rules often direct external requests on port 3389 to the internal server's RDP port.

Common Scenarios Involving RDP Port 3389

1. Connecting Remotely: To connect to a remote computer using RDP, the client application typically initiates a connection on port 3389 of the remote server.
2. Server Configuration: The server must have RDP enabled and be configured to listen on port 3389, unless a different port is specified.
3. Firewall Rules: If a firewall is present, it will require a rule that allows inbound traffic on port 3389 for RDP to function correctly.
4. Port Forwarding: For remote connections over the Internet, port forwarding is often configured on the router to forward incoming traffic on port 3389 to the internal server.

How to Change the Default RDP Port (Advanced Users)

• Using Registry Editor (regedit):

  • Navigate to HKEY_LOCAL_MACHINE\System\CurrentControlSet\Control\Terminal Server\WinStations\RDP-Tcp
  • Modify the "PortNumber" value (DWORD) to your desired port.
  • Restart the computer for the changes to take effect.

• Firewall Modification:

  • If you change the port, ensure that the Windows Firewall (or any other firewall) is configured to allow connections on this new port.

  Example: If you change the port from 3389 to 5555, you will need to update the firewall rules to allow TCP traffic on port 5555.

| Protocol | Port Number |
|----------|-------------|
| RDP | TCP 3389 |