The Remote Desktop Protocol (RDP) uses TCP port 3389 by default. It is possible to change the port used by the terminal server or PC being accessed by editing the registry. However, changing the port number does not guarantee security, as attackers can still scan for open ports and use brute force password techniques to access vulnerable networks. It is recommended to assess the need to have RDP open on systems and, if required, place any system with an open RDP port behind a firewall and require users to VPN in through the firewall, enable strong passwords, and use two-factor authentication.