Changing Remote Desktop Port: Secure Windows

The Microsoft Windows operating system, while ubiquitous, often faces security challenges necessitating proactive measures such as changing Remote Desktop Port settings. Implementing a non-standard port number, instead of the default 3389, directly impacts the attack surface visible to malicious actors employing network scanning tools like Nmap. System administrators at organizations such as the SANS Institute often recommend changing remote desktop port configurations as a fundamental hardening step, contributing significantly to a more secure remote access posture.

Securing Windows: A Deep Dive into Changing Your Remote Desktop Port

Remote Desktop Protocol (RDP) provides a convenient way to access your Windows computer remotely. However, its popularity also makes it a frequent target for malicious actors. One of the simplest, yet effective, security measures you can implement is changing your Remote Desktop port. This article provides a detailed guide on why and how to change your RDP port to secure your Windows machine.

Why Change the Default Remote Desktop Port?

The default RDP port, 3389, is well-known. Attackers frequently scan networks for open port 3389 connections to identify potential targets for brute-force attacks, vulnerability exploitation, and malware infections. Changing the RDP port effectively hides your machine from these automated scans. While not a foolproof security solution, it adds a significant layer of obscurity and reduces the likelihood of becoming an easy target.

Think of it like changing the locks on your house. While a determined thief can eventually break in, changing the locks makes it more difficult and deters casual burglars.

Here’s a breakdown of the benefits:

• Reduces exposure to automated attacks: Automated scanners often target default ports.
• Adds a layer of obscurity: Makes it harder for attackers to find your RDP service.
• Simplifies firewall management: Allows you to restrict access to the new port to specific IP addresses if desired.

Understanding the Risks

Before diving into the process, it’s crucial to understand potential risks:

• Incorrect configuration can disable remote access: Carefully follow instructions and double-check your work.
• Network firewall conflicts: Ensure your network firewall allows traffic on the new port.
• Requires updating RDP client configurations: You’ll need to specify the new port when connecting remotely.

Step-by-Step Guide to Changing the Remote Desktop Port

The process involves modifying the Windows Registry and updating your firewall rules.

1. Accessing the Registry Editor:

• Press the Windows key + R to open the Run dialog box.
• Type regedit and press Enter.
• Click "Yes" if prompted by User Account Control.

2. Navigating to the RDP Port Registry Key:

• In the Registry Editor, navigate to the following path:

  HKEY_LOCAL_MACHINE\System\CurrentControlSet\Control\Terminal Server\WinStations\RDP-Tcp

3. Modifying the Port Number:

• In the right pane, locate the PortNumber entry.
• Double-click PortNumber.
• In the "Edit DWORD (32-bit) Value" window:
  • Select "Decimal" under "Base".
  • Enter your desired port number (e.g., 5000). Choose a port number between 1024 and 65535 that isn’t already in use.
  • Click "OK".

4. Restarting the Remote Desktop Service:

• Press Windows key + R to open the Run dialog box.
• Type services.msc and press Enter.
• In the Services window, locate "Remote Desktop Services".
• Right-click "Remote Desktop Services" and select "Restart".

5. Configuring Windows Firewall:

Windows Firewall will need to be configured to allow incoming connections to the newly selected port.

• Search for "Windows Defender Firewall with Advanced Security" in the Start menu.
• In the left pane, click "Inbound Rules".
• In the right pane, click "New Rule…".
• Choose "Port" and click "Next".
• Select "TCP" and enter your new port number in the "Specific local ports" field. Click "Next".
• Choose "Allow the connection" and click "Next".
• Select the network types that apply to your situation (Domain, Private, Public) and click "Next".
• Enter a name for the rule (e.g., "New RDP Port") and click "Finish".

6. Verification and Testing:

After changing the port, it’s crucial to verify that the configuration is working correctly.

• Remote Connection: Attempt to connect to your computer remotely using your new port. You will need to specify the port number when connecting. For example, in the Remote Desktop Connection client, enter your_ip_address:new_port_number.
• Port Scanning: Use a port scanning tool (like Nmap) to verify that your new port is open and that the default port 3389 is closed.

Choosing a Suitable Port Number

Selecting the right port number is vital. Here are some considerations:

• Avoid common ports: Don’t choose ports frequently used by other applications or services. A list of common ports is readily available online.
• Choose a high port number: Ports above 1024 are generally safer.
• Document your choice: Keep a record of the port number you selected.

Troubleshooting Common Issues

• Unable to connect: Double-check the registry settings, firewall rules, and RDP service status.
• Firewall blocking connections: Ensure your firewall rules are correctly configured to allow traffic on the new port.
• Remote Desktop Service not running: Verify that the Remote Desktop Services service is started and set to automatic startup.

Illustrative Table: Common Errors and Solutions

Error	Possible Cause	Solution
Connection refused	Firewall blocking the new port	Verify inbound firewall rule is enabled and configured correctly for the new port.
Incorrect port specified	Typos in the RDP client or registry	Double-check the port number entered in both the registry and the RDP client.
RDP service not running	Service stopped or disabled	Start the "Remote Desktop Services" service and ensure it is set to automatic startup.
Network connectivity issues	General network problems	Verify network connectivity and DNS resolution. Check router configurations if necessary.

By carefully following these steps and paying attention to detail, you can successfully change your Remote Desktop port and enhance the security of your Windows system.

So, there you have it! Taking the simple step of changing your Remote Desktop Port is a really effective way to boost your Windows security. It might seem a little technical at first, but hopefully, this guide has made the process clear and manageable. Stay safe out there!