What Is Network Level Authentication and How Does It Work?

Want to make your Remote Desktop connections more secure and efficient? Network Level Authentication (NLA) adds a vital layer of protection by verifying users before a session starts. This guide explains what NLA is, why it matters, and how to enable or disable it when needed.

What Is Network Level Authentication?

Network Level Authentication (NLA) is a security feature for Remote Desktop connections. It requires users to authenticate before a remote session is established.

If you’re new to Remote Desktop, you may want to check out how to use Remote Desktop first to understand the basics.

In older versions of Remote Desktop Protocol (RDP), a session would begin before the user was verified. That meant the remote system had to allocate resources just to display the login screen, even if the user turned out to be unauthorized. This left systems more vulnerable to brute-force attacks and unnecessary resource use.

NLA improves this by verifying the user’s identity before any desktop or system resources are loaded. It offers several key benefits:

• Stronger security: Blocks unauthorized users from initiating remote sessions
• Better performance: Saves system resources by rejecting invalid connections early
• Enterprise support: Works well with Active Directory and other identity services

NLA is enabled by default on most modern versions of Windows, but both the client and host must support it for it to work properly.

How Does Network Level Authentication Work?

Network Level Authentication (NLA) changes the way Remote Desktop connections are handled by requiring users to authenticate before a session is fully established. This means the remote system won’t load the desktop or any resources until your identity is confirmed.

When you try to connect to a remote device using Remote Desktop, your client first communicates with the host to check whether NLA is required. If it is, your login credentials are sent using a secure protocol called CredSSP (Credential Security Support Provider).

Only after those credentials are verified does the system proceed to establish the actual desktop session. This process helps prevent unauthorized users from accessing or even reaching the login interface of the remote system.

NLA works effectively only when certain conditions are met:

• Both the client and the host must support RDP 6.0 or later
• The client device must run Windows Vista or newer
• The remote machine must be configured to enforce NLA and have proper user permissions set

By verifying a user early in the process, NLA helps reduce the risk of brute-force attacks and lowers system resource usage by rejecting unauthenticated users upfront. It’s a simple yet powerful upgrade to the traditional Remote Desktop Protocol workflow.

Benefits of NLA for Users and System Administrators

1. Improved Security

NLA stops unauthorized users before a full remote session starts. Since credentials are verified first, attackers can’t even reach the login screen, reducing the risk of brute-force or credential-stuffing attacks.

2. Lower Resource Usage

Without NLA, remote desktops load the login screen before checking credentials, which wastes system resources. NLA ensures that only verified users get access, saving memory and processing power.

3. Seamless Integration with Identity Services

NLA works smoothly with Active Directory and other enterprise authentication systems. It helps admins enforce consistent credential policies and simplifies user access control.

4. Fewer Attack Surfaces

By authenticating users early, NLA reduces the window of exposure for remote attacks, especially important for servers and systems accessible from the internet.

5. Better Control for Admins

Admins can enable or enforce NLA through Group Policy or the Windows Registry, making it easy to apply across multiple systems and maintain a consistent security baseline.

How to Enable Network Level Authentication?

Here’s how you can enable it in Windows:

1. Enable NLA Through System Settings

• Press Windows + R, type “SystemPropertiesRemote”, and press Enter.

• In the “Remote” tab, make sure “Allow remote connections to this computer” is selected.
• Then check the option “Allow connections only from computers running Remote Desktop with Network Level Authentication (recommended)”.

• Click Apply, then OK.

2. (Optional) Check or Enforce NLA in the Windows Registry

• Press Windows + R, type “regedit”, and press Enter. （You may see a User Account Control (UAC) prompt saying a program wants to make changes to your computer, this is normal. It appears because the Registry Editor can modify important system settings. As long as the publisher is Microsoft Windows, it’s safe to proceed.）
• Go to: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Terminal Server\WinStations\RDP-Tcp
• Look for a value called “UserAuthentication” and ensure it is set to 1 (which means enabled).
• Close the Registry Editor and restart your system.

Note: Editing the registry can be risky. Be cautious and back it up before making changes.

3. (For advanced users or IT admins) Enable NLA via Group Policy

• Open the Group Policy Editor by pressing Windows + R, typing “gpedit.msc”, and press Enter.
• Navigate to: Computer Configuration > Administrative Templates > Windows Components > Remote Desktop Services > Remote Desktop Session Host > Security.
• Double-click on “Require user authentication for remote connections by using Network Level Authentication” and set it to Enabled.

When and How to Safely Turn Off NLA (If Necessary)

Network Level Authentication (NLA) is an important security feature, but there may be cases when you need to disable it, temporarily or permanently. Before doing so, it’s important to understand the risks and when it’s appropriate.

When Might You Need to Turn It Off?

• Compatibility issues: Some older versions of Windows (like Windows XP) or third-party RDP clients don’t support NLA.
• Troubleshooting: If you’re locked out of a remote system due to misconfigured credentials or network issues, turning off NLA may help you regain access.
• Non-Domain environments: In small test labs or non-domain setups where strict security isn’t a priority, NLA might be unnecessary.

Warning: Disabling NLA weakens your system’s security. It allows unauthenticated users to reach the login screen, increasing the risk of brute-force attacks.

If you’re operating in a non-domain environment or using older systems that don’t support NLA, it’s especially important to protect your Remote Desktop traffic.

Using a secure VPN solution like LightningX VPN can help reduce exposure by creating a private tunnel between your device and the remote machine, ensuring that RDP access is limited to trusted networks even when NLA is turned off.

How to Turn Off NLA (Safely)

The steps to disable NLA overlap in some areas with the enabling process, such as using system settings, Group Policy, or the Registry. The intention and specific selections differ. Since turning NLA off lowers security, it’s important to follow these steps carefully and understand the implications.

Option 1: Using System Properties

1. Press Windows + R, type sysdm.cpl, and hit Enter.
2. Go to the Remote tab.
3. Under Remote Desktop, uncheck “Allow connections only from computers running Remote Desktop with Network Level Authentication (recommended)”.
4. Click Apply, then OK.

Option 2: Using Group Policy (for multiple machines)

1. Press Windows + R, type gpedit.msc, and press Enter.
2. Navigate to: computer Configuration > Administrative Templates > Windows Components > Remote Desktop Services > Remote Desktop Session Host > Security
3. Find “Require user authentication for remote connections by using Network Level Authentication”.
4. Set it to Disabled.

Option 3: Using the Windows Registry

1. Press Windows + R, type regedit, and press Enter.
2. Navigate to: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Terminal Server\WinStations\RDP-Tcp
3. Double-click the UserAuthentication value and set it to 0.
4. Close the editor and restart your computer.

Final Tip

Only disable NLA if you truly need to and re-enable it as soon as the issue is resolved. If you must run without NLA, make sure your firewall is configured properly, use strong passwords, and consider limiting RDP access to known IP addresses.

Troubleshooting Network Level Authentication Issues

Even when NLA is set up correctly, you might still run into problems, especially during remote desktop connections. Here are some common issues and how to resolve them:

“The Remote Computer Requires Network Level Authentication” Error

This usually means the remote machine has NLA enabled, but your client device doesn’t support it, or it’s not configured correctly. Try these steps:

• Make sure you’re using a version of Remote Desktop that supports NLA (Windows 7 and later usually do).
• Ensure your local machine is part of a domain or has valid credentials stored.
• Double-check that “Allow connections only from computers running Remote Desktop with Network Level Authentication” is selected in the remote system’s settings.

Credential Prompts Keep Appearing

If you’re asked to log in multiple times, even after entering the correct username and password:

• Make sure the “UserAuthentication” registry value is set to 1.
• Confirm your credentials are stored correctly in Windows Credential Manager.
• Disable any conflicting group policies that might override NLA behavior.

RDP Client Crashes or Fails to Connect

Sometimes a misconfigured firewall or antivirus can interfere with the NLA handshake:

• Temporarily disable your firewall or antivirus and see if the issue resolves.
• Allow inbound connections on port 3389, the standard RDP port.
• Restart the Remote Desktop Services on both the client and host machines.

Can’t Connect After Enabling NLA

If enabling NLA locks you out of your machine:

• Boot into Safe Mode with Networking.
• Access the Registry or Group Policy Editor to disable NLA temporarily.
• Reboot normally and reconfigure NLA settings once you regain access.

Compatibility Issues with Older Systems

Some older operating systems or third-party RDP clients don’t support NLA:

• Upgrade to a supported Windows version, if possible.
• Use Microsoft’s official Remote Desktop client for the best compatibility.
• If NLA must be disabled for access, do so cautiously and enable other security controls.

Conclusion

Network Level Authentication (NLA) adds an essential layer of security to Remote Desktop by verifying users before a session begins. It helps block unauthorized access, reduces system load, and integrates well with modern identity tools.

While it’s easy to enable and generally recommended, NLA can cause issues with older systems or misconfigured settings. If you need to disable it temporarily, do so carefully, and re-enable it when possible.

For most users and organizations, keeping the NLA turned on is a smart and effective way to secure remote access.