How to Disable Experimental QUIC Protocol in Google Chrome: A Comprehensive Guide

The QUIC (Quick UDP Internet Connections) protocol is designed to improve the performance of web applications. However, in some enterprise environments, it may be necessary to disable it for security or compatibility reasons. This article explores different methods to disable the experimental QUIC protocol in Google Chrome, particularly within a managed environment using tools like Jamf Pro.

What is QUIC and Why Disable It?

QUIC is a network protocol developed by Google that aims to provide a more reliable and efficient transport layer compared to TCP. It offers several benefits:

• Reduced latency
• Improved congestion control
• Multiplexing of multiple streams over a single connection

Despite these advantages, organizations might need to disable QUIC due to:

• Security concerns: New protocols can introduce unforeseen vulnerabilities.
• Network compatibility: Some network devices or firewalls may not fully support QUIC.
• Testing and control: To ensure consistent performance and behavior across the network.

Methods to Disable QUIC in Google Chrome

Several approaches can be used to disable the experimental QUIC protocol. Let's explore the most effective ones:

1. Using Chrome's Master Preferences File

The Google Chrome Master Preferences file is a common method for deploying Chrome with pre-configured settings. However, some users have reported issues with this method when trying to disable QUIC. Specifically, setting the QuicAllowed value to either true or false may still result in the chrome://flags page showing "Default."

2. Configuration Profiles and MDM (Jamf Pro)

Using a configuration profile or Mobile Device Management (MDM) solution like Jamf Pro is a more reliable approach. Here’s how you can do it:

• Create a Configuration Profile: Use Jamf Pro to create a new configuration profile for Google Chrome.
• Set the QuicAllowed Key: Add the QuicAllowed key to the profile and set its value to false.
• Deploy the Profile: Deploy this configuration profile to the managed devices.

Despite setting the QuicAllowed policy through a configuration profile, the chrome://flags page might still display "Default." To verify the policy is being enforced, check chrome://policy. The QuicAllowed policy should be listed as "false."

3. Google Admin Console (for Google Workspace Users)

If your organization uses Google Workspace, you can manage Chrome policies through the Google Admin console. This is a centralized way to control Chrome settings for all users in your domain.

• Force Sign-In: Ensure that users are signed into Chrome with their corporate credentials. This allows Chrome to retrieve policies from the Google Admin console.
• Disable QUIC in Admin Console: Navigate to the Chrome management section in the Google Admin console and find the setting to disable QUIC. Set this policy to disabled.

4. Verify QUIC is Disabled

After applying any of the above methods, it's essential to verify that QUIC is indeed disabled. Here's how:

• Check chrome://policy: This page shows all active Chrome policies and their current status. Look for the QuicAllowed policy and confirm that its value is set to false.
• Use a QUIC Test Website: Visit a website that tests for QUIC support, such as https://quic.nginx.org. This will confirm whether QUIC is enabled or disabled for your browser.

Troubleshooting

If you encounter issues while disabling QUIC, consider the following:

• Policy Conflicts: Ensure that there are no conflicting policies that might be overriding your settings.
• Chrome Updates: Chrome updates can sometimes reset policies. Re-apply the configuration profile or Google Admin settings after an update
• User Sign-In: For Google Admin policies to apply correctly, users must be signed in to Chrome with their corporate accounts.

Conclusion

Disabling the experimental QUIC protocol in Google Chrome requires careful configuration, especially in managed environments. While the chrome://flags page might be misleading, checking chrome://policy and using test websites will provide accurate confirmation. By using configuration profiles, MDM solutions like Jamf Pro, or the Google Admin console, organizations can effectively manage and control QUIC usage to meet their security and compatibility requirements.