Tag: UDP 443

Q: How can I disable QUIC for all employees using Windows Group Policy?

A: You can disable QUIC for employees using Group Policy settings for supported browsers like Google Chrome and Microsoft Edge. Here’s how:

• For Google Chrome:
  1. Open Group Policy Editor: Press Win + R, type gpedit.msc, and hit Enter.
  2. Navigate to Chrome Policies: Go to Computer Configuration or User Configuration > Administrative Templates > Google > Google Chrome.
  3. Set QUIC Policy: Find “Allows QUIC protocol” or “Experimental QUIC protocol”.
     • Edit to set it to Disabled.
  4. Apply and Update: Click Apply, then OK. Use gpupdate /force or restart machines for immediate effect.
• For Microsoft Edge:
  1. Open Group Policy Editor: As above.
  2. Navigate to Edge Policies: Go to Computer Configuration or User Configuration > Administrative Templates > Microsoft Edge.
  3. Set QUIC Policy: Look for “Allows QUIC protocol”.
     • Edit to set it to Disabled.
  4. Apply and Update: Click Apply, then OK. Update policy or restart machines.

Q: Can I block QUIC at the firewall level?

A: Yes, you can also block QUIC at your firewall by blocking UDP traffic on port 443:

• Firewall Configuration:
  • Block UDP Port 443: Configure your firewall to block outgoing UDP traffic on port 443. This will effectively prevent QUIC traffic since QUIC typically uses UDP over this port.
  • Considerations:
    • Ensure this does not interfere with other necessary UDP traffic on the same port or other services that might use UDP 443.
    • This approach will block QUIC for all applications, not just browsers, which might be more comprehensive but also more disruptive if not all UDP 443 traffic is intended to be blocked.

Q: How can I verify if the QUIC policy has been applied?

A:

• For Chrome: Navigate to chrome://policy/ in the browser to check if the QUIC policy is listed as “Disabled”.
• For Edge: Use edge://policy/ to confirm the policy setting.

Q: What should I consider when disabling or blocking QUIC?

A:

• Performance Impact: Disabling or blocking QUIC might affect browsing speed or functionality on websites optimized for QUIC.
• Policy Updates: Policy names or locations might change with browser updates; keep your GPOs and firewall rules updated.
• Fallback: Browsers will fall back to HTTP/2 or HTTP/1.1, potentially less performant.
• Network Level: Blocking at the firewall is a broad approach affecting all QUIC traffic, so careful planning is needed.

Q: Will disabling QUIC affect all applications?

A: No, browser policies mainly affect Chrome and Edge. Blocking at the firewall will impact all applications using QUIC on UDP 443.