Quick UDP Internet Connection (QUIC) speeds up connections and reduces bandwidth congestion on Chrome browsers. However, because QUIC works over User Datagram Protocol (UDP) and not Transmission Control Protocol (TCP), using QUIC can prevent filtering from being applied.
To ensure access to undesirable websites and content is blocked, you must block QUIC traffic.
Step 1: Block outbound traffic
Block outbound UDP traffic on ports 80 and 443 on your firewall. This will cause the request to fall back to TCP and be redirected to the proxy.
If Smoothwall is your firewall, go to Network > Firewall > Firewall Rules. Create a new Firewall Rule for UDP ports 80 and 443, with Drop or Reject as the Action.
Step 2: Set up HTTPS Inspection
Where possible (unless the network is for BYO devices), create an HTTPS Inspection Policy to Decrypt and Inspect everything.
Step 3: Set up Content Modification
Create a Content Modification Policy for Remove QUIC header, with Apply as the Action.