Enable HTTP/2 and HTTP/3

Learning Focus

By the end of this lesson you will know how to enable HTTP/2 and HTTP/3 on your SSL listener.

Steps

1. Navigate to Listeners → SSL listener → SSL tab
2. Set Enable HTTP/2: Yes
3. Set Enable HTTP/3 (QUIC): Yes
4. Save and Graceful Restart

Firewall for HTTP/3

# HTTP/3 requires UDP on port 443
sudo ufw allow 443/udp

# Verify
sudo ufw status | grep 443

Verification

# HTTP/2
curl --http2 -sI https://example.com | head -1

# HTTP/3 Alt-Svc header
curl -sI https://example.com | grep -i alt-svc

Key Takeaways

• HTTP/2 is a strong default — enable it on all SSL listeners.
• HTTP/3 requires UDP port 443 open in the firewall.
• Both improve page load performance for modern browsers.

What's Next

• Continue to Verification to test the complete SSL setup.