[SOLVED] Apache logs shows us we are using HTTP1.1 instead of HTTP2 protocol even HTTP/2 is enabled (through WAF)

Apache logs shows us we are using HTTP1.1 instead of HTTP2 protocol even HTTP/2 is enabled (through WAF)

Do you know why our apache logs shows us we are using HTTP1.1 instead of HTTP2 protocol even HTTP/2 is enabled in our server?

I make sure that mod_http2 module was already installed and loaded:

$sudo httpd -M | grep http2_module

http2_module (shared)

Also, I make sure virtualhost is configured to use HTTP2:

<VirtualHost *:443>

...

Protocols h2 h2c http/1.1

...

</VirtualHost>

The apache logs always shows us we are using HTTP1.1 instead of HTTP2 protocol:

XXX.WWW.YYY.ZZZ (XXX.WWW.YYY.ZZZ) - [25/Oct/2023:11:55:06 +0200] "GET /test_http2.php HTTP/1.1" 200 33

If we skip the WAF and we access directly to our server, we can see that HTTP2 is working: XXX.WWW.YYY.ZZZ (-) - [25/Oct/2023:11:53:07 +0200] "GET /test_http2.php HTTP/2.0" 200 33

It could be related with our WAF (in our case, Sucuri) or with our server configuration?

Solution

I'd like to answer my own question. The reason we're seeing requests using HTTP/1.1 at the hosting server is due to our WAF. Our WAF is built on Nginx, which doesn't support HTTP/2 for proxy connections to upstream servers : https://www.nginx.com/blog/http2-module-nginx/#QandA