HAProxy can't get HTTP/2 working

[flobernd]

Hi there,

I'm using the haproxy-devel package and have create a SSL/HTTPS frontend that connects to a HTTP (plain) backend. Everything is working fine so far.

Now I'm trying to enable HTTP/2 support for the frontend. After reading some tutorials, I added the alpn h2,http/1.1 to the bind (by adding it in the advanced input). According to the haproxy.cfg file this change was successful.

Sadly the frontend refuses to serve HTTP/2 (I'm using is-http2-cli - a NPM package - to check that). The pfSense webConfigurator supports HTTP/2 according to this tool and the installed OpenSSL version (OpenSSL 1.0.2u-freebsd) seems to be fine for ALPN as well.

Any ideas?

Best regards