Recently I added HTTP/2 protocol (derived from the formerly known SPDY protocol developed by Google) to my config since I haven’t found any references in my /etc/apache2 config files. It was quite simple to enable it.

a2enmod http2

A config file is needed too:

cat 01_http2.conf
Protocols h2 h2c http/1.1

Enable it:

a2enconf  01_http2

Restart server. Done.