Previously I use http/2.0 well on apache httpd2.4.18. Today I upgrade in to httpd2.4.25 and found that all my webpages went back to http/1.1 with a Upgrade: "h2"
response head on my Firefox v53.0. I've tried Browser won't upgrade to H2 altough "Upgrade" headers are sent but it didn't work.
The resopnse head is:
Date: Tue, 13 Jun 2017 04:40:05 GMT
Server: Apache/2.4.25 (Red Hat) OpenSSL/1.0.1e-fips mod_fcgid/2.3.9 Phusion_Passenger/5.0.18 mod_wsgi/4.5.7 Python/2.6
Upgrade: h2
Connection: Upgrade, Keep-Alive
Accept-Ranges: bytes
Vary: Accept-Encoding
Content-Encoding: gzip
Content-Length: 3489
Keep-Alive: timeout=5, max=100
Content-Type: text/html; charset=UTF-8
Why so? I did't change any configurations of my httpd server.