Apache/2.4.34 (Red Hat) OpenSSL/1.0.2k-fips 在 CentOS 7、PHP 7.4.33 上，我已按照以下指南安装并启用了 http/2如何从 Centos 包/yum 启用 http/2？。没有报告任何错误并且模块已加载但页面仍然通过 http/1.1 提供服务。
我已经从 prefork mpm 转移到 event，所以这不是问题。
这不是浏览器缓存问题。
Apache 已重新启动多次。
conf文件包括：
Protocols h2 http/1.1
SSL 协议指令为：
SSLProtocol all -SSLv2 -SSLv3
httpd -V 的输出：
Server version: Apache/2.4.34 (Red Hat)
Server built: Oct 11 2022 12:56:44
Server's Module Magic Number: 20120211:79
Server loaded: APR 1.4.8, APR-UTIL 1.5.2
Compiled using: APR 1.4.8, APR-UTIL 1.5.2
Architecture: 64-bit
Server MPM: event
threaded: yes (fixed thread count)
forked: yes (variable process count)
Server compiled with....
-D APR_HAS_SENDFILE
-D APR_HAS_MMAP
-D APR_HAVE_IPV6 (IPv4-mapped addresses enabled)
-D APR_USE_SYSVSEM_SERIALIZE
-D APR_USE_PTHREAD_SERIALIZE
-D SINGLE_LISTEN_UNSERIALIZED_ACCEPT
-D APR_HAS_OTHER_CHILD
-D AP_HAVE_RELIABLE_PIPED_LOGS
-D DYNAMIC_MODULE_LIMIT=256
-D HTTPD_ROOT="/opt/rh/httpd24/root/etc/httpd"
-D SUEXEC_BIN="/opt/rh/httpd24/root/usr/sbin/suexec"
-D DEFAULT_PIDLOG="run/httpd.pid"
-D DEFAULT_SCOREBOARD="logs/apache_runtime_status"
-D DEFAULT_ERRORLOG="logs/error_log"
-D AP_TYPES_CONFIG_FILE="conf/mime.types"
-D SERVER_CONFIG_FILE="conf/httpd.conf"
apachectl -M：
core_module (static)
so_module (static)
http_module (static)
access_compat_module (shared)
actions_module (shared)
alias_module (shared)
allowmethods_module (shared)
auth_basic_module (shared)
auth_digest_module (shared)
authn_anon_module (shared)
authn_core_module (shared)
authn_dbd_module (shared)
authn_dbm_module (shared)
authn_file_module (shared)
authn_socache_module (shared)
authz_core_module (shared)
authz_dbd_module (shared)
authz_dbm_module (shared)
authz_groupfile_module (shared)
authz_host_module (shared)
authz_owner_module (shared)
authz_user_module (shared)
autoindex_module (shared)
cache_module (shared)
cache_disk_module (shared)
cache_socache_module (shared)
data_module (shared)
dbd_module (shared)
deflate_module (shared)
dir_module (shared)
dumpio_module (shared)
echo_module (shared)
env_module (shared)
expires_module (shared)
ext_filter_module (shared)
filter_module (shared)
headers_module (shared)
http2_module (shared)
include_module (shared)
info_module (shared)
log_config_module (shared)
logio_module (shared)
macro_module (shared)
mime_magic_module (shared)
mime_module (shared)
negotiation_module (shared)
remoteip_module (shared)
reqtimeout_module (shared)
request_module (shared)
rewrite_module (shared)
setenvif_module (shared)
slotmem_plain_module (shared)
slotmem_shm_module (shared)
socache_dbm_module (shared)
socache_memcache_module (shared)
socache_shmcb_module (shared)
status_module (shared)
substitute_module (shared)
suexec_module (shared)
unique_id_module (shared)
unixd_module (shared)
userdir_module (shared)
version_module (shared)
vhost_alias_module (shared)
watchdog_module (shared)
dav_module (shared)
dav_fs_module (shared)
dav_lock_module (shared)
lua_module (shared)
mpm_event_module (shared)
proxy_module (shared)
lbmethod_bybusyness_module (shared)
lbmethod_byrequests_module (shared)
lbmethod_bytraffic_module (shared)
lbmethod_heartbeat_module (shared)
proxy_ajp_module (shared)
proxy_balancer_module (shared)
proxy_connect_module (shared)
proxy_express_module (shared)
proxy_fcgi_module (shared)
proxy_fdpass_module (shared)
proxy_ftp_module (shared)
proxy_http_module (shared)
proxy_hcheck_module (shared)
proxy_scgi_module (shared)
proxy_uwsgi_module (shared)
proxy_wstunnel_module (shared)
ssl_module (shared)
systemd_module (shared)
php7_module (shared)
https://tools.keycdn.com/http2-test：
HTTP/2 protocol is not supported.
ALPN extension is not supported.
已更新虚拟主机
<VirtualHost _default_:443>
DocumentRoot "/var/www/html"
ServerName ###
ServerAlias www ###
Protocols h2 h2c http/1.1
ErrorLog logs/ssl_error_log
TransferLog logs/ssl_access_log
LogLevel warn
SSLEngine on
SSLProtocol all -SSLv2 -SSLv3
SSLCipherSuite HIGH:3DES:!aNULL:!MD5:!SEED:!IDEA
Include /etc/letsencrypt/options-ssl-apache.conf
SSLCertificateFile /etc/letsencrypt/live/###.ro/cert.pem
SSLCertificateKeyFile /etc/letsencrypt/live/###/privkey.pem
SSLCertificateChainFile /etc/letsencrypt/live/###/chain.pem
</VirtualHost>