Install mod_remoteip in Cpanel Server

To install mod_remoteip in Cpanel Server, run

yum install ea-apache24-mod_remoteip

Edit file

vi /etc/apache2/conf.modules.d/370_mod_remoteip.conf

Add

RemoteIPHeader X-Forwarded-For
RemoteIPTrustedProxy 127.0.0.1 PROXY_SERVER_IP_HERE

Restart Apache.

systemctl restart apache2

At this stage, PHP applications will show the proper visitor IP addresses.

Apache access logs will still show the proxy server IP. To fix this, edit the Apache configuration file.

Find

LogFormat "%h %l %u %t \"%r\" %>s %b" common
LogFormat "%h %l %u %t \"%r\" %>s %b \"%{Referer}i\" \"%{User-Agent}i\"" combined

Replace with

LogFormat "%a %l %u %t \"%r\" %>s %b" common
LogFormat "%a %l %u %t \"%r\" %>s %b \"%{Referer}i\" \"%{User-Agent}i\"" combined

Restart Apache

systemctl restart apache2