Install libapache2-mod-rpaf by entering the following commands in the terminal:
sudo apt update sudo apt install libapache2-mod-rpaf
Description:
module for Apache2 which takes the last IP from the 'X-Forwarded-For' header
rpaf is short for reverse proxy add forward. . rpaf is for backend Apache servers what mod_proxy_add_forward is for frontend Apache servers. It does exactly the opposite of mod_proxy_add_forward written by Ask Bjorn Hansen. . It changes the remote address of the client visible to other Apache modules when two conditions are satisfied. First condition is that the remote client is actually a proxy that is defined in httpd.conf. Secondly if there is an incoming X-Forwarded-For header and the proxy is in its list of known proxies it takes the last IP from the incoming X-Forwarded-For header and changes the remote address of the client in the request structure.
Homepage: http://www.stderr.net/apache/rpaf/
Version: 0.6-13
Section: universe/web