A reverse proxy is a server that sits in front of web servers and forwards client (e.g. web browser) requests to those web servers. Reverse proxies are typically implemented to help increase security, performance, and reliability.
A reverse proxy server is an intermediate connection point positioned at a network’s edge. It receives initial HTTP connection requests, acting like the actual endpoint.
what is x-forwarded-for in netscaler:
when you’re using a 3rd party reverse proxy such as CloudFlare you will see the IP address from the reverse proxy instead of the actual Client IP Address on your webserver. This means that your logging will all show the same, internal, IP address and that IP Based Access Rules will not work. Fortunately, this is easy to solve by having NetScaler add the Client IP Address in the headers and rewriting the address on your webserver.