Application Request Routing (ARR) is an out of band module available for IIS 7.x and onwards.
ARR enables Web server administrators, hosting providers, and Content Delivery Networks (CDNs) to increase Web application scalability and reliability through rule-based routing, client and host name affinity, load balancing of HTTP server requests, setting up a reverse proxy and distributed disk caching.
This walkthrough will guide you through how to use URL Rewrite Module and Application Request Routing (ARR) to implement a reverse proxy server when the content server is not exposed to the outside world.
Scenario: Consider you have a site with external URL http://www.arr.com and the actual content is hosted on IIS server which is not exposed to the internet world and internal/ intranet URL is http://backendserver/. In this case, we will forward the requests to the ARR server and in turn, internally route it to the backend server.