The first step is to install the add-on module for Application Request Routing for IIS. With Windows Server 2012 R2 or later versions of Windows Server 2016 and 2018, you can use the Microsoft Web Platform Installer 5.1 (WebPI) to download and install the URL Rewrite Module. Just search for ‘URL Rewrite’ in the search options and click ‘Add’. You can also download the extension from IIS.net - https://www.iis.net/downloads/microsoft/application-request-routing.
Once the module is installed in IIS, you will see a new Icon in the IIS Administration Console, called URL Rewrite - you may note that Url Rewrite is also an add-on that can be installed separately, but that ARR uses functionality provided by Url Rewrite to allow the server to act as a reverse proxy. This icon is present at the level or each site and web-application you have in the server, and will allow you to configure re-write rules that will apply from that level downwards.
Open the IIS Manager Console and click on the Default Web Site from the tree view on the left. Select the URL Rewrite Icon from the middle pane, and then double click it to load the URL Rewrite interface.
Chose the ‘Add Rule’ action from the right pane of the management console, and the select the ‘Reverse Proxy Rule’ from thNow we can proceed to fill in the routing information based on the diagram above in the Wizard window that is provided to us.
The basic setup for the reverse proxy is now complete, with IIS able to capture incoming traffic and forward it to the backend server, and inspect responses from the backend server and rewrite URL links inside the responses to match the host headers that IIS uses to publish the site.