For a long time, ForeFront TMG (and ISA before it) has been the go-to Microsoft reverse proxy solution for many applications, including Exchange Server. However, with no more development roadmap for TMG 2010 a lot of customers are looking out for an alternative solution that works well with Exchange Server 2013.

The Windows team have added an additional component called Application Request Routing (ARR, or as Greg the pirate says, ARR!) 2.5 to the Internet Information Service (IIS) role, which enables IIS to handle reverse proxy requests. By using the URL Rewrite Module and Application Request Routing you can implement complex and flexible load balancing and reverse proxy configurations.

There are two options when implementing this solution and each have their pros and cons, which I'll cover in three posts. In this first post, we'll take a look at:

  1. Installation steps.
  2. Option 1 of implementing ARR as a reverse proxy solution for Exchange 2013 (this option is the simplest of the three configurations).

In the next 2 posts in the series, we'll cover the second option and some troubleshooting steps. The troubleshooting steps would also help you to verify if you have implemented the reverse proxy solution correctly.

Here's a diagram of the environment we'll use when discussing how to implement ARR.

--> please see the rest on the blog, part 2 & 3 also available : http://blogs.technet.com/b/exchange/archive/2013/07/19/reverse-proxy-for-exchange-server-2013-using-iis-arr-part-1.aspx