Microsoft Application Request Routing Version 3 for IIS

Microsoft Application Request Routing (ARR) 3 for IIS is a proxy based routing module that forwards HTTP requests to application servers based on HTTP headers and server variables, and load balance algorithms.
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    1.9 MB

    1.6 MB

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      Microsoft Application Request Routing (ARR) for IIS is a proxy-based routing module that forwards HTTP requests to application servers based on HTTP headers, server variables, and load balance algorithms.

      ARR Version 3 is an incremental release that includes all of the features from Version 2, and adds the following features:
    • Websocket support

    • Support for application-triggered session affinity opt out

    • failcheck reliability improvements

    • Various bug fixes

    • ARR version 3 and previous released cannot be installed side-by-side.

      More details can be found on
  • Supported Operating System

    Windows Server 2008, Windows Server 2008 R2, Windows Server 2012, Windows Server 2012 R2

    • Internet Information Services 7.0 or later must be installed
    • For WebSockets support, Internet Information Services 8.0 or later is required, and the WebSockets module must be enabled
    • ARR is dependent on several components:
    • URL Rewrite

    • Web Farm Framework

    • External Cache module

    • Do not attempt to install this package directly due to this dependency. To install ARR and all its components in the appropriate order, use the Microsoft Web Platform Installer ( and search for ARR within it. Alternatively, read the following blog post for instructions on installing ARR manually: