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2 min read

IIS Extensions: Application Request Router RTW and Dynamic IP Restrictions Beta

The old IIS Extensions train keeps on rollin’. Last month we hit RTW with the Web Platform Installer V1.0 (Why do we call it V1.0? Just wait until you see V2.0) and as you know, Web PI is the one-stop shop for discovering, downloading and installing the various components of the Microsoft Web Platform, be they application server modules, drivers, tools or IIS extensions. And while you’re over checking that out, take a look at the new version of, which provides a lot more detail on why the Microsoft Web Platform is the software of choice for building Web applications and solutions. It also has a pretty flower, which we thought was kinda apt for Valentine’s Day.

And so to today’s news, where two more IIS extension release updates join the fold, to help manage distributed Web server farms and to better protect those servers against unauthorized access or malicious requests: Application Request Router and IIS Dynamic IP Restrictions.

ARR, now reaching it’s RTW milestone, enables Web server administrators and hosting providers to increase Web application scalability and reliability through rule-based routing and load balancing of HTTP server requests. With ARR, administrators can optimize resource utilization for application servers, and so reduce management costs for Web server farms and shared hosting environments. Show me the money! The RTW version of ARR is fully supported and production ready, and adds new functionality since the Release Candidate, including:

  • An improved way to allocate and identify servers for host name affinity by including 2 providers: one based on round robin and the other based on memory consumption, to more evenly distribute the “load” across shared servers
  • Greater integration with IIS Manager, including the ability to manually override health statuses and configure HTTP and HTTPS ports for the application servers
  • Performance improvements in least response time load balancing algorithm

The other release we have today is a newcomer to the extensions stable – the beta of IIS Dynamic IP Restrictions. This extension provides IT Professionals and hosting providers with a configurable module that can help mitigate or block Denial of Service attacks or the cracking of passwords through brute-force methods. It does this by temporarily blocking IP addresses of HTTP clients who follow a pattern that could be indicative of such an attack. This module can be configured at the Web Server or the Web Site level for analyzing and blocking potentially malicious requests.

IIS Dynamic IP Restrictions integrates into IIS Manager and extends the existing IP Restrictions functionality, maintaining support for the functionality already provided by IPv4 Address and Domain Restrictions and also adding new support for IPv6 addresses. As a result, IT Administrators can build and use a static list of IP addresses and domain names that are denied or granted access, while still restricting suspicious IP addresses dynamically based on behavior. Learn more about how to use this new extension, try it out, and of course, let us know how you get on.