Tuesday, July 22, 2008
Using the ASP.NET Routing Engine with IIS6 on Win2k3

Today was one of those days where I almost was ready to jump out the window: I have been working long hours on building an ASP.NET web app based on the new routing framework introduced in .NET 3.5 SP1. Everything seemed to be going pretty well, until I deployed the whole app to a Win2k3 server with IIS6. Nothing worked at all!

As it turns out, ASP.NET routing does not work out of the box on IIS6. What you can do however, is add a wildcard script map that forces ASP.NET to process the routed URLs. Here's how you do that:

1. Open the properties of your web site in IIS6.
2. Go to the "Home Directory" tab and click "Configuration"
3. Click the "Insert..." button to add a new *wildcard* application map.
4. Make the executable the aspnet_isapi DLL as used for the .aspx application extension (copy the whole path from that setting to make your life easy).
5. Uncheck the "Verify that file exists" checkbox.

And that should do the trick. The downside is that every hit (even images) is now processed by ASP.NET. So on a high-traffic server, that could be a problem.