ASP.NET MVC on IIS6

It took me a bit, but I figured out how to make the extensions work with IIS 6. First, you need to rework the base routing to include .aspx so that they will be routed through the ASP.NET ISAPI filter.

routes.MapRoute(
    "Default",                                              // Route name
    "{controller}.aspx/{action}/{id}",                      // URL with parameters
    new { controller = "Home", action = "Index", id = "" }  // Parameter defaults
);

If you navigate to Home.aspx, for example, your site should be working fine. But Default.aspx and the default page address of http://[website]/ stop working correctly. So how is that fixed?

Well, you need to define a second route. Unfortunately, using Default.aspx as the route does not work properly:

routes.MapRoute(
    "Default2",                                             // Route name
    "Default.aspx",                                         // URL with parameters
    new { controller = "Home", action = "Index", id = "" }  // Parameter defaults
);

So how do you get this to work? Well, this is where you need the original routing code:

routes.MapRoute(
    "Default2",                                             // Route name
    "{controller}/{action}/{id}",                           // URL with parameters
    new { controller = "Home", action = "Index", id = "" }  // Parameter defaults
);

When you do this, Default.aspx and http://[website]/ both start working again, I think because they become successfully mapped back to the Home controller. So the complete solution is:

public class MvcApplication : System.Web.HttpApplication
{
    public static void RegisterRoutes(RouteCollection routes)
    {
        routes.IgnoreRoute("{resource}.axd/{*pathInfo}");

        routes.MapRoute(
            "Default",                                              // Route name
            "{controller}.aspx/{action}/{id}",                      // URL with parameters
            new { controller = "Home", action = "Index", id = "" }  // Parameter defaults
        );

        routes.MapRoute(
            "Default2",                                              // Route name
            "{controller}/{action}/{id}",                            // URL with parameters
            new { controller = "Home", action = "Index", id = "" }  // Parameter defaults
        );
    }

    protected void Application_Start()
    {
        RegisterRoutes(RouteTable.Routes);
    }
}

And your site should start working just fine under IIS 6. (At least it does on my PC.)

And as a bonus, if you are using Html.ActionLink() in your pages, you should not have to change any other line of code throughout the entire site. This method takes care of properly tagging on the .aspx extension to the controller.