IIS 7.5 URL Rewrite and 404 Not Found

Question

I'm trying to setup a reverse proxy using IIS to proxy request on port 80 to a local virtual machine on port 8080. The rewriting rule was setup using IIS GUI "Reverse Proxy" rule. However it work very strangely:

If there is a file/folder in the web folder (physical path), then the reverse proxy work. Otherwise, it throw 404 error.

For example, for a request to "http://example.com/myfile", if there is a file name "myapp" in the web folder then it get rewritten into "http://example.com:8080/myfile" properly. On the other hand, if there is no file "myfile" locally, then I get 404 error. It is as if there is something that check existence of a local file (and throw 404) before URL rewrite rules are processed.

I try disable some handles, re-order modules, and none seems to work :(

Running IIS 7.5 on Windows Server 2008 R2

Answer 1

If you have ASP.NET MVC application and get 404 error, this can be resolved by adding ignore path to routes.

routes.Ignore("path to ignore");

public class RouteConfig
{
    public static void RegisterRoutes(RouteCollection routes)
    {
        routes.IgnoreRoute("{resource}.axd/{*pathInfo}");
        routes.Ignore("api/controllerNmae/actionName");

        routes.MapRoute(
            name: "Default",
            url: "{controller}/{action}/{id}",
            defaults: new { controller = "Home", action = "Index", id = UrlParameter.Optional }
        );
    }
}

Answer 2

It worked for me by taking off the runAllManagedModulesForAllRequests="true" from modules element in configuration. I think this is causing to run all the site level modules first than reaching the UrlRewrite module.

Answer 3

Ok, I finally get it working by removing IsapiFilterModule and IsapiModule from the site.

Answer 4

I only needed a reverse proxy for one application server running locally. I was getting a 404 but then added <httpRedirect enabled="false" /> to my web.config in the site's physical directory and it worked. My web.config looks like this

<?xml version="1.0" encoding="UTF-8"?>
<configuration>
    <system.webServer>
        <httpRedirect enabled="false" />
        <rewrite>
            <rules>
                <rule name="ReverseProxyInboundRule1" enabled="true" stopProcessing="true">
                    <match url="(.*)" />
                    <action type="Rewrite" url="http://localhost:8153/{R:1}" />
                </rule>
            </rules>
        </rewrite>
    </system.webServer>
</configuration>