Getting IIS to Forward All Requests to ASP.Net

Setting up IIS to send all requests to ASP.Net (e.g. for a HttpHandler for a ReST service or for an ASP.Net MVC web app) is straight forward with .Net and IIS.

1) First ensure that your web application can handle all requests

This is already done for you in an ASP.Net MVC web app. But if you are creating a custom HttpHandler to handle all requests you'll need to go to the httpHandlers section of your web.config file add a reference to your HttpHandler for all HTTP verbs and extensions:

<system.web>
   <httpHandlers>
      <add verb="*" path="*" type="your.assembly.reference"/>
   </httpHandlers>
</system.web>

2) Setup IIS to route all request to your handler

a) IIS 5/5.1 (Win XP)

• Open the website properties in IIS
• Select the Home tab
• Click the Configuration button
• In new window select the Mappings tab
• Click the Add button
• In new window's executable field Browse to the ASP.Net ISAPI dll (usually something like C:\WINDOWS\Microsoft.NET\Framework\v2.0.50727\aspnet_isapi.dll)
• In the Extension field type .*
• Untick the Check that file exists box and click OK

N.B. There is a bug that if your OK button is not active you need to click the executable field text box, you should see the middle section of the text in the box change from /.../ to the full file path this should now make the OK button active.

b) IIS 6 (XP x64 & Windows Server 2003)

• Open the website properties in IIS
• Select the Home tab
• Click the Configuration button
• In new window select the Mappings tab
• Insert an entry in to the Wildcard application maps with the ASP.Net ISAPI dll (usually something like C:\WINDOWS\Microsoft.NET\Framework\v2.0.50727\aspnet_isapi.dll)
• Untick the check that file exists box and click OK

You should now see all requests being handle via your handler. If you are having issues, you may want to look at your IIS logs - but where are my IIS logs?. Good luck!