IHttpHandler

I was trying to create an HttpHandler to filter ALL incoming requests for my application, regardless of the file type or subdirectory. In my web.config file I added this

<httpHandlers>
<add
verb="*"
path="*"
type="Interceptor,Interceptor"
/>
</httpHandlers>

It doesn't work... UNLESS you add the extension mapping of:

.*

in IIS for the application settings.

Is there a way to do this without the mapping in IIS? Why doesn't the web.config entry override the IIS settings? Not a huge deal being it works with the additional setting, but the web.config entry should override. And subdirectory web.config files could be used to override the main directory settings. What does a path of "*" mean if not everything?