Custom 404 Errors Azure

I came across an issue tonight where first I didn't have a 404 error page setup and then secondly when the custom errors where setup I wasn't getting the 404 error message page for extensions and extensionless urls.

The first this is to setup custom error in the web.config add this in the system.web section.

<customErrors mode="On">

<error statusCode="404" redirect="/404-error.aspx"/>

</customErrors>

Secondly add this to the system.webserver section

<httpErrors errorMode="Custom">

<clear/>

<error statusCode="404" path="/404-error.aspx" responseMode="Redirect"/>

</httpErrors>

One other thing to note is the redirect in the customErrors section and the path in the error section must point back to the route "/".