404s for asp.net mvc solution doesn't work in production

I used Shay Jacoby's solution to route 404s and 500s a开发者_C百科nd it works great on my dev box: How can I properly handle 404 in ASP.NET MVC?

However, in production, it only routes 500 errors and 404s still get the default iis 404 messages. I think I'm missing something simple, any ideas?

I deployed the code to a local iis7 website and the 500 errors are being redirected. I can't think of what is different in the environments. Production is also iis7 and the code is identical.

Thanks

The .Net runtime won't even see the 404.

IIS uses the file extension to determine which IIS handler will process the request.

So, the only way for your app to handle 404's is to have IIS configured to send it directly to your app instead of handling it internally. Which is what you've done.

You might want to check out this question / answer for a few more details.