ASP.NET/IIS: 404 for all file types

Question

I set up 404 handler page in web.config, but it works ONLY when extension of URL is .aspx (or other which is handled by ASP.NET). I know I can setup static HTML page in website options, but I want to have a page. Is there any options to assign ASPX handler page for all request extensions in IIS?

Answer 1

The web.config can only set up errors pages for pages controlled by it's web site. If you have any other pages outside the purview of the ASP.Net application, then you set up handling for them in IIS. There's an option in there for configuring the 404 page where you can point it to your custom page.

Answer 2

Only other thing i can think of is passing ALL extensions to asp.net.

This way all types of files get processed by asp.net and your custom error page will work.

Answer 3

In the IIS application configuration, you can set a wildcard mapping (".*") to C:\WINDOWS\Microsoft.NET\Framework\v2.0.50727\aspnet_isapi.dll

Answer 4

The direct question was whether or not there are options to assign the ASPX handler to all request extensions: Yes, there is. I'll discuss how to do that shortly.

First, I think the "hidden" question -- the answer you really want -- is whether or not there's a way to redirect all 404 errors for pages other than ASPX, ASMX, etc. Yes, there is, and this is the better choice if it'll solve the issue you're having.

To redirect all 404s in IIS 6, right click your web application root (whether it be its own site or a virtual directory in the main site), and choose "Properties." From there, choose the "Custom Errors" tab. Find 404 in the list and change it to the redirect you want.

Now, if that won't suffice -- and I really hope it does -- yes, you can run every page through the ASPX handler. However, doing so comes at a fairly high cost in terms of efficiency -- raw HTML/image serving is considerably faster than anything dynamic.

To do this, right click your web application root and choose "Properties." Choose the "Home Directory" tab. Click "Configuration;" a new window will pop up. Copy the path from one of the ASP.NET page serves, and then use it for a wildcard application map.

Bear in mind, again, this is the wrong answer most of the time. It will negatively impact your performance, and is the equivalent of using a chainsaw to carve a turkey. I highly recommend the first option over this one, if it will work out for you.

Answer 5

For information:

This is one of the several nice things that IIS7 brings - all pages are routed through the handler such that you can do custom 404s and - usefully - directory and file level security for any file (based on the same web.config stuff as for asp.net files prior to IIS7).

So notionally "use II7" is an answer (will be "the" answer in time) - but of course its not a terribly practical one if you're not hosting/being hosted on W2k8 (or higher).

Answer 6

1. You can setup wild card mapping in IIS (Application configuration/Mappings/Wildcard mappings/ - just set aspnet_isapi.dll as executable and uncheck the Verify that file exists box) that will route all incoming requests to your app - so you can control the behavior directly from it.

2. You don't have to setup static page in your IIS application settings. Imho, you should be able to setup valid url (e.g. /error_handler.aspx) from your app that will be used as landing page in case of specific server error.