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That's it! Test your new protection scheme by using a Web browser to try and access a URL on your Web server with one of the protected path settings you set in this installer. It should redirect you to your CAS authentication server. You can also verify that the dll was loaded correctly by following steps a-f above and checking the status of the recently entered filter. It should have a green arrow to the left pointing up. If not, something would not let the filter load. Check the configuration file and all relevant files listed therein, as well as the location of the dll.
Accessing the authenticated user id
Currently, the CAS ISAPI module sets a header variable called "CAS-User" before passing the request on to IIS. In any server-side processing script (ASP, ASP.NET, .NET, Cold Fusion) you will be able to access this variable to get the authenticated user id.