I'd like to be able to determine whether Kerberos was used to
authenticate the user that is accessing an ASPX page protected by
Windows Integrated Authentication.

I've tried calling the 'WindowsIdentity.AuthenticationType' property
from within the page; the documentation for AuthenticationType claims
that 'Basic authentication, NTLM, Kerberos, and Passport are examples
of authentication types.';

see [url]http://msdn.microsoft.com/library/default.asp?url=/library/en-us/cpref/html/frlrfsystemsecurityprincipaliidentityclassauthenti cationtypetopic.asp[/url].

However, WindowsIdentity.AuthenticationType _always_ seems to return a
value of 'Negotiate', regardless of whether the client (browser box)
and web server are both in Win2K or Win2K3 domains, or a mixture, and
whether or not I am prompted by the browser for credentials, or passed
straight through.

Is this a limitation of the WindowsIdentity.AuthenticationType API
when used in an ASPX page, or more likely a configuration issue? If
the former, is there some other .NET API that can tell me what
underlying authentication system was used (e.g. Kerberos, NTLM)?

Any ideas gratefully received !

Jim