I thought I would show you how we in Microsoft Commercial Technical Support typically troubleshoot Kerberos authentication issues. This discussion should do much to get you more comfortable viewing network traces for Kerberos authentication problems. There are other ways to troubleshoot Kerberos; one could use the Kerberos event logging outlined in KB 262177. Although you could rely on this method, it will take a longer to resolve the issue and involves making some educated guesses without the network trace.

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