SPN checklist for Kerberos authentication with IIS 7.0/7.5

This post is more about the confusion that may arise around SPNs for setting up Kerberos authentication in IIS 7.0. IIS 7.0 has a new Kernel-mode authentication feature using which the ticket for the requested service is decrypted using Machine account (Local system) of the IIS server. It no longer depends upon the application pool Identity for this purpose by default and in turn improves the performance.

http://blogs.msdn.com/b/webtopics/archive/2009/01/19/service-principal-name-spn-checklist-for-kerberos-authentication-with-iis-7-0.aspx