No there is no kerberos plugin, but would be great when you could provide more info about what you want to do, so we can better assist you.If you're planning to achieve SSO / Single-Sign-On, you can do this via the http passthru authentication plugin (maybe in combo with the ldap auth plugin when you're using AD/ldap). Therefore check the following discussion: http://forum.osticket.com/d/discussion//http-passthru#latest