SQL spn and linked server double hop and kerberos

Good link to setup linked server and spn's

https://sqljana.wordpress.com/2017/06/16/sql-server-curse-of-linked-server-security-and-the-fix-pass-through-authentication/


https://www.alexandreviot.net/2014/09/30/sql-server-could-not-register-the-service-principal-name-spn/


Query to see if Kerberos is being used.