when you work with Sharepoint, the SPN Pattern must be set to %h
SPN Pattern can be:
- Empty : SPN will be constructed with reverse DNS
- HTTP/%s : SPN will be constructed with reverse hostname in local host file
- HTTP/%h : SPN will be constructed HTTP request host name (each application have a different service account with dedicated SPN... this SPN if based on request host header)
- HTTP/%s@REALM : SPN will be constructed with reverse hostname in local host file with different Kerberos Realm than account Realm
- HTTP/%h@REALM : SPN will be constructed HTTP request host name with different Kerberos Realm than account Realm