samba-tool does not use kerberos ticket

[Alexis]

Hello,

I use samba 4-1.12 as an AD on a opensuse13.1 server.
I use to setup a keberos ticket with
kinit administrator -k -t /usr/local/samba/private/administrator.keytab
and klist -l on opensuse13.1 give:
Principal name                 Cache name
--------------                 ----------
administrator at XXX.XX.XX       DIR::/run/user/0/krb5cc/tktiNk96S 


but for example   samba-tool dns serverinfo <server> will ask me password 
instead of using this kerberos ticket.

There was not such an issue when running samba in opensuse12.3 and I wonder 
if this is due to user.slice service which was had in openssue13.1 but I 
don't know where to go from here.

Maybe some of you had any clue to help me debug this issue.

Thank you.