root@client1:~# kinit user1

root@client1:~# mount.cifs //gate.corpX.un/share /mnt --verbose -o sec=krb5

user1@client1:~$ smbclient -k //gate.corpX.un/homes

root@client1:~# chmod +s /sbin/mount.cifs
root@client1:~# chmod +s /sbin/umount.cifs

user2@client1:~$ mkdir mnt/

user2@client1:~$ mount.cifs //gate.corpX.un/homes mnt --verbose -o sec=krb5
user2@client1:~$ umount.cifs mnt/

root@client1:~# cat /etc/fstab
...
//gate.corpX.un/homes mnt cifs rw,user,noauto,sec=krb5 0 0

user2@client1:~$ mount mnt
user2@client1:~$ umount mnt