[Samba] Ubuntu client ddns failure

[steve]

Update. It's to do with what works with nsupdate and what sssd 
internally to nsupdate.

sssd on Ubuntu sends only the short hostname with a dot:
update add lubuntu-laptop. 3600 in A 192.168.1.22
which fails with whatever Ubuntu 14.04 does with DNS

And yes, between us we've tried every conceivable combination of 
resolv.conf and /etc/hosts

sssd on openSUSE sends the full fqdn and so updates run fine.

And yes, I've built 1.11.5.1 on Ubuntu. It's the same. It still sends 
the short hostname. And still it fails.

It would be interesting to see what other distro's sssd send to 
nsupdate. You need at least d7 to get the nsupdate stuff. sssd -i -d7 
gets you there in real time.
Cheers,
Steve