[Samba] getent passwd not showing domain users at boot

[Mark Foley]

I've joined a member server to my Samba4 AD/DC Domain. It all works great,but I
have one minor problem at the moment. At boot-time, I want a list of domain
users. In my /etc/rc.local script I have:

/usr/bin/getent passwd > /etc/auto.domUsers 2>&1

This runs, but none of the domain users are listed, only local users. When I log
in and run `getent passwd` from the command line. I see all the configured
domain users.

What's the problem? Does the member server not have access to the domain
information for some period of time after booting? rc.local is supposedly the
last start-up script to run. 

AD/DC runs Samba 4.1.17.

member server is Ubuntu 14.04.3

THX - Mark