[Samba] Suggestions for cross site domain

[Wayne Merricks]

Hi all,

I have two offices connected via a VPN with approximately 200ms 
latency.  About 9 months ago I moved our UK office from a Samba 3 domain 
to a new Samba 4 domain.  At the same time, as a test, I connected up a 
DC server in India to the same Samba 4 domain, all was good.

Roll forwards to two weeks ago, I am starting to push out Samba 4 in 
India.  I hooked up a second server in India (identical hardware/Ubuntu 
14.04) and I get an uncaught exception when trying to join the domain:

ERROR(exception): uncaught exception - Failed to find a writeable DC 
for domain

I have done a fair bit of fiddling with no joy including demoting the 
old India server and then attempting to rejoin the domain.  This one now 
also gets the "Failed to find a writeable DC for domain" error so I'm 
even worse off than before.

If I create a DC in the UK office, it joins the domain and functions 
without any issues.  As far as I can tell the domain is functioning 
normally, it is just not accepting new DCs from the India office.

I'm running on Ubuntu 14.04 LTS with the repo Samba version 4.1.6.

Any ideas?  All I really need is user authentication across sites for 
about 6 Windows machines, their email is delivered to the UK so having 
different passwords gets annoying.

Regards,

Wayne Merricks