Migrating Active Directory - new DC can't be joined

I'm migrating an old Windows Server 2003 AD hosted on a VM to a new one based on Windows Server 2016 (also on a VM).

The Server 2003 (let's call it OLD-AD) was the only Domain Controller. Now I'm migrating this server by installing Active Directory on a new server (let's call it NEW-AD) and adding it as a Domain Controller.

So I followed this step-by-step guide : https://blogs.technet.microsoft.com/canitpro/2014/04/01/step-by-step-active-directory-migration-from-windows-server-2003-to-windows-server-2012-r2/ Except I didn't dcpromo OLD-AD yet to remove it as a DC.

It seems to work (rough translation of the message, our workstations/servers are not in english) :

$> nltest /dclist:mydomain.local
Get the list of domain controllers of « mydomain.local » from « \\OLD-
AD.mydomain.local ».
    OLD-AD.mydomain.local        [DS] Site : Default-First-Site
    NEW-AD.mydomain.local [PDC]  [DS] Site : Default-First-Site

But when I shut down OLD-AD, I'm not able to contact a DC for authentification anymore.

Also, this doesn't work :

$> nltest /dcname:mydomain.local
NetGetDCName failed : Status = 2453 0x995 NERR_DCNotFound

I have no idea where to look to get more informations and diagnose this issue. Any pointers will be appreciated !

Solution

I've seen this error before. It has nothing to do with your migration procedure. I've reproduced the error then ran it slightly differently with success. Run command like this instead and it will work:

nltest /dcname:mydomain

See example screenshot below: