title: Migrating Active Directory - new DC can't be joined
body: <p>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).</p>
  
  <p>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.</p>
  
  <p>So I followed this step-by-step guide : <a href="https://blogs.technet.microsoft.com/canitpro/2014/04/01/step-by-step-active-directory-migration-from-windows-server-2003-to-windows-server-2012-r2/" rel="nofollow noreferrer">https://blogs.technet.microsoft.com/canitpro/2014/04/01/step-by-step-active-directory-migration-from-windows-server-2003-to-windows-server-2012-r2/</a>
  Except I didn't dcpromo OLD-AD yet to remove it as a DC.</p>
  
  <p>It seems to work (rough translation of the message, our workstations/servers are not in english) :</p>
  
  <pre><code>$&gt; 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
  </code></pre>
  
  <p>But when I shut down OLD-AD, I'm not able to contact a DC for authentification anymore.</p>
  
  <p>Also, this doesn't work :</p>
  
  <pre><code>$&gt; nltest /dcname:mydomain.local
  NetGetDCName failed : Status = 2453 0x995 NERR_DCNotFound
  </code></pre>
  
  <p>I have no idea where to look to get more informations and diagnose this issue. Any pointers will be appreciated !</p>