DNS Servers

[Network_kenn]

I recently setup 2 new servers at my organization. Each server is at a separate site on 2 different subnets. At each site there is a Domain controller/DNS. I've pointed each domain controller to its self as the primary DNS address and the secondary DNS would be the next site. I have also sent both addresses to the network administrator to place them in the DHCP scope of the cisco router. Both addresses show up when I run a IP Config. When I turn off the primary domain controller the secondary domain controller does not communicate with the clients.but if the primary domain controller is online and I statically assign the secondary address to a clien it resolves to the domain name. What could possibly be the issue why the secondary domain controller does not take over the domain

[Georg Pauwen]

Hello,

are these Windows clients ?

[Network_kenn]

Yes windows 

[Georg Pauwen]

Actually I meant the clients, I assume the clients are Windows clients as well ?

So the domain controllers are the DNS servers ? And the clients have both DNS servers (ipconfig /all) ?

What if you issue the 'ipconfig /flushdns' on one of the clients after the primary domain controller goes down ?

[paul driver · Accepted solution]

Sounds like your DC's are not in sync, I would say check AD replication between them  first then also see if the dns servers are actually authorised in AD, however this is a question for a windows forum not cisco