Domain Name System – Problems with clients for secondary server dns

Good night! I'm trying to create a high availability environment in my work, to do that, I install a small laboratory installing 2 servers; one with WS 2008 R2 and the other with WS 2012 R2 (same as the real environment but the virtual ones). The domain controllers and dns were installed correctly in both and they are replicated without problems

  1. Server 1 (primary), WS 2008 R2, IP = / 24, primary dns =, secondary = return loop
  2. Server 2 (secondary), WS 2012 R2, IP = / 24, primary dns =, secondary = return loop

I did not use the built-in AD dns zone, instead, the primary / secondary zones were configured. The problem comes with the clients, if I do a query to primary dns it works fine, when the primary is off, I have no response from the secondary, even after a long wait. ipconfig / flushdns Neither works nor restart. Am I doing some bad configuration?

I get a good response with commands. repadmin / showrepl Y dcdiag / test: dns / dnsbasic, it seems that no errors were found. The funny thing is that when I use Linux I received a response from the secondary server.

Thanks in advance.