DC replication across two subnets


  • Hi,

    I have two sites connected via Site to Site VPN.  Each site has it’s own subnets.

    The smaller site is on subnet

    The larger site has clients on subnet and servers on

    There is routing setup between the subnets.

    Currently the DNS and DHCP on the larger site is done by W2012 server sitting on the subnet. This is also DC, but the clients are Macs, so they do not really use the domain controller for authentication.

    On the smaller site the DNS and DHCP is done by a router, but I want to change this to another W2012 server.

    The idea is that the two servers can server as backup of each other, in case one goes down the other can do DNS and DHCP in its place.

    I am just not sure how to set this up, I believe this can be done through the Active Directory Sites Services replication. If it was a flat network, then it would not be an issue, I am just not sure how this works across different subnets.

    Any push in the right direction would be much appreciated.

    Wednesday, March 22, 2017 1:12 AM

All replies

  • Hi

     Each DC will be point itself as primary on dns and secondary as other DC.Also for dhcp you can configure Dhcp failover cluster for redundancy.

    Dhcp failover cluster;

    And you should configure necessary port accesibilty for ds,dns and dhcp between site's.

    Active Directory Replication over Firewalls

    This posting is provided AS IS with no warranties or guarantees,and confers no rights. Best regards Burak Uğur

    Wednesday, March 22, 2017 7:17 AM
  • Thanks for the reply.  I will try to do this next week, and see how it works out.

    Basically I just set up the two domain controllers similarly, and they will replicate?  I will post more observation when I get into setting this up.


    Wednesday, March 22, 2017 7:54 PM
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    Friday, March 24, 2017 9:21 AM