Proper Way to set Preferred DNS Server on the Windows Domain Controllers themselves

domain-name-systemwindows-server-2012-r2

This may be a basic question, but I'm not sure how to properly phrase what I'm looking for, with a google search.

I have two Windows Server 2012 R2 domain controllers on the local network. Let's say Controller1 has an IP address of 192.168.1.1. Controller2 has an IP address of 192.168.1.2.

Our client machines on the network have Controller1 set as the preferred DNS, and Controller2 as the alternate choice.

My question is: What should the "Use the Following DNS Server Addresses" fields be set to, on the Domain controllers themselves? Currently, Controller1 has 192.168.1.1 (itself) set as the Preferred, and nothing set for the alternate. Controller2 has 192.168.1.1 set as the preferred, and 127.0.0.1 as the alternate.

This was set up a year ago, by someone who I'm not entirely sure knew what they were doing. I'm certainly no expert myself, and so I'd like to doublecheck if the current settings they had made make sense.

Thank you for your time.

Best Answer

I believe a Domain Controller's DNS servers are supposed to be other DCs then itself to avoid becoming "replication islands". Refer to https://technet.microsoft.com/en-us/library/ff807362(v=ws.10).aspx.

So, in your case, DC1 would use DNS servers 192.168.1.2, 127.0.0.1 and DC2 would use DNS servers 192.168.1.1, 127.0.0.1.