The domain name system (DNS) stores and associates many types of information with domain names, but most importantly, it translates domain names (computer hostnames) to IP addresses.
You must install DNS on Windows Server 2012 R2 according to the server documentation. Visit http://support.microsoft.com to learn how to install and configure DNS on Windows Server 2012 R2.
The instructions here are limited to Configuring DNS for Wireless APs Discovery.
For configuration on Linux, see Configuring DNS on a Linux Server.