The DNS Server (DNS) service enables DNS name resolution. It answers queries and update requests for DNS names. DNS servers locate devices that are identified by their DNS names and locate domain controllers in AD DS.

If the DNS Server service stops or if you disable it, DNS updates do not occur. The DNS Server service is not required to run on every computer. However, if there is no authoritative DNS server for a particular portion of the DNS namespace, the location of the devices that use DNS names in that portion of the namespace fail. Absence of an authoritative DNS server for the DNS namespace that is used to name Active Directory domains results in an inability to locate domain controllers in that domain.

The DNS Server service is only installed and activated if you install the DNS Server role.

This service is available on a Server Core installation of Windows Server 2008 R2 in addition to the Standard, Enterprise, and Datacenter editions of Windows Server 2008 and Windows Server 2008 R2.

The following table identifies the application protocols, network protocols, and ports used by the DNS Server service: