Active Directory uses DNS for three primary functions:
- Name resolution. DNS provides name resolution by translating host names into IP addresses.
- Namespace definition. Active Directory uses DNS naming conventions to name domains. Windows 2000 domain names are DNS domain names. For example, contoso.com is a valid DNS domain name and could also be the name of a Windows 2000 domain.
- Locating the physical components of Active Directory. To log on to the network and perform queries in Active Directory, a computer running Windows 2000 first must locate a domain controller or global catalog server to process the logon authentication or the query. The DNS database stores the information about which computers perform these roles and provides that information so that the request can be directed appropriately.