Locating Active Directory Servers
When an application requests access to Active Directory an Active Directory server (domain controller is located by a mechanism called the domain controller locator (Locator ) . Locator is an algorithm that runs in the context of the Net Logon service. Locator can find domain controllers by using DNS names (for IP/DNS-compatible computers) or by using Network Basic Input/Output System (NetBIOS) names (for computers that are running Microsoft® Windows® version 3. x , Microsoft® Windows® for Workgroups, Microsoft® Windows NT® version 3.5 or later, Microsoft® Windows® 95, Microsoft® Windows® 98, or for computers on a network where IP transport is not available).
In this chapter, the term "Windows NT 4.0–compatible Locator" refers to the locator process that is used by clients that are running Windows 3. x , Windows for Workgroups, Windows NT 3.5 or later, Windows 95, or Windows 98 to locate a domain controller in any domain, as well as by clients that are running Windows 2000 to locate a domain controller that is in either a Microsoft® Windows NT® version 3.51 domain or Microsoft® Windows NT® version 4.0 domain.
The focus of this chapter is on the process of locating a domain controller. For more information about DNS resolution of host IP addresses, see "Introduction to DNS" in the TCP/IP Core Networking Guide .