<P> A server running Active Directory Domain Services (AD DS) is called a domain controller . It authenticates and authorizes all users and computers in a Windows domain type network--assigning and enforcing security policies for all computers and installing or updating software . For example, when a user logs into a computer that is part of a Windows domain, Active Directory checks the submitted password and determines whether the user is a system administrator or normal user . Also, it allows management and storage of information, provides authentication and authorization mechanisms, and establishes a framework to deploy other related services: Certificate Services, Active_Directory_Federation_Services, Lightweight Directory Services and Rights Management Services . </P> <P> Active Directory uses Lightweight Directory Access Protocol (LDAP) versions 2 and 3, Microsoft's version of Kerberos, and DNS . </P> <P> Active Directory, like many information - technology efforts, originated out of a democratization of design using Request for Comments or RFCs . The Internet Engineering Task Force (IETF), which oversees the RFC process, has accepted numerous RFCs initiated by widespread participants . Active Directory incorporates decades of communication technologies into the overarching Active Directory concept then makes improvements upon them . For example, LDAP underpins Active Directory . Also X. 500 directories and the Organizational Unit preceded the Active Directory concept that makes use of those methods . The LDAP concept began to emerge even before the founding of Microsoft in April 1975, with RFCs as early as 1971 . RFCs contributing to LDAP include RFC 1823 (on the LDAP API, August 1995), RFC 2307, RFC 3062, and RFC 4533 . </P> <P> Microsoft previewed Active Directory in 1999, released it first with Windows 2000 Server edition, and revised it to extend functionality and improve administration in Windows Server 2003 . Additional improvements came with subsequent versions of Windows Server . In Windows Server 2008, additional services were added to Active Directory, such as Active Directory Federation Services . The part of the directory in charge of management of domains, which was previously a core part of the operating system, was renamed Active Directory Domain Services (ADDS) and became a server role like others . "Active Directory" became the umbrella title of a broader range of directory - based services . According to Bryon Hynes, everything related to identity was brought under Active Directory's banner . </P>

What directory service protocol is used by active directory and also supported by linux