Domain Controller 详解


原文：http://scientificera.com/windows/45-windows/224-what-is-a-domain-controller.html

Many of the computer engineers and users, especially involved in system networking have come across a Domain Controller. Without it there is no domain, means there can not be a controlled network

What is definition of a domain controller, what does a domain controller do? Where is it used? How does it work with non Windows-based systems? In this article, we will look at answers to all these questions.

First Learn What a Domain Is?

Before we learn what a domain controller is, knowing what a domain is will help you understand the concept of the domain controller better. So, what is a domain?

The answer to this question is simple: A domain is a set of interconnected resources on a Windows-based platform, such as printers, applications, etc) for a group of users. Users who are part of the domain (who are given usernames and passwords to log on
to the domain) are granted specific permissions to access the resources, which may be located on one or more servers in the network.

In other words, a domain is a logical group of computers that share a central database, called Active Directory (AD). The database contains the user security and accounts information for the resources in that domain. Any person who uses computers within
a domain gets his own account, which is



assigned access to resources within that domain.

Now To the Question: What Is a Domain Controller?

What is a domain controller? A domain controller (DC) or network domain controller is a Windows-based computer system that is used for storing useraccount data in a central database. A domain controller in a computer network is the centrepiece of the Active
Directory (AD) services that provides domain-wide services to the users, such as security policy enforcement, user authentication, and access to resources.

A domain controller is a great tool for system administrators, as it allows them to grant or deny users access to system-wide resources, such as printers, documents, folders, network locations etc, via a single username and password. Once a domain controller
is configured in a company, office or a building, it takes over the responsibility of responding to users’ security authentication requests, such as checking permissions, logging in, etc.

When a client computer joins a domain, any user can login to the domain c ontroller, using that computer. This benefit of that is that no matter which domain member (computer) he logs in from, he is able to access all his personal resources including the
files he placed on the Desktop, files in Documents, printers, and his personal desktop preferences.

Domain Controller Compatibility with Operating Systems

A domain controller can communicate with all domain members or workstations but there is a limitation to the Active Directory (AD) System. The limitation is that the domain controller must host a Windows-based operating system. It means that all the domain
members must also use the Windows operating system.

Fortunately, this limitation can now be overcome by use of Samba. Samba is open source software that allows workstations running other operating systems like OpenVMS, IBM System 390,Unix and Linux to interact with the domain controller. This is advantageous
as because of this network administrators gets much more flexibility in setting up a computer network. It is particularly very useful in large organizations in which different departments need different operating systems.

If you were seeking information on "definition of a domain controller" or "what is a domain controller", hope this article explained that well to you.