In this article, we will look at what is Domain Controller, how Domain Controllers work, and in particular, we will look at how the operating system (OS) and the Active Directory (AD) software interact with each other.
The domain controller (DC) is typically a member of a Windows Server 2003 (WS03) Active Directory (AD) domain. The AD domain is a collection of DCs, domain users, and resources. The domain is managed by a domain controller (DC) and a domain services manager (DSM).
In the AD domain, the DC maintains a directory service database, called the Active Directory, which stores information about all domain users, groups, and computers. The DC also stores security credentials, such as user accounts, passwords, certificates, and access rights, for each user and computer in the domain.
What is a Domain Controller
A domain controller authenticates users and computer devices in a domain, and can also control access to network resources.
In a typical domain, a domain controller is a highly-available server computer that provides network services for all domain users. A DC provides security services, such as user authentication and access control. A DC stores and retrieves user and group information for each user or group in the domain.
The domain controller can also provide other services, such as network file services, and can provide management services for other servers in the domain.
What do Domain Controllers do?
Finally, let’s look at what a domain controller does.
A domain controller authenticates users and computer devices in a domain, and can also control access to network resources.
What is the difference between a Domain Controller and a Server?
Finally, let’s talk about the difference between DC and a Server.
A domain controller is a server that is used to authenticate and authorize users in an Active Directory domain. A domain controller also provides network services to users in the domain.
Domain controllers provide many of the same functions as a server computer, but they do so for a domain instead of a single computer. A domain controller does not have to be a server computer. A domain controller can be a standalone computer or a computer that is part of a server computer.
What is the Active Directory domain?
In an Active Directory domain, a domain controller is the central repository of user information. This user information includes user names, passwords, and security credentials. In addition, the domain controller stores security groups that define access rights for users and computers.
Types of Domain Controllers
There are two types of domain controllers:
1) Primary Domain Controller (PDC)
2) Secondary Domain Controller (SDC)
Finally, let’s have a look at them separately what are they.
Primary Domain Controller (PDC)
The primary domain controller is a domain controller that stores user information and security credentials. In addition, the primary domain controller stores security groups that define access rights for users and computers.
In a Windows Server 2003 Active Directory domain, a primary domain controller (PDC) is the central repository of user information. This user information includes user names, passwords, and security credentials. In addition, the primary domain controller stores security groups that define access rights for users and computers.
Secondary Domain Controller (SDC)
In a Windows Server 2003 Active Directory domain, a secondary domain controller (SDC) is a domain controller that is used to provide additional authentication services. The secondary domain controller stores and retrieves user and group information for each user or group in the domain.
In addition, a secondary domain controller stores security credentials for each user or group. This information includes user accounts, passwords, certificates, and access rights.
Requirements for a Domain Controller
To be a domain controller, a server computer must meet these requirements:
- Have at least Windows Server 2003 operating system
- Be configured as a domain controller
- Have the Active Directory Domain Services role installed
Installing a Domain Controller
The domain controller installation process is similar to the installation of other server computers.
- To install a domain controller, follow these steps:
- Open the Server Manager console.
- Click Add Roles and Features, and then click Add Features.
- Select the Active Directory Domain Services role, and then click Next.
- Select the role services that you want to install, and then click Install.
- Restart the server computer.
- Verify that the domain controller is installed and that the Active Directory Domain Services role is installed.
Running a Domain Controller
After you have installed a domain controller, you must start it and configure it to be a domain controller.
- To start a DC, follow these steps:
- Open the Server Manager console.
- Click Start, point to Administrative Tools and then click Domain Controller.
- In the Server Manager console, click Start.
- Select the DC that you want to start, and then click Start.
- Click Start, point to Administrative Tools, and then click Services.
- In the Services window, select the service that you want to start, and then click Start.
Configuring a DC
The domain controller must be configured to be a domain controller
- Open the Server Manager console.
- Click Start, point to Administrative Tools and then click Domain Controller.
- In the Server Manager console, click Configure.
- In the New DC Wizard, click Next.
- In the Welcome to the New Domain Controller Wizard, click Next.
- Select the type of domain controller that you want to configure, and then click Next.
- In the Domain Name and DC Selection Wizard, select the type of domain controller that you want to configure, and then click Next.
- Select the location for the domain controller.
- Enter the following values for the administrative password.
- Enter the domain name of the domain.
- Enter the administrator password for the domain.
- Click Finish.
- The DC is configured to be a domain controller.
- To start the domain controller, follow these steps:
- Open the Server Manager console.
- Click Start, point to Administrative Tools and then click Domain Controller.
- In the Server Manager console, click Start.
- Select the domain controller that you want to start, and then click Start.
What are the benefits of using Domain Controllers over a stand-alone server?
In fact, there are many benefits to using Domain Controllers. A domain controller can provide the following:
Control of the domain
A domain controller is the first server computer that the system uses to contact the Active Directory. If the domain controller is unavailable, the system is unable to access the domain.
Managing security
A domain controller can manage security credentials. A domain controller can retrieve security credentials from other computers in the domain, such as servers or workstations.
Backup and recovery
A domain controller can provide backup and recovery capabilities. A domain controller can store backups of computers in the domain.
Remote access
A domain controller can provide remote access to computers in the domain. A domain controller can be accessed by remote users or computers, even if the computer is not directly connected to the domain.
Administration
A domain controller can provide centralized administration of a domain. A domain controller can store and retrieve information about users and groups.
Is Domain Controller important, why?
Yes, domain controllers are very important and so is their security. The DC holds very important information such as group policies (which contains the security settings), all the names and addresses of the computers on the network. So, they are a treasure of private information. We need to secure the DC because this is the honey pot that will be attacked by compromisers and risk the data of the entire network.
Pros and Cons of DC
Starting with the demerits, on one hand, DC is very important and on the other, it can cause the entire business to cripple.
Pros:
- Moving on to the brighter side, if DCs are maintained regularly and properly, they prove to be a boon for the network infrastructure.
- It provides central user management, to grant and revoke user access to the clients, from time to time.
It encrypts and stores the client data. - It enables resource and file sharing on the network to occur fluidly.
- Federated configuration for redundancy (FSMO): It assures you that the domain will be able to perform its primary function of authenticating users without interruption.
Cons:
- DC being the central hub of entire information, is most prone to attacks. Simply exploiting DCS grants them with an all-access key.
- To set up the DC, a large number of hardware and software requirements need to be fulfilled.
- The network is entirely dependent on DC uptime. DC down, all resources down.
- OS needs to be maintained and regular security updates need to be pushed.
Setting up domain Controller
- Configure a standalone server for your domain controller.
- If you are using Amazon Web Services, ignore this step.
- If not, the DC server should exclusively be for a DC and nothing else.
What happens when the Domain Controller goes Down?
Safe keep practices:
- Restrict physical and remote access to DC as much as possible.
- Only authorized System Admins must be allowed to configure and have access to DC.
- No other user should be allowed to access DC in any mode, including Terminal mode.
- Standardize the configuration of DC for easy reuse.
- Concluding, I want to say, nothing is 100 percent safe, it’s only safer.
Conclusion
The domain controller is the single most important component for any computer system. If the domain controller has been infected, it will take days, weeks or even months to identify and remove it. Therefore, a properly configured Windows 2003/2008 server is very important in network security. This guide contains an extensive step-by-step walk-through of the process of installing and configuring an Active Directory Domain Controller on Windows Server 2008. You will also learn about the many components of an Active Directory Domain and how they work together to allow network traffic to flow throughout your network.
