What is a Domain Controller? - InstaSafe (2024)

Implementing network security best practices is of the utmost importance to enable secure remote device access, extend security compliance, centralise user data and strengthen your security posture.

In today’s remote working environment, establishing a secure connection between your remote employee's devices and the corporate domain is vital to combat data centre security risks and make security management and compliance hassle-free.

This is where the domain controller and domain joining come in.

This article will show what a domain controller is, its types, and the benefits of domain control for your enterprise network. Let's begin!

What is Domain Controller?

A Domain Controller (DC) is a server that responds to the security authentication requests within a certain domain from network endpoints and verifies users on the computer network.

While domains provide a hierarchy for organising computers and users connected to your network, a Domain Controller keeps that data secured and organised.

The Domain Controller in Active Directory acts as a gatekeeper and holds the keys to your kingdom, allowing access to the domain resources. Hence, it runs the Active Directory Domain Services (AD DS) for request authentication within a domain.

Domain control also enforces security policies, authenticates users for a domain, and stores the user's account information in a secure way.

What is the Main Function of a Domain Controller?

Domain controllers are like security guards for a company's computer network. Their main job is to check if people are allowed to use the network and access files/programs.

Whenever someone tries to log into a computer or open a shared folder, the domain controller checks their username and password against a big list of approved users. If the password matches what's on the list, the domain controller lets them in.

But the domain controller doesn't just let anyone do whatever they want. It has a set of rules about what each user is and isn't allowed to do based on their role/position at the company. So, it enforces those rules about who can access what files/programs.

The domain controllers also communicate with each other. If one domain controller gets updated info about a new user account or updated permissions, it shares that info with the other domain controllers. That way, they all have the same accurate list of approved users and rules.

Basically, domain controllers functions control access by checking passwords against an approved list. They enforce rules about what users can do based on their role. They also share updated user info with each other to stay coordinated as the company's security team.

Why is a Domain Controller Important?

Whenever someone tries to log into a computer or use a network folder/program, the domain controller checks their username and password. If those login details don't match what's approved, the domain controller blocks them from getting in. This prevents unauthorised people from accessing private company data and systems.

But domain controllers don't just check passwords. They also have a rulebook of what each employee is permitted to do or not do on the network based on their job role and responsibilities. The domain controllers enforce these rulebooks to control what areas people can go and what actions they can take.

Having one centralised domain controller makes it much easier to manage all the user accounts, computer accounts and other rules for the whole company network. Employees only have to log in once, and the domain controller grants them access to all the programs and data for which they are approved.

Most companies actually have multiple domain controllers working together as a team. That way, if one domain controller goes offline, the others can take over so network access isn't interrupted.

How Does A Domain Controller Work?

Let us look at a Domain Controller example to understand its working.

Ideally, enterprises have several Domain Controllers—each having a copy of the Active Directory (AD).

All the user login credentials from the network are held and consolidated in the Domain Controller in the Active Directory service. Hence, DC uses the Active Directory to house the user database and login information.

So, when a user logs in to their domain, DC checks and validates their credentials, like usernames and passwords—to either permit or deny access for that user.

Thus, a remote Domain Controller helps manage and maintain your network security and user identity security—enforcing security policies across Active Directory domains.

Hence, here's a breakdown of the roles and responsibilities of a Domain Controller (DC):

• User authentication and validation to access your network.
• Regulating access and permissions—overseeing a user's access rights within the domain.
• Implementing network-wide rules and group security policies for passwords or granting access.

Let's learn more about the benefits and limitations of domain control for your enterprise.

Advantages and Disadvantages of Domain Controller

Domain Controller Advantages

Here are the Domain Controller advantages for your organisation network:

• Centralises user data management for efficient organisation and data storage.
• Enables user data encryption.
• Makes resource sharing for files and printers a breeze.
• Facilitates and provides more control over users' settings and entitlements.
• Simplifies network administrative workload.
• Enables Federation configuration for redundancy (FSMO).
• Maximises and ensures high network and data security.
• Easier to harden and lockdown for improved security.
• Increases collaborative possibilities within the domain.
• Easier to distribute and replicate across large networks.

Disadvantages of Domain Controller

Here are the limitations or cons of a Domain Controller (DC):

• It's important to check for hardware and software requirements and keep them up-to-date.
• Comes with the potential to be hacked and become an easy target for cyberattacks.
• Your network depends on the Domain Controller's uptime.
• You must ensure users' and the Operating System's (OS) stability and security.

What Are the Types of Domain Controllers?

There are two major types of Domain Controllers—read-only and read-write.

• Read-only: The read-only Domain Controller (DC) comprises a copy of the AD DS database, which is read-only.
• Read-write: A read-write Domain Controller comes with the ability to read and write to the AD DS database.

With that in mind, let's also understand what domain joining is and how it differs from Domain Controllers.

Domain Controller vs Active Directory: The Difference Between Domain Controller and Active Directory

Active Directory provides comprehensive database storage, while domain controllers are crucial security checkpoints operating under its policies for their respective domains. They work together to provide authentication, authorisation, and administrative capabilities network-wide.

In simple terms, the domain controller enforces security just for its assigned domain or area, while Active Directory provides a bigger, overarching structure that connects all the different domains and controllers together as part of the wider operational environment.

Here are the key differences between a domain controller and an Active Directory:

Domain Controller Best Practices

Following the proper security steps for domain controllers is really important to keep a company's network safe and well-managed. Here are some key things to do:

• Only Allow Minimum Access Needed - Don't give employees more access than they actually require for their job roles and responsibilities. The fewer areas they can access, the more secure things are.
• Turn On Login Monitoring - Set up the domain controllers to keep track of any suspicious login attempts. This helps catch potential hackers or security breaches early.
• Backup Data Regularly - Make sure to continuously back up all the data and settings on the domain controllers. That way, if one crashes, you can quickly restore it.
• Centralised Control Center - Having one central place to manage all the domain controller settings, user access, alerts, etc., makes it easier to stay on top of everything efficiently. Automate as many tasks as possible.
• Standardised Configurations - All domain controllers should have the same secure configuration settings and specifications. Use automated deployment tools to ensure consistency.

Following security best practices like these can really bolster the security and reliability of a network's core domain controllers against threats and misconfigurations.

Domain Controller vs Domain Joining

Many confuse these two terms—assuming domain joining and Domain Controller to be the same.

Domain Joining is a feature that allows your employees to securely connect to your work domain from a remote location using their enterprise login credentials. Hence, it enables them to join a domain of your enterprise effectively.

On the other hand, as we discussed, a Domain Controller is what determines whether users are eligible to join the Active Directory domain—validating their credentials from the Active Directory.

Get Started With Domain Joining With InstaSafe

Domain Joining and Controllers come with their own perks and vulnerabilities. While they strengthen your network and ensure maximum user data security and protection—choosing the right service and implementing domain controllers is paramount.

If you need a service to connect your remote employee devices to your corporate domain securely, check out our InstaSafe solutions. Get domain joining to ensure compliance with updated security protocols, push group security policies to remote devices, and enable maximum control over security patches and updates.

Book a demo today to learn more!

FAQs about Domain Controller

1. What does the domain controller do?

The primary function of a domain controller is to authenticate and validate users on a network, including enforcing group policies, verifying user credentials, and determining access rights.

2. What are the main components of domain controllers?

The main components of domain controllers in Windows Active Directory include the DNS server, Active Directory database, LDAP, DFS, and Group Policy.

3. What are the 3 main functions of Active Directory?

The three main functions of Active Directory are:

1) Easier resource location,

2) Centralised security administration, and