Introduction

In the ever-evolving landscape of cloud computing, managing user identity, authentication, and directory services has become increasingly important. Whether you’re running a fully cloud-based environment or integrating with on-premises infrastructure, understanding the differences between Managed Entra Domain Services and Active Directory Domain Services (AD DS) is key to optimizing your directory service strategy.

In this post, we’ll explore the strengths, weaknesses, and ideal use cases of each service, and discuss why Managed Entra Domain Services might be the preferred option for many modern cloud-driven businesses.

What is Active Directory Domain Services (AD DS)?

Active Directory Domain Services (AD DS) is a widely used on-premises solution for managing users, groups, and computers. It is often used in enterprise environments to facilitate user authentication, directory management, and secure access to resources within a corporate network.

Key Features

• Centralized Management:
  AD DS enables centralized management of user and device access to resources across an organization.

• Group Policy:
  It supports complex Group Policy implementations, allowing IT administrators to manage user settings, security policies, and software deployment.

• Comprehensive Security:
  AD DS offers strong security measures, including Kerberos-based authentication, multi-factor authentication, and certificate-based authentication.

• Integration with Windows:
  It is tightly integrated with Windows operating systems, making it an ideal choice for environments that rely heavily on Microsoft products.

Pros and Cons

Pros

• On-premises Control:
  Full control over the directory service, security policies, and domain configuration.

• Integration with Legacy Systems:
  It integrates seamlessly with legacy on-premises applications and systems that require traditional Active Directory features.

• Customizability:
  Offers extensive customizability in terms of security policies, organizational units (OUs), and Group Policy Objects (GPOs).

Cons

• Complexity in Management:
  AD DS requires manual setup, management, and maintenance, which can be time-consuming and resource-intensive.

• Limited Cloud Integration:
  While AD DS can be extended to the cloud via Azure AD Connect, this adds complexity, and it may not be as seamless as native cloud solutions.

• Infrastructure Overhead:
  Requires on-premises infrastructure, including physical or virtual servers, which can lead to additional costs for hardware, maintenance, and operational overhead.

What is Managed Entra Domain Services?

Managed Entra Domain Services, often referred to as Azure AD DS, extends the capabilities of Azure Active Directory (Azure AD) by providing domain services in the cloud. This fully managed service allows businesses to use directory services like domain join, LDAP, and Kerberos, all within the Azure ecosystem. Managed Entra Domain Services is especially beneficial for organizations leveraging hybrid or fully cloud-based environments.

Key Features

• Fully Managed:
  Azure handles the management of domain services, including patching, updates, and high availability.

• Seamless Azure Integration:
  Being part of the Azure ecosystem, it integrates smoothly with other Azure services such as Virtual Machines, Azure Files, and Azure Kubernetes Service (AKS).

• Domain Join and Group Policy Support:
  It provides traditional Active Directory functionalities like domain join for Azure virtual machines and support for Group Policy.

• Scalability:
  Azure AD DS offers dynamic scalability, allowing businesses to scale their directory services up or down based on demand without additional infrastructure management.

Pros and Cons

Pros

• Fully Managed Service:
  Azure handles all aspects of service management, including backups, patching, and scaling, reducing operational overhead.

• Cloud-Native:
  Seamlessly integrates with Azure cloud resources, making it an ideal solution for hybrid or fully cloud-based environments.

• Scalability and Flexibility:
  Easily scale resources up or down based on workload requirements, without the need for manual intervention or additional infrastructure.

• Reduced Complexity:
  Simplifies the deployment and maintenance of Active Directory in the cloud, making it an attractive option for businesses looking to reduce complexity and focus on core operations.

Cons

• Limited Customization:
  Although it supports most traditional Active Directory features, there are some limitations in customization compared to on-premises AD DS, particularly with Group Policies and schema modifications.

• Not Suitable for All Workloads Organizations with complex, heavily customized environments or legacy applications may encounter compatibility challenges.

• Pricing:
  Managed Entra Domain Services can be costlier than traditional AD DS, depending on the scale and usage of the service.

Why You Should Choose Managed Entra Domain Services

Seamless Azure Integration Managed Entra Domain Services is designed to work seamlessly with Azure services. If your organization is already in the cloud or is transitioning to a hybrid model, using Azure AD DS simplifies your infrastructure. It eliminates the need to configure complex hybrid setups with Azure AD Connect and reduces the friction between on-premises and cloud environments.

Reduced Operational Overhead With Azure handling the management of domain controllers, patching, and scaling, you save valuable time and resources that can be better spent on other areas of your business. If you’re looking for a set-and-forget solution that scales with your needs, Managed Entra Domain Services is an excellent choice.

Ideal for Hybrid and Cloud-First Environments If your organization is increasingly adopting a cloud-first approach, using Managed Entra Domain Services is a logical step. It provides the flexibility to manage users and resources in the cloud while still leveraging familiar Active Directory features.

Improved Security and Compliance With automatic updates and security patches managed by Microsoft, Azure AD DS reduces the risk of vulnerabilities and security breaches. It’s also built with high availability in mind, ensuring your directory services are always up and running.

Cost Efficiency in the Cloud For businesses running predominantly in Azure, Managed Entra Domain Services can prove to be more cost-effective compared to maintaining an on-premises AD DS setup. There’s no need to invest in physical hardware, virtual machines, or dedicated resources, allowing you to better control costs.

Deploying Managed Entra Domain Services with Bicep

If you’re ready to deploy Managed Entra Domain Services (Azure AD DS) in your Azure environment, using Bicep as an Infrastructure-as-Code (IaC) tool can significantly streamline the process. Bicep is a domain-specific language (DSL) that simplifies the authoring of Azure Resource Manager (ARM) templates, allowing you to define your infrastructure declaratively in a more concise and readable format.

To assist with your deployment, I’ve created a GitHub repository that provides templates and modules for deploying Managed Entra Domain Services through Bicep. You can find the repository here: BWC Bicep Repository

What’s Included in the Repository?

The repository includes pre-configured Bicep modules for the following tasks:

Setting up Managed Entra Domain Services (Azure AD DS): The primary module for creating a Managed Entra Domain Services instance in Azure. Custom Domain Configuration: A module to configure custom domains in Azure AD DS if your organization requires integration with existing on-premises Active Directory or custom domain names. High Availability Setup: Configuration for enabling multi-region deployment and ensuring high availability for your domain services. Group Policy and LDAP Configuration: Basic and advanced templates to manage Group Policy and configure Secure LDAP (LDAPS) for secure communication.

How to Use the Repository

Clone GitHub Repository

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git clone https://github.com/builtwithcaffeine/bwc-bicep-repository.git

Navigate to Bicep folder

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Set-Location -Path .\entraid-domain-services\

Check params.bicep

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using './main.bicep'

// Default Values
@description('Default Parameter Values')
param location = ''
param locationShortCode = ''
param environmentType = ''
param deployedBy = ''


// Virtual Network
@description('The name of the virtual network to be created.')
param vnetAddressSpace = [
  '192.168.0.0/24'
]

@description('The name of the subnet to be created.')
param subnetAddressPrefix = '192.168.0.0/24'

// Entra Domain Services
@description('The name of the domain to be created.')
param domainName = 'ad.builtwithcaffeine.cloud'

@description('The name of the resource to be created.')
// NOTE: Character Limit is: 19
param resourceName = 'builtwithcaffeine'

@description('Domain Services Sku')
@allowed([
  'Standard'
  'Premium'
])
param domainServicesSku = 'Standard'

@description('Additional recipients for notifications.')
param additionalRecipients = [
  'alerts@builtwithcaffeine.cloud'
]

Deploy Entra Domain Services

Resource Deployment:

• ‘Domain Controller Services’ Enterprise Application
• ‘AADC Domain Administrators’ Entra Id Security Group
• Resource Group
• Virtual Network
• Network Security Group
• Load Balancer (Public)
• Public IP Address
• Log Analytics Workspace
• Entra Domain Services
• Network Adapter Interfaces (Provided from Two Virtual Machines)

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.\Invoke-AzDeployment.ps1 -targetScope 'sub' -subscriptionId 'xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx' -environmentType 'dev' -location 'westeurope' -deploy

The deployed resources:

Advisory: Cost Overview

Just wanted to make you aware of the Sku Options available for Entra Domain Services.
They come in the following flavours Standard, Enterprise, Premium

If you want to get more information on costings you can check the Microsoft Docs

Why Use Bicep for Entra Domain Services?

• Simplicity:
  Bicep simplifies the process of deploying and managing resources in Azure by providing a more readable and maintainable alternative to JSON ARM templates.

• Automation:
  With Bicep, you can automate the deployment of Managed Entra Domain Services, reducing the chances of human error during manual setup.

• Scalability:
  The repository provides scalable templates, allowing you to quickly adapt and scale your deployments across multiple regions or environments as your needs grow.

• By using this repository,
  you can quickly deploy Managed Entra Domain Services and configure your Azure environment with minimal effort.

Wrap Up

Both Active Directory Domain Services (AD DS) and Managed Entra Domain Services offer robust directory services, but they cater to different use cases. AD DS excels in environments that need fine-grained control over domain services and require integration with legacy on-premises systems. However, as organizations increasingly move to the cloud, Managed Entra Domain Services emerges as the better solution for those who want to minimize management overhead, scale seamlessly, and integrate directly with Azure resources.

For most modern, cloud-first, or hybrid environments, Managed Entra Domain Services simplifies directory management, reduces complexity, and provides a cost-effective, scalable solution that supports your cloud journey.