Difference between Azure AD vs AWS Directory Service (Comparison)

Cloud computing is in – and it’s here to stay. When it comes to tech companies, Microsoft and Amazon are two of the biggest players in the cloud computing field. They have two products – Azure AD vs AWS Directory Service, respectively – which make life easier for administrators. Although they may seem the same, they’re not; and we will be looking at the differences that actually exist between these two products.

What is Azure AD?

Azure Active Directory or Azure AD is Microsoft’s cloud-based identity and access management (IAM) solution. It is the backbone of Microsoft 365, the company’s flagship office productivity suite.

Azure AD uses Security Assertion Markup Language (SAML) or OpenId authentications to connect applications while also using group assignments (dynamic groups, etc.) to determine who can access what.

In an office environment, Azure AD acts as a multi-tenant, cloud-based IAM service that allows employees to sign in and access external resources like Microsoft 365 and an increasing array of other third-party SaaS applications. Of course, access to local and corporate applications and digital assets can also be managed by Azure AD.

Azure AD also uses (and offers) single sign-on (SSO) authentication services where users are authorized to access numerous applications by signing in just once.

Because Azure AD is backward-compatible, it can easily integrate into, and sync with, networks that still run Microsoft Active Directory (AD) – the older, on-premises authentication version of the tool. In fact, Azure AD can be run as a cloud tool, allowing AD users to sign in to their machines using the cloud directory service. Alternatively, these organizations can also take advantage of Azure AD – without the need to make a complete switch over – because it can also be integrated to run in hybrid mode.

Azure AD has three editions:

  • Free Edition – offers user and group management, device registration, self-service password change, and synchronization with on-premises directories. It is limited to 10 applications per user configured for SSO.
  • Basic edition – extends the free edition’s capabilities by combining group-based access management, self-service password reset for cloud applications, and usage of an application proxy. This edition also has a Microsoft high availability (99.9% uptime) service level agreement.
  • Premium edition – designed to accommodate organizations with more demanding IAM needs. It supports dynamic groups and self-service group management, self-service password reset with password writeback, self-service IAM, identity protection, and security in the cloud. It provides cloud write-back capabilities, Cloud App Discovery, Azure Active Directory Connect Health, and advanced reports.

What is AWS Directory Service?

AWS Active Directory Service for Microsoft Active Directory is also known as AWS Managed Microsoft Active Directory (AD). Its main purpose is to serve as a bridge between AWS and Active Directory. In other words, AWS Directory Service is used to extend AD within AWS.

It is, in fact, built on top of AD making it easy to sync data between AD and AWS. This also makes it easier for administrators used to the AD environment to continue using it as Active Directory cloud while their users simply move into accessing the cloud without the need for new accounts or passwords.

Just to be clear, AWS Directory Service can be pictured in three scenarios:

  • Self-managed AD – where an administrator deploys a new AWS cloud-based AD DS environment that they manage on their own.
  • Hybrid AD setup – where the administrator extends their existing, on-premises AD DS into the AWS cloud.
  • AWS Managed Microsoft AD – where they fully adopt Directory Service for Microsoft Active Directory (AWS Managed Microsoft AD).

At present, there are two editions of AWS Managed Microsoft AD:

  • Standard Edition – optimized to be a primary directory for SMBs with up to 5,000 employees; it comes with 1GB storage and supports up to 30,000 directory objects, like users, groups, and computers.
  • Enterprise Edition – designed to support larger organizations with up to 500,000 directory objects; it comes with 17 GB of storage.

Difference between Azure AD vs AWS Directory Service

Ok; so, the first thing we need to understand is that both Azure AD and AWS Directory Service perform the same basic task: they are tools to manage authentication and access of digital assets.

The difference is the scope they are responsible for. Let’s have a look at each service’s features individually to comprehend these scopes:

Azure AD Features

Azure AD became much more flexible – and farther-reaching – than AD because it is entirely cloud-based. It allowed administrators the choices of on-premises (via Azure AD Connect), cloud or hybrid directories that allowed users to connect to devices in all three architectures.

More features:

  • Apart from making all apps and resources equally available to both on-premises and cloud-based users, it also allows them to benefit from security features like SSO, MFA, conditional access, and much more.
  • Administrators can easily control a larger domain (or several domains) of users and their access to applications; they can also use governance controls that are built into Azure AD to apply automated lifecycle management and privileged access limitations.
  • Azure AD also allows administrators to automate provisioning between Windows Server Active Directory and cloud applications like Microsoft 365.
  • Developers can use Azure AD as a standards-based approach to enabling security features like SSO and also to personalize their user interfaces and user experiences (UI/UX) using existing organization data that is accessed through APIs.
  • Azure AD is the more recent version of Microsoft’s products and allows administrators the luxury of implementing state-of-the-art security measures like assessing and mitigating threats of, for example, malicious users’ attempts at accessing digital assets.

AWS Directory Service Features

Implementing AWS Directory Service means administrators don’t need to learn a new skill – the GUI, policies, configurations, etc. remain familiar, making it easier for them to fully adopt and leverage the tool.

Of course, their scope of influence widens, as they also enable their users to go beyond their network and adopt cloud computing – AWS, to be more precise.

AWS Directory Service Features
AWS Directory Service Use Cases

More AWS AD features:

  • Since AWS Managed Microsoft AD is itself built on AD (it’s just running on the AWS infrastructure), it is easy to migrate any AD-dependent applications while also cutting out the need to manage the underlying infrastructure itself. After all, it is managed by AWS.
  • All AD credentials can connect to AWS applications – like Amazon Relational Database Service (RDS) for SQL Server, PostgreSQL, and Oracle database engines.
  • They can sleep better at night as their operation is backed by a high-availability guarantee from AWS that is spread across multiple Availability Zones.
  • The tool also offers multi-region replication where administrators can deploy and use a single AWS Managed Microsoft AD directory across multiple AWS Regions making it easier, and cheaper, to deploy and manage Windows and Linux workloads on a global scale.

Which Directory Service is best?

As we have seen, there is no direct competition between these two products. It is, in fact, all about the tool being suitable for the task. So, to make it easier, let’s have a look at which tool to use and when:

Choose Azure AD…

  • If you need to extend existing on-premises AD implementations to Azure AD.
  • If you need an inexpensive AD–compatible service with common directory features that are also cloud-native.
  • If you need to configure access to applications and configure SSO and multi-factor authentication to cloud-based SaaS applications.
  • If you need an identity management solution to manage and provision users and groups.
  • If you need to enable the smooth merging between organizations or independent units or domains.

Choose AWS Directory…

  • If you want a feature-rich managed Microsoft Active Directory that is hosted in the AWS cloud.
  • If you want to minimize AD infrastructure operational management – or even completely avoid doing the heavy lifting – by moving the whole architecture into the cloud.
  • If you don’t want to be bothered by time and energy wasted on maintenance, domain management, system and server patching, as well as backing up of mission-critical system and operational data.
  • If you need peace of mind with guaranteed uptimes and professional support.
  • If you want to empower your users by giving them access to AWS enterprise applications and services like AWS Workspaces, Amazon RDS, AWS Workdocs, and AWS Workmail.

Again, AWS manages the entire basic infrastructure and you are only responsible for the Active Directory data – life is easier as an administrator.

Using both Azure AD and AWS Directory Service

In cases where it comes to “either-or” situations between Azure AD and AWS Directory Service, we have seen that there are some considerations to be taken into account before making a choice.

However, there is a third solution: using both. Administrators can connect Azure Active Directory to AWS Single Sign-on (SSO) once, manage permissions to AWS centrally in AWS SSO, and allow their users to sign in using Azure AD as they access assigned AWS accounts and applications.

This is a win-win situation as both tools are in play. The rule of thumb here would be: “Don’t get rid of the ‘old‘, just integrate it into the ‘new‘.

Avatar for Liku Zelleke
Liku Zelleke

Liku Zelleke is a technology blogger who has over two decades experience in the IT industry. He hasn’t looked back since the day, years ago, when he discovered he could combine that experience with his other passion: writing. Today, he writes on topics related to network configuration, optimization, and security for Cloud Infrastructure Services.

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