What Is AWS Directory Service?
AWS Directory Service provides multiple ways to use Microsoft Active Directory with other AWS services. You can choose the directory service with the features you need at a cost that fits your budget.
Use Simple AD if you need an inexpensive Active Directory–compatible service with the common directory features.
Select AWS Directory Service for Microsoft Active Directory (Enterprise Edition) for a feature-rich managed Microsoft Active Directory hosted on the AWS cloud.
Our third option, AD Connector, lets you simply connect your existing on-premises Active Directory to AWS.
Which to Choose?
The following information will help you decide which AWS Directory Service option is right for you:
Simple AD is a Microsoft Active Directory–compatible directory from AWS Directory Service that is powered by Samba 4. Simple AD supports commonly used Active Directory features such as user accounts, group memberships, domain-joining Amazon Elastic Compute Cloud (Amazon EC2) instances running Linux and Microsoft Windows, Kerberos-based single sign-on (SSO), and group policies. This makes it even easier to manage Amazon EC2 instances running Linux and Windows, and deploy Windows applications in the AWS cloud.
Many of the applications and tools you use today that require Microsoft Active Directory support can be used with Simple AD. User accounts in Simple AD can also access AWS applications, such as Amazon WorkSpaces, Amazon WorkDocs, or Amazon WorkMail. They can also use AWS Identity and Access Management roles to access the AWS Management Console and manage AWS resources. Finally, Simple AD provides daily automated snapshots to enable point-in-time recovery.
Note that you cannot set up trust relationships between Simple AD and other Active Directory domains. Other common features not supported today by Simple AD include DNS dynamic update, schema extensions, multi-factor authentication, communication over LDAPS, PowerShell AD cmdlets, and the transfer of FSMO roles.
When to use
In most cases, Simple AD is the least expensive option and your best choice if you have 5,000 or less users and don’t need the more advanced Microsoft Active Directory features.
AWS Directory Service for Microsoft Active Directory (Enterprise Edition) is a managed Microsoft Active Directory hosted on the AWS cloud. It provides much of the functionality offered by Microsoft Active Directory plus integration with AWS applications. With the additional Active Directory functionality, you can, for example, easily set up trust relationships with your existing Active Directory domains to extend those directories to AWS services.
If you are in the Frankfurt region, you can use Microsoft AD to enable multi-factor authentication by integrating with your existing RADIUS-based MFA infrastructure to provide an additional layer of security when users access AWS applications. For more information, see Multi-factor Authentication Prerequisites (Microsoft AD).
AWS Directory Service for Microsoft Active Directory (Enterprise Edition) does not support fine-grained password polices.
When to use
Microsoft AD is your best choice if you have more than 5,000 users and need a trust relationship set up between an AWS hosted directory and your on-premises directories.
AD Connector is a proxy service for connecting your on-premises Microsoft Active Directory to the AWS cloud without requiring complex directory synchronization or the cost and complexity of hosting a federation infrastructure.
AD Connector forwards sign-in requests to your Active Directory domain controllers for authentication and provides the ability for applications to query the directory for data. After setup, your users can use their existing corporate credentials to log on to AWS applications, such as Amazon WorkSpaces, Amazon WorkDocs, or Amazon WorkMail. With the proper IAM permissions, they can also access the AWS Management Console and manage AWS resources such as Amazon EC2 instances or Amazon S3 buckets. You can also use AD Connector to enable multi-factor authentication by integrating with your existing RADIUS-based MFA infrastructure to provide an additional layer of security when users access AWS applications.
With AD Connector, you continue to manage your Active Directory as usual. For example, adding new users, adding new groups or updating passwords is all accomplished using standard directory administration tools with your on-premises directory. Thus, in addition to providing a streamlined experience for your users, AD Connector enables consistent enforcement of your existing security policies, such as password expiration, password history, and account lockouts, whether users are accessing resources on premises or in the AWS cloud.
When to use
AD Connector is your best choice when you want to use your existing on-premises directory with AWS services.
For information about the AWS Directory Service API, see the AWS Directory Service API Reference.
Working with Amazon EC2
A basic understanding of Amazon EC2 is essential to using AWS Directory Service. We recommend that you begin by reading the following topics:
What is Amazon EC2? in the Amazon EC2 User Guide for Windows Instances.
Launching EC2 Instances in the Amazon EC2 User Guide for Windows Instances.
Security Groups in the Amazon EC2 User Guide for Windows Instances.
What is Amazon VPC? in the Amazon VPC User Guide.
Adding a Hardware Virtual Private Gateway to Your VPC in the Amazon VPC User Guide.