Scenario 3: Active Directory integration with AWS
For organizations heavily invested in Microsoft Active Directory, extending their identity and access management to AWS is crucial for maintaining security and operational consistency. This scenario outlines how to create a holistic identity management experience across on-premises and AWS environments, enabling single sign-on and unified access controls.
Characteristics
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Identity integration: Extension of on-premises Active Directory to AWS through Directory Service options (AWS Managed Microsoft AD or AD Connector), enabling consistent identity management across hybrid environments.
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Authentication framework: Implementation of unified authentication mechanisms allowing users to access both on-premises and AWS resources with existing AD credentials, supporting single sign-on (SSO) capabilities through AWS IAM Identity Center.
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Access control strategy: Centralized management of security policies and access permissions, using existing AD groups and security policies while integrating with AWS IAM roles and policies for cloud resource access.
Reference architecture
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Self-managed Active Directory on EC2 is a common approach for organizations needing full control over their AD infrastructure. This brings authentication and authorization closer to AWS workloads, addressing network and security requirements effectively.
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Extending self-managed AD on EC2 to Directory Services can be achieved by creating a trust with AWS Managed Microsoft Active Directory. This enables AWS services reliant on Managed AD to use the existing self-managed AD identity source.
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Alternatively, a trust between on-premises AD and AWS Managed AD can be established using VPN or Direct Connect, meeting specific networking and security needs. This also opens the possibility of migrating the entire forest to AWS Managed AD, potentially decommissioning self-managed AD.
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AD Connector serves as a simple gateway solution for extending self-managed AD running on EC2 to AWS services, offering an alternative integration approach.
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For on-premises scenarios, AD Connector can also be utilized over a secure VPN or Direct Connect connection, providing flexibility in network design.
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AWS IAM Identity Center can integrate with AWS Managed AD as an identity source, with the capability to expand to multiple self-managed AD forests or domains if required.
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Alternatively, AD Connector can be used to connect self-managed AD as the identity source for AWS IAM Identity Center, though this is limited to one forest or domain.
Configuration notes
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Self-managed AD infrastructure: When implementing AD on EC2, deploy Domain Controllers across multiple Availability Zones for high availability. Configure security groups to allow only necessary AD ports, implement appropriate site-to-site replication, and use AWS Backup for automated system state backups. Common challenges include DNS configuration and replication latency, which are addressed through proper subnet design and monitoring. Set up CloudWatch alerts for DC health and performance metrics.
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AWS managed Microsoft AD integration: Establish two-way trust relationships with appropriate security filtering. Configure DNS conditional forwarders between environments, implement selective authentication if needed, and use AWS Managed Microsoft AD delegated administration. Key considerations include password policies synchronization and Group Policy Object strategy. Monitor trust health through Directory Service console and CloudWatch metrics.
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Network connectivity configuration: Design redundant connectivity using both AWS Direct Connect and VPN as backup. Implement appropriate route tables and network ACLs, maintain proper DNS resolution between networks, and configure bandwidth allocation for AD traffic. Common issues include asymmetric routing and DNS resolution failures, which can be resolved through proper route configuration and DNS forwarding setup.
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Identity Center and SSO setup: Configure AWS IAM Identity Center with appropriate directory integration (either Managed AD or AD Connector). Implement attribute-based access control (ABAC) using AD group membership, set up permission sets aligned with security policies, and establish user portal access. Monitor authentication failures and implement appropriate remediation processes for access issues.
