1.2 - Physical Components of AD

Domain Controller (DC)

The Domain Controller (DC) is the backbone of an Active Directory environment, ensuring seamless network operations by managing authentication, authorization, and directory services.

Functions:

• Hosts AD DS Directory Store: The DC maintains a full copy of the Active Directory database (Ntds.dit), which stores vital data about users, groups, policies, and more. This centralized repository ensures data consistency and supports resource management.

• Authentication & Authorization: DCs verify the identity of users and devices attempting to access network resources. They evaluate credentials and enforce access permissions based on security policies, enabling single sign-on (SSO) functionality across resources.

• Replication: Active Directory employs a multi-master replication model where changes on one DC are replicated to others, ensuring data consistency across the domain. This mechanism minimizes downtime and maintains service availability.

• Administrative Access: DCs allow administrators to manage the directory, including creating user accounts, applying Group Policy Objects (GPOs), and configuring permissions. These operations ensure that the network runs securely and efficiently.

Security Considerations:

• Risks of Compromise:

  • Unauthorized access to sensitive resources.

  • Theft or tampering with directory data.

  • Potential propagation of malware or further attacks.

• Mitigation Strategies:

  • Deploy redundant DCs to enhance fault tolerance.

  • Implement monitoring systems for unusual activity.

  • Regularly audit configurations and permissions.

• Resilience in Large Environments:

  • Multiple DCs distribute workloads and prevent a single point of failure.

  • Global catalog servers enhance query performance across forests.

AD DS Data Store

The AD DS Data Store, represented by the Ntds.dit file, is the heart of the Active Directory system. It securely stores all directory-related data, ensuring reliable operations and resource management.

Key Features:

• Data Storage:

  • Stores objects like user accounts, groups, organizational units, and attributes.

  • Includes sensitive information, such as password hashes (encrypted).

• Access Control: Only authorized domain controller processes can interact with the data store. Attempts to access the file directly are logged and restricted.

• Replication: Changes made to the data are propagated across all domain controllers in a domain, ensuring consistency and redundancy.

• Location: By default, the Ntds.dit file resides in %SystemRoot%\NTDS.

Importance in AD Operations:

• Essential for user authentication and resource allocation.

• Serves as the central point for enforcing directory-wide policies.