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Domain controller

(also DC)

Domain controller definition

Domain controller is a server that processes authentication requests and validates users' identities on networks. Network users and computers can be organized in a hierarchical structure using domains. The domain controller is responsible for storing and protecting this information. The domain controller is the centerpiece of an Active Directory (AD) network. Although cybercriminals can employ a variety of techniques, including direct attacks on data centers, to gain privileged access to a network, DCs can be secured and even put to use in the detection of ongoing cyberattacks.

Functions of a domain controller:

  • Validation and authentication. The domain controller verifies users' network access eligibility. The user's identity is verified by comparing their password and username to Active Directory.
  • Permission and access regulation. The domain controller controls users' hierarchical placement. The system uses Active Directory to check if a user has permission to use domain resources and then uses that user's entitlements to see which domain resources they should be able to use.
  • Group policy implementation. The domain controller carries out the rules and regulations regarding security.

Benefits of a domain controller:

  • Centralized user administration
  • Enables the sharing of documents and output devices
  • Through federated configuration (FSMO), data can be distributed and replicated across all main networks for added reliability

Limitation of a domain controller:

  • Requires additional security
  • Failure of the domain controller, which authenticates users, will cause network damage
  • DC failure can damage networks, making it a popular cyberattack target
  • Domain controllers power networks. Deploying them in clusters reduces downtime risk

Tips to make domain controllers more secure:

  • Act upon threat intelligence
  • Keep an eye on the domain controller and check its logs
  • Restrict who can log in to the domain controller and how
  • Limit the number of people who can become domain administrators
  • Use strict authentication procedures, such as multi-factor authentication, and rigorous security policies
  • Make sure your domain controller isn't connected to the web
  • Domain controllers are required to use the latest OS release