Active Directory (AD) is a hierarchical directory service that is used to secure network resources, user accounts, and data. As a result, it serves as the primary on-premises identity store for authenticating and authorizing access across a variety of applications and services for organizations of all sizes.
Understanding AD
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At the top of the AD hierarchy is the forest, which serves as the overarching security boundary and contains one or more domains that share a common schema, configuration, and global catalog. Each domain functions as a logical partition within the forest, managing its own users, groups, and computers while maintaining automatic trust relationships with other domains in the same forest.
It is important to note that a domain is not a security boundary. It can be used as an administrative boundary, but administrators in the root domain have access to all domains in the forest, and administrators in child domains can impact other domains. Within a domain, Organizational Units (OUs) are used to organize objects for administrative purposes and policy application. While OUs are not security boundaries, they enable delegation of control to specific administrators for subsets of directory objects. This structure allows organizations to maintain centralized control while distributing administrative responsibilities and enforcing security policies effectively.
The value of AD lies in its ability to centralize network management and security. It simplifies how users access resources by enabling on-premises single sign-on and role-based access control. AD also plays a key role in helping organizations meet compliance requirements through policy enforcement.
AD has been used by enterprises for over 25 years and much has changed in a quarter of a century. Legacy AD environments present a wide variety of challenges. Over time, they can become overly complex. This complexity amplifies security configurations, which have become inadequate. Issues such as excessive elevated privileges or weak authentication settings and protocols often lead to compromised network infrastructure. Managing user permissions and access rights can also become difficult, particularly in environments where roles and responsibilities change frequently.
Assessing Your Current AD Environment
It is critical to understand the current state of your AD environment. To help you manage your AD investment, Ravenswood offers an AD Health Check (ADHC). Our ADHC provides a comprehensive report assessing the configuration, Active Directory security and operational procedures of an AD Forest. The expertise of our team, coupled with a very detailed and actionable report about the health of your AD, will help you optimize your AD environment, increase its security, and support prioritization of items that need to be addressed.
Some examples of findings the ADHC often uncovers are:
- Stale user account and computer account list that should be deprovisioned
- Legacy protocols with weak security that are still being used
- Privileged administration groups with more members than needed
- Kerberos configurations that can easily be compromised, such as unconstrained delegation
- Misconfigured replication between domain controller systems
- Weak password policies or absent lockout mechanisms
- Time synchronization issues critical for Kerberos authentication
- Legacy trust relationships that are no longer required
Best Practices for Design & Structure
A well-organized AD structure is essential for effective administration, improved security, and long-term scalability. When an AD forest is designed thoughtfully from the start, it is easier to manage users, apply consistent security policies, and adapt to future organizational changes.
Naming Standards
Clear, consistent naming standards are foundational to a well-organized and managed AD. Descriptive names for organizational units (OUs), groups, and users help administrators quickly understand the purpose and scope of each object. As an example, a simple naming scheme for standard user accounts, administrative privileged accounts, and service accounts could be employed.
Account Type | Account Prefix |
|---|---|
Standard User | No Prefix |
Service Account | svc_ |
Privileged Account | admin_ |
This clarity reduces errors and simplifies day-to-day tasks. Standards for naming can help easily differentiate between named user accounts, service accounts, and privileged accounts.
Organizational Unit (OU) Design
The structure of OUs should reflect the organization’s logical layout—typically by department, geographic location, or business function. A logical OU hierarchy not only helps with administrative delegation but also makes it easier to apply group policies in a targeted and efficient way. As an example, rights to reset passwords for standard users in a “People” OU can be delegated to a help desk group. Likewise, a set of group policies can be linked to an OU that holds end user workstations, and another set of group policies can be linked to an OU that contains servers.
The ability to easily create OUs and the flexibility they offer needs to be tempered with reasonable levels of complexity. Older AD environments suffer from OU sprawl. This is often due to historical mergers and acquisitions, or outdated design decisions. A well-maintained and thoughtful OU structure can simplify delegation and application of policy. OUs should only be added to apply Group Policy Objects or to set up delegation within AD.
Wherever possible, organizations should consolidate and simplify AD infrastructure. This streamlines management, increases consistency, and makes it easier to enforce security policies across the environment. Centralizing control in this way not only strengthens security but also reduces administrative overhead and operational risk.
Access Controls, Permissions, & Securing Active Directory
Effective access management is critical to securing an AD environment. At the core of this approach is the principle of least privilege, which means users and groups should only have the minimum permissions necessary to perform their jobs. This reduces the risk of accidental or intentional misuse of access.
Properly managing permissions starts with Role-Based Access Control (RBAC). Instead of assigning access to individual users, permission should be granted to roles that reflect job functions. These roles are then mapped to groups in AD. This makes it easier to manage access consistently and reduces the risk of excess permissions for users. As roles or responsibilities change, it’s important to regularly review and update access rights to ensure they remain appropriate.
Privileged accounts, such as domain admin roles, require additional safeguards. These accounts should be separate from standard user accounts and used strictly for administrative tasks. Modern authentication functionality such as Windows Hello for Business should be enforced for all privileged access to add an extra layer of protection. It’s also essential to monitor and audit these accounts regularly to detect unauthorized or suspicious activity.
Securing AD goes beyond managing permissions; it requires a strong focus on protecting the infrastructure itself. Domain controllers, the servers that run AD, must be secured appropriately. Physically, they should be housed in secure, access-controlled environments to prevent unauthorized access. On the network side, domain controllers should be placed in dedicated VLANs, with access tightly restricted through firewalls and access control lists (ACLs). Organizations should also review and modify default security settings to ensure they align with current security standards rather than relying on potentially outdated configurations.
Well managed end user credentials are another critical line of defense. Some companies have been able to make the jump to eliminating passwords, while many are still on that journey. Until that time, password hygiene remains important. Using services such as Microsoft’s Entra Password Protection can significantly reduce the chances of compromises caused by weak passwords, particularly when coupled with a strong password policy and lockout mechanisms.
These tactics also help reduce the risk of brute-force attacks. In addition to eliminating passwords for users, using Group Managed Service Accounts (gMSAs) for service accounts can greatly reduce attack vectors. gMSAs are accounts that many applications, such as SQL server and Entra ID Connect can leverage. They use very long, complex passwords that rotate automatically every 30 days by default. Windows Server 2025 offers even stronger security options for service accounts with delegated Managed Service accounts. In addition to improvements in security, dMSA’s can be used to replace or supersede a standard account used as a service account.
For end users, phishing proof authentication methods are ideal. Phishing-resistant authentication uses methods that attackers cannot easily intercept or replicate, even if users are tricked. It typically relies on cryptographic authentication tied to a physical device, such as a security key that supports FIDO2.WebAuthN standards. Another option is passkeys. Passkeys are a newer evolution of FIDO2, where the credential (private key) is stored in your device’s secure storage (like your phone or laptop) and can sync across devices via cloud service.
These methods validate both the user and the service they are accessing, ensuring that credentials cannot be reused on a fake site. As a result, even if a user clicks on a phishing link, authentication will fail against an illegitimate service.
Monitoring & Maintenance
Maintaining a healthy AD environment requires consistent attention and ongoing oversight. Routine audits play a vital role in this process. From a compliance standpoint, regular Active Directory auditing help ensure the organization meets industry standards and regulatory obligations. Audits also support security by uncovering vulnerabilities, misconfigurations, or excessive permissions that could be exploited. On the operational side, they help detect issues that may affect performance or disrupt the user experience.
Security monitoring plays a key role as well. A Security Information and Event Management (SIEM) system can collect and analyze logs from across the environment, providing visibility into potential threats. Alerts should be configured for activities like repeated failed login attempts, unauthorized changes, or access to sensitive data, enabling faster detection and response.
Keeping AD up to date is equally important. Security patches and software updates should be applied promptly to protect against known vulnerabilities. Regular Active Directory backup procedures are essential to safeguard AD data in the event of hardware failure, data corruption, or cyberattacks. These backups should be part of a tested disaster recovery plan, ensuring that AD can be restored quickly and reliably if needed. Organizations should also establish comprehensive Active Directory recovery procedures, including Active Directory forest recovery protocols for worst-case scenarios where the entire forest needs to be restored.
Automated tools can greatly enhance the efficiency and accuracy of monitoring efforts. AD monitoring solutions provide real-time insights into performance, security events, and compliance status. Automated reporting helps administrators stay informed with regular summaries of AD health, enabling proactive maintenance before small issues become major problems.
The Importance of Modernizing Your AD Infrastructure
Many organizations still rely on legacy AD environments that were built years ago and have not kept pace with modern IT needs. Modernizing AD can be challenging due to compatibility issues with legacy applications and older protocols. Older applications can stop working as you implement newer, more secure configurations such as enforcing NTLM v2 and LDAP signing.
The modernization process begins with a thorough assessment of the existing environment. This includes identifying outdated components, evaluating security risks, and pinpointing areas that require reconfiguration or replacement. Based on the assessment, a detailed migration plan should be developed. The plan must account for minimizing downtime and ensuring business continuity, often by segmenting the migration into manageable phases.
Implementation should follow a staged approach—starting with non-critical systems to test the process and identify potential issues before moving on to core components. Reviewing logs to see what older protocols are still being used is a great first step to identify what could block upgrades. Throughout the process, it’s essential to validate each step and ensure systems function as expected before progressing further.
Call to Action & Conclusion
A secure, well-structured, and up-to-date AD environment is essential for maintaining operational efficiency and protecting organizational assets. From thoughtful design and strong access controls to ongoing maintenance and modernization, each element plays a critical role in supporting a resilient AD infrastructure.
Continuous assessment is key. As technology evolves, so should your AD environment. Regular audits, strong security policies, and proactive modernization efforts help ensure AD remains aligned with business needs and industry standards.
IT teams are encouraged to take practical steps now—review current configurations, enforce least privilege, apply patches regularly, and monitor AD health. Staying current with best practices is not only a technical necessity but also a strategic advantage.
At Ravenswood, we specialize in helping organizations strengthen and optimize their AD environments. Ravenswood offers many services related to AD. Three of our primary offerings around AD are:
- AD Health Check
- Modern AD Tiering Design and Implementation
- Modern Privilege Access Workstation design and implementation
All our work with AD will always be tailored to meet your unique challenges and goals. Whether you’re facing legacy infrastructure issues or preparing for future growth, we’re here to help.
Take the first step toward a more secure and efficient AD. Contact Ravenswood Technology Group today to schedule a free consultation or AD Health Check.
