AZ-800 Administering Windows Server Hybrid Core Infrastructure Exam

Deploy and Secure Entra Domain Services Instances

Microsoft Entra Domain Services (Entra DS) provides managed domain features—like domain join, group policy, LDAP, and Kerberos/NTLM authentication—without deploying on-premises domain controllers. You begin by creating a managed domain in the Microsoft Entra admin center and integrating it into your Azure virtual network. Ensuring proper networking and administrative access is critical to stable operations. This setup extends your on-premises Active Directory capabilities into Azure for a seamless hybrid environment.

Configuring a managed domain starts with meeting DNS naming rules and setting up network integration. For example:

• DNS Suffix: Use a routable, conflict-free domain name.
• Subnet Setup: Assign a dedicated subnet that no other Azure resources share.
• Administrator Access: Add users to the AAD DC Administrators group for management.
  Finally, confirm that the domain is reachable and healthy before moving on. Monitoring connectivity helps catch issues early.

Securing your Entra DS instance means enforcing Conditional Access and robust password policies. You should apply conditional access rules—such as requiring multi-factor authentication (MFA)—to all synchronized accounts. Define password complexity and expiration settings that meet your organization’s standards, then synchronize password hashes from on-premises AD for consistent authentication. Regularly review and update these policies to maintain a strong security posture.

Managing synchronization ensures user and group objects stay current between on-premises Active Directory and your Entra DS managed domain. Use Microsoft Entra Connect to control which users and groups sync and how often updates occur. Decide on a full or scoped synchronization based on your environment’s needs and compliance requirements. Monitoring sync jobs and reviewing logs helps prevent replication issues and keeps identity data accurate.

To support applications that require LDAP, enable secure LDAP (LDAPS) on your managed domain. You must upload a valid SSL certificate and open port 636 in your network security groups (NSGs). Perform regular security audits to verify certificate validity and NSG rules. Maintaining LDAPS ensures encrypted directory access and protects credentials in transit.

Conclusion

Deploying and securing Microsoft Entra Domain Services involves creating a managed domain, configuring DNS and network settings, and assigning administrative roles. You then enforce conditional access and password policies to protect user sign-ins and credentials. Synchronizing objects with Microsoft Entra Connect keeps identity data up to date across environments. Finally, enabling secure LDAP ensures applications can access directory data over encrypted connections. These steps together deliver a robust, hybrid identity solution in Azure.