Which feature should be enabled to ensure data synchronization between domain controllers?

To ensure data synchronization between domain controllers, enabling Active Directory Replication is essential. Active Directory uses replication to maintain consistency of directory data across different domain controllers within a network. This process ensures that changes made in one domain controller, such as updates to user accounts, group memberships, or ACLs, are propagated to other domain controllers in a timely manner.

Replication occurs at set intervals and can work in real time for certain types of updates, which is critical for maintaining a consistent view of the directory for users and applications accessing it. Without enabling Active Directory Replication, each domain controller would operate independently, potentially leading to outdated or inconsistent data across the network.

Other features listed may serve different purposes; for example, the Global Catalog facilitates searching for information across multiple domains and may speed up the replication process but does not itself handle synchronization. Domain Controller Synchronization is not a formal term or feature in Active Directory. DSN Configuration relates to DNS settings, which support Active Directory but do not directly manage data synchronization. Therefore, the core functionality needed for data synchronization between domain controllers is achieved through Active Directory Replication.