Complete Windows Server 2012 Practice Test 2025

The protocol primarily used with Active Directory for user authentication is LDAP (Lightweight Directory Access Protocol). LDAP is specifically designed for accessing and maintaining distributed directory information services over an internet protocol network. In the context of Active Directory, it allows both directory searches and authentication operations.

When a user attempts to log in to a Windows domain, their credentials are sent to the domain controller, which utilizes LDAP to query the directory for the user's information and authenticate the user. This makes LDAP an essential component of Active Directory environments, as it not only helps in authenticating users but also in retrieving user attributes, managing group memberships, and facilitating secure communication between clients and directory services.

The other options listed do not serve the purpose of user authentication in Active Directory. FTP (File Transfer Protocol) is primarily used for transferring files, HTTP (Hypertext Transfer Protocol) is used for transferring web pages, and SNMP (Simple Network Management Protocol) is utilized for network management and monitoring. Therefore, their functionalities do not align with the core requirements of user authentication in a directory services context.