Which ports are open by default on a Samba 4 Active Directory Domain Controller? (Choose three.)

• A. 443/TCP, 138/TCP, 389/TCP
• B. 138/TCP, 389/TCP, 445/TCP
• C. 53/TCP, 138/TCP, 445/TCP
• D. 389/TCP, 53/TCP, 139/TCP

Answer: (B)

On a Samba 4 Active Directory Domain Controller, the default ports that are open include 389/TCP, which is used for the Lightweight Directory Access Protocol (LDAP), essential for directory services in Active Directory. Port 445/TCP is used for SMB (Server Message Block) protocol, which facilitates file sharing, and for communication between clients and services in Windows networking environments. Port 138/TCP, associated with the NetBIOS Datagram Service, also plays a role in support functions like browsing and networking with other devices.

This understanding is crucial because it highlights the essential services that must be available for a Samba Domain Controller to function correctly within a mixed environment, especially for the interoperability with Windows systems. The other options fail to include these correct combinations of ports that are critical for the functionality of a Samba Active Directory setup.