A network administrator needs to ensure all network ports use a security method that only...

802.1X provides port-based network access control that requires authentication before a switch port grants full network access. It uses a supplicant (client), an authenticator (switch/AP), and an authentication server (commonly RADIUS) to validate credentials or certificates. This directly supports the requirements: it reduces spoofing compared with MAC-based controls because authentication can be identity- and certificate-based rather than relying on easily forged MAC addresses; it is centrally managed through AAA infrastructure and policy (users/devices/groups); and it produces auditable logs via the authentication server and network devices, enabling accountability and investigation. Network+ security objectives emphasize AAA, NAC, and strong access controls for both wired and wireless networks. MAC filtering and basic port security rely largely on MAC addresses and are susceptible to spoofing; they also tend to be harder to manage at scale and provide weaker centralized auditing. ACLs control traffic flows but do not authenticate endpoints at the port level, so they cannot ensure “only authenticated devices” can connect. Therefore, 802.1X is the technology that best meets all stated requirements.