While configuring a new access layer switch, the administrator, Joe, was advised that he needed to make sure that only devices authorized to access the network would be permitted to login and utilize

Log analysis is a detective control that reviews existing activity after the fact and does not prevent unauthorized devices from connecting.

VLAN management segments network traffic but does not by itself authenticate or authorize which devices are permitted to connect.

Network separation isolates network segments but does not enforce per-device authentication or block unauthorized devices from plugging in.

802.1x is the IEEE standard for port-based Network Access Control that requires devices to authenticate before being granted network access. It works with an authentication server (typically RADIUS) to verify device or user credentials before the switch port is enabled, directly preventing unauthorized devices from using network resources.