Cisco Port Security Configuration!! | IPCisco.com . Port security is a network feature on switches that controls access by limiting which devices (based on their MAC addresses) can connect to a port, preventing unauthorized users from joining the network, by allowing only specific MACs or a set number of MACs, and taking action (like shutting down the port) on violations to protect against threats like MAC spoofing. It’s configured per port and enhances network security in corporate, government,