What feature allows routers to control device access based on the hardware address of a network card?

The feature that enables routers to control device access based on the hardware address of a network card is MAC Address Filtering. This function allows network administrators to specify which devices can access the network by allowing or denying access based on each device's Media Access Control (MAC) address, which is a unique identifier assigned to network interfaces for communications on the physical network segment.

When MAC Address Filtering is configured, the router checks the incoming MAC addresses of devices attempting to connect to the network against a list of approved (or disallowed) addresses. If a device’s MAC address is on the allowed list, it can join the network; if not, it is blocked from accessing network resources. This method enhances network security by limiting access only to recognized devices.

The other options serve different purposes: Network Address Translation (NAT) is primarily used for translating private IP addresses to a public IP address to manage internet and intranet traffic. Port Forwarding directs incoming traffic for a specific port to a particular device within the internal network but does not control access based on hardware addresses. SSID Broadcasting is related to wireless network visibility but does not involve controlling access based on hardware MAC addresses.