What feature allows you to control client connections to a wireless network by specifying hardware addresses?

The feature that allows you to control client connections to a wireless network by specifying hardware addresses is MAC address filtering. This security measure works by allowing access only to devices whose MAC (Media Access Control) addresses are explicitly permitted. When a device attempts to connect to the network, the router or access point will check its MAC address against a predefined list. If the MAC address of the device is on the list, it will be granted access, while devices not on the list will be denied entry.

This method is particularly useful for managing which devices can connect to a network, enhancing security by limiting potential unauthorized access. Though it's not foolproof—because MAC addresses can be spoofed—it does add an additional layer of control over who can join the network.

The other options, while related to wireless networking, do not serve the same purpose. SSID broadcasting is about making the network identifiable to users; WPA encryption is a security protocol for protecting data transmitted over the network, and channel selection pertains to managing frequency channels to reduce interference. None of these options provide the specific capability of controlling access based on individual hardware addresses.