Which of the following is listed as a security measure for wireless networks?

• A. SSID (Network ID)
• B. Firewalls
• C. MAC Address Filtering
• D. VPN

Answer: (C)

Controlling which devices can join a wireless network is a common security measure, and MAC address filtering does that by using a whitelist of hardware addresses. The access point checks each device’s MAC address as it tries to connect and only grants access if the address is on the approved list. This provides a straightforward way to limit who can associate with the network at the data-link layer, which is why it’s recognized as a wireless security measure.

Other options don’t function as direct access controls for wireless clients. Hiding the SSID is security through obscurity and doesn’t truly prevent connections or protect data. A firewall protects network traffic at the edge, not the process of authenticating wireless clients. A VPN secures data traffic, often for remote access, but it isn’t a wireless access-control mechanism for local network connections. While MAC filtering has weaknesses (it can be spoofed and requires maintenance), it is the most clearly defined example of a wireless-specific security measure among the choices.