How do MAC addresses participate in securing wireless frames?

• A. MAC addresses are used only for logical addressing and not for access control.
• B. Each frame includes the BSSID but not the source/destination MAC.
• C. Each frame includes source and destination MAC addresses and BSSID, enabling filtering, access control, and roaming.
• D. MAC addresses are randomly generated for each frame.

Answer: (C)

MAC addresses in wireless frames act as fundamental identifiers that tie each frame to the devices and the local network segment. Every 802.11 frame carries the sender’s MAC address (source), the intended recipient’s MAC address (destination), and the BSSID, which is the MAC address of the access point’s basic service set. This combination lets devices determine whether a frame is meant for them and helps the network decide how to handle it.

With the source, destination, and BSSID present, filters can be applied to deliver frames only to the correct station or AP, and security policies can control who is allowed to send or receive frames on a given network. The BSSID specifically identifies the AP (or the specific BSS) that provides the connection, which is crucial for roaming: as a client moves from one AP to another, the BSSID changes, guiding frames to the new AP while maintaining the overall connection and security state.

MAC addresses are not randomly generated for each frame, and frames do carry both source and destination addresses along with the BSSID, not just the BSSID alone. They are also not used purely for logical addressing without any access-control role.