Example embodiments relate to preventing MAC spoofing. In this manner, the embodiments disclosed herein enable sending, from a requesting mobile device, a generic advertisement service (GAS) message on a channel. Responsive to sending the GAS message, a first GAS response message and a second GAS response message may be received on the channel within a predetermined time period after sending the GAS message on the channel. A first CSI fingerprint from the first GAS response message may be compared to a stored CSI fingerprint. A second CSI fingerprint from the second GAS response message may also be compared to the stored CSI fingerprint. Responsive to the first CSI fingerprint being a closer match to the stored CSI fingerprint than the second CSI fingerprint, the requesting mobile device may be connected to an access point associated with first GAS response message.