A first request is sent from a station to an access point. The station receives a first response from the access point that includes a first sequence number, and stores the first sequence number. The station sends a second request to the access point and sets a waiting period for receiving a response from the access point. The station receives a second response from the access point and a third response from a second access point during the waiting period. The second response includes a second sequence number and the third response includes a third sequence number. The station determines that the second response is a legitimate response by comparing the second and third sequence numbers to the first sequence number.