A method for link setup includes sending a first authentication message including a user identifier to an access point (AP). A second authentication message sent by the AP according to the user identifier is received and includes an EAP method request message and a ANonce of the AP. A first PTK is generated according to the ANonce, an SNonce, and a first MSK. A third authentication message is sent to the AP. The third authentication message includes an EAP method response message, the SNonce, and a first MIC that is generated according to the first PTK. A fourth authentication message is sent by the AP when it authenticates, according to a second PTK, that the first MIC is correct. The fourth authentication message includes an EAP-Success message, configuration information configured by the AP for the terminal, and a second MIC. The second MIC is authenticated according to the first PTK.