Based on a method provided in the embodiments of the present invention, a control plane device sends an advertisement message to a forwarding plane device, and the forwarding plane device buffers the advertisement message and sends the buffered advertisement message to a host, thereby avoiding excessive signaling interactions between the control plane device and the forwarding plane device, so as to improve implementation efficiency of the control plane device and the forwarding plane device, and improve performance of the control plane device and the forwarding plane device.