A network, including a first switch, a second switch, and a controller, where a management port of the first switch is coupled to a first forwarding port of the first switch, and a third forwarding port of the first switch is coupled to a fourth forwarding port of the second switch. In a boot phase of the network, the first switch communicates with a Dynamic Host Configuration Protocol (DHCP) server using a preset flow table, and obtains an Internet Protocol (IP) address of the first switch. The controller learns a connection relationship between forwarding ports of the first switch and the second switch using a probe packet and a probe flow table in order to control the first switch and the second switch.