A router including a memory having instructions stored thereon; and a processor configured to execute the instructions stored on the memory to cause the router to perform at least the following: acquiring a private network data packet from a private network, and attaching identification information to the private network data packet, the identification information indicating via which port of a plurality of ports of the router the private network data packet is acquired; determining whether a bridge mode is set for the port indicated by the identification information of the private network data packet; in response to the determining that the bridge mode is set for the port indicated by the identification information of a first private network data packet acquired, assigning a public network IP address to the first private network data packet; and transmitting the first private network data packet by using the public network IP address.