Systems and methods for secured global LAN

A network device comprising:

• a processor;
• a networking interface configured to communicate with a cloud controller and at least one peer device;
• and
• a storage component preloaded with a public network address associated with the cloud controller and an identifier of the network device, wherein the public address associated with the cloud controller was preloaded in the storage component of the network device when the network device was manufactured;
• the storage component further storing instructions which, when executed by the processor, cause the network device to perform a process including:
• identifying the network device to the cloud controller by sending a registration message including the identifier of the network device to the public network address associated with the cloud controller;
• requesting the private network connection with a peer device to the cloud controller, wherein the request message does not include any identification of the peer device, as the cloud controller identifies the network device and the peer device as devices assigned to a common client account;
• receiving, from the cloud controller, an authorization message including a public network address associated with the peer device, wherein the authorization message includes a pre-shared key generated by the cloud controller based on the identifier of the network device and an identifier of the peer device;
• directly connecting to the peer device based on the authorization message to establish a virtual network among a private network to which the network device belongs and a private network to which the peer device belongs;
• determining, based on assignment records of the cloud controller, that the peer device is originally assigned to a previous account and therefore the peer device is a second-hand device;
• and
• updating, at the cloud controller, the assignment records of the cloud controller so that the second network device is assigned to the account instead of the previous account
• periodically synchronizing, between the cloud controller and the peer device, to update status of the public network address associated with the peer device;
• receiving a status change, from the peer device to the cloud controller, that the peer device obtains a private network address from a router's dynamic host configuration protocol (DHCP) service;
• and
• tracing back packets transmitted from the peer device to identify a mapping relationship between the public network address prior to the status change and the private network address after the status change for the peer device, and storing the mapping relationship in a database of the cloud controller.

A method for establishing a virtual network among a plurality of private networks, comprising:

• transmitting a registration message from a network device to a cloud controller that is associated with a public network address, wherein the public network address associated with the cloud controller was preloaded in the network device when the network device was manufactured, the registration message including a dynamic public network address associated with the network device;
• sending, from the network device to the cloud controller, a request message to establish a virtual network between the network device and a peer device, wherein the request message does not include any identification of the peer device, as the cloud controller identifies the network device and the peer device as devices assigned to a common client account;
• receiving, at the network device from the cloud controller, an authorization message including a public network address associated with the peer device, wherein the authorization message includes a pre-shared key generated by the cloud controller based on a series number of the network device and a series number of the peer device;
• and
• directly connecting to the peer device based on the authorization message to establish the virtual network among a private network to which the network device belongs and a private network to which the peer device belongs;
• wherein the virtual network is a Virtual Private Network (VPN) and wherein the pre-shared key is unique for a pair of the network device and the peer device;
• periodically synchronizing, between the cloud controller and the peer device, to update status of the public network address associated with the peer device;
• receiving a status change, from the peer device to the cloud controller, that the peer device obtains a private network address from a router's dynamic host configuration protocol (DHCP) service;
• and
• tracing back packets transmitted from the peer device to identify a mapping relationship between the public network address prior to the status change and the private network address after the status change for the peer device, and storing the mapping relationship in a database of the cloud controller.