Patent ID: 8832314

Claim:
An information synchronization method between a first local area network device in a first local area network and a second local area network device in a second local area network, comprising: acquiring, by the first local area network, declaration information of the first local area network device in the first local area network, wherein the declaration information is used to declare a state of the first local area network device in the first local area network, and further comprises an allocated private address of the first local area network device in the first local area network; mapping, by the first local area network, the allocated private address of the first local area network device into a corresponding external address according to a preset mapping relation between private addresses and external addresses; and sending, by the first local area network, a notification message carrying the external address of the first local area network device to the second local area network, so as to enable the second local area network to store the external address of the first local area network device and notify the state of the first local area network device to the second local area network device in the second local area network; wherein establishment of the preset mapping relation comprises: acquiring, by the first local area network, an allocated private address in the second local area network; based on the allocated private address of the first local area network device and the allocated private address in the second local area network, determining, by the first local area network, a private address unused by the first local area network and the second local area network as an external address when the allocated private address of the first local area network device is in conflict with the allocated private address in the second local area network; assigning, by the first local area network, the external address to the first local area network device; and establishing, by the first local area network, a mapping relation between the private address and the external address of the first local area network device.