1. An information sharing method between neighboring nodes, comprising the steps of: exchanging a message for information sharing between the neighboring nodes in a lower layer and an upper layer of a network; wherein when a state change in said neighboring nodes in said lower layer is detected, each node determines whether or not to transmit said message for information sharing in said upper layer according to contents of the detected state change in said neighboring nodes, wherein an upper layer protocol part in each node for exchanging the message for sharing information with the neighboring nodes in the upper layer of the node refers to a routing table in a lower layer protocol for exchanging topology information with the neighboring nodes in the lower layer of the network to detect a state change in the neighboring nodes in said lower layer, measures frequency at which said information is updated for each of said information, and when the state change in the neighboring nodes in said lower layer is detected, determines whether or not to transmit said message for information sharing according to a threshold value of a state change set for each information based on update frequency of said information measured for each information to be shared, and according to a standby time set for each information based on update frequency of said information.