The present invention relates to a wireless network, and more particularly, a method (*“and system”?*) which a mobile station discovers a neighbor network in an Internet protocol based wireless network, a network management server for enabling the method, and a method of operating the network management server. A network management server of a wireless network system, the server including: a neighborhood (NH) database maintaining configuration information with respect to at least one neighbor network; a communication interface receiving a request message for capability/configuration information of the neighbor network from a mobile station which is connected via a predetermined access point or a base station; and a database management unit extracting the capability/configuration information of the neighbor network which is included in the request message by referring to the neighborhood database, and controlling a reply message including the capability/configuration information to be transmitted to the mobile station via the communication interface.