IP over Ethernet is one of the world's most widely used network structure; however, ARP Spoofing attacks still remain as a serious security threat on the local area network. Despite the seriousness, there is no protective mechanism (or system) that can effectively protect against ARP Spoofing attacks available yet. This paper will propose an ARP query process that corresponds with the current IP/MAC mapping correlations based upon the existing ARP protocol and the "Direct Communication" characteristic of the LAN, which can effectively protect against ARP Spoofing attacks without an increase of investments in personnel and equipments or change of network structures