Recover method while monitoring the mac address information

PURPOSE: A method of monitoring and recovering media access control (MAC) address information is provided to solve failure on a local area network (LAN) by recovering a modified MAC address into a predetermined reference MAC address in a network interface card (NIC). CONSTITUTION: An NIC is connected to a LAN through a LAN cable (S100). A unique MAC address is set on the NIC (S200). Modification of the MAC address set on the NIC is monitored and detected (S300). When the MAC address is modified, the modified MAC address is recovered to predetermined reference MAC address information (S400). [Reference numerals] (S100) Step of connecting network interface card (NIC) to local-area network (LAN) via local-area network (LAN) cable; (S200) Step of setting unique media access control (MAC) address on the NIC by electrically connecting with the NIC; (S300) Step of monitoring and detecting modification of the MAC address set on the NIC; (S400) Step of controlling to be recovered to predetermined reference MAC address information, when the MAC address is modified