<Li> ZigBee / 802.15. 4 / 6LoWPAN wireless personal - area networks </Li> <P> On broadcast networks, such as Ethernet, the MAC address is expected to uniquely identify each node on that segment and allows frames to be marked for specific hosts . It thus forms the basis of most of the link layer (OSI Layer 2) networking upon which upper layer protocols rely to produce complex, functioning networks . </P> <P> Although intended to be a permanent and globally unique identification, it is possible to change the MAC address on most modern hardware . Changing MAC addresses is necessary in network virtualization . It can also be used in the process of exploiting security vulnerabilities . This is called MAC spoofing . </P> <P> In IP networks, the MAC address of an interface can be queried given the IP address using the Address Resolution Protocol (ARP) for Internet Protocol Version 4 (IPv4) or the Neighbor Discovery Protocol (NDP) for IPv6 . In this way, ARP or NDP is used to relate IP addresses (OSI layer 3) to Ethernet MAC addresses (OSI layer 2). </P>

What the hexadecimal code in a mac address represents