Описание тега mac-address
A Media Access Control address (MAC address) is a unique identifier assigned to network interfaces for communications on the physical network segment.
A MAC address is a 48 bit identifier assigned to every device connected to a network. They are normally written as 6 octets displayed as hexadecimal digits, for example 08:01:27:0E:25:B8. The first 3 octets identify the manufacturer, the last 3 are to ensure that each address for that manufacturer is unique.
MAC addresses are used for numerous network technologies and most IEEE 802 network technologies, including Ethernet. Logically, MAC addresses are used in the Media Access Control protocol sub-layer of the OSI reference model.