A MAC address is a 6-byte address that allows a NIC to be uniquely identified on the network. The first three bytes (00:D0:59) identify the manufacturer of the card; The last three bytes (09:07:51) are the Universal LAN MAC address, which makes the interface unique.
As data is passed up or down through the OSI model structure, headers are added (going down) or removed (going up) at each layer—a process called encapsulation (added) or decapsulation (removed).
|OSI Layer||Major Functions|
|Application||Provides access to the network for applications and certain end-user ...|