MAC addresses are usually written in the form of 12 hexadecimal digits. The manufacturer then assigns a unique value for the last 3 bytes, which ensures that every MAC address is globaly unique. Manufacturers agree to give all NICs a MAC address that begins with the assigned OUI. It is a hardware address, which means that it is stored in the firmware of the network card.Įvery network card manufacturer gets a universally unique 3-byte code called the Organizationally Unique Identifier (OUI).
A Media Access Control (MAC) address is a 48-bit (6 bytes) address that is used for communication between two hosts in an Ethernet environment.
