MAC Address

The MAC address is the permanent, physical identity of a network device. It is assigned to the network interface card (NIC) at the time of manufacture and never changes.

MAC stands for Media Access Control. It is also called the physical address or hardware address. Every NIC has a unique MAC address engraved on it during production, making it a permanent identifier. Because of this, the machine on which the NIC is installed can be physically identified on a network using its MAC address.

Each MAC address is a 12-digit hexadecimal number (48 bits in length). It is divided into two halves of six digits each (24 bits per half):

• The first six digits (24 bits) contain the manufacturer's ID, known as the Organisational Unique Identifier (OUI). This identifies the company that made the NIC.
• The last six digits (24 bits) represent the serial number assigned to that specific card by the manufacturer. …