Media Access Control addresses play a crucial role in the functioning of local area networks (LANs) and other networked devices. These addresses are used to uniquely identify network interfaces, such as network interface cards (NICs) in computers and other devices that connect to a network.
They function at the:
The data link layer of the TCP/IP Model
The link layer (layer 2) of the OSI Model
What is the purpose of a MAC address?
MAC Address structure
Example : 00:1A:2B:3C:4D:5E
A MAC address is typically a 48-bit or 64-bit binary number, represented in a hexadecimal format. It is commonly written as six pairs of two hexadecimal digits separated by colons or hyphens, such as "00:1A:2B:3C:4D:5E" or "00-1A-2B-3C-4D-5E."
Which of the following is the correct representation of a MAC address?
MAC Address Assignment
MAC addresses are assigned by the manufacturer of the network interface card.
The first half of the MAC address (24 bits) is known as the OUI (Organizationally Unique Identifier), which is assigned to the manufacturer by the IEEE (Institute of Electrical and Electronics Engineers).
The second half is assigned by the manufacturer to uniquely identify each NIC they produce.
The first three groups in a MAC address represent the of the device.
MAC address spoofing
MAC address spoofing is a technique used to change or falsify the Media Access Control (MAC) address of a network interface. This process involves modifying the MAC address of a network adapter, such as a network card or a wireless interface, to impersonate another MAC address.
This can be used for legitimate & malicious purposes:
Increased privacy
Bypassing network controls (such as 15 minute free internet access in airports)
Performing Man In The Middle (MITM) attacks on routers or other devices.
the mac address of a device can make it difficult to track the origin of a network attack.
