MAC Address

A Media Access Control address (MAC address), also called physical address, is a unique identifier assigned to network interfaces for communications on the physical network segment. It is a unique identifier assigned to network devices by their manufacturers. It is used at the Data Link Layer of the OSI model to identify devices within a local network.

NIC turns data into an electrical signal that can be transmitted over the network. MAC addresses are used as a network address for most IEEE 802 network technologies, including Ethernet and WiFi.

MAC addresses are most often assigned by the manufacturer of a network interface controller (NIC) and are stored in its hardware, such as the card’s read-only memory or some other firmware mechanism. If assigned by the manufacturer, a MAC address usually encodes the manufacturer’s registered identification number and may be referred to as the burned-in address(BIA).

What really is a MAC Address

A MAC address is a 48-bit binary value expressed as 12 hexadecimal digits (4 bits per hexadecimal digit). It may also be known as an Ethernet hardware address (EHA), hardware address or physical address. It is divided into two parts: the first three bytes represent the manufacturer ID, and the last three bytes represent a unique identifier assigned by the manufacturer.

Example of a MAC address for an Ethernet NIC: 00:0a:95:9d:68:16. Some well-known manufacturers of network adapters or NICs are TPLink, Dell, Belkin, Nortel, Huawei, RLG and Cisco. These manufacturers all place a special number sequence (called the Organizationally Unique Identifier or OUI) in the MAC address that identifies them as the manufacturer.

The OUI is typically right at the front of the address. For example, consider a network adapter with the MAC address “00-14-22-01-23-45”. The OUI for the manufacture of this router is the first three octets – “00-14-22”. Here are the OUI for some well-known manufacturers.

• Dell: 00-14-22
• Nortel: 00-04-DC
• Cisco: 00-40-96
• Huawei: 00-18-82
• ZTE: 00:19:C6
• Alcatel Lucent: 00:1A:F0
• Belkin: 00-30-BD
• Vodafone: 00:24:89
• Qualcomm: 00:24:89
• Samsung: 00:E0:64
• Apple: 00:F4:B9

Characteristics of a Mac Address

• Each MAC address is unique, ensuring that devices on the network can be easily identified and managed.
• MAC addresses are hard-coded into the hardware of a network interface card (NIC) and cannot be changed, except in rare cases where the manufacturer provides a specific tool to do so.
• MAC addresses are used to deliver frames to the destination device within a local network. They are used in conjunction with ARP (Address Resolution Protocol) to resolve IP addresses to MAC addresses for communication on a LAN.

Importance of the MAC Address

MAC addresses aid in Network Identification and are used to identify devices on the same network, making it easier to manage and troubleshoot network issues. They can be used for security measures such as MAC filtering, which restricts access to a network based on approved MAC addresses.

Finding a MAC Address

The guides below would help you know the MAC Address of a device.

Windows

Use the command ipconfig /all in the command prompt to find the MAC address.

MacOS

Go to System Settings, then Network, and then Advanced Settings to find the MAC address.

Unix/Linux

Use the command ifconfig -a or ip link list to find the MAC address

Harmony OS

Open Settings – Tap the Settings icon on your Harmony OS device. – Scroll down and select Status. View Wi-Fi MAC Address – In the Status menu, you will see the Wi-Fi MAC address. This is the device MAC address of your Harmony OS device.

MAC Cloning

MAC cloning is the process of changing a device’s MAC address to match the MAC address of another device, often used to bypass network restrictions or to connect to a network that requires a specific MAC address.

MAC addresses make it easy to identify and manage devices on a network and are widely supported and compatible with many systems. In rare cases, MAC addresses can collide, causing network disruptions and making it difficult to identify and manage devices. In whole, MAC address is a unique identifier assigned to network devices by their manufacturers. It is used to identify devices within a local network and is essential for network communication and management. The next time you go shopping, check the MAC address as part of your verification.

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