MAC Address (Media Access Control Address)
A MAC address is a unique physical identifier assigned to a network device at the hardware level (Data Link Layer of the OSI model). It is used for data transmission within a local network and allows precise identification of each device connected to an Ethernet or Wi-Fi network.
How It Works
Every network device — such as a computer, router, smartphone, or printer — has its own MAC address embedded in its network interface card (NIC). The address consists of 48 bits and is usually represented in hexadecimal format, for example: 00:1A:2B:3C:4D:5E.
When transmitting data within a LAN, devices use MAC addresses to deliver frames. A network switch determines which port to forward a frame to by referencing the recipient’s MAC address.
Applications
MAC addresses are used in local networks for frame routing and device identification. In network settings, they help control access, manage device connections, and create whitelists. In both corporate and home environments, MAC addresses are also used for DHCP binding, linking specific IP addresses to particular devices.
Advantages
- Unique and permanent hardware identifier.
- Enables connection control and access filtering.
- Simplifies network security configuration.
- Compatible with all Ethernet and Wi-Fi standards.
Example
A network administrator can configure a router to allow network access only for devices with specific MAC addresses, enhancing security and preventing unauthorized connections.
Frequently Asked Questions
A MAC address is a permanent hardware identifier, while an IP address is assigned dynamically to enable communication over the Internet or between networks.
Yes, most devices allow temporary software-based changes to the MAC address, but it usually reverts to the factory value after reboot.
It can be viewed in network settings, in the network adapter’s properties, or using commands such as ipconfig /all (Windows) or ifconfig (Linux/macOS).
A router uses MAC addresses to deliver data frames to the correct devices within a LAN and to apply access control or filtering rules for network security.
