What Is a MAC Address?

A media access control (MAC) address uniquely identifies digital devices. A device can have several MAC addresses because each network interface needs a different address. For example, although desktops typically only have one MAC address, laptops often have two. Laptops usually have integrated WiFi in addition to Ethernet ports, giving system configurations two distinct MAC addresses. 

You’ll typically see a MAC address represented by six groups of two hexadecimal digits. Hyphens or colons separate those digits. For example, if you locate your device’s MAC address, it could be similar to this: 00:9A:CD:3C:4D:5E.

Fun fact: The first six digits in the address identify the manufacturer of the hardware. For example, you might see:

- CC:46:D6 for Cisco 

- 3C:5A:B4 for Google, Inc.

- 3C:D9:2B for Hewlett Packard

- 00:9A:CD for Huawei Technologies Co., Ltd.h2

What is a MAC address used for?

A MAC address identifies different devices using the same local network, such as computers, smartphones, gaming consoles, and more. When you go online, networking protocols use this address at the data link layer to ensure data packets go to the right place. 

Including the MAC address in the packet header allows routers and switches to route the data correctly without you having to do anything on your end.

How is a MAC address different from an IP address?

Your MAC address and internet protocol (IP) address identify your particular network device. Yet the MAC address routes data to your devices on that network. You can’t change your MAC addresses because it’s a permanent identifier linked to the physical hardware. 

On the other hand, an IP address lets you route data to outside networks. Plus, it can change. For instance, if you trade in your smartphone, the new one could use the same IP address when you set it up. Or, if you change your network setup, you might have a different IP address for the same device.

Benefits of MAC addresses

Identifying devices is just one of the advantages MAC addresses have to offer. Benefits include the following: 

• It makes identifying and managing local network devices easy 

• Widely used and supported, making MAC addresses compatible with many systems 

• Helps streamline device communication on a network to allow for efficient communication without additional routing or addressing at the network layer

IT personnel can use MAC addresses to enhance security by only allowing network access to authorised devices. The unique identifications can also make troubleshooting easier, as the hardware address can be used to track down the source of a problem. 

Keep in mind. Because manufacturers assign MAC addresses at the time of the device’s manufacture, you can’t easily change them. At the same time, MAC addresses lack encryption, which opens the door to someone intercepting them. It’s possible for someone to spoof MAC addresses relatively easily. This vulnerability can leave networks vulnerable to unauthorised devices and access. 

Related terms

• CPU

• Router

• Command-line interface

• Patch panel

• Firewall

Learn more with Coursera 

A media access control (MAC) address refers to permanent identifiers linked to physical hardware. They handle routing data on local networks and ensure data packets are delivered to the right place.

Learn more about MAC addresses and IP addresses when you complete the Google IT Support Professional Certificate on Coursera. This beginner-level course allows you to learn quickly and helps you acquire essential skills for an entry-level IT job. The Professional Certificate covers technical support fundamentals, operating systems, and administration.