What Is a MAC Address?

A media access control (MAC) address uniquely identifies digital devices. In fact, a device can have several MAC addresses because devices need a different address for each network interface. 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. Those digits are separated by hyphens or colons. For example, if you locate your device’s MAC address, it could like 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.

Read more: Information Technology (IT) Terms: A to Z Glossary

What is a MAC address used for?

A MAC address identifies different devices using the same local network like computers, smartphones, gaming consoles, and more. When you go online, the 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 both identify your particular device on a network. 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

MAC addresses offer several advantages:

• 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 authorized devices. The unique identifications can also make troubleshooting easier, as it’s possible to track down the source of a problem using the hardware address. 

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 unauthorized devices and access. 

Related terms

• CPU

• Router

• Command-line interface

• Patch panel

• Firewall

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If you’re interested in learning more about MAC addresses, IP addresses, and more consider the Google IT Support Professional Certificate on Coursera. This beginner-level course, allows you to learn at your pace and helps you acquire essential skills for an entry-level IT job. The Professional Certificate covers topics like technical support fundamentals, operating systems, and system administration.