What Is a MAC Address?

Key takeaways

• A media access control (MAC) address is a unique identifier for digital devices, such as desktops and laptops.

• When performing a MAC address lookup for your device, you’ll typically see it represented by six groups of two hexadecimal digits, such as 00: 9A: CD: 3C: 4D: 5E.

• When looking up the vendor for your MAC address, the first six digits identify the manufacturer; for example, CC: 46: D6 is Cisco.

You can’t change your MAC address because it’s a permanent identifier linked to the physical hardware, but you can spoof it. Discover more about a MAC address, including what it is, what it’s used for, and how it differs from an IP address in this article. Then, if you’re ready to begin developing your skills in IT, enroll in the IBM IT Support Professional Certificate. In as little as three months, you can learn about cloud infrastructure, IT service management, hardware troubleshooting, general networking, and more.

What is a MAC address?

A MAC address uniquely identifies digital devices. In fact, a device can have multiple 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 Wi-Fi 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 be similar to this: 00: 9A: CD: 3C: 4D: 5E.

Can a MAC address tell you what the device is?

Fun fact: The first six digits of the address identify the hardware manufacturer. 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.

What is a media access control (MAC) address used for?

A MAC address identifies devices on the same local network, like computers, smartphones, gaming consoles, and more. When you go online, network protocols use this address at the data link layer to ensure that data packets reach the right destination.

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.

Read more: Network Switches: What Are They and How Do They Work?

What is the MAC address vs. 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 device on that network. You can’t change your MAC address 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, such as local device identification, compatibility with other systems, and efficient communication between devices. Discover more details about these and other benefits:

• 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

• Assists in restricting network access to known devices and spots unauthorized devices attempting to join the network

• Makes diagnosing network problems easier by narrowing down the devices involved.

IT personnel can use MAC addresses to enhance security by only allowing network access to authorized devices. The unique identifiers 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 by switching the MAC address that the network interface reports in the software, without changing the actual hardware. 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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