A MAC address is a unique identifier or address assigned to a network interface on a device. It helps devices to identify each other when they communicate over a local network, such as a home WiFi network or office network.
The term MAC stands for Media Access Control, and a MAC address is associated with a particular network interface and does not change, unlike an IP address, which can change depending on the network a device joins. For example, a laptop may have different IP addresses on different networks, but it will have one MAC address for its WiFi adapter on all networks.
A MAC address is usually a 48-bit address and is represented as six groups of two hexadecimal characters.
For example:
00:1A:2B:3C:4D:5E
It may also be written using hyphens:
00-1A-2B-3C-4D-5E
The hexadecimal system uses the numbers 0–9 and letters A–F. The first portion of a traditional MAC address may help identify the organization associated with the network hardware, while the remaining portion identifies the particular interface. MAC addresses play an important part in how Ethernet and WiFi networks deliver data to the correct device. Understanding what they are, how they work, and where they are used can also help when configuring a WiFi router or troubleshooting network connectivity.
What Is the Purpose of a MAC Address?
The main purpose of a MAC address is to provide a device’s network interface with a specific identifier on the local network. When devices are communicating on the same local network, the network equipment or router needs to determine where Ethernet frames should be delivered. For instance, you could have your laptop, smartphone, smart TV, and printer connected to the same router. The router or network uses MAC addresses to distinguish between these devices and to the correct destination device when forwarding local network traffic.
Remember that this communication through MAC addresses is different from communication across the internet, where IP addresses are used for routing between networks.
MAC Address vs IP Address
| Feature | MAC Address | IP Address |
|---|---|---|
| Main role | Identifies a network interface on a local network | Identifies a device/interface at the network layer |
| OSI Layer | Layer 2 | Layer 3 |
| Usually associated with | Network interface | Network configuration |
| Can change? | Yes (in special cases) | Yes |
| Used for local frame delivery | Yes | No |
| Assigned by | Manufacturer or operating system configuration | Router, DHCP server, ISP, administrator, etc. |
| Example | 00:1A:2B:3C:4D:5E | 192.168.1.1 |
Can a MAC Address Be Changed?
Yes, in some instances, a MAC address can sometimes be changed or overridden in software. This is commonly referred to as MAC spoofing when an interface is configured to present a different MAC address than its original one.
In other cases, a router or network interface may be configured to clone another MAC address. This is called MAC cloning, and it is usually done when internet service providers associate internet service with a particular device’s MAC address. If a customer replaces their router, MAC cloning could allow the new router to present the previously registered address and gain internet access.
MAC cloning and spoofing should only be performed on equipment and networks that you are legally authorized to configure. Changing a MAC address does not magically change the device’s internet connection speed, and it does not provide access to a WiFi network whose password you do not know.
How to Find Your MAC Address
The exact procedure varies, depending on the device and the operating system.
Windows
- Open Command Prompt and run the following command: ipconfig /all
- Look for Physical Address under the relevant network adapter.
macOS
- Go to System Settings > WiFi > Details.
- The MAC address may be listed as the WiFi address.
Android
- Go to Settings > About Phone > Status.
- Or look under the device’s WiFi/network settings.
The exact menu can vary between Android manufacturers.
iPhone
- Go to Settings > General > About.
- Look for the Wi-Fi Address.