What a Mac address is and why you need it

A MAC address (Media Access Control address) is a unique identifier assigned to every device that connects to a network — your laptop, phone, printer, or smart TV. It looks like a string of six pairs of numbers and letters, such as 00:1A:2B:3C:4D:5E. Your router uses MAC addresses to recognize which devices are on your network and decide what traffic to allow or block.

When you set up network security rules — like restricting which devices can connect to your Wi-Fi, or creating a guest network that blocks access to your main computers — you often need to provide the MAC address of the device you're controlling. Some routers also use MAC filtering to allow only specific devices to connect, which requires you to know the address beforehand.

The process differs slightly depending on whether you're using Windows, macOS, or Linux, but in each case you're looking for the same piece of information in a slightly different place.

Key Takeaways

  • Your MAC address is a unique identifier that your router uses to recognize your device on the network.
  • On Windows, open Command Prompt and type ipconfig /all to find the "Physical Address" listed next to your network adapter.
  • On macOS, go to System Settings, select Network, choose your connection, and click Advanced to find the MAC address under Wi-Fi or Ethernet.
  • On Linux, open a terminal and type ip link show or ifconfig to locate the address labeled "link/ether" or "HWaddr".
  • Write down your MAC address before configuring router security settings, since you'll need it to add your device to an allowed list.

Finding your MAC address on Windows

The quickest way on Windows is through Command Prompt. Press the Windows key, type cmd, and open Command Prompt. Type ipconfig /all and press Enter. A list of all your network adapters will appear.

Look for the adapter you use to connect — either "Ethernet" if you're plugged in with a cable, or "Wireless LAN adapter" if you're on Wi-Fi. Under that adapter's name, find the line labeled Physical Address. That's your MAC address. It will be formatted as six pairs of characters separated by hyphens, like A4-B2-8C-1D-9E-F3.

If you have multiple network adapters listed (which is common), make sure you're copying the address from the one you actually use. If you're unsure which is active, look for the one with an "IPv4 Address" listed — that's the one currently connected to your network.

Finding your MAC address on macOS

On macOS, open System Settings and click Network in the left sidebar. Select the connection type you use — either Wi-Fi or Ethernet — from the list on the left.

Once you've selected your connection, click the Advanced button in the lower right corner. A new window will open. At the top, you'll see a tab for either Wi-Fi or Ethernet depending on what you selected. Click that tab, and you'll see your MAC Address listed clearly on the screen. Copy it exactly as shown.

If you're on an older version of macOS, the path may be slightly different — you might find it under System Preferences instead of System Settings — but the general steps are the same: Network settings, your connection type, Advanced, then look for the MAC address field.

Finding your MAC address on Linux

On Linux, open a terminal window. Type ip link show and press Enter. Your output will list all network interfaces on your machine. Look for the one you use — typically eth0 for Ethernet or wlan0 for Wi-Fi.

Next to the interface name, you'll see a line starting with link/ether followed by your MAC address. It will look like link/ether a4:b2:8c:1d:9e:f3. The address itself is the part after link/ether.

If ip link show doesn't work on your system, try ifconfig instead. Look for the line labeled HWaddr (hardware address) — that's your MAC address. Both commands show the same information; they're just different ways to access it.

What to do with your MAC address once you have it

Once you've found your MAC address, write it down or save it somewhere you can find it later. When you log into your router to set up security rules — like enabling MAC filtering or creating device-specific access controls — you'll paste this address into the router's configuration page.

Different routers have different interfaces, but the process is usually: log into your router's admin page (often 192.168.1.1 or 192.168.0.1 in your browser), navigate to security or device settings, and add your MAC address to the allowed list. Your router's manual or support page will show you the exact steps for your model.

Keep in mind that if you ever replace your network card or buy a new device, that device will have a different MAC address. You'll need to find its address and add it to your router's list separately.

Troubleshooting if you can't find your MAC address

If you're following the steps above and not seeing a clear MAC address field, check that you're looking at the right network adapter. On Windows, make sure the adapter shows an IPv4 address — if it doesn't, it's not currently connected. On macOS, confirm you clicked Advanced after selecting your connection type. On Linux, double-check that you're looking at the right interface name.

If you're still stuck, another option is to check your router itself. Log into your router's admin page and look for a list of connected devices. Most routers display the MAC address of every device currently on the network, so you can identify your computer by its name and read the address from there. This method works on any operating system.

Frequently Asked Questions

Can I change my MAC address?

Yes, but it's rarely necessary. On Windows, macOS, and Linux you can spoof your MAC address temporarily using system settings or terminal commands, but the change resets when you restart. Permanently changing it requires modifying your network driver, which is complex and usually not worth doing unless you're troubleshooting a specific network problem.

Do I need a different MAC address for Wi-Fi and Ethernet?

Yes. If your device has both a Wi-Fi adapter and an Ethernet port, each one has its own MAC address. When you set up router rules, you need to add the address for whichever connection type you actually use. If you sometimes use Wi-Fi and sometimes use Ethernet, you may need to add both addresses to your router's allowed list.

What if my MAC address keeps changing?

Some devices randomize their MAC address for privacy reasons — this is common on newer phones and laptops. If you're trying to set up router rules and the address keeps changing, check your device's privacy settings. On Windows, look for "Random hardware addresses" in Wi-Fi settings. On macOS, check the Wi-Fi privacy option in Network settings. Disabling this feature will keep your MAC address stable.

Is my MAC address the same as my IP address?

No. Your IP address is assigned by your router and changes over time; your MAC address is built into your network hardware and stays the same. Your router uses the MAC address to identify your device on the local network, and the IP address to route traffic to it. Both are needed for your device to communicate on a network.