How to find the MAC address of a device

A MAC address is a permanent identifier that is burned into network interface cards (NICs) used in computers as well as other network-connectable devices such as printers, routers, television set-top boxes, and video game systems. Unlike an IP address, a MAC address does not change, and it's a way for devices to identify each other on a network.

MAC address filtering is a relatively strong security measure you can take for your home or office network. By enabling MAC address filtering, any device whose MAC address does not match a MAC address on the list that you specify won't be able to access your network. MAC address filtering is especially useful for wireless networks.

In order to use MAC address filtering, you'll need to know the MAC addresses of all the devices that you want to be able to connect to your network. A MAC address consists of six groups of two characters, and each group is separated by either a colon (:) or a hyphen (-).  The characters can be numerals (from 0 to 9) or letters (from A to F).

For a networked printer or copier, you can typically find the MAC address by printing out a configuration page. On some printers it may be called something different, like an information page or a network settings page.  This page should list all of the device's network configuration settings, including the MAC address. The MAC address may be called physical address, Ethernet address, hardware address, or something else, but you can recognize it by looking for the six two-character sets separated by a colon or hyphen.  (If you're not sure how to print a configuration page from your copier or printer, you can find instructions for many different brands and models here:  http://configpages.blogspot.com/)

Smart phones have MAC addresses as well, but they can be trickier to find.  On an iPhone, the MAC address is labeled as the WiFi Address, and on other smart phones it may be called something similar. Just like with printers, you can recognize the MAC address by its unique format. Some BlackBerries will display the MAC address on the phone's Status screen (under Options); on others it can be found under Manage Connections.

If a device is already connected to your local network, you may be able to find its MAC address by using your router's web interface. Most routers allow you to access their settings by typing the router's IP address (often 192.168.1.1 for a home network) into your web browser and logging in with your username and password. Depending on your router's software, you might be able to view a list of all devices connected to your network, along with each device's MAC address.

If you're running Windows Vista or Windows 7, you can find the MAC address of any device on your network by using the Network Map. In the Network and Sharing Center, click Network Map or View Full Map in the upper right corner, and a visual representation of your network will be shown.  Just hover over any device listed, and you should see it's MAC address.

(Originally published on Helium.com, August 2010)