A MAC address is a unique identifier assigned to your network card, and some networks implement MAC address filtering as a method of security. Spoofing a MAC address can be desired for multiple reasons, and it is very easy to spoof your MAC address in Mac OS X 10.4, 10.5, 10.6, and 10.7. For the purpose of this article, we are going to assume you want to spoof your Mac’s wireless MAC address. So without further ado, here’s a 3 step process on how to do it:

 

Retrieving your current MAC address

First, you’re going to want your current wireless MAC address so you can set it back without rebooting. Launch the Terminal and type the following command:

ifconfig en1 | grep ether

You’ll know see something like:

ether 00:12:cb:c6:24:e2

And the values after ‘ether’ makeup your current MAC address. Write this down somewhere so you don’t forget it. If you do, it’s not the end of the world, you’ll just have to reboot to reset it from a change.

Spoofing a MAC address

To spoof your MAC address, you simply set that value returned from ifconfig to another hex value in the format of aa:bb:cc:dd:ee:ff. You can generate a random one if need be.

For this example, we will set our wireless MAC address to 00:e2:e3:e4:e5:e6 by issuing the following command:

sudo ifconfig en1 ether 00:e2:e3:e4:e5:e6

The sudo command will require that you enter your root password to make the change.

Verifying the Spoofed MAC address worked

If you want to check that the spoof worked, type the same command as earlier:

ifconfig en1 | grep ether

Now you will see:

ether 00:e2:e3:e4:e5:e6

Meaning your MAC address is now the value you set it to. If you want to further verify the spoof, simply login to your wireless router and look at the ‘available devices’ (or attached devices) list, and your spoofed MAC address will be part of that list.