Sunday, January 19, 2014

How to spoof MAC address on WiFi (airport) interface

I was stuck between the planes this weekend, for a long time.

In airports there are some free WiFi networks that allow you to surf Internet for free half an hour (hello Munich airport) or a bit more (hello Frankfurt airport). Once you have used all your free time, if you try to register again, you will be kicked out. That is because the system remembers your MAC address and does not let you in for free anymore. Luckily, with Apple computers, there is a way around this issue.

First, you need to check which interface is used for WiFi. Run ifconfig on terminal window to see which one is connected. Usually it is en0 or en1.

Once you know, thank, you need to do the following:

1. disassociate airport with the following command:

sudo /System/Library/PrivateFrameworks/Apple80211.framework/Versions/Current/Resources/airport -z

On this step you will be disconnected from WiFI

2. spoof the MAC address:

sudo ifconfig en1 ether 00:11:22:33:44:55

Now you are ready to re-connect to WiFi again, with a new MAC address. Remember, this does not survive reboot.

Happy surfing