A MAC address is an identification code. It’s used to define physical devices in a network, so that the network knows exactly which devices it is in communication with. There are plenty of practical reasons to have MAC addresses. It helps prevent criminals from imitating devices they don’t actually have, and is useful in creating a number of network filters for protection or organization.
Typically a MAC address remains unchanged forever, defining a specific network interface card for as long as it lasts (that’s sort of the point). However, this ID code can be changed, and we’re going to discuss how – and why – to do it.
Let’s talk about spoofing
Changing your MAC address, especially when doing it frequently, is called spoofing. The word “spoofing” does have a negative connotation – after all, it makes it sound like you’re trying to fool someone. However, there are plenty of worthwhile reasons to change your MAC address. Many people do it for privacy. Switching MAC addresses regularly makes it very difficult for networks to track your device and how you are using it. If you are using time-out Wi-Fi that only gives you, say, an hour of free Wi-Fi access (some businesses, like airports, do this), you can keep getting free Wi-Fi by switching your address from time to time.
However, there are also some downsides to spoofing. The big one is that companies often have security filters in place that only allow certain employee devices to access their networks. If you spoof an address, the network will no longer recognize you. This is why it’s important to record your original MAC address before you change it! It’s also why spoofing a work device is often a bad idea – save this trick for your personal, non-BYOD computers if possible.