What is a MAC Address and How It Relates to Your Anonymity

Reading materials online about MAC addresses, you can find many claims that the MAC address does not affect anonymity, that it cannot be used to identify a person, track their activity, or determine their location...

These are all myths, and I will try to debunk them, but let's start with the theory. If you read my publications, particularly the chapter on VPN, you know well that information exchange on the internet occurs thanks to IP addresses.

Your Wi-Fi router has an IP address, from which it sends data to the IP address of the website's server, and the site returns a response to the router's IP address. Next, the Wi-Fi router needs to exchange data with the devices connected to it, but how does it do that?

Imagine that a packet of information was sent from the website's server and reached the router via a fiber optic cable – how should the router understand which device to forward it to? How does the router differentiate between connected devices?

This is where the MAC address comes into play – a unique identifier for each device that has access to the network. It consists of six pairs of letters/numbers (a six-byte number), where information about the manufacturer (the first three most significant bytes) and the model of the network device is encoded. You can determine the manufacturer of a device by its MAC address, for example, on this website. The MAC address is also called a physical address, as it is hardcoded into the device itself, rather than being assigned virtually like an IP address.


We explained how to find your MAC address in this chapter.

To be honest, this is a very simplified model that will not withstand criticism from colleagues, but it perfectly reveals the role of the MAC address for the uninitiated user. We will delve deeper into the workings of the Wi-Fi router in the chapter dedicated to Wi-Fi.

So, all devices that connect to the network have a MAC address, but beyond the router, it is not transmitted, as data exchange on the Internet occurs based on IP addresses. Right, you might be wondering: what is the danger of the MAC address then?

The danger is that when the Wi-Fi module is turned on, any of your devices, whether it be a laptop, tablet, or phone, reveals its MAC address to anyone who wants to obtain it. This is publicly available information that, unfortunately, cannot be hidden without giving up the use of the Wi-Fi module in your device.