Yes, but it’s kinda useless.
You’re correct . . . it could put a big dent in laptop burglaries if MAC addresses were truly traceable. It would at least increase the odds of stolen equipment being recovered.
But they’re not traceable . . . at least not in any way that could help.
Let’s look at why.
Become a Patron of Ask Leo! and go ad-free!
MAC addresses are unique identifiers for each network interface on your device. While they do identify the device, when used in networking they travel only as far as the next device, like your router. That limits the usefulness of MAC addresses for any kind of device location or tracing.
MAC addresses are unique — sort of
A Media Access Control (or MAC1) address is a unique 48-bit number2 assigned to every network interface. If your computer has multiple network interfaces — say both a wired ethernet port and a wireless network adapter — each interface will have its own MAC address.
In theory, it’s unique. In theory, every network card or network interface should have its own unique MAC address, different from every other network card or interface on the planet.
There are three problems:
- Occasionally, manufacturers don’t ensure they’re unique, so multiple network interfaces can have the same MAC address.
- In many network interfaces, the MAC address can be set in software — meaning whatever the original MAC address, it can be changed.
- Some operating systems now randomize the MAC address.
So the uniqueness on which we might want to rely is not 100% reliable.
But that isn’t really the biggest problem.
MAC addresses travel only so far
The MAC address is used by the network to identify which piece of hardware a packet of information is to be sent to. While the IP addresses involved indicate the original source3 and ultimate destination, a MAC address is used only on connections from one piece of networking equipment to the next.
That means when information leaves your computer, it has your computer’s network adapter’s MAC address. But when it arrives at your router, that MAC address is removed. When your router sends the information further upstream to your ISP’s router, it contains the MAC address of your router. When it moves from the ISP’s router to another router on the internet, it contains the MAC address of the ISP’s router.
And so on.
When it comes to data traveling over the network, your MAC address never makes it further than the first piece of networking equipment between you and the internet.
MAC addresses gone wild
MAC addresses, however, have been used for other things.
For example, since MAC addresses are theoretically unique, a MAC address could be used as a unique identifier for tracking the actions being taken by or on a specific computer. (I’m not aware of specific situations where this is done — I suspect other unique identifiers are easier to use — but it also wouldn’t surprise me if a MAC address were used in this way somewhere.)
The MAC addresses of the network adapters on your computer are easily readable by software, and could be used for just about anything . . . except tracking your stolen laptop via its network connection.
Subscribe to Confident Computing! Less frustration and more confidence, solutions, answers, and tips in your inbox every week.
I'll see you there!
Footnotes & References
1: Completely unrelated to Apple –except that like all computers, your Mac’s network adapter has a MAC address. But it’s unrelated to it being a Mac from Apple.
2: Meaning it can have a value between 0 and 281,474,976,710,655.
3: The original source at that time. IP addresses are typically dynamic and often change.