Helping people with computers... one answer at a time.
A MAC address can easily be traced for as far as it travels. The problem is a MAC address doesn't travel far enough to be useful.
I know that all computers have a unique MAC address. But how traceable are they? If my laptop gets stolen, and I know my MAC address, can I get back to it if the person stole it gets connected to internet, even after formatting the machine and thinking that it's safe to connect? Seems like this could stop laptop burglaries if that MAC address thing is traceable.
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You're correct ... it could put a big dent in laptop burglaries if MAC addresses were traceable. Or it would at least increase the odds of stolen equipment being recovered.
But they're not. At least, not in any way that could help.
Let's look at why.
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A MAC, for "Media Access Control" address is a unique number that's assigned to every ethernet network interface.
In theory, it's unique anyway. In theory, every network card or network interface should have its own unique MAC address that is different from every other network card on the planet.
There are two problems:
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Occasionally, manufacturers don't ensure that they're unique, so multiple network interfaces can in fact have the same MAC address.
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The MAC address can be set in software in many network interfaces, meaning that whatever the original MAC address, it can be overridden later.
So the uniqueness that we might want to rely ... can't be relied on.
But that isn't really the biggest problem.
The MAC address is used by the network to identify which piece of hardware a packet of information is to be sent to. In other words, it's used only on connections from one piece of networking equipment to the next.
That means that when information leaves your computer it has your computer's MAC address, but when it arrives at your router that MAC address is removed. When the information is sent by your router further upstream to your ISP's router, it contains the MAC address of your router. When it moves from the ISPs router to another router on the internet, it contains the MAC address of the ISPs router.
And so on.
Your MAC address never makes it further than the first piece of networking equipment between you and the internet.
There are various alternative solutions that you might want to look into for stolen laptop recovery. While not all survive a reformat of the machine, many thieves actually try to connect a stolen laptop as-is in order to recover or steal the data thereon as well, at which point these tracing tools kick in.
And, of course, you'll want to make sure that the data on your laptop is secure no matter what.
Article C3635 - January 24, 2009 « »
Leo A. Notenboom has been playing with computers since he
was required to take a programming class in 1976. An 18 year career as a programmer at Microsoft soon followed.
After "retiring" in 2001, Leo started Ask Leo! in 2003 as a place for answers
to common computer and technical questions. More about Leo.
November 4, 2011 12:05 AM
Leo,
The MAC is changed on every router that it goes througg, noy when arrives but when is sending!
just gotta see an IP Packet between two routers.
December 18, 2011 2:20 PM
could say a big corporate company with the right hardware/software access your mac address as so to identify you?
18-Dec-2011
January 20, 2012 10:43 PM
One thing that I believe is an exception to the rule is when one connects to the internet using an ISP's "Hotspot" or Wifi Network (like Xfinity, Optimum Wifi) on the road or some of those "free" connections like the ones in McDonald's, Starbucks, etc. Some of these hotspots require you to have an account and log-in first, while others are free to roam on or give you a time-limited trial. I experimented with the "free" ones (no log-in credentials needed) and realized after going to the same spot several days that my MAC address was totally traceable because obviously the ISP controls their switches and routers (I cleaned all cookies, etc so I know it was MAC-related tracing). If you actually look at the first URL once you start browsing, you will see your MAC address as identifier at the end of the URL, as a way of remembering you the next time you are on their network. Also, the "fine print" disclaimers on these connections (which no one bothers to read) explain that your MAC address is being logged. If you think about it, in theory, if a laptop was stolen and you knew your mac address and someone tried to log on one of these hotspots, the ISP should be able to identify such connection, however I'm assuming that only law-enforcement would be able to obtain such records and as Leo kindly pointed out, equipment manufacturers can't ensure that a MAC is unique...just food for thought...cheers
January 21, 2012 5:10 PM
Hello Leo,
I have a problem with one comment you made in this article. The MAC address of a networking device has nothing to do with the Media Access Control sublayer of the Data Link Layer of the OSI model. The MAC address is an identifier that is put on every networking device that is made. The MAC sublayer on the other hand deals with how data is put on the physical media.
22-Jan-2012
January 26, 2013 4:38 AM
Hi, I have MAC Address of my stolen laptop as well as Service Express code can i trace that stolen laptop by using any tools in online or any web site for know the details of my system working location(portal IDs, gmail ids, facebook, ... etc) that user using my mac id.