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Can the MAC address of a computer be traced to the serial number of a computer?

I have the MAC address that is trying to break into my wireless router. Knowing the serial number of the computer would possibly help me find the owner. Is this possible?

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9 Answers 9

Not likely.

Part of the MAC address identifies the manufacturer of the device. The rest is defined by that manufacturer. With that, you're narrowing down the possibilities a bit -- for example, you know that it's a wireless device made by Intel.

You're not narrowing it down too much though. Most Windows laptops I've used in the past five years all use Intel made internal wireless cards.

And... it's not too difficult to spoof a MAC address.

If you know the MAC address of the intruder, why not just block it? That won't help you identify the perp (unless somebody complains that he/she can't connect), but it will secure you a bit more.

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the main point here is "spoof a mac address". as long as you can do that even a 'real' serial number has no value ... –  akira Oct 13 '09 at 15:34
    
„Most Windows laptops I've used in the past five years all use Intel made internal wireless cards.” Or Broadcom. –  kinokijuf Jan 29 '12 at 10:05

Just a side note, given the title of the question:

In IPv4, MAC addresses do no propagate all the way over the network (nor the internet). True, the first router will know it (like the wireless router in the question). But further on in the network (on the internet) the MAC address of the requesting computer is no longer visible.

In IPv6, the 64 bit "host" part of the full 128 bit address is often automatically generated from the MAC address of your computer (not your modem/router). Sites like ipv6-test.com will then show the MAC address of your current computer when you're using IPv6, and will try to determine the vendor given the public database of MAC address ranges, as assigned by IEEE. Whether or not the MAC address is used, is configured on your computers (not on the router). See How to avoid exposing my MAC address when using IPv6? for details.

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Was just about to say the same thing! Great minds and all that :) –  mickburkejnr Feb 3 '11 at 16:17
    
@mick, I learned something new today; see How to avoid exposing my MAC address when using IPv6? –  Arjan Feb 9 '11 at 19:21

The computer (or just the network card) could have been purchased off the shelf with cash, which would mean that even if the MAC address was traceable to a particular computer, there would be no way to identify the owner. The ease with which MAC addresses can be spoofed would further invalidate any attempt to identify the owner.

If you just want the problem to go away, switch to using WPA2 on your network. There are more interesting options available as well.

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When purchasing new laptops and similar equipment, I've often seen the MAC address printed on the outside of the box and used as a unique device identifier (e.g., for inventory tracking), so there's a very good chance that at least the retailer the equipment was purchased from would have a record of it. I wouldn't be at all surprised if the manufacturer also knows what warehouse that device was shipped to and the warehouse has a record of which retailer they sent it to. As others have already said, though, none of those records will do you a bit of good without a court order demanding their release.

Another point is that MAC addresses, as a general rule (such as in IPv4, but not in IPv6), do not survive past the first router they encounter, after which the next hop is made using the router's MAC address. You didn't specify whether the person you're complaining about is trying to break in over a wireless connection or over the wired connection to your ISP, but, if it's the latter, you're seeing the MAC for your ISP's router, not the attacker's computer.

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The last paragraph is often not true for IPv6. (And was actually addressed in my answer.) –  Arjan Feb 7 '11 at 13:14
    
@Arjan: True, but "as a general rule" (the qualifier I used), IPv6 isn't being used today. (And I can't even plead ignorance on your having mentioned this, as I had upvoted your answer before adding mine. My fault and I have edited my answer to strike out that assertion.) –  Dave Sherohman Feb 7 '11 at 15:24

Depends on the vendor. I'm sure manufacturers like Dell keep record of which components are in which computer. The first 3 hex chunks of the MAC will indicate the vendor, there is a complete table of them for comparison here (56k beware). I'd suggest for now just using MAC filtering to keep the user in question away from your router.

I'm actually at school right now and the list is spot on, the first 3 parts of my MAC is 00-1A-A0 and it's a Dell.

Can it be traced? more than likely.

Will you be given information from a vendor to help you trace it? probably not.

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I make carrier grade networking equipment for a living. We have no way to track a MAC address to a specific customer, and I highly doubt Dell does either. It gets programmed and stuck in a box on a big pile of boxes.

The easiest way to track this guy down is going to be to let him on your network and capture his traffic using Wireshark until he gives up some personal information. Once you've gathered enough, a nicely crafted welcome page greeting him by name should be enough to get him to leave you alone.

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This is off topic, but are you doing MAC address filtering on your wireless network? If you have a whitelist of addresses that are only the devices that you yourself have authorized to be on the network, then it does prevent people from using it unless they spoof one of your aforementioned authorized devices.

Unfortunately it also makes it a pain when guests come over and want to connect.

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Why is MAC-based authentication insecure? -- superuser.com/questions/19383/… –  Arjan Oct 13 '09 at 15:28
    
Thanks. I'll be reading that. –  Omniwombat Oct 13 '09 at 19:15

Furthermore I don't think that Dell will provide you with the name of the person, just because you tell them your story.

I guess you need some judge to enforce that for you. And for that you have press charges against unknown.

So even if it was possible (which it probably is for large computer companies like Dell or HP), do you really want to go that far.

And then you have to consider all those hundreds of people you build there computer from scratch, or the local computer store who does that for the customer. (Almost all of the desktop PCs also have wireless now - so it doesn't have to be a laptop). Furthermore: my mobile also has wireless.

I guess using a good mechanism like WPA2 should give sufficient security to block him. And that is probably enough for you and much less stressful :).

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Yep. Even if you do know the serial number of the computer with the network adapter, they aren't going to give you a name anyway. –  John T Oct 13 '09 at 15:30

As Doug stated, you could block the specific MAC address, or you can up your security and only ALLOW specific MAC addresses to access your router. This will give you the added security and frustrate the want-to-be intruder.

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Blocking will only annoy the intruder until they spoof another MAC address already connected. See other answers (and associated comments) about the ineffectiveness about MAC filtering as a security measure. –  Doug Harris Oct 13 '09 at 15:39

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