Help! I've been scammed. Is it possible to trace a computer via the MAC address??

[her209]

I tend to think that more than 281,474,976,710,656 interfaces have been manufactured.

280 trillion... I don't think so. I do think its possible for a NIC manufacturer to exhaust its allocation of MAC addresses though.

 

[Nuwave]

MAC addresses are not unique. They don't need to be.

Do you really think that a 48 bit number is enough to uniquely identify every single Ethernet interface ever made? I tend to think that more than 281,474,976,710,656 interfaces have been manufactured.

MAC addresses only need to be unique in so far as being unique on a single layer 2 broadcast domain. Outside of that, you could have two identical MACs one hop away from each other and there wouldn't be a problem.

If you take into account that Manufacturers have to register the first 24 bits of a mac address, then they only need to manufacture 16,777,216. I'm sure companies have ran out of addresses before they could get another block.

And again what others have said, only MAC address within a broadcast domain are required to be unique to work properly.

280 trillion... I don't think so.

I don't think that is unreasonable. Modern laptops will have at least 2 or 3 MAC addresses. (Wireless NIC, Multiple Wired NICs). Smartphones with WiFi have a MAC. Networking equipment manufactures may choose to have a unique mac on each edge port. Don't forget all the stuff that has been thrown out since the dawn of ethernet. The list really goes on and on. It's not hard to believe that 281 trillion interfaces have been made.

 

[Emulex]

you do know that snowleopard phones home every time you connect - google locationd and submitdiag.

Apple loves to know where you are.

 

[Glob]

It is really not up for debate. It is a known fact that MAC addresses are issued as globally unique, but that on some hardware, they are user-configurable. Until you can present some evidence to the contrary, please stop speculating over how many Ethernet interfaces have been created in the world, etc.

 

[alkemyst]

What more evidence to you want than knowing of at least 6 times this issue has come up?

My brother is a CCIE for one of the largest companies in the world doing large scale deployments regularly. My friends that encountered this also work in large scale deployments.

Large scale being 10,000+ devices at a time.

Whether it's do to a bad cloning, database screw up or whatever; they have encountered identical BURNED IN MACS on their networks and have had to correct it.

So according your little text book, yeah...unique. According to the real world, like much of what you will find in those texts....very different.

 

[Glob]

alkemyst, all I can determine at this point is that you're full of shit. Your anecdotes mean nothing to me.

 

[Damn Dirty Ape]

Yah - not really sure what he was thinking...


=|

any smart store will have a counterfeit pen, some protection. what an idiot telling him to knowingly commit a crime.

 

[alkemyst]

alkemyst, all I can determine at this point is that you're full of shit. Your anecdotes mean nothing to me.

So I doubt if I got a CCIE to post you'd buy it either.

Good luck working the help desk.

 

[Glob]

You mean you'd create a new account as your "CCIE friend" to disprove me with anecdotes again? The fact that you can't produce any sort of evidence to support your claim tells the entire story.

Here kids, read the Wikipedia article, and pay special attention to the "Address details" section.

 

[jlazzaro]

You mean you'd create a new account as your "CCIE friend" to disprove me with anecdotes again? The fact that you can't produce any sort of evidence to support your claim tells the entire story.

Here kids, read the Wikipedia article, and pay special attention to the "Address details" section.

yes in theory every MAC address globally SHOULD be unique. you cant honestly think that for every Ethernet interface that has ever been produced there has NEVER been a single duplicate BIA. manufacturing errors, improper tracking, etc...shit happens.

i have never seen it in production, but probability > you. should it happen? no. has it ever happened? absolutely.

 

[alkemyst]

You mean you'd create a new account as your "CCIE friend" to disprove me with anecdotes again? The fact that you can't produce any sort of evidence to support your claim tells the entire story.

Here kids, read the Wikipedia article, and pay special attention to the "Address details" section.

Hmm, people that know me here know my brother is a CCIE in Routing and Switching, this past week he passed the Storage LAB to become one of 34 for the in world to have R&S and Storage and only one of about 100 or so with Storage at all.

You need realize in many things the textbook answer is not the way it really plays out in the real world.

It really doesn't matter to me what you do believe. In this case anecdotal evidence is 100% valid coming from CCIE's even more so. I am just a CCNA, but if a CCIE tells me the way it really works, I am going with there statement.

 

[alkemyst]

I spent the extra 5 minutes and present you with this:

http://www.intel.com/support/motherboards/server/stl2/sb/cs-007538.htm

 

[Dark Shroud]

You should turn it over the Feds or locals and try to get the person who counterfeited the money.

In the U.S.A. the Feds (FBI) will not get involved unless the scam is $5000.00 or more. Or very specific events happened.

Police report filed yet? I'm assuming they called the police when you presented the fake bills at the bank?

That depends on the bank and type of incident. Counterfeit currency actually falls into the jurisdiction of the Secret Service.

To the OP, please file a police report if you haven't already. And get letter from the bank about the bills being fake to give a copy of to the police. Keep the original for yourself. Make sure you do this in case this person has pulled this scam before so police can track this person. If he's caught you could help put him away by doing this.

If you still have the info on the Mac you might be able to talk to Apple about traceing/locating it depending on circumstances.

It's already been said but money orders or specificly certified bank checks are what you should only take for high ticket items in the future if you don't want to use Paypal or Google checkout.

 

[alkemyst]

western union in reality if you want safety.

USPS money orders as well as certified bank checks have been counterfeited.

 

[Glob]

alkemyst, although I know this is only going to generate a new series of attempts to defend your incorrect understanding of the subject, here is the very first part of the description of the problem Intel gives in the PDF (if you even read it):

Every network adapter must have a unique 6-byte hardware address, usually called the "Medium Access Control" (MAC address). It consists of two parts; a 3-byte manufacturer ID called Organizational Unique Identifier (or OUI) and a unique 3-byte network adapter ID number assigned by the manufacturer.

So what you need to take away from this is that duplicate MACs being burned into equipment is a MISTAKE, and Intel admitted as much and instructed those who bought boards with duplicate MACs to call customer service, probably so that the boards could either be returned for replacement, or if programmable, have the MAC overwritten with a new assignment.

I really don't care who you say says MACs are not globally unique, they absolutely are. If duplicate MACs are burned into equipment from the factory, it is a MISTAKE. It is NOT normal, and it should NOT happen. Someone finding duplicate MACs on a LAN (without users changing their MACs) would be a pretty extreme coincidence warranting further investigation of any hardware bought from the manufacturer who duplicated those addresses.

So let's go back to your original statement:

Mac Addresses aren't unique.

You are wrong. Accept it, learn from it, and move on.

 

[alkemyst]

WTF?

Like I said they are not unique in the real world. Whether unintentional or not it does indeed happen.

Those that buy major install gear hit these time to time.

Now you are just flailing.

lolz.

I think printer #14 needs toner.

 

[slashbinslashbash]

Ok, geeze, you guys are both right and at this point are just talking past each other due to ego and semantics.

It happens occasionally in the real world, but it should not happen theoretically, and even given that some tiny percentage of errors happen, it would seem to a naive observer that there is a vanishingly small chance that 2 identical MACs would show up on the same network, and therefore finding such duplicates should be exceedingly rare (collisions in a space of 2^48.... I'd think that the chances of getting killed by a meteor would be greater).

However, given one of the known example failures (the Intel boards with the same MACs), on the contrary it seems very likely that such examples will occur, since the random events are not sufficiently isolated from each other. If a motherboard has two NICs, in almost all situations those NICs will be on the same network. And if a company placed an order for some number of servers, chances are the motherboards would be from the same batch and therefore all have the same problem, and chances are they will all go on the same network.

There are different levels of truth depending on how simplified you want to make things -- and most everyday speech is quite simplified and relies on a generally agreed common meaning for the words used. The statement "Women have female genitalia" is true as a general rule, and if you made that statement in public, 99.9% of people would not disagree with it. But there are extremely rare exceptions where people are hermaphrodites or in some other way nonconforming to this rule. That doesn't mean the rule is false per se, but just that it's insufficiently specific to account for all possibilities. To be 100% correct, you'd have to have a significantly longer statement that included detailed definitions for the terms "women" and "female genitalia". Most people are not accustomed to speaking in such absolute terms.

 

[alkemyst]

no ego involved here. I simply stated its happened the other dude didn't believe it.

I never stated that MACs should not be unique. Just that in the real world they simply are not always.

I know of about 6 times this happened.

To me that's enough to know it's not absolute. I have never encountered a duplicate MAC personally, I have met people sexually that don't follow the biology book.

 

[zagood]

I have met people sexually that don't follow the biology book.

For posterity.

 

[alkemyst]

For posterity.

i'd have no problem repeating it.

 

[mvbighead]

Mac Addresses aren't unique. It's not totally uncommon in huge rollouts to have two devices share the same MAC, hence why almost all modern devices allow the user to reassign a MAC.

To me, your first statement kills your argument that you were just proving the point of the mistakes and such.

Your Statement - It's not totally uncommon in huge rollouts to have two devices share the same MAC, hence why almost all modern devices allow the user to reassign a MAC.

This is complete and utter bull shit. It is absolutely uncommon in huge roll-outs for a device to share a common MAC. If it does, it is generally an error on the part of the manufacturer. You've "heard" of 6, so what does that tell you? And based on those 6, I would be willing to bet they were a flaw either from a manufacturing standpoint, or someone supplied a MAC that was not unique within their environment (either to a VM or to a NIC that supported such changes).

Your argument is essentially the same as someone saying that VIN numbers on vehicles are unique. You would argue that they are not because you've heard of a case where two were found to be not unique, when nearly everyone knows that a VIN is unique to each car.

I guess to stop the BS-ing, lets say it this way:

MAC address are intended to be unique. It is extremely rare to find a case where a MAC address is assigned to two separate pieces of hardware.

Is that fair to say?

 

[alkemyst]

i never said it was common. so fuck you.

 

[sygyzy]

Whoa, this really got heated. Why are you guys getting all upset? I think it's safe to say that the idea of MACS is they SHOULD be unique but shit happens. I believe Alkemyst when he says he's come across duplicate MAC addresses but that's clearly not part of the design.

 

[xCxStylex]

Whoa, this really got heated. Why are you guys getting all upset?

E thugs don't step down. Both are right and both are wrong, but neither will accept that

MVbighead 2 posts above sums it up best.

quote -->
"MAC address are ***intended*** to be unique. It is extremely rare to find a case where a MAC address is assigned to two separate pieces of hardware."

This thread was still interesting to me because I always believed the textbook lesson that manufacturer burned in mac IDs were unique, but obviously, things and ppl can fuck up, even intel.

 

[mvbighead]

i never said it was common. so fuck you.

You said it was "not totally uncommon." That's BS. It is very uncommon.

Do I need to provide a definition of common? You're playing this game as if MAC addresses aren't intended to be unique... they are, very much so. Finding duplicate MACs on physical devices is very, very uncommon. <- this is exactly the opposite of what you said, and that is what caused the other guy to enter this debate with you.

And... so fuck you?