# Faking a MAC adress



## curly08 (Feb 21, 2005)

Hi all-

Is there a way to fake a MAC address? I'm not going to do anything bad or illegal, I just need to reregister a computer at school, and the only way of doing this is by "showing" showing the network a new MAC adress.  Thanks!


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## scruffy (Feb 22, 2005)

I think there is a way of doing it, but it takes recompiling the kernel from source.  You're probably better off asking the school admins how to re-register the computer...


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## Zammy-Sam (Feb 22, 2005)

I heard of apps doing this and I know some of my "friends" use them. But somehow I don't like to share it, since it could be used for hacking into other filtered / protected networks.
Anyway, welcome to the forum.


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## curly08 (Feb 22, 2005)

Zammy-Sam,

Is there a way I can contact you privately? I promise that hacking is not my intention.

David


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## bobw (Feb 22, 2005)

Click on Zammy's Orange name to Send Private message.


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## Zammy-Sam (Feb 22, 2005)

Curly08,
although I didn't yet receive a pm, I cannot tell you the apps name. First of all, I don't know them but I will need to ask. Second, I don't know you. If you were a friend to me like Bob, I would surely trust you when you say you won't use it for hacking. You could easily ask the network admins to fix your login with the new mac address but yet you prefer to use hacking software. Sorry, but this doesn't make sense to me.
I hope you understand..


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## Mephisto (Feb 22, 2005)

Not that it matters but changing your MAC in and of itself is not particularly useful when hacking.  It is only useful in conjunction with other techniques that anyone who needs to ask about how to change the MAC would not know or if they did it is likely they would botch the hacking attempt.

Put simply it requires a patch to the kernel as Scruffy mentioned.  This is true for almost all BSD based kernels.  If you need to ask where to find it the hack is probably unwise for you to attempt.  In Linux and Windows it is easier, but we are not discussing either of these platforms.  

Please do yourself a favor and just contact your administrator.  If you did something that makes you afraid to contact your administrator then I respectfully submit that you learn to live with the consequence of your actions.  (Not a very sympathetic soul am I?)


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## bioteq (Mar 2, 2005)

Neither identifying nor changing your MAC address is illegal, unless stated otherwise by your isp/administrator, being paranoid is not healty... but being stupid may kill you, I believe that holding back widely available information is quite silly.

All unix based systems have this "feature" of changing MAC addresses embedded, there is no need for additional software, everything you need is a terminal and possibly google.

What you're looking for is the ifconfig command.
Please note that if you change the mac address against the will of an administrator it is his right and privilige to cancel your access to the network entirely, and believe me unless he is a complete dumb ass there are ways of detecting spoofed mac addresses on a network.


PS. Hardly anyone seriously considering hacking would ask this kind of a question...


Best regards

Teq


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## Pengu (Mar 2, 2005)

Um. somehow, regardless of hacking, im inclined to believe it would be easier to simply "re-register" the machine on the network.


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## Zammy-Sam (Mar 2, 2005)

bioteq, many networks only have a MAC filter. A user faking such an address in order to have network and file access is hacking himself into the system. It might not be as tricky as other hacking methods, but still remains the same: accessing a system that is somehow protected.
And welcome to the forum.


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## scruffy (Mar 2, 2005)

bioteq

0 19:35 mark@Inch:mark $ ifconfig en0 ether 00:50:e4:c0:9c:2d
ifconfig: ioctl (SIOCAIFADDR): permission denied
1 19:35 mark@Inch:mark $ sudo !!
sudo ifconfig en0 ether 00:50:e4:c0:9c:2d
Password:
ifconfig: ioctl (SIOCAIFADDR): Operation not supported

Nope, you still need a kernel patch - the ifconfig command supports the option to change the MAC address only on kernels that provide the underlying support.  All ifconfig does is translate a nice readable command into the appropriate system call.  If the syscall isn't implemented, no dice.

And, I share your opinion on open disclosure of information.  I wasn't hiding information, but I'm not going to take someone all the way through patching xnu either.


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## JamesDam.com (Mar 6, 2005)

sudo the command and it will work.  At least I got the same error message as above on my ibook, and sudoing fixed it.


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## steffl133 (Mar 7, 2005)

changing a macadress is just standard. with windows it can be done very easily and also with linux. i think that also the command shown here for mac should be able to work.
also it is a standard option for each router. 
stephan


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## scruffy (Mar 21, 2005)

Note in my post, the second attempt to run the command (with sudo) - "option not supported".


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