How do I change the MAC address of my network card?

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4

I have a local network in a Windows system where the Admin gives permission to the PCs by their MAC address. But he is on vacations and I have a new PC.

How can I change the MAC address of my new PC to have the same MAC address as the old one?

I know this can be used for spoofing the address, but this is local, so I don't think I will have a problem.

Artur Carvalho

Posted 2009-10-02T08:36:29.103

Reputation: 1 617

@BrianKnoblauch, Blame yourself for not having a tool to identify networks with identical MAC addresses. – Pacerier – 2015-04-06T16:00:51.987

8Ugh. I hate it when people do that. I've been the unlucky person that ended up troublshooting network failures due to multiple identical MAC addresses on the same broadcast domain. MAC address cloning is evil, please don't do that unless people are dying all around you you have absolutely no other option to save them. :-) – Brian Knoblauch – 2009-10-02T12:57:58.473

4@Brian, you downvoted b/c his Admin is on vacation? – hyperslug – 2009-10-02T13:07:21.057

2What do you advise Brian? – Artur Carvalho – 2009-10-02T17:42:55.200

1Clone the old PC's but add 1. or 2. or whatever. MACs are pretty random, it's not likely you'll have 2 sequential on the same network. – quack quixote – 2009-10-02T17:55:45.597

4@Artur, you could also swap the MAC addresses of two PC's to prevent collision, if someone inadvertently plugged the old one back in. – hyperslug – 2009-10-02T21:49:59.977

@hyperslug good suggestion – quack quixote – 2009-10-04T02:06:40.200

1one example where hyperslug's suggestion will fail (causing the problem Brian is concerned about) is if the old hardware is given a fresh install of new OS and then placed back on the network. the new OS will by default use the old hardware's original MAC. – quack quixote – 2009-10-05T23:27:38.930

Answers

6

I have used these instructions in the past and they work great

There’s a C++ command-line utility called Macshift that allows Windows XP users to change their MAC address to any other valid address. I’ve written about how to use it and how to create shortcuts to change your MAC address on-the-fly. I’ll first explain how to use Macshift for any MAC change, then I’ll show you how to make Windows shortcuts using the command-line options. I’ve also made a small script to make it easier to use, but the script isn’t necessary. Macshift usage
Macshift is a command-only utility, so you need to learn the options to use it.

admintech

Posted 2009-10-02T08:36:29.103

Reputation: 6 970

2note the Macshift program is listed WinXP ONLY. – quack quixote – 2009-10-02T08:49:44.380

21

From Here

Method 1:

This is depending on the type of Network Interface Card (NIC) you have. If you have a card that doesn't support Clone MAC address, then you have to go to second method.

a) Go to Start->Settings->Control Panel and double click on Network and Dial-up Connections.

b) Right click on the NIC you want to change the MAC address and click on properties.

c) Under "General" tab, click on the "Configure" button

d) Click on "Advanced" tab

e) Under "Property section", you should see an item called "Network Address" or "Locally Administered Address", click on it.

f) On the right side, under "Value", type in the New MAC address you want to assign to your NIC. Usually this value is entered without the "-" between the MAC address numbers.

g) Goto command prompt and type in "ipconfig /all" or "net config rdr" to verify the changes. If the changes are not materialized, then use the second method.

h) If successful, reboot your system.

Method 2:

This should work on all Windows 2000/XP systems

a) Go to Start -> Run, type "regedt32" to start registry editor. Do not use "Regedit".

b) Go to "HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\ Control\Class\{4D36E972-E325-11CE-BFC1-08002BE10318}". Double click on it to expand the tree. The subkeys are 4-digit numbers, which represent particular network adapters. You should see it starts with 0000, then 0001, 0002, 0003 and so on.

c) Find the interface you want by searching for the proper "DriverDesc" key.

d) Edit, or add, the string key "NetworkAddress" (has the data type "REG_SZ") to contain the new MAC address.

e) Disable then re-enable the network interface that you changed (or reboot the system).

Method 3:

Use the program Etherchange

Method 4: ( windows 9x)

Use the same method as Windows 2000/XP except for the registry key location is "HKEY_LOCAL_MACHINE\System\ CurrentControlSet\Services\Class\Net" and you must reboot your system.

joe

Posted 2009-10-02T08:36:29.103

Reputation: 11 615

@BrandonWang, Except it doesn't work. At least for some network adapters: http://superuser.com/a/63618/78897

– Pacerier – 2015-04-07T12:38:44.707

@joe, What does rdr mean? – Pacerier – 2015-04-07T12:39:39.097

Any success with this recently? Does not seem to work anymore... – Demiurg – 2016-11-08T11:29:20.017

regedt32 is a stub that launches regedit on >=XP. – Hello71 – 2010-09-20T01:55:11.660

1There was no need to delete the answer. – BinaryMisfit – 2009-11-06T17:35:00.960

3

A very important note for Windows 7 users: MAC spoofing only works with windows 7 if the new MAC's second hex digit is one of the following: 2,6,A,E.

Meir

Posted 2009-10-02T08:36:29.103

Reputation: 149

@Meir, Or qualifications would do well too. – Pacerier – 2015-04-06T16:05:09.053

1While that may be true, can you provide some documentation to proof your point? – Der Hochstapler – 2012-05-27T10:54:51.340

3

Go into properties for Network Connection. Click "Configure" next to desired network adapter and on Advanced tab you should have one field for MAC address. Usually it is named "Address", "Locally Administered Address" or something similar. There you have text box in which you can type desired MAC.

Take care that you turn off original PC (or change it's MAC also).

Josip Medved

Posted 2009-10-02T08:36:29.103

Reputation: 8 582

+1 for not needing to install anything. – hyperslug – 2009-10-02T09:47:12.003

1"Network Address" is another common name for the field. – quack quixote – 2009-10-02T09:57:31.403

3

ukanth

Posted 2009-10-02T08:36:29.103

Reputation: 9 930

3

It is worth mentioning that in a MAC address the least significant bit of the first octet is a multicast flag (multicast addresses have it set to 1), so the adapter's address should normally have it set to 0. This means that valid values of the first octet must end with 0, 2, 4, 6, 8, A, C or E.

Moreover, the second-least-significant bit of the first octet is used to distinguish between globally and locally administered addresses (if it is 1, the address is locally administered), and certain adapters (e.g. Intel Wireless) may enforce this by not allowing to change the address to another "globally unique" one. Hence, the value of the first octet must end with 2, 6, A or E.

gino0631

Posted 2009-10-02T08:36:29.103

Reputation: 56

2

Some network adapters allow you to change the MAC address of a network adapter through their configuration dialog:

enter image description here

An example is shown in this screencast. But please keep in mind that this doesn't relate to all network adapters!

digitalPBK

Posted 2009-10-02T08:36:29.103

Reputation: 121

2

You don't specify your OS, so I'm assuming a Windows flavor. Here's a decent writeup of changing MACs on Windows as well as a wide variety of other systems.

Note that that page and Systech's link both recommend a program called Macshift that's listed as WinXP ONLY.

quack quixote

Posted 2009-10-02T08:36:29.103

Reputation: 37 382