June 23rd, 2002, 03:26 AM
MAC addresses-changing for WIN2k and LINUX
A MAC (Media Control Access) address is a unqiue 12 digit 48 byte long number, unqiue to every network adapter ever made. The first 3 sets of numbers, or the first 6 numbers are the ID of the network adapter manufacturer, and the last 3 sets, or the last 6 numbers are the ID that the manufacturer gave to that specific adapter. MAC addresses were made to be fixed, unchangable. Also, many ISPs designate an IP to a MAC address so if say a router is added, then the MAC address would change and the ISP might shut down the account. To find out your MAC address, that is if you have a network adapter, then you can use winipcfg or ipconfig if you have windows, or you can use ifconfig -a in linux or unix systems. I have heard that it is possible to change MAC addresses from the My Network Places interface in Windows 2000, though this is not possible for all MACs and I have not been able to confirm this yet. Also I have heard that the same can be done using the ifconfig utility in linux and unix boxes. And one more thing, is that, at least with the ifconfig utility that the MAC changing is not permanent, and only lasts for the duration of the uptime, so when you have to reboot, it would have to be done all over again, though perhaps somebody will automate it sometime.
In using any of the ways described below you absolve me of any responsibility or wrongdoing for any harm done to your computer.
To change the address in linux on ethernet card eth0, try using something like this,
#ifconfig eth0 hw ether XX:XX:XX:XX:XX:XX
In Windows2k try going to your "control panel", then double clicking your "network and dial up connections", right click the connection that uses the NIC (network adapter) and click properties. Then press "configure" and then "advanced" and then "locally administered address". Then enter the new MAC address.
This can also be done in the registry, using Regedt32, go to
And enter your new MAC address. You must reboot for the registry changes to take effect, after you have done so, try typing "net config rdr" in the command prompt to see if the changes have taken effect or not.
June 23rd, 2002, 06:48 AM
And one more thing. If you have any suggestions for an originial tutorial, post them, I'll research them and write one best I can.
June 23rd, 2002, 10:31 PM
Oh yeah, and I suppose you could probably also check if you MAC changed in Win2k by using ipconfig, but I just don't know, seeing as how I don't have it.
June 23rd, 2002, 11:27 PM
When doing this you actually wouldn't be changing the MAC address, only changing what the things connecting to your comp. Think it is. Which would be why your MAC address wouldn't change permanently because it is stored on the NIC itself. Im pretty sure on a ROM chip(because it makes sense.) To improve the tutorial you may want to start out by explaining what a MAC address is so people would know why they wanted to change it, it's use in security, stuff along that lines.
- ShadowTech - Never Fail, Never Falter, Never Fall
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June 23rd, 2002, 11:31 PM
Perhaps I'll explain MACs in my next tutorial. And the MAC, I have heard is stored and changable with an EEPROM. Yeah, I know that it is impossible to actually change the address because the address is ingrained in the firmware. You would have to change it to actually change the MAC address, but it is doubtful anybody will go to the trouble to change the MAC address on the firmware, so here are some easy low cost solutions. And thanks for the input.
June 24th, 2002, 04:37 AM
Just wanted to point out that I'm pretty sure it's a 48 bit long number. Everything else looks pretty good though....
A MAC (Media Control Access) address is a unqiue 12 digit 48 byte long number
June 24th, 2002, 04:44 AM
Oops. Mistake there, obvious one. I'll fix that up right away and thanks for the input, bye and thanks again.
June 24th, 2002, 04:44 AM
waytallgel is right, 48 bits, 6 bytes (in hex, 1 byte = 2 digits, hence 12 digit number)
Credit travels up, blame travels down -- The Boss
June 24th, 2002, 04:45 AM
Um, I tried to edit it, but you can only edit until 1440 minutes after you post the message, and it has been longer than that for me, guess I can't fix it. Thanks for finding it though. And please don't delete your post, as people can read the correction from there.
July 14th, 2002, 08:43 PM
What if i want to change my MAC address permanently ?
I have 2 PCs each with LAN cards and one out of them is on a broadband internet connection.
Our ISP has installed a firewall with MAC address check - so i cannot login though other PC !!
Can I change MAC address on a Win 98 box by hook or crook ?