MAC address

This is not just necessarily a feature of the OS. It depends on the NIC as well. If your NIC does not accept MAC address cloning, it won't work.

Ah I didn't know this was a non-standard feature, thanks for straightening it out! However, I'm thinking, even if the NIC doesn't support this, placing it in promiscuous mode and maybe adding some static ARP entries wherever needed, wouldn't it work (in conjunction to the configuration at the OS level)?

hey lets do this.... can every one mention whic nic card we all are using and who all are able to get to the change value location...... and :roll: if its mac cloning where exactly the changed mac address is stored.... is it in the registeries of OS ??? :

I think the ability to "change" the MAC address is a feature of the driver for the card. So if the driver/card supports it, you can. And if they don't (which is the majority) then you can't

Hmm personally I've never had a problem in changing the reported MAC in any of my 6-7 PCI ethernet adapters (of various chipsets). At least not with the drivers coming with the linux and freebsd kernels.

dwyane, in fact it's in the memory. In windows the whole registry -or at least a large part of it- is loaded into memory, so it is enough to modify the appropriate registry key, which lays in: [code:1]
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Class\{4D36E972-E325-11CE-BFC1-08002bE10318}[/code:1]
There are also several graphical applications for this, like macmakeup and smac . In Unix-like systems the change is applied through the ifconfig interface directly to memory, so it is also necessary to be automatically executed upon reboot through some startup script.