apngss@yahoo.com wrote:

> I have couple questions regarding MAC address changes:
>
> 1) When we change the MAC address, it will change the firmware of NIC,
> or just temporary change?
> My observation is just temporary change.

As far as I know, it's temporary.

>
> 2) Do you think changing MAC address can secure the machine more? I
> mean at least hackers
> cannot keep track on the machines that easily? Well, maybe hackers
> should use IP address,
> but my observation is that when I change the MAC address, IP address
> will change as well.

It makes no difference for security. MAC addresses are relevant only on the
local network. They are discarded as soon as your packets pass through a
router.

>
> 3) I try it myself, when I change the MAC address, it will change the
> IP address as well.
> IP address is assigned by ISP, maybe ISP assigns the IP address based
> on the MAC address
> of the machine as well? MAC address identifies the network card, and IP
> address identifies
> the computer on the internet.

The ISP doesn't assign an IP address based on the MAC address. It assigns a
new address to what appears to be a new computer. It won't reassign the
previous one, until the lease expires.