How to change MAC without letting eth0 down?

htlin · 06-29-2005, 04:25 AM

Hi All,

I would like to try to change MAC address while the network interface "eth0" is not going to be down.

Does anyone know how to achieve that?

ps¡G I just can use "ifconfig" to down the "eth0" first and then change MAC and then up it.

Crashed_Again · 06-29-2005, 05:41 AM

I thought MAC addresses were given to nic cards and could not be changed.

sind · 06-29-2005, 06:19 AM

Quote:

I thought MAC addresses were given to nic cards and could not be changed.

You can change the MAC address of a card temporarily under Linux with:

# ifconfig eth<n> down
# ifconfig eth<n> hw ether <MAC>
# ifconfig eth<n> up

Quote:

I would like to try to change MAC address while the network interface "eth0" is not going to be down.

Does anyone know how to achieve that?

AFAIK you have to take the interface down before changing the address. The Linux kernel prevents you from changing the MAC address on a running interface; I would guess that is to prevent bad things from happening...

~sind

ubrals · 07-05-2005, 12:42 PM

Hi.

And how about to reset to the default MAC address?
I know I can do it by a script, but is there a parameter to reset to the default MAC address?
Does anybody know that?

thanks,

Miguel.
.