Subject: Re: bpf write() to local host
To: Joel Wilsson <>
From: Joel Wilsson <>
List: tech-net
Date: 02/01/2003 00:27:19
On Tuesday, January 21, 2003, at 07:39  pm, Joel Wilsson wrote:
> On Tuesday, January 21, 2003, at 05:40  pm, der Mouse wrote:
>>> Back to the original issue, there is no problem using locally
>>> administered MAC address for a 2nd card in a sun box.
>> ...except convincing the driver to use it.
>> Or does -current have some uniform way to do that now?  As of
>> ifconfig.8 1.53 (the most current I have at ready hand), I don't see
>> any option for it - perhaps it's not in ifconfig.
> Would you like to do something like this?
> ifconfig en0 link 00:03:93:ce:11:32
> I think I can throw together a patch for ifconfig to enable that...

I thought this would be easy, but it's not. Only because our ethernet
drivers are stupid. All ethernet interfaces should pass ioctls they
don't handle themselves to ether_ioctl, but they don't.

ether_ioctl can change the link layer address (ioctl SIOCSIFADDR),
so if we change all if drivers to do the above this would be possible.
Seems like Free- and OpenBSD has already done this.

I'm willing to make patches for this if it's the right approach.