Subject: Re: What makes a good fake MAC address?

From: Stephen Hemminger <[email-masked]>
Date: Wed, 22 Apr 2009 14:13:26 -0700

On Wed, 22 Apr 2009 13:48:27 -0700
Inaky Perez-Gonzalez <[email-masked]> wrote:

> 
> Hi All
> 
> The Intel i2400m WiMAX driver behaves as an ethernet device, and
> currently when sending packets to the netdev stack, it fakes an
> ethernet header, sets the "from" mac address to zeroes and the "to"
> to it's own MAC address.
> 
> The WiMAX network can be considered to be a point-to-point (up to the
> gateway) connection, all IP based, so there are not MAC addresses
> from our gateway (not to mention that it can change behind us).
> 
> The problem with using a zero mac address is that it confuses the
> bridging software (and maybe others). I was wondering, what would be
> a fake mac address we could put in there that is legal for this kind
> of "faking"? [or the closest thing to legal?]
> 
> Thanks!
> 

You want really want hw to have real mac, but if not use
random_ether_addr()