Re: MAC address setting for ether card

On Wed, 22 May 2002, Ziegler Ga'bor wrote:

> I am a linux user who is looking for recent Linux ethernet cards that
> supports the setting of the HW MAC address from driver (i.e., with the
> ifconfig command).

Drivers that derive from my example code should all work properly with
'ifconfig .. hw ether ...'.

Setting the station address this way takes effect only until the next
time the driver is loaded.  This is the best approach -- there is almost
never a good reason to change the station address in the EEPROM.

> (I would like to access a cable modem service with
> two Linux boxes w/o each time re-registering the MAC address with the
> provider. Naturally, only one of the machines would connect at the
> same time, so there would be now MAC address conflict)
>
> Scanning the drivers/net section of the 2.2.17 kernel source, it seems
> only the drivers de4x5.c, depca.c, ewrk3.c drivers support this. These
> drivers are for mainly Digital cards out-of-stock now.

IMNSHO, these drivers were written without understanding the proper
semantics.  By writing their own method to set the station address they
allow changing the station address when the interface is 'up', but extra
code introduces race conditions.

-- 
Donald Becker				[email protected]
Scyld Computing Corporation		http://www.scyld.com
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