[vortex] "3Com Vortex"-type NIC must assume different MAC

[Soren A]

Hello,

I am a very new-ish Debian user. I am a competent programmer and have no 
fear of source code (in "C" that is). I'm running Stable (3.0_1 I think) 
and the kernel 2.4.18. On a laptop.

My new laptop is Network-challenged due to a non-working Winmodem (that's 
another issue entirely; I have researched extensively and it's going to be 
a while before it is working, it isn't working yet for other GNU/Linux 
users either - PCTel modem 2304WT). I *Need* to be connected to the 'Net. 
Goes without saying.

I have this Winbox that I am composing this posting on; it is connected to 
Adelphia Powerlink (full, normal flavor, not semi-cable) through their 
Scientific Atlanta cablemodem. I was told at account setup time that the 
system (DHCP of course) had registered my NIC card's MAC address 
(station address, node address) and would not work if any other NIC was 
used. So, what I need is to be able to shutdown WinDOS and unplug the 
ethernet cable from the Winbox, and plug it into my laptop on occasion, 
then at other times to unplug it from the laptop and back into the Winbox 
(where I do Cygwin development, which, while not a truly Free OS, is at 
least an expedient means for propagating the strengths and virtues of Free 
Software to those still under Bill's Thumb and in sore need of 
Enlightenment...). I need both to work, but not simultaneously -- thus as 
you see, no violation of my TOS (which in this case specifies they are only 
providing service to a single computer).

The Cablemodem-HOWTO indicates that [paraphrased from memory] ~"the 
majority of [drivers for] NIC cards allow their MAC address to be 
overridden so that they can appear to be a different station address" and 
that's what I (badly) need to do. What I don't know is *if, how, when, and 
where*. I don't know IF the driver for my card will allow it -- when I 
tried a test it didn't work (I got a DEVICE-OR-RESOURCE-BUSY error worded 
something like that). My card's detailed identity is:
    3Com PCI 3c905C "Tornado" at 0x3000 vers.LK1.1.16
whatever all that means ;-)

WHEN is the proper time in the initialization chain for bringing up the
network (and everything else) to try to issue a command to the NIC? I
think this must have something to do with /etc/init.d and files in the
rc.X hierarchy. WHERE is the file that issues the command to load the
driver (which is a module, I've confirmed that support for my NIC is
built as a module in my kernel, by doing 'lsmod')? HOW is the invocation
to be done -- I've seen it suggested that something like should work: 

  root$ ifconfig eth0 [IP-address] [optnetstuff] \ #line cont.
    hw ether AA:BB:CC:DD:EE:FF

Is this the right style in which to specify the MAC numerically?

My perusal of the source code for the driver (in my current kernel's 
sources) finds no mention at all of *setting* the station address (the 
MAC).

Thanks. Debian still rocks, never did I dream of being able to use a 
computer with so much access to all the internals of the platform. These 
temporary troubles will be overcome... thanks Donald Becker et al for all 
the effort put into this base of code for the ethernet cards.

   Soren A


-- 
"So, tell me, my little one-eyed one, on what poor, pitiful,
defenseless planet has my MONSTROSITY been unleashed?"
                       - Dr. Jumba, Disney's "Lilo & Stitch"