Subject: Re:RE: Changing MAC addresses?
To: David Woyciesjes <DAW@yalepress3.unipress.yale.edu>
From: Lets Go Canes! <LetsGoCanes@webmail.bellsouth.net>
Date: 06/15/2000 14:04:31
On boxes running OpenVMS, the Ethernet interface has to allow the MAC address to be changed in order to support DECnet. Since most DEC/Compaq Alphas are capable of running OpenVMS, it would make sense that the Ethernet controllers all support the ability to change the MAC address. OTOH, if the box was built specifically for NT, its conceivable it may have an Ethernet interface that doesn't support this function.
At Thu, 15 Jun 2000 13:47:29 -0400, you wrote:
> If I'm correct, MAC addresses are hardwired into the chips on any
>network interface. Part of the address identifies the manufacturer of the
>interface, and I'm not positive what the rest of the address is for. Type of
>a serial number (of sorts), I guess. So to replace them, you would need to
>reprogram one of the chips on the NIC itself.
> Why change the MAC address anyway? I'm confused there...
> Does anyone know the full story?
>--- David A Woyciesjes
>--- C & IS Support Specialist
>--- Yale University Press
>--- (203) 432-0953
>--- ICQ # - 905818
>> From: der Mouse
>> Sent: Thursday, June 15, 2000 12:36 PM
>> To: firstname.lastname@example.org
>> Subject: Changing MAC addresses?
>> The system in question is an AlphaPC 164LX 533, with a 21140A-based de0
>> and a 3c905B-based ex0 (according to dmesg - full messages below).
>> I wish to cause one or both of those to run with a different MAC
>> address than its default. (More specifically, I want the machine to
>> use the same MAC address on some subset of its interfaces.) I'm
>> prepared to hack drivers as necessary...BUT...dev/pci/if_de.c is a maze
>> of twisty little function pointers, all different, and I'm not even
>> sure I've *found* the relevant driver files for the ex; it appears to
>> be scattered over at least three directories. So what I'm looking for
>> is someone who knows those drivers enough to give me an initial hand
>> up, finding the appropriate place to wade in with a machete...anyone
>> willing and able?
Let's Go Canes!