MAC address...

[Pankaj Chawla]

Hi

I am not sure but i think the mini documents mention somewhere that

all mini's come with same mac address. Is that true. Arent all ethernet

cards across the world supposed to have a unique MAC address?

Thanks

Pankaj

PS: I havent verified with real mini yet but since I happen to read thought

will check here only as I will need multiple mini's to cross check in real :-)

[elucches]

08:90:90:90:90:90

[Pankaj Chawla]

That was my point. Why do all minis come with same MAC address. Shouldnt

the ethernet adaptor have it own unique MAC address already assigned or am

I missing something? 

Thanks

Pankaj

[Charles Springer]

Ranges of MACs have to be purchased by companies. There is potential for a serial number/MAC scheme under discussion.

-- Charlie

--
Industrial ARMWorks
www.andahammer.com
253 851-0227

[BobC]

It's true Ethernet cards should all have a unique address, but this is
programmed by the manufacturer into an EEPROM on the adapter. The bare
Ethernet IC does not come with an allocated address, as Charles says
number ranges need to be purchased from the IEEE.

Often with development or OEM type boards they do not come with a
properly allocated address, it reduces the cost.

[M P]

I've been using dead-companies allocated ranges. For example, "Pr1me
Computer" -- it's unlikely you'll ever find one of these on a LAN
anywhere near you!

Michael

[greatonne]

M P: How do you change your mac address in u-boot? I have tried the
"set ethaddr 08:00:2f:00:00:02" but after that the network won't work
anymore. If I change it back to what it was with set ethaddr, it will
work again. Also according to a few tutorials the mac variable can be
set only once and then it can't be written anymore, is that true? So
what is the proper way to change MAC on the mini2440?

[M P]

You must be doing something wrong on your LAN, the setenv is the way
to change the MAC in u-boot, and no, there's no limitations to
changing it (where does THAT comes from..)

Michael

[Bill Sargent]

I'd guess that goes along the same lines as how home routers pretend
to be another MAC address (spoof) and theres no limits on those either.
It's a strange assumption that it can only be written once. As far as I
know it's not a hardware chip that this is being written to, it's just
spoofing another address using software.

Bill

[DigitalWiz]

Actually, I remember seeing something in the U-boot documentation
about only being able to write the MAC address once, but it's a
configuration option. So if you set the option right, you have the
ability to change the MAC as often as you want.

Doug

[greatonne]

Well if I change it with the "set ethaddr 08:00:2f:00:00:02" and
saveenv I get:
SIOCSIFADDR: No such device
eth0: ERROR while getting interface flags: No such device
eth0: ERROR while getting interface flags: No such device
Bind socket to interface: No such device
Failed to bring up eth0.

in debian which I have installed using this guide:
http://webcache.googleusercontent.com/search?q=cache:AXVaKp7XYhEJ:blog.leshak.ru/english/pages/how-to-install-debian-50-lenny-to-arm-qq2440/comment-page-1/+leshak+mini2440&cd=5&hl=en&ct=clnk&gl=fi&client=firefox-a

And I have compiled u-boot exactly as described here:
http://wiki.linuxmce.org/index.php/Mini2440

At least here they say that the MAC can be set only once (but maybe
that's not the case at this time as the mac clearly changes, the
interface just won't work anymore):
http://www.petalogix.com/resources/documentation/petalinux/userguide/Bootloaders/UBoot/UBMacStorage

So does somebody know why eth0 can't be found after changing mac?

[Bill Sargent]

I had all kinds of weird problems with the mini and Debian. This was
one of them and I hadn't even messed with the MAC address. I think
theres some kind of weird patching they do to their kernel and udev
etc... I've been meaning to sit down with it again but just haven't had
the time.

Bill

[Daniel Serpell]

Hi!

On Thu, Jul 8, 2010 at 12:13 PM, greatonne <hopp...@gmail.com> wrote:
> Well if I change it with the "set ethaddr 08:00:2f:00:00:02" and
> saveenv I get:
> SIOCSIFADDR: No such device
> eth0: ERROR while getting interface flags: No such device
> eth0: ERROR while getting interface flags: No such device
> Bind socket to interface: No such device
> Failed to bring up eth0.
>

If you change the mac address, Debian gives the ethernet a new name,
(as it guesses that you replaced the device with a different one), so it is
probably "eth1" now.

To reset the name again, you need to delete the file
/etc/udev/rules.d/70-persistent-net.rules , it will be regenerated on the
next boot.

Daniel.

[greatonne]

Thanks, that worked!