mac address problem

garry saddington garry at schoolteachers.co.uk
Sun Sep 17 09:07:27 UTC 2006


On Sun, 2006-09-17 at 07:54 +0100, Simon Hobson wrote:
> garry saddington wrote:
> 
> >We bought a bunch of Wyse Winterms cheaply to use in an LTSP setup.
> >About one third of them work perfectly by flashing them with a kernel
> >and an initial ram disk.
> >However, the others do not work and the problem is that they all report
> >their mac address as 00:00:00:00:00:00.
> 
> Now you know why they were cheap ;-)
> 
> >Consequently they all get the
> >same ip address from dhcp and everything gets a little confusing!
> 
> Not only that, but even if they did get different addresses (which 
> you could do by setting different client-ids BTW), networking would 
> still not work because the MAC address is used to identify the 
> intended recipient of each packet.
> 
> >Is there any way to solve this? We thought about a kernel parameter
> >specifying mac address on boot but all our searches have not found
> >anything. Can someone here suggest an avenue to follow?
> 
> There will almost certainly be a utility somewhere to allow you to 
> set the mac address of the device and store it in non volatile memory 
> - the manufacturer probably has such a utility.
> 
> It might be more fruitful to look at the network port hardware rather 
> than the terminal as a whole, not having looked into it, I would 
> imagine that most ethernet chips include a small memory for such 
> configuration values.
When these things fire up they do a flash self-check and report a good
mac address to screen. It is only on boot when they broadcast the wrong
address. So internally they know the correct mac address. That is why we
suspect a kernel problem. They have come out of a large network running
Windows NT and so they must have worked correctly some time. Another
observation is that the ones that do not work have different motherboard
revisions which are all made in China. The good ones are all made in
Taiwan!!

We bought 250 of these things for £1000 and about 60 are good. That
means we still got them cheap but we would still like to get the others
going.
regards
Garry






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