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Re: Ethernet MACaddress constantly changing



Hello James M.,

On 12-Aug-99, you wrote:

<snip>...

LJM>  MAC addr is another story.
LJM> That should be fixed to the adaptor and never change.  (Well,
LJM> almost never.  There are a few that have mac addresses that
LJM> are able to be modified with a special utility.  The only ones
LJM> I know about are for older minicomputers...)
LJM> 

Likewise, I have encountered systems where the Eth Addr could be changed
but again, it was a long time ago and I think they were minis.  I doubt
the 3Com NIC Eth could be changed.

LJM>> I have a portable with a 3Com 3CCE589ET CPCMCIA network
LJM>> adapter. I'm also running arpwatch on my network to check for
LJM>> "ellegal aliens".  I noticed that everytime a reboot my portable
LJM>> from linux to windows or the other way around I get a message
LJM>> from arpwatch that the Ethernet address of my portable changed.
LJM>> Shouldn't the ethernet address be network-card-specific. Is either
LJM>> Linux or Windows98 changing my Ethernet address and ifso why?
LJM>> 

Assuming arp on Debian is like other unixes I've used, go to another m/c
on your network and ping your laptop then arp -a it - this should
return the Eth.  Do it before and after rebooting the L/T.

Also, does arpwatch give you the addresses?  Are the addresses
consistent - is the change always from addr A to addr B or does it
vary.  For example, if you boot from Windoze to Debian and then back to
W, what addresses are reported by arpwatch and what do you get by
ping/arp -a at each step?

Could this just be the NIC Eth going to null during the re-boot?

Regards,

LeeE
-- 

http://www.spatial.freeserve.co.uk




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