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[lwip-users] Re: [lwip] Deploying Ethernet MAC addresses
From: |
Adam Dunkels |
Subject: |
[lwip-users] Re: [lwip] Deploying Ethernet MAC addresses |
Date: |
Thu, 09 Jan 2003 00:43:59 -0000 |
Hi Leon and Jason!
Thanks for your information regarding the Ethernet OUIs. I have been using
Jason's technique. grabbing the MAC address of an old unused card that is
kept physically far away from the test system.
Also, I just found this [http://www.certsoft.com/mac.htm] page, that states:
"Please note that the most significant byte of an Ethernet MAC address has
two special bits in it. The LSB bit is set to one to indicate that this is a
group address instead of an individual address. The next bit is zero if this
is an universally administrated address (OUI purchased from IEEE). If this
bit is one then the entire 48 bit address is locally administrated and no OUI
is used."
If this is true, it means that any MAC address in the range 40:00:00:00:00:00
- 7f:ff:ff:ff:ff:ff could be used for private networks.
/adam
--
Adam Dunkels <address@hidden>
http://www.sics.se/~adam
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