Doesn't flipping the field make it Either U/L ?
U --- Universal
L --- Local
Basically if the 2nd most significant bit is set (the 7th
bit in this case
from left to right) then it means that the MAC is localy
administered.
Here is an explanation:
*U/L = 0*
Universally administered address: the adapter uses its
burned-in MAC
address.
*U/L = 1*
Locally administered address: the adapter uses a logical
address (assigned
by network administrator). U/L=1 may result in a hex code of
0x02 in the
first byte. The U/L bit is always set when a logical address
is assigned
(even if the assigned address doesn't follow this
convention). Therefore, it
is impossible to imitate a burned-in address; but other
logical address may
be imitated at any time.
http://www.synapse.de/ban/HTML/P_LAYER2/Eng/P_lay207.ht
ml
-Abel
On 9/29/06, David Ristau wrote:
>
> The MAC address is not unique, it is diverse. Think
about the number of
> devices using MAC address and the number of available
unique ID's per
> manufacturer...for the past 20 years or so .
>
> 6 bytes - 16 million combinations per manufacturer ID
>
> The possibility of getting a NIC with a duplicate MAC
address on your
> local
> network in the same broadcast domain, is etremely low.
but is possible, it
> has happened to people I've worked with.
>
> a long story but, to summarize, that was one long
horrific night
> of network troubleshooting.
>
> as for flipping the field - I haven't a clue.
Message Posted at:
http://www.groupstudy.com/form/read.php?f=7
&i=114067&t=114052
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