Lpc2000

Thanks for the input.

Actually there are 2^48 MAC addresses existent in the world.The 1st three octets are assigned by the IEEE. Look up the link for details:

http://anonsvn.ethereal.com/ethereal/trunk/manuf 

After which i feel, the network product the companies sell  can configure the last 5 octets. If the production doesn't suffice, they need to buy more first three octets.

Anyways, the best way to set the address, an appropriate one, would be to take one from an already bought network card.

Cheers,
Vineet.


Ryan Niemi <ryan@...> wrote:     --- In lpc2000@yahoogroups.com, "FreeRTOS Info" <nospam@F...> wrote:
 >
 > > Hello,
 > >   Every network equipment  has  a unique MAC address for it. Does the
 > Wiznet NM7010A ethernet controller also have a >MAC address of its
 own.  If
 > no what should the address be, as the MAC register needs to be set.
 > 
 > If you wish your device to be on a public network or sold
 commercially then
 > you have to buy a MAC address separately for each device and program
 it into
 > the NM7010A registers.  If you have complete control over the network
 > accessibility and the devices connected to the network you can use
 any MAC
 > address within spec, provided each is unique within the network.
 
 Actually MAC addresses aren't purchased individually, IEEE will assign
 you an OUI (the first 3 octets of the MAC address) for a fee that's
 around $1250 the last time I checked.  Then you're responsible for
 assigning MAC addresses within your OUI at your own discretion.  This
 gives you around 16.7 million MAC addresses.  Sadly, IEEE's opinion is
 that MAC addresses are not transferrable.  One company that purchased
 an OUI a while back attempted to sell pieces of it to anyone who
 couldn't justify buying a whole OUI block, but IEEE promptly objected.
 
 Although choosing a random MAC address is generally considered bad
 form for equipment you've going to sell (and it's probably worth
 noting that this isn't a rare occurence, many companies with
 low-volume ethernet products actually do this), the odds of ever
 having a MAC address collision are exceedingly low.
 
 There are 140737488355327 valid MAC addresses (noting that
 00:00:00:00:00:00 is not valid, and the broadcast/group bit must be
 clear).  Divide by the number of other ethernet hosts you expect to be
 on the network.  Let's say 1000 hosts, just for kicks.  You have a 1
 in 140737488355 chance of having a MAC address collision if you choose
 a MAC address at random.  On the otherhand, the odds of winning the
 Powerball jackpot (a nationwide lottery in the US, for non-US people
 on the list not familiar with Powerball) is 1 in 146107962.  You are
 963x more likely to become a multi-millionaire in your lifetime, than
 to experience a MAC address collision in your lifetime on a LAN with
 1000 ethernet hosts.  Or, you'll have hit the smaller $200K Powerball
 prize an average of 39493 separate times by the time you've
 experienced a MAC address collision.
 
 As i recall, there's a range of MAC addresses set aside for testing
 and prototyping, that you can use for internal use however you want. 
 I can't remember at the moment what OUI's they are.
 
 -Ryan
 
 
 
 
             

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