Ya correct, probably there was a typo.
Cheers,
Vineet.
Ryan Niemi <ryan@ryan...> wrote: --- In lpc2000@lpc2..., vineet jain
<vineetrvce@y...> wrote:
>
> 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:
No, the LSB of the first octet must be clear on a valid MAC address.
This is the broadcast / group (multicast) bit. Thus, there are 2^47 -
1 *valid* MAC addresses (since 00:00:00:00:00:00 is not valid), which
yields 140737488355327 valid MAC addresses.
> 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.
A MAC address contains 6 octets, not 8 as you suggest. The first
three are assigned by IEEE to a specific manufacturer, and is known as
the OUI. Look at the link you provided, which is Ethereal's
hopelessly outdated copy of the IEEE OUI list, and lists the OUI's
(first 3 octets) of the manufacturers. The manufacturer may configure
the last 3 octets, not 5. If there were 5 configurable octets, there
could only be 256 ethernet manufacturers in the world. Rather, there
are 3 octets for the OUI, and 3 octets manufacturer-assigned.
Here's the MAC address breakdown:
yy:yy:yy:zz:zz:zz
yy:yy:yy = IEEE-assigned OUI
zz:zz:zz = Manufacturer-assigned
Additionally, the first octet of the OUI may not have the LSB set.
There are 2^23 possible OUI's, and 2^24 possible manufacturer-assigned
addresses within an OUI.
-Ryan
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MAC address for NM7010A
Started by ●January 12, 2006
Reply by ●January 15, 20062006-01-15
Reply by ●January 23, 20062006-01-23
> 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.
As an aside the FreeRTOS.org download includes a demo that uses a NM7010
with an LPC2106.
Regards,
Richard.
http://www.FreeRTOS.org
> 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.
As an aside the FreeRTOS.org download includes a demo that uses a NM7010
with an LPC2106.
Regards,
Richard.
http://www.FreeRTOS.org
