robertmee said:...but didn't know if every two digit code can have A1 to Z99. With the proliferation of Net aware devices, it's interesting to see if this could ever be exhausted.
Paulus said:I believe that each two digits are 0 - FF, giving a total of 274,941,996,890,625 MAC addresses.
I guess that they're going to run out one day ... then what?
robertmee said:274 Trillion...Guess we're a ways off from that
So who manages all those assignments?
Damn, forgot that in all instances, 0 is a valid address number, thereby making 256 possibilities for each, and not 255 (FF).dmroeder said:They also say that a 48bit address allows for 281,474,976,710,656 possible ID's.
rdrast said:IEEE Standards Org.
http://standards.ieee.org/regauth/oui/index.shtml
And, as Peter mentioned above, they are assigned in blocks to companies. The first 3 Octets (11:22:33:xx:xx:xx) are assigned solely to a single company, leaving the remaining 3 octets (xx:xx:xx) to uniquely identify each manufactured device.
Note, that companies that make a LOT of devices will have multiple first-three assignments.
Most (maybe every) PC operating system allows for the MAC addresses to be changed, or spoofed. This doesn't change the address stored in the ethernet card, but it does change how the card reports itself to the outside network. There may not be (or should not be) duplicate hardware MAC address, but I can assure you that duplicate MACs exist.Peter Nachtwey said:Each manufacturer is assigned a block of MAC addresses and manufacturer must never use the same MAC address twice. This way there are never going to be duplicate Mac addresses.
Just because YOU don't have a reason to change the MAC address doesn't mean that there is no reason that anyone else might want to.Peter Nachtwey said:There is no reason to change the MAC address.
jimbo3123Just because YOU don't have a reason to change the MAC address doesn't mean that there is no reason that anyone else might want to.[/QUOTE said:We aren't talking about PC systems. We are talking about embedded systems.