There is a standard format, as indicated. As for how many MAC's

can be issued, remember that the number is in hex with each pair

having 70 (alpha & numeric) combinations and each set of 6 having

the possibility of 5 different permutations. (I think I got this

right regarding combinations and permutations.) That could cover

all of the communication devices used in digital electronics.

GR

Wow. You missed it. If you did it the easy way, you'd get it right.

First, digits 0-9 and A-F define 16 values (same as 4 bits), so each

pair has 256 possible values, not 70.

Anyway, a *much* easier way to look at it (IMO): there are 12 hex

digits, each representing 4 bits, so the MAC address represents a 48-bit

binary number.

Thus the possible values are 0 to (2^48 - 1), or 0 to about 2.81x10^14

(AKA 2.81E14).

The current human population of the earth is about 7x10^9.