On Fri, 28 Nov 2003 14:47:41 +0100 "Anthony G. Atkielski" <anthony@xxxxxxxxxxxxx> wrote: > (or perhaps not diminished at all). However, in reality, dividing the > field in this way may reduce the address space by a factor of as much > as nineteen orders of magnitude. Again and again, engineers make this > mistake, and render large parts of an address space unusable through > careless, bit-wise allocation of addresses in advance. The 48-bit addresses in IEEE/L2 protocols are divided in half as well as have a couple bits set aside to denote local/global scope and unicast/multicast addresses. It seems to have worked out pretty well. John