nanog mailing list archives

Re: IPv4 address length technical design


From: George Herbert <george.herbert () gmail com>
Date: Wed, 3 Oct 2012 12:31:48 -0700

On Wed, Oct 3, 2012 at 12:22 PM, Izaac <izaac () setec org> wrote:
On Wed, Oct 03, 2012 at 06:52:57PM +0200, Seth Mos wrote:
"Pick a number between this and that." It's the 80's and you can
still count the computers in the world. :)

And yet, almost concurrently, IEEE 802 went with forty-eight bits.  Go
figure.  I'm pretty sure the explanation you're looking for is: It was
with the word size of the most popular minis and micros at the time.

The 48 bit MAC was 1980; notable that it was not primarily handled in
software / CPUs (ethernet key functionality is in dedicated interface
hardware, though the stack is MAC-aware obviously).  CPU register bit
length is less critical when you have a dedicated controller of
arbitrary bittedness handling MACs.


-- 
-george william herbert
george.herbert () gmail com


Current thread: