Waste will kill ipv6 too

William Herrin bill at herrin.us
Wed Dec 20 20:57:27 CST 2017


On Wed, Dec 20, 2017 at 1:48 PM, Mel Beckman <mel at beckman.org> wrote:

> I won’t do the math for you, but you’re circumcising the mosquito here. We
> didn’t just increase our usable space by 2 orders of magnitude. It’s
> increased more than 35 orders of magnitude.
>

Hi Mel,

The gain is just shy of 29 orders of magnitude. 2^128 / 2^32 = 7.9*10^28.

There are 2^128 = 3.4*10^38 IPv6 addresses, but that isn't 38 "orders of
magnitude." Orders of magnitude describes a difference between one thing
and another, in this case the IPv4 and IPv6 address spaces.


Using a /64 for P2P links is no problem, really. Worrying about that is
> like a scuba diver worrying about how many air molecules are surrounding
> the boat on the way out to sea.
>

It's not a problem, exactly, but it cuts the gain vs. IPv4 from ~29 orders
of magnitude to just 9 orders of magnitude. Your link which needed at most
2 bits of IPv4 address space now consumes 64 bits of IPv6 address space.

Then we do /48s from which the /64s are assigned and we lose another 3 or
so orders of magnitude... Sparsely allocate those /48s for another order of
magnitude. From sparsely allocated ISP blocks for another order of
magnitude. It slips away faster than you might think.

Regards,
Bill Herrin


-- 
William Herrin ................ herrin at dirtside.com  bill at herrin.us
Dirtside Systems ......... Web: <http://www.dirtside.com/>


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