Waste will kill ipv6 too

William Herrin bill at herrin.us
Fri Dec 29 00:38:17 CST 2017

On Thu, Dec 28, 2017 at 7:24 PM, Ricky Beam <jfbeam at gmail.com> wrote:

> Back to the main theme... artificially cutting the address space in half,
> just makes the point even stronger. IPv6 address space is, in fact, half as
> big as people think it is, because we've drawn a line at /64

Hi Ricky,

Your math is a little off. Drawing the line at /64 doesn't cut the address
space in half, it shrinks it by roughly 19 orders of magnitude. There are
10^38 IPv6 addresses but only 10^19 IPv6 /64 LANs.

-- and the catastrophic part is people *ARE* wiring that into hardware.
> Every example I've seen people bat around about just how big 2^128 is,
> ignores the reality of Real World Networking(tm). They ignore
> infrastructure. The ignore route table size. They ignore the sparse nature
> of hierarchical address assignment. In the "10B people === 10B /48's"
> example, that's a dense PI allocation scheme that will lead to a global
> routing table approaching 10B routes -- you can't aggregate a random
> selection of /48s -- with zero consideration for how those 10B networks
> will interconnect.
> The simple truth is, we're doing the exact same thing with IPv6 that we
> did with IPv4: "The address space is so mind alteringly large we'll never
> use even a fraction of it." *pause* "Umm, wait a minute, we're carving this
> turkey up alarmingly fast." Will we use up the entire thing? Of course we
> will; it's not, in fact, *infinite*, so we *will* eventually assign all of
> it. It's going to happen a lot faster than most people think, as we're so
> cavalier with handing out vast amounts of space for which most people will
> never use more than (a) one LAN, and (b) a few dozen addresses within that
> single LAN. Will it happen in 5, 10, 100 years? The later is a safer bet.
> (not that I'll be around to collect) But just like IPv4, some decades down
> the road, people will see how stupid our allocation scheme really is, and
> begin a new "classless" era for IPv6. The short of it is, we got here
> first, so we don't have to give a shit about being efficient or frugal.


Bill Herrin

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

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