[182010] in North American Network Operators' Group
Re: Dual stack IPv6 for IPv4 depletion
daemon@ATHENA.MIT.EDU (Harald Koch)
Thu Jul 9 12:01:14 2015
X-Original-To: nanog@nanog.org
In-Reply-To: <1b2903db305f4e1fa65400b0743397bd@pur-vm-exch13n1.ox.com>
Date: Thu, 9 Jul 2015 12:01:11 -0400
From: Harald Koch <chk@pobox.com>
To: Matthew Huff <mhuff@ox.com>
Cc: NANOG list <nanog@nanog.org>
Errors-To: nanog-bounces@nanog.org
On 9 July 2015 at 11:42, Matthew Huff <mhuff@ox.com> wrote:
> What am I missing? Is it just the splitting on the sextet boundary that is
> an issue, or do people think people really need 64k subnets per household?
>
One thing you're missing is that some of these new-fangled uses for IP
networking will want to do their own subnetting. It's not "here's a subnet
for the car", it's "here's a /56 for the car to break into smaller pieces
as required".
A /56 isn't 256 subnets, it's 8 levels of subnetting (or 2 levels, if
you're human and want to subnet at nibble boundaries). A /48 is 16 (or 4)
levels. I have four vehicles, so I'd want to carve out a /52 for "the car
network" to make the routing and security easier to manage, and leave room
for expansion (or for my guests...)
One more consideration for you: we're currently allocating all IPv6
addresses out of 2000::/3. That's 1/8th of the space available. If we
discover we've messed up with this sparse address allocation idea, we have
7/8ths of the remaining space left to do something different.
--
Harald
