[182374] in North American Network Operators' Group
Re: Dual stack IPv6 for IPv4 depletion
daemon@ATHENA.MIT.EDU (Owen DeLong)
Wed Jul 15 17:34:18 2015
X-Original-To: nanog@nanog.org
From: Owen DeLong <owen@delong.com>
In-Reply-To: <21926.51395.248847.677579@world.std.com>
Date: Wed, 15 Jul 2015 14:34:13 -0700
To: Barry Shein <bzs@world.std.com>
Cc: "nanog@nanog.org" <nanog@nanog.org>
Errors-To: nanog-bounces@nanog.org
> On Jul 15, 2015, at 13:55 , Barry Shein <bzs@world.std.com> wrote:
>=20
>=20
> On July 15, 2015 at 09:20 owen@delong.com (Owen DeLong) wrote:
>>=20
>> There are two ways to waste addresses. One is to allocate them to =
users who
>> don=1B,Ab=C2=80=C2=99t actually use all of them.
>>=20
>> The other is to keep them on the shelf in the free pool until well =
past the useful
>> life of the protocol.
>=20
> I'd add a third which is segmentation and I think that's a real
> threat. That is, assigning large chunks to specific functions by
> policy usually in support of technical needs. For example IPv4's
> multicast block. Poof, 224/4 gone. Or similar.
>=20
> Suddenly it's not 2^N bits it's just N bits.
>=20
> My claim is that such segmentation tends to grow over time as people
> find good arguments to segment.
>=20
fd00::/8 is already wasted on ULA.
fe80::/10 (effectively fe00::/8) is already allocated (somewhat =
wastefully, as a /64 probably would do the trick) to link local
ff00::/8 is already allocated to multicast.
That covers multicast and RFC-1918. Are there any other IPv4 =
segmentations that you can think of?
I=E2=80=99m not being snarky=E2=80=A6 I=E2=80=99m genuinely interested.
Given that we came up with 3 total segmentations in IPv4 over the course =
of 30 years of IPv4 protocol use,
which consumed a total of /4(multicast)+/8+/12+/16(RFC-1918)+/16(link =
local) of IPv4 and 3 /8s of IPv6.
Even if we toss 5 more /8s to segmentation over the next 30 years, I =
think we=E2=80=99re OK, though we would have
burned through a /5 at that point in segmentation.
I think effectively, we can consider that e000::/3 is essentially set =
aside for such purposes and we still have
5/8ths of the address space after burning through the current /3 of =
unicast and a second /3 of unicast while
we contemplate a more restrictive policy.
Owen
> --=20
> -Barry Shein
>=20
> The World | bzs@TheWorld.com | =
http://www.TheWorld.com
> Purveyors to the Trade | Voice: 800-THE-WRLD | Dial-Up: US, PR, =
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