[182391] in North American Network Operators' Group
Re: Dual stack IPv6 for IPv4 depletion
daemon@ATHENA.MIT.EDU (Owen DeLong)
Wed Jul 15 20:48:44 2015
X-Original-To: nanog@nanog.org
From: Owen DeLong <owen@delong.com>
In-Reply-To: <op.x1t3y0kqtfhldh@rbeam.xactional.com>
Date: Wed, 15 Jul 2015 17:48:39 -0700
To: Ricky Beam <jfbeam@gmail.com>
Cc: nanog@nanog.org
Errors-To: nanog-bounces@nanog.org
> On Jul 15, 2015, at 14:43 , Ricky Beam <jfbeam@gmail.com> wrote:
>=20
> On Wed, 15 Jul 2015 17:23:52 -0400, Owen DeLong <owen@delong.com> =
wrote:
>> I will point out that nobody has said =E2=80=9Cwhat the F*** were =
they thinking=E2=80=9D when they made it possible to use 4GB of RAM =
instead of just 640k, but lots of people have said =E2=80=9Cwhat the =
F*** were they thinking when they limited it to 640k.=E2=80=9D
>=20
> Actually, they did. And "PAE" was invented. (or "re-invented", as =
various paging mechanisms had existed for many decades by then)
Huh?
You=E2=80=99re missing the point or deliberately ignoring it, hard to =
tell which.
Vast address availability has never lead to WTF moments.
Restrictive addressing, OTOH, has created many WTF moments.
I look at NAT and I think WTF were they thinking, but it was an =
unfortunate consequence of the 32-bit limitation of IPv4.
It=E2=80=99s an effort at coping with the limitations, however misguided =
it may be.
I look at providers handing out /60 and I think WTF are they thinking. =
There=E2=80=99s no legitimate reasoning behind it.
Why repeat the same mistakes again by limiting IPv6 deployments to =
something less than /48?
As to your arguments on segmentation, no, RFC1918 is 3 segments because, =
again, of limitations in IPv4. In IPv6,
it=E2=80=99s still only one segment. Arguing that the 4th (which =
actually isn=E2=80=99t RFC-1918) is a segmentation isn=E2=80=99t =
entirely valid
as it=E2=80=99s more of an allocation than a segmentation and in any =
case, all of them are more than covered in the single
existing IPv6 segmentation of fc00::/0 or even fd00::/9.
Class E isn=E2=80=99t so much a segmentation as an early error that =
never got corrected. By the time anyone recognized the
need to fix class E, it was easier to move to IPv6 than to repair that =
part of IPv4, so we moved on.
255/8 is not really still applicable and does not apply to IPv6 in any =
way, so I don=E2=80=99t think you can count that one.
Same with 0/8. These weren=E2=80=99t segmentations, they were =
limitations of the technology at the time those RFCs
were written.
You can argue that localhost is a segmentation, I suppose, but in IPv6, =
it has reserved ::1/128.
Everything else in ::/3 is still available to the best of my knowledge.
So, in terms of total impact on IPv6, we=E2=80=99ve got three =
segmentations other than Unicast that are carried forward
from IPv4. No more, no less. (unless someone comes up with something not =
yet mentioned).
Owen
