[181839] in North American Network Operators' Group
Re: Dual stack IPv6 for IPv4 depletion
daemon@ATHENA.MIT.EDU (Mel Beckman)
Sun Jul 5 19:33:17 2015
X-Original-To: nanog@nanog.org
From: Mel Beckman <mel@beckman.org>
To: Matthew Kaufman <matthew@matthew.at>
Date: Sun, 5 Jul 2015 23:33:09 +0000
In-Reply-To: <5599BC82.1070403@matthew.at>
Cc: "nanog@nanog.org" <nanog@nanog.org>
Errors-To: nanog-bounces@nanog.org
Matthew,
You can be part of the solution or part of the sarcasm.=20
-mel via cell
> On Jul 5, 2015, at 4:25 PM, Matthew Kaufman <matthew@matthew.at> wrote:
>=20
>> On 7/4/2015 5:09 AM, Josh Moore wrote:
>> Traditional dual stack deployments implement both IPv4 and IPv6 to the C=
PE.
>> Consider the following:
>>=20
>> An ISP is at 90% IPv4 utilization and would like to deploy dual stack wi=
th the purpose of allowing their subscriber base to continue to grow regard=
less of the depletion of the IPv4 space.
>=20
> Admirable goal.
>=20
>> Current dual stack best practices seem to recommend deploying BOTH IPv4=
and IPv6 to every CPE.
>=20
> That's what "dual stack" means, yes.
>=20
>> If this is the case, and BOTH are still required, then how does IPv6 he=
lp with the v4 address depletion crisis?
>=20
> Well, you dual-stacked your subscribers about 5-8 years ago, and about 3-=
5 years ago we're basically done moving all content they might wish to acce=
ss to IPv6 as well. So about a year ago, you've been able to offer an IPv6-=
only product that actually works just fine... and you charge extra for IPv4=
(which most people don't want/need at this point)
>=20
>> Many sites and services would still need legacy IPv4 compatibility.
>=20
> Well,... because you and every other ISP dual-stacked over 5 years ago, a=
nd the transition is just about done, I wouldn't call it "many" at this poi=
nt.
>=20
>> Sure, CGN technology may be a solution but what about applications that =
need direct IPv4 connectivity without NAT?
>=20
> By now, there aren't any such applications in wide use. A few legacy thin=
gs that couldn't be updated, sure, and for those you can still offer IPv4 a=
ddresses and access to the few people willing to pay extra for that.
>=20
>> It seems that there should be a mechanism to enable on-demand and effici=
ent IPv4 address consumption ONLY when needed.
>=20
> That's not needed, because with everyone on IPv6, there's more than enoug=
h IPv4 space available for you... and if you need to buy some, it is almost=
worthless, so the prices are near zero.
>=20
>> My question is this: What, if any, solutions like this exist?
>=20
> Nobody bothered to build sharing strategies because it was clear that it =
wouldn't be needed as IPv6 deployment ramped up over the last decade.
>=20
>> If no solution exists then what is the next best thing? What would the =
overall IPv6 migration strategy and goal be?
>=20
> Just continue the dual-stack approach for those who need it, as you've be=
en doing for 5+ years. For the rest, IPv4 is historic.
>=20
>>=20
>> Sorry for the length of this email but these are legitimate concerns and=
while I understand the need for IPv6 and the importance of getting there; =
I don't understand exactly HOW that can be done considering the immediate i=
ssue: IPv4 depletion.
>=20
> Fortunately, the recent ARIN announcement is of no real concern, because =
you and everyone else moved to a nearly 100% IPv6 Internet years ago.
>=20
> Matthew Kaufman
>=20
