[181843] in North American Network Operators' Group
Re: Dual stack IPv6 for IPv4 depletion
daemon@ATHENA.MIT.EDU (Mel Beckman)
Mon Jul 6 09:44:22 2015
X-Original-To: nanog@nanog.org
From: Mel Beckman <mel@beckman.org>
To: Lee Howard <Lee@asgard.org>
Date: Mon, 6 Jul 2015 13:44:18 +0000
In-Reply-To: <D1BFF78A.B6AC5%Lee@asgard.org>
Cc: Josh Moore <jmoore@atcnetworks.net>, "nanog@nanog.org" <nanog@nanog.org>
Errors-To: nanog-bounces@nanog.org
And let's all complain to the MPLS working group to get IPv6 support finish=
ed up!
-mel beckman
> On Jul 6, 2015, at 6:27 AM, Lee Howard <Lee@asgard.org> wrote:
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> Some thoughts. . .
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> =B3Native dual-stack=B2 is =B3native IPv4 and native IPv6.=B2
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> =B3Dual-stack=B2 might be native, or might by =B3native IPv6 plus IPv4 ad=
dress
> sharing.=B2
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> Your IPv4 address sharing options are CGN, DS-Lite, and MAP. There are
> operational deployments of all three, in the order given. You need them
> close enough to your customers that traffic will return over the same
> path. You can=B9t share state among a cluster of boxes, but that=B9s not =
the
> end of the world; a device failure sometimes causes loss of state. MAP is
> the hot new thing all the cool kids are doing.
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> Look to your router and load balancer vendors for devices that do these.
> CGN is the only one that doesn=B9t require updates to the home gateway. T=
he
> more IPv6 your customers use, the smaller your CGN/AFTR/MAP can be.
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> Think about how you=B9ll position it to customers. It=B9s difficult to ch=
ange
> a customer=B9s service mid-contract. At some point, a customer is no long=
er
> profitable: if NAT costs and service calls add up, you may be better off
> buying addresses or losing the customer. You may need to buy some IPv4
> addresses to give you time; contact a broker.
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> You may be surprised how hard it is to root IPv4 out of the system. Don=
=B9t
> buy anything you can=B9t manage over IPv6, including servers and
> applications. Sorry, vendor, I can=B9t buy your cluster, I don=B9t have t=
he
> IPv4 address space to provision it.
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> Lee
>=20
> On 7/4/15, 8:09 AM, "NANOG on behalf of Josh Moore"
> <nanog-bounces@nanog.org on behalf of jmoore@atcnetworks.net> wrote:
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>> Traditional dual stack deployments implement both IPv4 and IPv6 to the
>> CPE.
>> Consider the following:
>>=20
>> An ISP is at 90% IPv4 utilization and would like to deploy dual stack
>> with the purpose of allowing their subscriber base to continue to grow
>> regardless of the depletion of the IPv4 space. Current dual stack best
>> practices seem to recommend deploying BOTH IPv4 and IPv6 to every CPE. I=
f
>> this is the case, and BOTH are still required, then how does IPv6 help
>> with the v4 address depletion crisis? Many sites and services would stil=
l
>> need legacy IPv4 compatibility. Sure, CGN technology may be a solution
>> but what about applications that need direct IPv4 connectivity without
>> NAT? It seems that there should be a mechanism to enable on-demand and
>> efficient IPv4 address consumption ONLY when needed. My question is this=
:
>> What, if any, solutions like this exist? If no solution exists then what
>> is the next best thing? What would the overall IPv6 migration strategy
>> and goal be?
>>=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 immediat=
e
>> issue: IPv4 depletion.
>>=20
>>=20
>> Thanks
>>=20
>> Joshua Moore
>> Network Engineer
>> ATC Broadband
>> 912.632.3161
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>=20
