[182257] in North American Network Operators' Group
Re: Dual stack IPv6 for IPv4 depletion
daemon@ATHENA.MIT.EDU (Owen DeLong)
Tue Jul 14 13:30:33 2015
X-Original-To: nanog@nanog.org
From: Owen DeLong <owen@delong.com>
In-Reply-To: <D2CB379F-8E2C-4A60-96A8-F91A533499DB@beckman.org>
Date: Tue, 14 Jul 2015 10:30:23 -0700
To: Mel Beckman <mel@beckman.org>
Cc: "nanog@nanog.org" <nanog@nanog.org>
Errors-To: nanog-bounces@nanog.org
You don=92t think holding nearly 7/8ths of the address space in reserve =
for a future addressing policy is adequate judiciuosness?
The IPv4 /8s constituted 1/2 of the address space. The /16s another 1/4, =
and the /24s an additional 1/8th at the time.
Overall, that was 7/8ths of the address space assigned to unicast and =
9/16ths allocated if you included multicast.
In IPv6, we have 1/8th set aside for unicast, 1/256th for multicast, =
1/256th for ULA, 1/1024th for link-local, and
a couple of infinitesimal fractions set aside for other things like =
localhost, IPV6_ADDR_ANY, etc.
As I said, let=92s be liberal as designed with the first /3. If I=92m =
wrong and you can prove it in my remaining lifetime, I will happily
help you develop more restrictive allocation policy for the remaining =
3/4 while the second /3 is used to continue growing the
IPv6 internet.
Whatever unexpected thing causes us to finish off the first /3 likely =
won=92t burn through the second /3 before we can
respond with new policy. We still have almost 3/4 of the address space =
available for more restrictive allocations.
Frankly, I bet about 1/8th of the IPv4 address space probably is in the =
hands of the top 64 organizations. Maybe more.
In this case, 1/8th of the address space will more than cover the entire =
known need many many many times over, even
with very liberal allocations.
Owen
> On Jul 14, 2015, at 10:13 , Mel Beckman <mel@beckman.org> wrote:
>=20
> Owen,
>=20
> By the same token, who 30 years ago would have said there was anything =
wrong with giving single companies very liberal /8 allocations? =
Companies that for the most part wasted that space, leading to a faster =
exhaustion of IPv4 addresses. History cuts both ways.=20
>=20
> I think it's reasonable to be at least somewhat judicious with our =
spanking new IPv6 pool. That's not IPv4-think. That's just reasonable =
caution.=20
>=20
> We can always be more generous later.=20
>=20
> -mel beckman
>=20
>> On Jul 14, 2015, at 10:04 AM, Owen DeLong <owen@delong.com> wrote:
>>=20
>> 30 years ago, if you=92d told anyone that EVERYONE would be using the =
internet 30 years
>> ago, they would have looked at you like you were stark raving mad.
>>=20
>> If you asked anyone 30 years ago =93will 4 billion internet addresses =
be enough if everyone
>> ends up using the internet?=94, they all would have told you =93no =
way.=94.
>>=20
>> I will again repeat=85 Let=92s try liberal allocations until we use =
up the first /3. I bet we don=92t
>> finish that before we hit other scaling limits of IPv6.
>>=20
>> If I=92m wrong and we burn through the first /3 while I am still =
alive, I will happily help you
>> get more restrictive policy for the remaining 3/4 of the IPv6 address =
space while we
>> continue to burn through the second /3 as the policy is developed.
>>=20
>> Owen
>>=20
>>=20
>>> On Jul 14, 2015, at 06:23 , George Metz <george.metz@gmail.com> =
wrote:
>>>=20
>>> That's all well and good Owen, and the math is compelling, but 30 =
years ago if you'd told anyone that we'd go through all four billion =
IPv4 addresses in anyone's lifetime, they'd have looked at you like you =
were stark raving mad. That's what's really got most of the people who =
want (dare I say more sane?) more restrictive allocations to be the =
default concerned; 30 years ago the math for how long IPv4 would last =
would have been compelling as well, which is why we have the entire =
Class E block just unusable and large blocks of IP address space that =
people were handed for no particular reason than it sounded like a good =
idea at the time.
>>>=20
>>> It's always easier to be prudent from the get-go than it is to rein =
in the insanity at a later date. Just because we can't imagine a world =
where IPv6 depletion is possible doesn't mean it can't exist, and exist =
far sooner than one might expect.
>>>=20
>>> On Tue, Jul 14, 2015 at 12:22 AM, Owen DeLong <owen@delong.com =
<mailto:owen@delong.com>> wrote:
>>> How so?
>>>=20
>>> There are 8192 /16s in the current /3.
>>>=20
>>> ISPs with that many pops at 5,000,000 end-sites per POP, even =
assuming 32 end-sites per person
>>> can=92t really be all that many=85
>>>=20
>>>=20
>>> 25 POPS at 5,000,000 end-sites each is 125,000,000 end-sites per =
ISP.
>>>=20
>>> 7,000,000,000 * 32 =3D 224,000,000,000 / 125,000,000 =3D 1,792 total =
/16s consumed.
>>>=20
>>> Really, if we burn through all 8,192 of them in less than 50 years =
and I=92m still alive
>>> when we do, I=92ll help you promote more restrictive policy to be =
enacted while we
>>> burn through the second /3. That=92ll still leave us 75% of the =
address space to work
>>> with on that new policy.
>>>=20
>>> If you want to look at places where IPv6 is really getting wasted, =
let=92s talk about
>>> an entire /9 reserved without an RFC to make it usable or it=92s =
partner /9 with an
>>> RFC to make it mostly useless, but popular among those few remaining =
NAT
>>> fanboys. Together that constitutes 1/256th of the address space cast =
off to
>>> waste.
>>>=20
>>> Yeah, I=92m not too worried about the ISPs that can legitimately =
justify a /16.
>>>=20
>>> Owen
>>>=20
>>>> On Jul 13, 2015, at 16:16 , Joe Maimon <jmaimon@ttec.com =
<mailto:jmaimon@ttec.com>> wrote:
>>>>=20
>>>>=20
>>>>=20
>>>> Owen DeLong wrote:
>>>>> JimBob=92s ISP can apply to ARIN for a /16
>>>>=20
>>>> Like I said, very possibly not a good thing for the address space.
>>>=20
>>>=20
>>=20
