Dual stack IPv6 for IPv4 depletion

Tue Jul 14 18:56:34 UTC 2015

Mel Beckman wrote:
> Owen,
> 
> By the same token, who 30 years ago would have said there was anything
> wrong with giving single companies very liberal /8 allocations? 

Actually 30 years ago it was very difficult to get a /8 even for a US Gov
organization. I have firsthand experience with being refused. As much as
people on this list like to paint a fantasy about 'the liberal policies of
the good-old- days' it was not as wild and loose as it is often made out to
be. 40 years ago it was easier to get a /8 than it was 30 year ago, but
there were still restrictions. At the end of the day, your impact on the
routing system determined which bucket you were put in, because the global
routing table was the scarce resource that needed management.

> Companies
> that for the most part wasted that space, leading to a faster exhaustion
of
> IPv4 addresses. History cuts both ways.

Call it waste if you want, but it is more likely that it was just allocation
a decade ahead of need, and that need would likely not have developed if the
global routing system collapsed due to too many /16's being allocated before
routers could handle that. 

> 
> 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.

"Reasonable caution" was only allocating 1/8th of the space up front, and
recommending that end sites be limited to a /48 without justifying more (rfc
3177). "IPv4-think" is refusing to acknowledge the math, and insisting that
just because the average consumer has been limited to a single subnet for
the last 15 years, that it was all they will ever need. Rewind the clock 16
years and you found that the restriction was a single mac-address, because
'nobody needs anything more than a single computer'. 

CPE developers have to manage their costs, and they will build to the limits
of what is available across the majority of providers. When that is
artificially restricted by unnecessary  "IPv4-think" conservation, you will
build a deployed base that has limited capability. Just as it is still
taking time to remove the deployed base of IPv4-only cpe, getting rid of
limitations will be slow, difficult, and costly. Fast forward 30 years, and
the network managers of the day will be asking why the clowns who insisted
on such an artificially restricted allocation model could be so short
sighted because they will not have been tainted by or understand
"IPv4-think". 

IPv6 is not the last protocol known to mankind. IF it burns out in 400-500
years, something will have gone terribly wrong, because newer ideas about
networking will have been squashed along the way. 64 bits for both hosts and
routing was over 3 orders of magnitude more than sufficient to meet the
design goals for the IPv4 replacement, but in the context of the dot-com
bubble there was a vast outcry from the ops community that it would be
insufficient for the needs of routing. So the entire 64 bits of the original
proposal was given to routing, and the IETF spent another year arguing about
how many bits more to add for hosts. Now, post bubble burst, we are left
with 32,768x the already more than sufficient number of routing prefixes,
but "IPv4-think" conservation believes we still need to be extremely
conservative about allocations. 

Tony

> 
> We can always be more generous later.
> 
>  -mel beckman
> 
> > On Jul 14, 2015, at 10:04 AM, Owen DeLong <owen at delong.com> wrote:
> >
> > 30 years ago, if you'd told anyone that EVERYONE would be using the
> > internet 30 years ago, they would have looked at you like you were stark
> raving mad.
> >
> > If you asked anyone 30 years ago "will 4 billion internet addresses be
> > enough if everyone ends up using the internet?", they all would have
told
> you "no way.".
> >
> > I will again repeat. Let's try liberal allocations until we use up the
> > first /3. I bet we don't finish that before we hit other scaling limits
of IPv6.
> >
> > If I'm 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.
> >
> > Owen
> >
> >
> >> On Jul 14, 2015, at 06:23 , George Metz <george.metz at gmail.com> wrote:
> >>
> >> 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.
> >>
> >> 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.
> >>
> >> On Tue, Jul 14, 2015 at 12:22 AM, Owen DeLong <owen at delong.com
> <mailto:owen at delong.com>> wrote:
> >> How so?
> >>
> >> There are 8192 /16s in the current /3.
> >>
> >> ISPs with that many pops at 5,000,000 end-sites per POP, even
> >> assuming 32 end-sites per person can't really be all that many.
> >>
> >>
> >> 25 POPS at 5,000,000 end-sites each is 125,000,000 end-sites per ISP.
> >>
> >> 7,000,000,000 * 32 = 224,000,000,000 / 125,000,000 = 1,792 total /16s
> consumed.
> >>
> >> Really, if we burn through all 8,192 of them in less than 50 years
> >> and I'm still alive when we do, I'll help you promote more
> >> restrictive policy to be enacted while we burn through the second /3.
> >> That'll still leave us 75% of the address space to work with on that
new
> policy.
> >>
> >> If you want to look at places where IPv6 is really getting wasted,
> >> let's talk about an entire /9 reserved without an RFC to make it
> >> usable or it's 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.
> >>
> >> Yeah, I'm not too worried about the ISPs that can legitimately justify
a
> /16.
> >>
> >> Owen
> >>
> >>> On Jul 13, 2015, at 16:16 , Joe Maimon <jmaimon at ttec.com
> <mailto:jmaimon at ttec.com>> wrote:
> >>>
> >>>
> >>>
> >>> Owen DeLong wrote:
> >>>> JimBob's ISP can apply to ARIN for a /16
> >>>
> >>> Like I said, very possibly not a good thing for the address space.
> >>
> >>
> >