Another v6 question

Owen DeLong owen at delong.com
Thu Jan 27 01:33:25 UTC 2011


On Jan 25, 2011, at 3:35 PM, Max Pierson wrote:

> >I think you may still be missing my point...
> >There are way more /48s available than will ever get used.
> >There are way more /32s available than will ever get used.
> 
> No, I think you're missing my point. Your statements above are of your opinion. The same opinion was said about v4 30 years ago which is why we are where we are today (again, opinions). Reality shows otherwise. 
> 
V4 30 years ago -- expected consumption: ~60 /8s of 256.

IPv6 today -- expected consumption: Maybe 15 /12s of 4096.

The scales in question are vastly different.

> In your opinion, IPv6 is it. We'll NEVER have to do this again. We'll never have to implement NAT (or some other translation protocol) again. We'll never have to worry about running out of space. If thats the case, then why are so many folks arguing over what to give to end users?? It doesn't matter by your opinion. Give em what they want!! There's no possible way we can use that many addresses.
> 
Not at all... In my opinion, IPv6 will probably last about 30-50 years. In my opinion, IPv6 addressing will outlast IPv6 usability on other fronts. I absolutely think we'll have to do this all again. I just don't think that addresses are going to be the thing we run out of next time.

I think people are arguing over what to give end users because people are generally bad at large-number arithmetic. The human brain can visualize things up to as much as a few hundred. Some people can even visualize a couple of thousand. Beyond that, our neurons just think of things as randomly larger magnitudes of "a really big number". It all gets lumped into "a whole lot" and we lose site of the numeric realities.

> Lets get back to reality. No one, and i'll say it once more, NO ONE knows if v6 is the end all be all. (I would agree with you in regards of our lifetime we won't even use a drop in the bucket). It only took ~10 years to figure out they did it all wrong the first time around. Can you speak for the next 100 years, what about 200 years?? (Not that it matters to us anyway, we'll be long gone by then. But they way you put it is that this beast we're dealing with will never have to be revamped again. Future proof! To me, that line of thinking is a little short-sided). 
> 
No, that's not what I said at all. What I said was that addressing isn't going to be the constraint that causes us to have to revamp it next time.

Let's put it in perspective... If we give a /48 to every end site, then, we have
enough addresses for 281,474,976,710,656 end sites. There are currently
<7,000,000,000 people on the planet, so, let's assume we give each of them
10 buildings (home, work, a summer cottage, and 7 spares for whatever).
That consumes 70,000,000,000 /48s. Now we're down to 281,404,976,710,656
/48s remaining. If we build 1,000 new end sites every second, we will
need 281,404,976,710 seconds to use them all up. At 86,400 seconds
per day, that's 3,257,002 days or 8,923 years.

I'm pretty sure that we will not be able to sustain building 1,000 new
structures per second for 8,923 years. To do it in 200 years, we
would have to build almost 50,000 new structures every second.

I realize there have been some amazing periods of growth on the
internet, but, even at the peak of the .COM boom, even Cisco wasn't
building at anywhere near that rate.

However, all of this is a bit out of context from what I was saying.
The point was that if you're trying to figure out how big routers are
going to have to be for near-term IPv6 or even medium-term IPv6
deployment, counting the total possible number of prefixes isn't
a useful metric because the actual utilization will be nowhere
near that large and the numbers are impossible to use as an
engineering spec. for any technology yet known.

> 
> Some will care and adapt as we all hope they would, some will simply find another provider with v4 space to spare thats not charging. This won't stop until RIR/LIR's stop re-issuing v4 space. At that point, then the squeeze is on and I would imagine ALL ISP's will charge at that point because they're getting charged for having v4 space.
> 
There will come a time (likely this year) when there isn't another provider with v4 space to spare that you can find. One that doesn't charge for it? That'll probably happen even earlier.

I think that the RIR/LIRs won't have to stop reissuing space. I think we'll rapidly reach a point where space isn't coming back to them to be reissued. At least not in meaningful quantities.

> >I don't think IPv4 will continue to grow for all that long. I think the plug will get pulled by ISPs desperate to reduce the spiraling costs of continuing to >support IPv4. When it starts becoming increasingly expensive to get ISPs to provide IPv4 services, the rest of the internet will begin to move rapidly >away from IPv4.
> 
> >I anticipate this will take about 5-10 years after IPv4 runout at ARIN/APNIC/RIPE (which will be nearly simultaneous).
> 
> I would agree to this as well, 5-10 years of weaning off v4 at that point is probably what we'll end up seeing, although I would say that 5-10 years in this industry is a relatively long time. Probably much longer than any of us want to see v4 stick around anyway.
> 
Well, that's <6-11 years from today.

I'd like to see IPv4 go away in ~3 years. Any faster would be too traumatic.
I think 6 years is a perfectly reasonable time frame. I think if it takes 11 years
it will be because of significant foot-dragging by some key organizations.
I'm not convinced that foot-dragging is as likely as some people are, but,
there's enough probability to provide some wiggle room in the numbers.

Owen




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