[162514] in North American Network Operators' Group
Re: "It's the end of the world as we know it" -- REM
daemon@ATHENA.MIT.EDU (Geoff Huston)
Wed Apr 24 04:28:29 2013
From: Geoff Huston <gih@apnic.net>
In-Reply-To: <CA+qj4S_Pwfc_sh_rcJFDn5kCxwSB8X4yoJGPQwa9wraTnqw+HA@mail.gmail.com>
Date: Wed, 24 Apr 2013 09:44:09 +1000
To: <nanog@nanog.org>
Errors-To: nanog-bounces+nanog.discuss=bloom-picayune.mit.edu@nanog.org
On 24/04/2013, at 8:10 AM, Andrew Latham <lathama@gmail.com> wrote:
> On Tue, Apr 23, 2013 at 5:41 PM, Valdis Kletnieks
> <Valdis.Kletnieks@vt.edu> wrote:
>> I didn't see any mention of this Tony Hain paper:
>>=20
>> http://tndh.net/~tony/ietf/ARIN-runout-projection.pdf
>>=20
>> ARIN predicted to run out of IP space to allocate in August this =
year.
>>=20
>> Are you ready?
>=20
The prediction of runout business is extremely hard. All of these =
predictions are based on the basic premise that what happened yesterday =
will most likely happen tomorrow. And in a world of very large =
populations this is highly likely - the larger the population its often =
the case that the smaller the impact of individual variations in =
behaviour. That means that once you get a very large population you'd =
expect a relatively low level of uncertainty in trend-based predictive =
models.
But the world of addresses is not so well behaved. For some years now =
we've seen the address world bifurcate into a small number of very large =
actors and a large number of much smaller actors. In the address world =
it was observed that less than 1% (its closer to around 0.5%) =
individual allocations account for more than half of the number of =
allocated addresses. This becomes a problem in the predictive models, as =
the dominant factor in address consumption is now the actions of some 20 =
or so very large entities. If they all fronted at the registry's front =
doors and asked for a three month allocation, and do so again in 90 =
days, and so on, then its pretty obvious that ARIN's remaining 40M =
addresses would not last more than one or two iterations of this cycle.
But what has been apparent in the ARIN region since the IANA runout of =
February 2011 has not been panic, but restraint. If you look at the =
run-down' of the address pool in ARIN over time =
(http://www.potaroo.net/tools/ipv4/arin-pool.png), you could certainly =
make the case that there was a pronounced run on address resources in =
ARIN in the last quarter of 2010, but it all changed in 2011. The =
ensuing 14 months following IANA runout, through 2011 and early 2012, =
saw a pronounced change in the region, and ARIN's address consumption in =
that period slowed down to a consumption rate that got as low as 1M =
addresses per month. This coincided in a change in the address =
allocation policy to reduce the time horizon of "demonstrated need" from =
12 months to 3 months, but that factor alone would not account for the =
entirety of this slow down in the address consumption rates over this 14 =
month period.=20
Following a single largish allocation in early 2012 we've seen the ARIN =
address consumption rate increase somewhat, and the average rate of =
address consumption is currently around 2M addresses per month. If this =
rate of address consumption continues, the ARIN will reach its last /8 =
in early 2014, and if this rate persists, then the registry will exhaust =
its pool around the end of that year, or early 2015.
But given the uncertainty factors here as they relate to the =
distribution of large and small consumers in this area and changing =
sentiment about whether or not panic is a factor in address demands, I'd =
have to comment that the uncertainty factor of any prediction is high. =
Its quite plausible that exhaustion could occur some 6 - 9 months =
earlier than these dates.=20
However, personally I find it a little hard to place a high probability =
on Tony's projected exhaustion date of August this year. I also have to =
qualify that by noting that while I think that a runout of the remaining =
40 M addresses within 4 months is improbable, its by no means =
impossible. If we saw a re-run of the address consumption rates that =
ARIN experienced in 2010, then it's not outside the bounds of =
plausibility that ARIN will be handing out its last address later this =
year.=20
thanks,
Geoff
