[arin-ppml] IANA IPv4 /8 burn rate.... (was Re: Steppingforward, opening my mouth and removing all doubt about)

Milton L Mueller mueller at syr.edu
Thu Aug 28 14:22:45 EDT 2008

> -----Original Message-----
> Behalf Of Iljitsch van Beijnum
> > of course everyone will use a lot of them.  When they become scarce
> > and expensive, people will start conserving IPv4.
> How is that a good thing?

When you don't know how long it will take to convert, and are uncertain
about the cost of migration, stricter conservation allowing for a longer
transition, if needed, is prudent policy. If a longer transition period
is not needed, a transfer policy does no harm, as the resources become
devalued more rapidly.

> IPv6 addresses are free, because whatever the cost is, after dividing

Business/economic reality check: nothing is free. Certainly not a
protocol that requires heavy investments in new equipment and human
resources/skills. So you don't compare the cost of addresses, you
compare the cost of delivering internet service using the two protocols.

Insofar as you are making a serious argument, it is contained here:

> What we should do is try to make the switch to IPv6 as painless as we
> can. The most important part of that is to make it predictable: we
> need to know what's going to happen in the next 5 years or so. 

Interesting. You think we can make the migration "predictable" by
erecting a brick wall. One logical consequence of this argument: no need
to wait, we can do it tomorrow, or as soon as ARIN agrees to adopt a
flag date where IPv4 just ends. Agree? 

You should. Because if you want to keep handing out IPv4 for the next 3
years or however long the free pool lasts, that is actually inconsistent
with your position, it adds to uncertainty because we don't know exactly
when it will deplete. Could be sooner, could be later. Uncertainty. Bad.

So your position is that starting, say, Jan 1 2009 we just stop handing
out IPv4 blocks. Very clear. You have eliminated all uncertainty about
the v4 address pool.

Do you _really_ think the results of that will be "predictable?" 

Can you _really_ predict, with reasonable levels of probability, that
you will even prevent private unauthorized transfers from taking place
under those circumstances? Much less what migration strategies will be
I don't see arbitrary limits on the use of IPv4 as decreasing the
uncertainty of the migration in any appreciable way.

But why not go whole hog with the uncertainty argument: let's just get a
decree to stop operating the IPv4 internet tomorrow. That would really
clear things up, eh? Certainly everyone would know exactly where they
stood with respect to v4 and v6. But the adjustments would be anything
but "painless" as you put it.

> Any policy change means that there will be a bigger difference between
> what's being predicted and what will happen, 

I'm afraid that that's not true. You are assuming that the migration is
1) a linear, progressive and predictable process and 2) will occupy a
known time period. Both assumptions are shaky. 

A transfer policy is a hedge. It maximizes efficient utilization of
remaining v4 resources while in no way precluding IPv6 migration. 

> so all policy changes are
> at least somewhat harmful, and potentially very harmful. So we should
> only make the ones that are extremely obvious wins.

In an environment of IPv4 scarcity, with large swaths of v4 address
blocks known to be underutilized, and with occupiers of address
resources needing an incentive to migrate, allowing holders of those
address blocks to financially benefit from releasing them is an obvious
win. That's the only reason I support it. 

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