[arin-ppml] Use of "reserved" address space.

michael.dillon at bt.com michael.dillon at bt.com
Mon Jun 28 04:16:18 EDT 2010

> Part of my reason for preferring 240/4's use as private addresses is
> that you can reasonably hope to control what goes on inside your own
> network.

Right. So use 126/8 inside your network.

> What isn't debatable is that we're approaching a dire shortage and
> right now 240/4 is a honking lot of address space that benefits
> exactly _nobody_.

Somebody calculated how long this would extend the IPv4 lifetime and
it turned out to only be a few months. That is not a honking lot, but
a drop in the bucket. 

And we are not approaching a dire shortage. We are approaching the land
of plenty, but to get there we first have to cross the scorching desert.
The clever folk crossed it in winter, but now it is summer and the 
laggards are suffering accordingly. But even for them, the land of
plenty has room amongst its green meadows and shimmering lakes.

> > Better to focus on v6 transition.
> Myopic. Unless another credible solution presents, IPv4 carrier NATs
> -ARE- the v6 transition.

It's not so simple. Carrier Grade NAT costs money. Some companies will
dump low profit customers to recover addresses for more lucrative use.
Some will forcefully move customers to new IPv6 services for the same
reason. Economics will be the driver and different companies have very
different internal economics.

And let's not forget that companies are run by decision makers. These
may just ignore the problem and jump ship. This is a common practice 
amongst the next-quarter-focused MBA crowd. It may well drive a few
into bankruptcy, and then the companies who have IPv6 services ready wil
be able to grow their network fast enough to take on the sudden rush of

We really cannot predict anything other than the fact that it is now too
late for a smooth transition, and we are in for a couple of years of
Internet operations chaos.

--Michael Dillon

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