ISP customer assignments

Michael Dillon wavetossed at
Thu Oct 8 15:29:39 UTC 2009

> Sorry to be a curmudgeon and let me play devil's advocate for a minute.  I
> realize that the address space is enormous; gigantic, even, but if we treat
> it as cavalierly as you all are proposing, it will get used up.  If its
> treated like an infinite resource  that will never, ever be used up as we
> have done with every other resource on the planet, won't we find ourselves
> in a heap of trouble?

Of course, you are right.

That's why, when some people took a close look at the numbers based on
a /48 per site, and published their findings, the RIRs made an adjustment to
address allocation policy so that it was acceptable to allocate a /56 for a
consumer customer, i.e. private residence of some sort. By doing that, they
calculated that they could mitigate the small risk that we would run very low
on IPv6 addresses around 100 years from now. Having made the change, we
are now confident that there are plenty of IPv6 addresses to last more than
a century, which basically means that you and your children and your grand
children will all be dead when IPv6 gets close to exhaustion.

Geoff Huston wrote this: <>
to explain the small risk, and his proposals to adjust the HD ratio and go to
a /56 for private residential assignments was basically accepted. If only a few
of the biggest cable ISPs use the /56 model, then we are OK.

I have great confidence that our descendants will avoid the Idiocracy and
be capable of designing and deploying a replacement for IPv6 if that is ever
needed. <> Last time I checked, my
taps were still delivering fresh clean "toilet water", not Brawndo energy drink.

--Michael Dillon

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