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Re: [arin-announce] IPv4 Address Space (fwd)

  • From: william
  • Date: Mon Oct 27 18:10:46 2003

> Does anybody have statistics for assigned-but-not-announced space? I'd be
> willing to bet there will be more and more dead space over the years, and
> in fact quite a bit of "increasing usage" is just churn.
I have these statistics at

At above page look specifically at the blue part of the graph for assigned- 
but-not-allocated space. I actually looked at opposite (assigned & routed 
- this I named "routing utilization ratio") as way to determine efficiency
of RIR policies. This ratio is very high for the new ARIN ip blocks (97%),
but as you pointed above the churn is high for older blocks and only 42% 
of allocated space in 192/8 is actively routed. The ratios are in between 
around 60%-80% for other old blocks and these numbers both has to do with 
allocation policies that were not developed at the time and with churn due 
to dead companies. I have done analysis for different time periods, see:

If you need data on exact amounts, you will need to do your own substraction
use allocation statistics data from
and substract current use data from

> Does anybody honestly think companies will commit the capex needed to
> implement IPv6?
Not without additional benefits. We need either applications that are
working a lot better at ipv6 or we may yet have to see ipv4 space ran out
before it becomes clear to everybody that ipv6 is a must.

William Leibzon
Elan Networks