Address clustering intuition

Jim Dixon jdd at
Fri Nov 10 07:26:36 UTC 1995

On Thu, 9 Nov 1995, Geert Jan de Groot wrote:

> On Thu, 09 Nov 1995 10:16:39 -0700  "Walter O. Haas" wrote:
> > I've formed an intuition that, if all IP addresses were portable (ie.
> > independent of ISP) and assigned on a strictly geographic basis, then
> > there would *automatically* be clustering of addresses equivalent to
> > that obtained from CIDRization as a result of marketplace forces and
> > the practicalities of technology.
> No, this does not work. Looking at Europe, I know of several ISPs
> to which the shortest path from here (Amsterdam, the Netherlands)
> is via MAE-EAST; they either don't have external connectivity
> on the continent itself, or we have no provider willing to provide
> transit between here and their continental connectivity.

This is a very strange argument.  There is always someone willing 
to provide transit for the right fee.
> There is a second, similar reason: assume that A and B each operate
> in the same area. They use different carriers for transit to MAE-EAST.
> Who of these is going to announce the aggregated announcement?

What aggregated announcement?  Under his scheme, IP addresses are
distributed geographically.  Transit carriers would be responsible
for getting a packet to the correct regional distribution center.
Carriers would peer there and pick up their own customers' traffic.

> > Note that this results from the address being, not the property of the
> > ISP or the end user, but rather of a geographic location.  In other words
> > under my scheme if I picked up and moved a hundred miles I'd have to
> > renumber, but if I just switched ISPs I wouldn't.

Jim Dixon                                           jdd at
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