[arin-ppml] End non-public IPv4 assignments?

William Herrin bill at herrin.us
Mon Jan 24 12:08:01 EST 2011

On Mon, Jan 24, 2011 at 9:28 AM, Leo Bicknell <bicknell at ufp.org> wrote:
> Several companies in the financial services sector operate "exchanges".
> To you and I these look just like an internet peering point, the
> operator runs a layer 2 fabric where multiple parties connect.  The
> one I have personal experience with had about 150 companies connected
> last time I checked.  The companies are allowed to talk to each
> other, the one I worked on was used for check clearing between
> banks.
> This block though will never appear on the Internet you can reach
> from your home DSL line.

Thanks Leo.

Playing devil's advocate here: if blocks from these networks will
never appear on the Internet, why isn't the entire 32-bit address
space available to them? What's wrong with overlap between addressing
on the public Internet and addressing on strictly private networks
like financial exchanges, check-clearing networks, electric smartmeter
networks or DoD's SIPRnet? More to the point: what's wrong enough that
it justifies removing those addresses from use on the largest TCP/IP
network (the Internet) where there's a critical shortage?

> I think it would be interesting for ARIN to provide some statistics,
> but my gut tells me that the number of situations like this that
> pass muster with the ARIN staff is small, so I think this is an
> area that isn't even worth thinking about.

It is and it isn't. There's a very large amount of address space out
there which is allocated but does not appear on the public Internet.
The first step to reclaiming part of it for use on the public Internet
would be to stop authorizing new uses.

Bill Herrin

William D. Herrin ................ herrin at dirtside.com  bill at herrin.us
3005 Crane Dr. ...................... Web: <http://bill.herrin.us/>
Falls Church, VA 22042-3004

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