An informal survey... round II

Kevin Oberman oberman at
Thu Aug 30 14:46:40 UTC 2007

> Date: Thu, 30 Aug 2007 10:18:41 -0400
> From: Andrew D Kirch <trelane at>
> Sender: owner-nanog at
> John Curran wrote:
> > At 9:12 AM -0400 8/30/07, William Herrin wrote:
> >   
> >> On 8/30/07, John Curran <jcurran at> wrote:
> >>     
> >>> I.E.  If at some time unknown around 2010, ISP's stop receiving
> >>> new allocations from their RIR, and instead use of many smaller
> >>> "recycled" IPv4 address blocks, we could be looking at a 10x to
> >>> 20x increase in routes per month for the same customer growth.
> >>>       
> >> John,
> >>
> >> Why should we announce tiny recycled blocks? If there is a /16 in the
> >> swamp in which half the space is free but its all /24's, why wouldn't
> >> wouldn't we allocate all the free /24's to a single entity and
> >> instruct the entity to announce it as a "holey" /16? The existing /24
> >> holders will override (punch holes in) the /16 for their /24's.
> >>     
> >
> > Consider large ISP's that can no longer obtain from the large blocks
> > (e.g. /12 to /16) but instead must beg/barter/borrow blocks from others
> > which are several orders  of magnitude smaller (e.g. /16 through /24)
> > every week to continue growing...  such obtained blocks would be
> > announced into the routing system very rapidly as we try to keep
> > IPv4 running post depletion of the free address pool.  When this
> > inflection point is reached, how much headroom do we have given
> > equipment being deployed today?
> >
> > /John
> Is there a possible revenue stream here for larger ISP's to begin 
> charging their customers for not aggregating, and creating a penalty fee 
> for each borken route?  We're running out of IPv4 space (and I don't 
> think this can be solved with IPv4).  We're running out of routes for 
> the Cisco Sup2 engine (among others), but unless someone makes money on 
> it, this won't be solved.

When customers start having problems due to router RIB and/or FIB
overflow, they will seek other providers. So someone will make money and
someone else will lose it. Economics works well when things break

Of course, what happens when there is simply no IPv4 space is another
issue as there will be no new space for anyone. But some providers will
run out of their allocations long before others. If those who run out
have resources, the market in IPv4 addresses (which does not exist since
addresses are just numbers and not property) will get very active and
will provide its own incentives which may or may not be stabilizing or
R. Kevin Oberman, Network Engineer
Energy Sciences Network (ESnet)
Ernest O. Lawrence Berkeley National Laboratory (Berkeley Lab)
E-mail: oberman at			Phone: +1 510 486-8634
Key fingerprint:059B 2DDF 031C 9BA3 14A4  EADA 927D EBB3 987B 3751
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