An informal survey... round II

John Curran jcurran at
Thu Aug 30 13:40:56 UTC 2007

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.
>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?


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