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Re: IPv6 address space shortages (was: Re: A simple question)

2003-04-29 13:18:50
We are still not out of IPv4 address space. I don't know the projections
for address space depletion, but I think the IPv6 problem won't be so much
address space depletion as route space depletion. I think it will be
unwieldy to have a million or 2 million or 10 million distinct routes.
Aggregation won't happen the way things are currently organized.

<soapbox> I think the RIRs (at least for IPv6) need to be organized
differently. In order for address space to be hierachical, for efficient
aggregation and routing, addresses have to be given out locally, like
phone numbers.  Unfortunately, that isn't how ISP's or the address
registries are organized. Fees are strongly biased towards big companies,
yet the small and medium sized companies generate most of the revenue.
It costs way too much money to get IPv6 space for every town to have their
own address space, so that even barn, cow, and coke machine can be
connected to the internet.  Something needs to give.  </soapbox>

                --Dean

On Tue, 29 Apr 2003, John C Klensin wrote:



--On Sunday, 27 April, 2003 22:24 -0700 Bill Manning
<bmanning(_at_)ISI(_dot_)EDU> wrote:

% As John Klensin pointed out on this same list several weeks
ago % (and I'm sure he said it better than I will), the
decision to % use ambiguous local addressing in IPv4 (i.e. RFC
1918 addresses) % was partially motivated by the desire to
conserve IPv4 address % space.  In IPv6, we don't have an
address space shortage, so there % is no reason to introduce
architectural complexity to conserve % address space.
%
% Margaret

    "dont' have an address space shortage..." - Margaret
    -YET-
    IPv4 didn't have one either, in its early days.

Bill, regardless of what other features are there and what other
justifications might exist, the primary problem and hence design
goal that brought IPv6 into existence was "not enough address
space".   If we can (even in our paranoid moments) reasonably
anticipate running out of space, then it is time to send the
IPv6 addressing architecture back to the drawing board and
replace it with something that supports variable or
extensible-length addresses.   I really can't imagine a rational
enterprise voluntarily deciding to convert to IPv6 if they are
told it only has a lifetime of NN years, where NN is less than
at least a major fraction of a century.

For that purpose, I think "running out of space" can be defined
as finding ourselves with a need to adopt allocation policies or
strategies (now or later) that force people into non-unique
addresses to conserve space.

It seems to me that if you, or anyone else, wants to make the
case that the IPv6 address space isn't going to be large enough,
you need to do so explicitly and immediately (five years ago
would have been better, but maybe we know more now).   While I,
personally, would have preferred extendable length addresses, it
feels to me that saying "yet" at this stage in the game is just
pointless sniping unless you are willing to argue for calling a
halt at this stage and redesigning.

    regards,
        john







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