On 9/12/07, ietf-discuss(_at_)vix(_dot_)com <ietf-discuss(_at_)vix(_dot_)com>
http://sa.vix.com/~vixie/ula-global.txt has my thoughts on this, which
i've appropriated without permission from hinden, huston, and narten
and inaccurately failed to remove their names from (since none of them
supports the proposal). in fact, nobody in the ietf intelligensia
supports the proposal. the showstopped is that this appears to many as
an end-run around PI, and the fear is that there's no way to prevent it
are they still refusing to put it into the queue or do anything? Even after
several month? Well let really hope that will change now when/if
IPv6-wg change the name to 6man and we can start working again!
For the record, we had a series of discussions among authors, Paul,
experts, etc on the ULA topic right after IETF-69 to try to see if we
can sort out what the problems are and move forward.
For background, we already have ULAs than can be allocated by
the sites themselves. These are defined in RFC 4193.
The question on the table (and also part of 6man charter)
is whether we need an additional type of ULAs, one that is
centrally allocated. Such addresses might be useful for a couple
of reasons. One reason is that we could guarantee uniqueness,
which might be important, e.g., for a company that is running
a lot of small company networks as a business, and wants to
ensure the address spaces do not collide. But another, more
important stated reason was that we should have a way give
people address space that is different from PI in the sense
that those addresses are not recommended to be placed
in the global routing table.
Arguments against such address space relate to the
- The costs for any centrally allocated space are likely going to
be the same, so what is the incentive for the customers to
allocate ULA-C instead of PI?
- There is no routing economy that would push back on
advertising more than the necessary prefixes, so
what is the incentive that keeps the ULA-C out
of the global routing table as years go by? (When
the companies that allocated ULA-C grow, merge,
need to talk with other companies, etc.)
The end result of our discussions was that we clearly do not
have agreement on the way forward, and we settled for
writing a draft about the issues instead. That is still in the
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