Bob Hinden writes:
> If this means globally routable provider independent addresses. Then it
> is, of course, correct that this would solve many of the problems
> too. Unfortunately, there is a big problem why this isn't a practical
> choice we can make now. We don't have, IMHO, any idea how to make
> globally routable provider independent addresses work at scale in the
> Internet. There are a number of problem area.
Bob,
The issue I have is that there are a number of
problems that are all interrelated in various
ways: renumbering, multihoming, mobility, address
stability, etc which we as IETF'ers need to take
into consideration for building a net which will
be useful 10 years from now. I suspect that there
is no "right" answer aka silver bullet because of
all of the conflicting requirements, so the
ultimate answer is likely to be some form of
picking palatable poison (ppp for short).
You're certainly right that we have no good clues
as to how to scale PI up to Internet scaling. On
the other hand, we know that NAT's will step in
the second that they are expedient and solve a
problem -- inelegantly -- not feasible other ways.
And we all know what a horrible hack NAT's
are. Nor do I see how anybody can suggest with a
straight face that there will not be NAT's which
bridge local addressing domains with the global
addressing domain. It wouldn't even surprise me
that that even happens today; heck I probably know
the product manager responsible for it.
But I'm sorry, if NAT's become a de-facto
necessity for v6 native networks (putting aside
the need for v4/v6 NAT's), then I find the entire
premise of ipv6's utility deeply undermined. Quite
possibly fatally. So without trying to be too
preachy, I think that we really should have a
preponderance of evidence that we absolutely,
positively cannot make either PI and/or
renumbering based solutions work in a way that
people can deploy and use them.
I fully understand the compelling arguments of
Moore's law and disaggregated addresses in the
current internet. Obviously any PI solution could
not be naive. However, it doesn't seem to me that
there's been nearly enough work to develop a PI
friendly Internet. And even though Fred's
operational renumbering uncovered all kinds of
other intractibilities -- especially as you want
to scale it down to smaller networks, I still
think the jury is out. Also: we can be pretty
certain that any PI solution and/or renumbering
solution if it exists will highly likely have
serious warts. But this needs to be compared to
alternative: NAT's. NAT's being required to deploy
in real life basically says that the internet
stupid-network/global addressing design was
flawed. Are we really ready to make such a
pronouncement? Are we ready to say that global
transparency lost the argument? The market place
pretty much says that, but are we ready?
Maybe this train has long since left the station
and the IETF is impotent change that, but it sure
seems to me that if we cannot solve this in such a
way that NAT's aren't the inevitable result (eg,
the path of least resistance) then we should
immediately change tacks and embrace addressing
realms and ALG forwarders through those realms as
an architectural principal.
Thus, a lot is riding on this IMO, and my feeling
is that the vehemence of the uncomfort with
locally scoped addresses is that it tacitly
concedes our inability to keep with the
architectural principal of a dumb globally
addressed network. And I also get the feeling that
there is not anything approaching consensus to
admit defeat on that architectural principle, so
even these small sensible steps that you propose
nonetheless seem grave in their global
implications.
So if we can't deal with requirements of address
stability and/or renumbering, etc without
non-global addressing realms, let's document it,
reassess our architectural principles, and move
on. Until then, we're just pushing off the
inevitable confrontation: a confrontation which
IMO will decide the shape of the net for years to
come. Quite frankly the marketplace will decide
for us with NAT's in the mean time, no matter how
much myself or anybody else whines about it. Let's
at least drive this to a conclusion one way or the
other from an engineering standpoint to see if
this is both technically and economically
hopeless. Until then, we're just gnashing.
Mike
--------------------------------------------------------------------
IETF IPng Working Group Mailing List
IPng Home Page: http://playground.sun.com/ipng
FTP archive: ftp://playground.sun.com/pub/ipng
Direct all administrative requests to [EMAIL PROTECTED]
--------------------------------------------------------------------
