Mike,

Let me see if I can understand your concerns better. It seems to me
that your main objection to the hain/templin draft is that you see it
as implying a particular solution genre, that being a limited range
addressing scheme to replace site-locals. If this is what you find
objectionable, then may I assume you are of the opinion that site
locals don't *need* to be replaced? If so, then it seems you would
favor an IPv6 addressing architecture that contains only link-local
and global unicast addresses, i.e., nothing in between?

The hain/templin draft discusses requirements for sites that frequently
change provider points of attachment, sites that are disconnected or
intermittently-connected to providers, sites that merge with other sites,
etc. In these cases, we require local application stability independent of
any provider-assigned addressing. This requirement is not satisfied by
link-locals for medium/large sites that comprise multiple links. Thus,
all we have left are globals and the only way the "active" sites I described
above could use these  would be if the global prefixes could be obtained
independent of any provider. Fine; so this just means that the sites would
get their own prefixes and tell providers which prefixes to advertise
instead of the other way around - right?

This would all be fine were it not for the fact that it would lead to
immediate global routing table explosion on the order of the number
of sites that procure their own prefixes which could be quite large.
I'm willing to suspend disbelief and say that sometime down the
road we might have a solution for scalable global routing, but in
what timeframe can we expect to see something like that deployed?
1yr? 5yrs? 10yrs? longer?

Scalable global routing in a flat addressing space certainly seems
like a utopian scenario if it can be achieved. But, if the deployment
timeframe is looking like mid/long term, then we still need some
sort of replacement for site-locals in the near term - right?

Thanks -  Fred
[EMAIL PROTECTED]



Michael Thomas wrote:

[EMAIL PROTECTED] writes:
> If you think the document has a scoping issue (no pun intended),
> then let's discuss that with a measured tone.

Yes, I think it has scoping issues. A name change,
for starters. It should first lay out requirements
of network operators, etc in terms of what they
need to accomplish not how they can accomplish it.
Take as a very large for example, address
stability. That's not the requirement, per
se. What they want is for topology tweaking to not
adversely affect running applications. However
protocols such as TCP are incapable of sustaining
sessions across address changes which is typically
needed when you want to move topology around.
That's the reason I say that "stability" is a
solution, not a requirement. Keeping addresses the
same is *a* way of keeping applications from
breaking, but not the only one. Mobile IP
obviously comes to mind, and there are other ways
we could envision like Fred's attempt at
operational renumbering.

Another example is your "well known prefix". I'd
think that the requirement is that certain
services and/or classes of devices need to be
isolated and/or invisible from the other parts of
the net. A well known prefix is a way to do that,
but it doesn't necessitate local scope and again
isn't the only way to wall stuff off.


I really don't want to drag this into a meta
argument about the merits of various solutions,
but only to point out that the entire document is
structured in a way that the answer is foregone.
That's not what we need right now. We need
something that tries to be unbiased about the
ultimate compromises we're going to have to make
by saying what we want (requirements), what the
possible frameworks are for addressing the
requirements, and most especially what their
possible downsides are. We don't need boosterism
which tries to paper over the warts; all possible
solutions have problems, what we need is an honest
evaluation so that we can decide which path is the
least objectionable.

Mike
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