>-----Original Message-----
>From: Brian Dickson [mailto:[EMAIL PROTECTED]
>Subject: Re: what problem is solved by proscribing non-64 bit prefixes?
>The problem, fundamentally, is one's position in a hierarchy (of IPv6
>assignments or pd's).
>
>In many markets, there is a (very) limited pool of ISPs (let along ISPs
>offering IPv6 !!).
Agreed, but that is not what we are talking about :).
>
>And, consequently, the ability to ask for and receive something other than
a
>single /64, is limited by the availability of ISPs in the local pool who
>offer it.
>It doesn't much matter whether
>the assignment of a /64 is dynamic or static - either way it bites.
>
>There is no guarantee that even a *single* ISP in any particular pool of
>local ISPs, has enough clue to offer this, or the ability to offer it
>(regardless of reason underlying the inability).
>
>This isn't something I, as a customer, have *direct* control over, and I
may
>not have an alternative (other ISP offering what I want).
>
>And it doesn't matter *why*.
I guess I just fail to see why
1) the provider isn't giving you more ... they *really* should ...
try to get them clued in
2) something like "Proxy w/ ULAs behind it" fails this scenario.
... it is almost directly analogous to the current IPv4+NAT
situation that you would in.
Failing those, you are free to break the /64 boundary if you really must -
routers will still route, etc.
... you are just signing up for pain - manual configuration, etc.
... "sub-optimal", to say the least.
>
>In such a situation, I am effectively "painted into a corner" (e.g. when
>viewing IPv6 space as a Heat Map / Hilbert curve).
>
>"Bits to the left of me, Bits to the right, Here I am - Stuck in the middle
>again".
>(Apologies to the original artist and those who don't like puns.)
>
>The question is, what does one do in such a scenario, and/or what *can* one
>do?
See above :).
>
>If the ability to do what one wants, is permitted by non-64 bit prefixes,
>life is good.
>DHCPv6, or more flexible versions of SLAAC, CGA, etc., are needed for this.
For some values of "good", perhaps.
>
>If only 64-bit prefixes can be used, then one gets only one 64-bit prefix
to
>use for everything. Good luck with that.
>
>Basically, in the absence of the ability to subnet arbitrarily (on
>non-64 bit boundaries), I'm at the mercy of my upstream.
>
>128 bits doesn't look so wonderful in such a scenario, I would surmise.
>
>Nobody is a winner. :-(
>
>Brian
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