Re: old GSE idea

[Brian E Carpenter <brian@hursley.ibm.com>]

I think we should fly up one level and discuss a hypothetical
world in which addresses in A000::/3 are deemed to be mutable
in flight between bits 3 and 47 inclusive. See what it does
to TCP, SCTP and IPSEC for example. Then fly down again and look 
at the idea of doing GSE within A000::/3.

   Brian

Sean Doran wrote:
> 
> On Thursday, Apr 10, 2003, at 06:41 Europe/London, Peter Tattam wrote:
> 
> > I wonder if some of it may be relevant to recent discussions.  (you
> > might want
> > to ignore the junk about ARPing for routing id's - that probably won't
> > fly)
> > The relevant bit is the break up of the address bits.  Apologies if it
> > resembles other drafts.
> 
> No need to apologize.
> 
> In general, the idea is that there is a bit of space that is free for
> the
> network to rewrite at will because it is not an end-to-end value.
> One way of looking at it is that it is a way of cooperating with NAT
> by way of a trade-off: sacrifice a part of the address for the network
> to adjust, and constrain the amount of work host developers need to do
> to accomodate their existence.   There is probably a more p.c. way
> of putting this, but I am not the department of warm and fuzzy feelings.
> 
> Personally, I like this approach because it's obviously workable today.
> However, I prefer at this point to consider the option of unifying the
> v4 and v6 Internet routing tables for operational reasons, at least for
> now.
> Perry Metzger and I  had a friendly (well...) exchange about this on
> a public list some time ago (3-4 Dec 1999).  The general idea is that
> leveraging off v4 experience and expertise is attractive to large
> operators
> and other in-the-core supporting organizations, and is acceptable
> to host-side and other at-the-edge folks because it needn't get in the
> way
> thanks to tunneling, 6to4 and the like.
> 
> So, rather than maintain a routing system specific to GSE, as in your
> GSE+,
> why not just stuff a v4 address into the v6 one, such that the v4
> address
> (for example) describes the decapsulation point of an IPv6-in-IPv4
> tunnel?
> 
> This doesn't seem to be prima facie at variance with your old idea,
> which
> correctly identifies an effective requirement for an "AFI"-like
> subfield in the
> higher-order bits of the v6 address in order to experiment with
> different
> routing and addressing semantics within the existing v6 address and
> header syntax.
> 
>         Sean.

-- 
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Brian E Carpenter 
Distinguished Engineer, Internet Standards & Technology, IBM 
On assignment at the IBM Zurich Laboratory, Switzerland