/127 between routers?

[michael.dillon at bt.com]

> What worries me in Mark's proposal (if it's that not inflating the
strength of what he's saying) is that we might end up with 8+8 by
stealth - CPE which only recognises 64-bit prefixes, big-iron routers
that route 64-bit prefixes in the fast path and relegate anything longer
to slower processing. 

Sounds good to me. If hardware designers can provide a way to speed up
some traffic, then that is a good thing.

>  It feels as though someone should be deciding either that subnet
prefixes should never be longer than 64 bits or championing the right
for prefixes to be any old length you want.

Championing? This is not politics, this is technology. If the technology
allows for divide and conquer to be applied to separating traffic into a
fast path and a slow path, then it will happen.

The same argument applies to management systems - what happens when the
only systems available assume that the longest subnet prefixes is /64
because that's what's currently in use (RFC 4291 2.5 vs 2.5.1)?  What
about staff training?

Then people will renumber their networks to use /64 prefixes on all
their p-t-p links. Staff training is easy, or maybe we should say that
any competent operator already has ongoing staff training in place so
whatever comes along, it can be handled.

> I think the key realisation I've come to with IPv6 is that you get 
> enough address space that you don't just have to worrying about 
> allocating it out to make things work, you can allocate it out to also

> make addressing *convenient* to work with, with as simple as possible 
> usually also being most convenient. 

Yes, yes and yes again. Keep it simple and don't worry about waste
because
to date, we haven't really got a definition of "waste" for IPv6. The
only 
place where you have to worry is that an operator who gives customer
sites
a prefix shorter than /48 must make sure that they can justify it when
their
initial /32 (or whatever) is used up.

I (FWIW) think the key realisation with IPv6 is that we have too many
bits available and don't really know what to do with them.  :-)

That's why only 1/8th of the IPv6 address space is allotted for global
unicast.

--Michael Dillon