Stephen Sprunk wrote:
Thus spake "Keith Moore" <moore(_at_)cs(_dot_)utk(_dot_)edu>
At the same time, IETF needs to understand that optimizing for
deployability first and scalability second often succeeds whereas the
reverse often fails. We need to understand how to design protocols
that can be deployed quickly and yet be upgraded gracefully as the
real requirements for long-term widespread use of the protocols
This is the true failing of the IPng effort: all the attention was
focused on the end result, with virtually no effort towards a viable
That's actually not true; at least one proposal that got some traction
was very focused on a viable transition model. But more people were
concerned about the end result. And I do think this is a kind of
A contributing factor was that the IETF designed IPng in a vacuum and
tossed it over the wall to operators, and completely ignored (and is
still ignoring) feedback on why people aren't deploying it.
To me it looks like operational issues drove all of the design changes
between v4 and v6. But the operational issues were ISP operational
issues, not operational issues in enterprise networks.
But it's almost a given that there would be a long feedback path. The
users will be the last to understand and react to any major
architectural change. It's hard for them to really know what they're
getting and how to deal with it until it actually ships in products that
they're using. Also, users are very diverse, and the way the network
is used is constantly changing, so it's hard to anticipate what users
will need, say, 10 years hence when the stuff finally gets deployed.
Also add in how long it took MS to ship an OS with v6 on by default;
that should have happened by 1998 or 2000 -- not 2007.
Well, it took them until 1995 to ship IPv4, and even then it wasn't "on
by default". :)
NAT-PT was a reasonable solution to this (with a few tweaks), since it
could make hosts _appear_ to be dual-stacked with little effort, but
it offended the purists and was killed despite there being nothing to
No, NAT-PT was not a reasonable solution, because it would have crippled
the IPv6 network even moreso than the NATted IPv4 network, in addition
to trashing DNS, and without providing any incentive to move to a
native (non-NATted) IPv6 network.
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