[address-policy-wg] Re: Fallacy by Kurt (was Re: IPv6 Policy Clarification - Initial allocation criteria "d)")

Kurt Erik Lindqvist;

With your fallacy denied, why do you replay the well known
fallacy of NAT that NAT is transparent to the upper layers?

It is of course for those having some expertise on the Internet
architecture that entities performing address rewriting between
layer 4 of a peer is no transparent.

> Based on this it was proposed to concentrate on solutions that are 
> either "fat-ip" or wedgelayers at layer "3.5".

So, it is simply wrong.

An easy counter example is an application protocol carrying raw
address such as IPv4 FTP. Another easy counter example is
applications over UDP.

Layer 3.5 means an interim layer to perform address rewriting
with which multihoming is supported without upper layer changes.

Such approach does work to let all the existing upper layer
accept incoming packets, regardless of their locators.

However, with the unmodified upper layer, it is impossible
for the interim or lower layers when to try alternate address
of its peer.

That is, such approach does not work to let any of the existing
upper layer generate outgoing packets with proper destination
locators.

Thus, there is no such thing as the magical layer 3.5.

That NAT and the layer 3.5 interoperate with TCP means nothing.

							Masataka Ohta