Ah, okay. So, as I understand it, this is not an issue of DAD but an
issue of DNA, and, more specifically, a matter of how precisely we
implement it.
Disabling DAD on that interface certainly looks too
much if the purpose is to allow node-local communication using a
"detached" address. One possibility would be to introduce a tweakable
switch that disables the DNA operation at the risk of allowing the
small window on link up. Another, probably more substantial but
probably cleaner change would be to allow using a detached address for
(node) local communication (e.g., allow bind() but filter out packets
using a detached address if they are sent to the wire rather than
loopback).