Thus spake "Robert Elz" <kre(_at_)munnari(_dot_)OZ(_dot_)AU>
| To assign more than one address to every host means the host must
| have an intelligent means of deciding which address to use.
Yes, but the amount of intelligence actually needed is pretty minimal.
(It is actually harder to decide between multiple available global
prefixes, than to decide between global and site local - the former is
a difficult problem, the latter is almost trivial).
Agreed. But the former is a problem nobody has solved after a couple
decades' effort. Choosing a source address today is a problem only for
dual-homed hosts, which are fairly rare; I see no compelling reason to bring
this afflication to every IPv6 host until the problem is solved.
| I don't trust the hosts (either OS or the user) with that decision
| any more than I trust them with QOS.
But you do trust them to select a suitable outgoing interface, to pick
a usable router, and to choose amongst several different possible
addresses for the destination (over which you most often have no
control).
Most hosts have one interface, one source address, and one default gateway
(or two that are equally valid). Recall the KISS principle.
S
Stephen Sprunk "God does not play dice." --Albert Einstein
CCIE #3723 "God is an inveterate gambler, and He throws the
K5SSS dice at every possible opportunity." --Stephen Hawking