Date: Sat, 19 Apr 2003 17:51:19 -0400
From: Valdis(_dot_)Kletnieks(_at_)vt(_dot_)edu
Message-ID:
<200304192151(_dot_)h3JLpKuL019276(_at_)turing-police(_dot_)cc(_dot_)vt(_dot_)edu>
| So if it's expected that both global and site-local addresses are available,
| why are we bothering with making things more complicated?
Because we need stable addresses for local use.
Something tells me you've never actually lived in an environment where your
global address changes moderately frequently. If you had, you wouldn't
be so quick to ignore this need.
| That's exactly *why* they're broken - if you've suddenly had a global
| address show up, there's now a danger of leaking a local address, so it's
| not safe to use site-local anymore.
What is the danger here, and why do I, the user, care? What I know is
that I want me local communications to just keep on working smoothly,
whatever happens to external connectivity and the addresses I get from
there.
| Well.. all you need to do to fix this is to make a rule that if a
| global prefix becomes available, the site-local prefix is no longer
| appropriate and must be withdrawn.
Can't possibly work.
| This *still* leaves the problem of using site-local behind a NAT, though.
First, while I can imagine people existing who would be stupid enough to
do that, I find it hard to figure out what their reasoning would be.
But if you assume that there are people (and there most probably are) who
are so sold on the "benefits" of NAT, that they're going to use NAT no
matter how much you show them that there is in fact no benefit at all
(which for a site with an IPv6 global /48, and site locals, is certainly
true) then why would you care what address they're using behind the NAT?
That is, whether it is SL, LL, or some random "global" prefix they calculated
by tossing coins.
I find it almost inconceivable to believe that anyone is deciding the fate
of SL addressing by reference to NAT - that's simply too ludicrous (and sad)
to contemplate.
kre