Thus spake "Keith Moore" <moore(_at_)cs(_dot_)utk(_dot_)edu>
being able to distinguish an ambiguous address from a global address
doesn't solve the problem of requiring hosts or apps to be aware of
topology in order to make address selection.
A host/app needs to be similarly aware of topology (and security policy) to
make any reasonable selection between multiple global addresses. Adding
non-globals to the mix doesn't make things significantly worse.
Yes, we need to complete the work on making the 38 bits globally
unique, but that can't happen if we start by eliminating the first 10.
If we can agree on how to make the first 48 bits globally unique, does
it really matter what values are assigned to the first 10 bits?
Yes, it does. Having a common prefix for non-global addresses makes the job
of network managers much simpler, and thus reduces the likelihood of leaks.
Does it need to be a 10-bit prefix? Not really, but FEC0::/10 is already
(yes, GUPIs, NOT SLs. they WILL be routed between sites, for good
reasons, and we shouldn't try to stop this)
Since this is the first time I've seen "GUPI" used, should I assume that
means a globally unique provider-independent prefix which isn't globally
routed? If so, I think you're using that term in the same sense Tony uses
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