with "global unicast" basically i assume "global reachability".
I think we discovered during the original ULA discussion
that global scope and global uniqueness do not imply
global reachability. We have no way to express VPN style
reachability using scopes.
as i mentioned previously, VPN is about how to
- encrypt/authenticate communication with your laptop and your
organization (like IBM)
- and pretend that you are inside your organization network
there's no real point in using, or requiring, ULA for this.
you can just use IBM PI or PA for the IPv4/v6 address inside the
IPsec tunnel. i wonder what Apple corporate VPN is using - i guess
it would be within 17.0.0.0/8.