And if the addresses used at the host are unique, it gets rid of many
of the problems caused by overlapping use of RFC 1918 addresses in IPv4.
There's still some issues related to traceability of traffic over the
network, but maybe those are manageable.
The source and destination address are globally unique. As such you know
where the traffic comes from as all these prefixes are correctly
registered in whois. This means that an end-site organization might have
5 /48's in whois: one they use for "ID", this can be a special block
like ULA, PI or just a block they get from one of their upstream ISPs,
and maybe 4 from their upstream ISPs.
I am fairly convinced, however, that the more address prefixes a site
has above some small number, the slower and less reliable applications
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