John Stracke <francis(_at_)ecal(_dot_)com> writes:
Wasn't one of the design goals of IPv6 to make renumbering easier,
so that people could move from small assignments to large ones?
Yes. IPv6's primary tool in this regard is that it supports multiple
addresses simultaneously. To renumber, you add a new address to each
of your devices (corresponding to the addresses appropriate for the
new ISP) and start using it. For a transition period, both addresses
work equally well. When everything is switched over to the new
address, you simply stop using the old address. There are mechanisms
in IPv6 that make this approach straightforward (i.e., specifying when
to start using the new addresses, how long to overlap using both the
old and new ones, and when to finally retire the old addresses). No
flag day, no need to even reboot machines.
Thomas