Look, we have two choices: we can make the addressing follow the 'net's
topology, or we can make the 'net's topology follow the addressing. They
*have* to be connected, *we* only get to chose which comes first.
Making the addresses follow the topology means that we have a lot more
flexibility to make the connectivity respond to traffic patterns, policy
demands, etc, etc; the addresses then trail along behind. If the topology has
to follow the addressing, you *can't* have the topology be completely free to
respond to user's needs.
Well, if we use a concept of dynamic communities, by using tools to constantly
analyze 'show ip bgp' outputs, and compare against existing community
strucutures, I think we can built a distribution filter that can isolate
specific routes to where they need to be, providing only a very minimum
of free transit to various providers. It encompasses a combination of
geographic and provider based addressing, and would float between the two
as migrations occur (probably on a weekly basis).
I'm working on such a thing now. Don't know when I'll have a proposal