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 finished, though. -- Dave Siegel President, RTD Systems & Networking, Inc. (520)318-0696 Systems Consultant -- Unix, LANs, WANs, Cisco dsiegel@rtd.com User Tracking & Acctg -- "Written by an ISP, http://www.rtd.com/ for an ISP."