On Sat, Jun 28, 2008 at 10:07 AM, David Conrad <[EMAIL PROTECTED]> wrote: > While I agree that a cost/benefit analysis needs to be done, I think it > worthwhile to keep in mind the alternatives. The alternatives (as far as I > am aware) are: > > a) PI for everyone
David, If I understand your meaning here, I'd describe this as "BGP PI for Everyone => Randy Bush's $10M routers." > b) NAT > > I hope you'll agree that alternative (a) alone is not scalable in the long > term. One can imagine a scenario where you have a universe of NATs > connected via PA assigned end points, however I'd argue this is actually a > locator/ID split where the IDs are not globally unique. I disagree with characterizing NAT as an alternative. NAT's likely contribution to the routing problem is already represented in the status quo. Unless you're aware of a clever new way to use NAT to relieve routing pressure that isn't an obvious non-starter? > Am I missing an alternative? Two more: 1. Status Quo. We continue to suppress table growth at the RIR level. Users continue to spend uncounted manhours on renumbering tasks. Users continue to lose productivity to address-state issues (e.g. spam filtering). The indirect cost due to the BGP table size continues to creep northward, helping squeeze out smaller ISPs. Mobility remains cumbersome. IPv6 without NAT remains nonviable because of the interior server renumbering problem. 2. New IP layer-4 protocols and change everything up to layer 7. Suppose that in addition to propagating routes, the routing protocol also performs optimization of address assignments. That is, it dynamically instructs "downstream" systems to change their addresses in a manner that improves address aggregation "upstream." In a perfect hierarchy you'd get perfect topological aggregation. The internet is not a perfect hierarchy, so in order to still get good aggregation you have to draw some line between systems large enough that they won't accept renumbering requirements from their peers and systems smaller than that which accomplish multihoming by acquiring multiple address sets from each upstream hierarchy. The only way to combine the two effectively is to remove identity from layer 3 addressing altogether so that layer 3 addressing only reflects the current locations within the topology. That means you rebuild layer 4 to get node identity from some other source than layer 3 and you propagate that change up the stack to layer 7. Regards, Bill Herrin -- William D. Herrin ................ [EMAIL PROTECTED] [EMAIL PROTECTED] 3005 Crane Dr. ...................... Web: <http://bill.herrin.us/> Falls Church, VA 22042-3004 -- to unsubscribe send a message to [EMAIL PROTECTED] with the word 'unsubscribe' in a single line as the message text body. archive: <http://psg.com/lists/rrg/> & ftp://psg.com/pub/lists/rrg
