In your letter dated Thu, 28 Jul 2011 17:08:01 +0900 you wrote: >Philip Homburg wrote: >> I think the problem is that we don't know how to do 'proper' address >> selection. > >I know and it's trivially easy. > >11 years ago in draft-ohta-e2e-multihoming-00.txt, I wrote: > > End systems (hosts) are end systems. To make the end to end principle > effectively work, the end systems must have all the available > knowledge to make decisions by the end systems themselves. > > With regard to multihoming, when an end system want to communicate > with a multihomed end system, the end system must be able to select > most appropriate (based on the local information) destination address > of the multihomed end system. > >which means an end system should have a full routing table, IGP >metrics in which tell the end system what is the best address of >its multihomed peer. Full routing table should and can, of course, >be small.
Even in the unlikely case that it would be feasible to give every host a complete copy of the DFZ routing table... That still would leave a lot of issues open... 1) End-to-end latency. Maybe some future generation BGP provides that, but that doesn't help now. 2) For 6to4, the use of anycase. You probably need a link-state routing protocol to allow a host to figure out which relays are going to be used on a give path. 3) Filters in firewalls. I'd love to see a routing protocol that reports the settings of all firewalls in the world :-) 4) Other performance metrics, like jitter, packets loss, etc. Maybe you can do some experiments and report on how well your draft works for deciding when to prefer a 6to4 address over IPv4. _______________________________________________ Ietf mailing list Ietf@ietf.org https://www.ietf.org/mailman/listinfo/ietf
