Robert Raszuk wrote:
*"Instead, APIs and applications must be modified to detect and react against the loss of connection."* Well it is clear that you are making an implicit assumption that quality of the available paths is equal and all you need to care about is end to end connectivity/reachability.
No, as is written in draft-ohta-e2e-multihoming-03.txt: Once a full routing table is available on all the end systems, it is easy for the end systems try all the destination addresses, from the most and to the least favorable ones, based on the routing metric. Note that end to end multihoming works with the separation between inter domain BGP and intra domain routing protocols, if BGP routers, based on domain policy, assign external routes preference values (metric) of intra domain routing protocols. One may still be allowed, though discouraged, to have local configuration with dumb end systems and an intelligent proxy. But, such configuration should be implemented with a protocol for purely local use without damaging the global protocol. IGP metric is used as route preference, though, some workaround of proxy (last paragraph) or having partial routing table on near ISPs (not mentioned in the draft) may be necessary, until global routing table becomes small enough to be able to be held by ordinary hosts. Note that at the time the draft was written, IPv6 global routing table was small, which means, at that time, IPv6 worth deploying despite all the flaws in it. Masataka Ohta
