> Let's put it this way: the registries are instructed that only top level
> providers should get one of these addresses. Everyone who does not qualify
> supposedly get a delegation from a TLA, or several delegations in the case
> of multi-homed networks.
of course, this requires that sending hosts or applications make
intelligent decisions about which destination address to use
(and which source address to use with a particular destination
address), usually in the absence of any information which might
inform the decision.
it's not at all clear that this can work well enough to be a general
purpose multihoming mechanism, at least not without adding a fair
amount of extra infrastructure and complexity - i.e. a mechanism
which hosts or applications can use to query the network to determine
relative proximity of several different addresses. if it does turn
out to work it will probably be because all of the available prefixes
for both the source and destination host are so reliable and have so
much available bandwidth that most of the time that it doesn't matter
which of the available addresses you use. (it's tempting to say that
multihoming will work quite well for those cases where you don't need
multihoming... but that is a bit of an exaggeration)
to be fair, "traditional" multihoming doesn't scale well enough
to use that approach either.
maybe we just need for Internet service to be as reliable as telephone
service.
Keith
