This all makes good sense to me. The only thing that I question in is whether the random /64 subnet prefixes get generated by the routers or the hosts on the link - and I suspect the latter makes more sense once you start looking at transition scenarios.
The way I see it, self-configuring networks get built from the bottom-up, so they should start with /64 prefixes for each link and the routers should figure out how to route between those links by exchanging reachability information for those prefixes. That means that they can't aggregate, and that imposes a scaling limit on self-configured networks, but surely we don't expect self-configuring networks to be as large as managed ones? > I think we are getting into tensions because the Hinden/Haberman draft is > trying to do two things: specify local addresses and specify a mechanism of > ensuring uniqueness. I agree with the former; I don't think the latter is > the right solution for all deployment spaces. > > As tersely as possible, what is a local address? > > A local address is a unique* PI address with the additional property > that it is invalid for use on the public internet and actively filtered > by such. > > Key properties: > > (1) Because local addresses are unrouteable globally, they avoid the > perceived aggregation problems of PI addresses. > > (2) Because local addresses are PI, they are independent of the presence or > absence of PA addressing schemes and service providers. > > Property (2) of PI is attractive for 'local' communication in environments > where PA addresses are unavailable or have unsatisfactory stability. > > > Now, what about that 'uniqueness' property? > > Because of the possibility of merging, we agree uniqueness is good. > However, the fundamental uniqueness requirement is that each "subnet" has a > unique /64 prefix (notwithstanding that multiple "subnets" may exist on one > physical media / interface). In some deployment scenarios, it will be > desirable to allocate a unique /48 prefix to the entire network and manually > or automatically subdivide (requires a prefix propagation mechanism). In > others (specifically ad-hoc scenarios), it is more useful to allocate a > unique /64 to each subnet. ...etc. -------------------------------------------------------------------- IETF IPng Working Group Mailing List IPng Home Page: http://playground.sun.com/ipng FTP archive: ftp://playground.sun.com/pub/ipng Direct all administrative requests to [EMAIL PROTECTED] --------------------------------------------------------------------
