Erik, >> to expand on the ideas I presented on MLSR (or rather MLSRv2 as it hasn't >> really been described anywhere) as a method for numbering a routed home. >> please let me be clear that I'm not convinced this is a good idea. i.e. why >> not just get< /64? >> I do think we could get something working though. >> >> routers can be in an arbitrary topology. all routers running a routing >> protocol. >> the site prefix (/64) is either advertised in the IGP with a new LSA or >> proxying of RA messages is done (split horizon). >> a router advertises the same /64 prefix (in a PIO) on all of its interfaces. >> L bit is 0. >> >> the link model here is that all hosts are off link from each other. >> link-local scope is restricted to only the physical link. multicast >> link-local scope as well. > > And I assume the routers would pass around /128 routes for the hosts in the > home, and would automatically inject such a route when the SAVI-style table > learns about a new address. > Are those assumptions correct?
yes. >> a host uses SLAAC (or DHCP) to create an address, then does DAD as normal. >> the first hop router uses it's routing topology database >> to check for conflicts. similar mechanisms described in SAVI are used to >> glean address information from the host. the SAVI binding >> database is then used to inject host routes into the IGP. > > What happens when the router crashes - does it loose its SAVI-style table? > Does it keep it in stable storage? it could. > If it looses it, then nobody would know on what link the hosts are, since the > hosts aren't required to periodically send any announcement to the routers. indeed. directly connected hosts would get a L2 event. in the more creative department you could run with low timers, and you could enforce a direct mapping between MAC address, link-local address and global address. thereby being able to recreate global address binding state just from a link-local addresses. > What happens when a packet arrives for an IP address that is in the /64 > prefix for the home, but there is no /128 route for it? Flood everywhere? > Drop? drop I'd imagine. > We looked that this when we worked on 6lowpan-nd, and concluded that by doing > explicit registrations from hosts to routers (the Address Registration > Option) with a lifetime we can make such networks work well without requiring > stable storage. > > But that implies a host change. yes, registration makes this safer. I just intended to point out that this could be one tool in the toolbox. not that we should necessarily build homenets this way. cheers, Ole _______________________________________________ homenet mailing list homenet@ietf.org https://www.ietf.org/mailman/listinfo/homenet
