Hi Phil, Philip Levis wrote: > I think the idea of a whiteboard is powerful. It definitely makes more > sense than "shout out."
Yes. DHCP has proven itself useful, and for many reasons other than just avoiding "shout out". > single coordinating node, however. Your text puts it precisely: > "consider that LowPANs *usually* have a sink of some sort" (emphasis > mine). Forcing this to be centralized requires such a node exist and > therefore precludes certain kinds of LowPANs. A solution may simply be to configure your IP addresses using an IID derived from the EUI-64, which must be unique within a PAN. If you really want automatic assignment of short addresses, then that's a different beast. But it might not be worth the overhead. > That being said, this approach seems to implicitly assume mesh under? > Nodes "use Neighbor Discovery to determine the link-layer addresses for > neighbors known to reside on attached links and to quickly purge cached > values that become invalid." ND could operate on a single hop basis. Let's be clear on what kind of hop. I'm sure you meant a single 15.4 radio hop, not an IP hop. > This simplifies everything. The place where the whiteboard approach is > necessary is for DAD. But given that the goal is eventual consistency on > address assignment, it may be possible to distribute the table in an > effective way. While I agree it does simplify many things, it doesn't simplify everything :-). RFC 4861 explicitly assumes multicast-capable links with reflexive and transitive reachability. DAD is only one example. ND is also used for redirect and to propagate network parameters. In a route-over configuration, the mechanisms currently defined aren't very useful in a route-over 15.4 PAN. I'm currently signed up to work on an I-D that addresses this case, as it is an interesting case to consider. -- Jonathan Hui _______________________________________________ 6lowpan mailing list [email protected] https://www.ietf.org/mailman/listinfo/6lowpan
