Hi, Sorry for the late response. I know Zach already is taking care of the issues. Here is one clarification from implementation point of view.
> > It seems to me that if the addresses are global, presumably built on a off- > link prefix there is no problem. > [SC>] Agree with Mathilde. There should not be any issue if the implementation is done right. Note, that if multihop DAD is implemented for route-over scenario, then some change in the IPv6-stack is needed. The reason is that we are using same prefix over multiple hops. When the data is sent to the 6LBR's address, it should not first look into the NCE table because it is an off-link address. It should look into the routing table and then resolve the nexthop address through Neighbor Cache. If the implementation is not mindful about this change in behavior, the traditional behavior might first look into the NCE table thinking that 6LBR address is a on-link address as it is sharing the same prefix with the sending interface. This is purely an implementation issue. If routing protocol is not running, then the packet is sent to the default-router address. Default-router MAC address is resolved at the NCE. The ND message(RA, NA) response to the requestor will be handled separately and will be sent directly to the requestor. So, if one runs the multi-hop DAD with route-over topology which is conceptually different than the concept of regular IPv6 subnet and link, then some stack code needs to be updated to handle the differences. However, Erik previously offered a separate message type for multihop DAD - which should clean-up some of the confusions of overloading NS/NA. Thanks, -Samita > > The ABR is address fe80::33:44 so it will now send a multihop ND message. > > The regular IPv6 sending algorithm will first search the NC for > connectivity > > before sending through the default router (fe80::11:22). > > Actually what the IPv6 algorithm says is " Next-hop determination for a > given unicast destination operates as > follows. The sender performs a longest prefix match against the > Prefix List to determine whether the packet's destination is on- or > off-link. If the destination is on-link, the next-hop address is the > same as the packet's destination address. Otherwise, the sender > selects a router from the Default Router List" > " Once the IP address of the next-hop node is known, the sender > examines the Neighbor Cache for link-layer information about that > neighbor." > > Best, > Mathilde > _______________________________________________ > 6lowpan mailing list > [email protected] > https://www.ietf.org/mailman/listinfo/6lowpan _______________________________________________ 6lowpan mailing list [email protected] https://www.ietf.org/mailman/listinfo/6lowpan
