Hi Pascal, The proxy-ND that you described from the draft may not always work....consider the case where a backbone node attempts to "ping6" a 6lowpan node.
To the backbone node, the 6lowpan devices appears as "on-link" since the ER responds with NS on behalf of the 6lowpan device. This will cause the backbone node to communicate with the 6lowpan device using its link-local address as the source address. Then the 6lowpan device has no way to respond back to the backbone node since it only knows the link local address and not the global address of the backbone node ( unless 6lowpan routers can forward packets with link-local destinations ). Did I miss something here ? -Regards, Joseph ------------------------------ Date: Tue, 17 Nov 2009 18:36:37 +0100 From: "Pascal Thubert (pthubert)" <[email protected]> Subject: Re: [6lowpan] Thoughts on draft-ietf-6lowpan-nd-07 To: "Colin O'Flynn" <[email protected]>, "Carsten Bormann" <[email protected]>, "Alexandru Petrescu" <[email protected]> Cc: 6lowpan <[email protected]> Message-ID: <[email protected]> Content-Type: text/plain; charset="us-ascii" Hi Colin: I think you're describing the draft. Basically the edge router does proxy-ND over the backbone. So if a node on the backbone looks up a 6LoWPAN device, the edge router answers NS with NA on behalf of the device. So the node sends packets via the edge router. The edge router forwards back to the device over the lowpan. As you figures, this is why the device needs to periodically maintain the binding with the edge router. This is somewhat similar to mobile IPv6 though there's no tunnel. Pascal _______________________________________________ 6lowpan mailing list [email protected] https://www.ietf.org/mailman/listinfo/6lowpan
