Hi, Jonathan, Thanks for your quick reply.
Unfortunately I am still a bit confused. Based on your reply, I guess that the case 1 is meant only for the case of tunnel exit-point being the final RPL router along a path, when the tunnel is used. The same RPL instance mentioned in case 2 perhaps means the RPL instance in the outer header when a tunnel is used and when the RPL router is not the final RPL router along a path, and does the case 2 also apply to a case where RPL router is the final RPL router along a path? Does the case 3 only apply to the RPL router being the final RPL router along a path when tunnel is used but not to the RPL router not being the final router along a path? If the answer is yes, by the outer-most IPv6 header, did you mean the outer-most IPv6 header of the inner packet and does RPL Instance in this context mean any RPL instance that the RPL router joined? I'd appreciate if you can clarify furthermore. BR, Kundok > -----Original Message----- > From: Jonathan Hui [mailto:jon...@cisco.com] > Sent: Friday, December 16, 2011 2:00 PM > To: Park, Kundok > Cc: ipv6@ietf.org > Subject: Re: I-D Action: draft-ietf-6man-rpl-option-06.txt > > > Hi Kundok, > > If the RPL router is serves as the tunnel-exit, it falls into case 1 and > removes the outer-most header in the usual way. If the IPv6 header after > decapsulation includes another RPL Option, the router uses the RPL > Instance of that RPL Option and evaluates the forwarding rules again (this > time applying case 2 or 3). RPL can support a hierarchy of RPL routing > topologies. > > Does that help? > > -- > Jonathan Hui > > On Dec 16, 2011, at 8:55 AM, Park, Kundok wrote: > > > Hi, Jonathan, > > > > I have a question on the following text on version 6, on page 8. > > > > " > > 2. Datagrams destined elsewhere within the same RPL Instance are > > forwarded to the correct interface. > > > > 3. Datagrams destined to nodes outside the RPL Instance are dropped > > if the outer-most IPv6 header contains a RPL Option not generated > > by the RPL router forwarding the datagram. > > " > > > > Can you clarify the meaning of the (same) RPL instance in the above > text? Is it the RPL instance in the outer-most IPv6 header? For instance, > if a RPL packet is tunneled to a RPL router using another RPL instance and > the recipient RPL router is the exit point of the outer tunnel, must the > router discard such a packet whether the router joined the RPL instance of > the inner packet or not? > > To phrase it differently, can RPL be used in a virtual network over a > network which happens to use another RPL instance as an underlying routing > protocol? > > > > Thank you. > > > > BR, > > Kundok Park > > Texas Instruments > > -------------------------------------------------------------------- > > IETF IPv6 working group mailing list > > ipv6@ietf.org > > Administrative Requests: https://www.ietf.org/mailman/listinfo/ipv6 > > -------------------------------------------------------------------- -------------------------------------------------------------------- IETF IPv6 working group mailing list ipv6@ietf.org Administrative Requests: https://www.ietf.org/mailman/listinfo/ipv6 --------------------------------------------------------------------
