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 --------------------------------------------------------------------
