> + router - a node that forwards IPv6 packets not explicitly > + addressed to itself. [See Note below]. > + ... > + Note: it is possible, though unusual, for a device with multiple > + interfaces to be configured to forward non-self-destined packets > + arriving from some set (fewer than all) of its interfaces, and to > + discard non-self-destined packets arriving from its other interfaces. > + Such a device must obey the protocol requirements for routers when > + receiving packets from, and interacting with neighbors over, the > + former (forwarding) interfaces. It must obey the protocol > + requirements for hosts when receiving packets from, and interacting > + with neighbors over, the latter (non-forwarding) interfaces.
> Is there really anything more that needs to be said? Is such a box has IFA and IFB as forwarding interfaces and IFC as a non-forwarding interface, how should it behave when a packet is received on IFA addressed to an on-link destination on IFC? (Note the above text talks only about "forwarding from" and IFA is a forwarding interface.) I think the right answer is that it should ignore any "routes" related to IFC when forwarding packets i.e. it needs to follow the subset of the forwarding table that applies to IFA and IFB. But no document states that. As pointed out numerous times, RFC 2461 doesn't say what a multihomed node should do. Example cases are: - sending to a link-local destination; should it send neighbor solicitations out all interfaces? should it require that the application specify the scope id? - when there are routers, the routers do not advertise on-link prefixes or they do advertize and the destination does not match an on-link prefix, what should a multihomed host do when sending a packet to a non-link-local address? should it send the packet to a default router on each interface? if not, how does it select which one? (the router preferences draft might be part of this answer) - when there are default routers on some interfaces but not on all, does that change any of the answers to the above questions? See also appendix A in RFC 2461. Erik -------------------------------------------------------------------- IETF IPv6 working group mailing list [EMAIL PROTECTED] Administrative Requests: https://www1.ietf.org/mailman/listinfo/ipv6 --------------------------------------------------------------------
