Thanks! One small question - if the neighbor is not resolved yet, will the lookup yield a glean adjacency? If that is the case, depending on the type of the result, I should punt the packet to either ip6_rewrite or ip6_discover_neighbor?
Thanks, -nagp On Wed, Apr 12, 2017 at 10:40 PM, Neale Ranns (nranns) <nra...@cisco.com> wrote: > > > Hi nagp, > > > > I do indeed mean the result of a ip6_fib_table_lookup. The goal of a > lookup is ultimately to find the adjacency to use (and thus eventually get > to ip6_rwrite node). Since you know the adjacency’s full description, it is > more efficient to retrieve it directly from the adjacency data-base and go > directly to ip6_rewrite. > > > > As you say, if one where to do a lookup for a link-local address in the > FIB, then one should use the interface as part of the key, i.e. a /160 > lookup, or perhaps in a per-interface link-local address only ‘FIB’. But > VPP has no such function. The adjacency data-base serves this purpose*. > > > > Regards, > > Neale > > > > *if you are using this in the data-plane though, we should consider > alternatives. > > > > *From: *Nagaprabhanjan Bellaru <nagp.li...@gmail.com> > *Date: *Wednesday, 12 April 2017 at 14:04 > *To: *"Neale Ranns (nranns)" <nra...@cisco.com> > *Cc: *vpp-dev <vpp-dev@lists.fd.io> > *Subject: *Re: [vpp-dev] How to send packets from control plane to a link > local IPv6 address? > > > > Thanks Neale! > > By the "result of the lookup" do you mean looking up through > ip6_fib_table_lookup? I don't this lookup taking a interface also (for the > link local case). Please correct my understanding. > > Thanks, > > -nagp > > > > On Wed, Apr 12, 2017 at 4:30 PM, Neale Ranns (nranns) <nra...@cisco.com> > wrote: > > Hi nagp, > > > > If you know the destination address is link local and you know on which > interface, then the result of the lookup will result in the adjacency for > that link-local address on that interface, i.e. the adjacency you would get > back from; > > adj_index_t ai = adj_nbr_add_or_lock(FIB_PROTOCOL_IP6, VNET_LINK_IP6, > <ll_add>, <interface>); > > > > now you have the adjacency, the lookup is not required, so you can send > the packet directly to ip6_rewrite/ip6_discover_neighbor. There is an > example of this in the BFD code (see bfd_udp_input()). > > > > Hth, > > neale > > > > *From: *<vpp-dev-boun...@lists.fd.io> on behalf of Nagaprabhanjan Bellaru > <nagp.li...@gmail.com> > *Date: *Wednesday, 12 April 2017 at 11:27 > *To: *vpp-dev <vpp-dev@lists.fd.io> > *Subject: *[vpp-dev] How to send packets from control plane to a link > local IPv6 address? > > > > Hi, > > How can I send packets to a link local IPv6 address? I know the interface > on which the packet has to be sent, but when I enqueue the packet to > "ip6_lookup" node, how can I encode the interface such that the neighor > resolution happens on that interface and the packet gets transmitted? > > Thanks, > > -nagp > > > >
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