RE: [nemo] RE: draft-ietf-nemo-home-network-models-05

["Pascal Thubert \(pthubert\)" <[e-mail]>]

>>> This above paragraph makes no particular sense at all, since a HA
>>> doing proxy ND for a LFN node which is below MR will intercept
>>> packets from all the neighbours of HA addressed to LFN, even though
>>>  it is the MR who should intercept or receive those packets.
>>>
>>> There can be no "proxy ND" for an LFN on HA's link as long as the
>>> normal ND of same LFN is not happening on the home link.
>>
>> [Pascal] Please read again. The "Nodes on the registered prefixes"
>> means nodes  (eg. LFNs) attached to MRs that are away from home. Thus
>>  MRs can not intercept the packets to the LFN over the Home Link.
>
>For some reason "intercept" was perceived by you as something where MR
>must do proxy ND in order to receive.  I didn't mean so, sorry.  I
meant
>MR should "receive" (or "intercept") packets for LFNs when away from
>home.  This happens by MR receiving packets tunnelled by HA.  The HA
has
>"intercepted" those packets for LFNs by doing proxy ND for MR's Home
>Address exclusively, and not by doing proxy ND for any LFN address.  It
>makes no sense for HA to do proxy ND for LFN address.
>
>Again, HA doing proxy ND for LFNs is something topologically invalid.
>Proxy ND of a host should be done on a link where the real ND for that
>host is topologically valid.

[Pascal] Are we off-sync? This chapter talks about the aggregated mode,
so the whole /48 is topologically correct on the Home Link. That's
section 6 of:
http://www.mobilenetworks.org/~pthubert/draft-ietf-nemo-home-network-mod
els-xx.txt

The /48 is what the HA advertises in RA's on the Home Link. All nodes on
the link think that the whole /48 is on that link. So they will have a
connected route to the /48 over the home link, and lookup any node in
the /48 at ND level.

But in fact, (some of) the /48 space is partionned into MNPs affected to
MRs. Thus the problem.
Note: Personally, I do not favor the aggregated model, I prefer the
extended. We discussed that long ago, remember?

>
>Moreover, there are potentially 2^64 LFNs behind an MR with MNP /64.
HA
>has no means to know which of those are active.  So will it send 2^64
>periodic NAs as part of its proxy ND for LFNs?

[Pascal] No, it will answer to NS coming from the Home Link for any
address that matches a registered MNP, and then pass the packets over
the tunnel.

>
>Pascal:
>> Thus, on the Home Link, the Home Agent must intercept all the packets
>>  for ALL the Mobile Network Nodes on the registered prefixes - that
>> is for ALL nodes attached to Mobile Routers that are away from Home.
>> This should be a layer 2 operation, rather than layer 3.  The Home
>> agent might, for example,  perform some form of ND proxying for all
>> addresses in all registered Mobile Network Prefixes.  The Home Agent
>> must also protect the MNP space from autoconfiguration by
>> uncontrolled visitors at Neighbor Discovery level.
>
>Is there a known implementation where the HA intercepts all the packets
>for ALL the Mobile Network Nodes by doing proxy ND for their addresses?
>
>Does anyone plan to write such an implementation?
>
[Pascal] Dunno. Don't ask me if I like it... But something like that has
to be done if MNs or hosts connect to the home link... Part of the price
to pay to support aggregated mode.

Pascal