RE: [6lowpan] off-link model in the 6lowpan talk:draft-ietf-6lowpan-nd-07

Hi Zach:

A useful (informational) reference. 

I understood that we now call the whole LoWPAN the link though we still 
restrict the use of link local for the radio range.

Autoconf still uses the radio range as link. Also it is has:

"
   o  There is no mechanism to ensure that IPv6 link-local addresses are
      unique across multiple links, hence they can not be used to
      reliably identify routers.
"

Which we make untrue: 6LowPAN ND introduces that mechanism.

We took great care to validate uniqueness of the link local address
across 
a bounded set (that is not limited to the link local scope) that we used

to call the subnet and now call the non transitive link.

Thus we still can use the link local address of our first hop routers. 

We tend to agree with the conclusions like use the global addresses for 
most everything but the reasons are slightly different.

I'm unsure what pages you want to save with this. But I trust you'll do
good as usual.

Pascal

>-----Original Message-----
>From: 6lowpan-bounces@ietf.org [mailto:6lowpan-bounces@ietf.org] On
Behalf Of Zach Shelby
>Sent: mardi 10 novembre 2009 02:43
>To: Carsten Bormann
>Cc: Hemant Singh (shemant); ipv6@ietf.org; 6lowpan; Dave Thaler
>Subject: Re: [6lowpan] off-link model in the 6lowpan
talk:draft-ietf-6lowpan-nd-07
>
>Carsten presented 6lowpan-nd to 6man today, which was useful. A
>comment that came in from Dave Thaler was to re-use the autoconf
>model. Everyone should take a look at:
>
>http://tools.ietf.org/html/draft-ietf-autoconf-adhoc-addr-model-00
>
>This greatly simplifies the editorial/terminology work for us in
>6lowpan. It looks like we can directly reference this autoconf
>addressing model. It should remove about 3-4 pages from our draft ;-)
>They have come to the same conclusions regarding the off-link model,
>use of IPv6 addresses and DAD. Otherwise it looks like 6lowpan-nd is
>technically compatible with that model.
>
>Zach
>
>On Nov 10, 2009, at 10:34 , Carsten Bormann wrote:
>
>> Hemant,
>>
>> it is probably best if you copy 6lowpan@ietf.org for discussing this.
>>
>>> Note that if the multi-link, multi-hop network has all client nodes
>>> as off-link to each other, then there is only one type of regular
>>> ND (RFC4861) RA that can signal off-link.  This is an RA with no
>>> PIO (Prefix Information Option).
>>
>> Our RAs typically have a PIO with L bit off and A bit on (actually
>> usually a 6IO with a couple bits of additional information, but
>> since -07 the classic PIO works too).
>>
>>> So if the RA has no PIO, how are the lowpann client nodes acquiring
>>> their IPv6 address global address without SLAAC getting no prefix
>>> from?  In 6man, we would like to know how are the lowpan clients
>>> acquiring their address and do they even have a global v6 address?
>>
>> Yes, they do have global addresses; that is the whole point of
>> running IPv6.
>>
>>> I think I heard some mention of ULA, so that gives me a hint of
>>> global address use because ULA has same scope as a Globally Unique
>>> Address (GUA).
>>
>> The slide about ULA was for the disconnected case ("ad-hoc LoWPAN").
>>
>>> Therefore it would be interesting to see the IPv6 ND RA config on
>>> the lowpan edge routers.
>>>
>>> Anyone has working models of this work to demo to us during any
>>> future IETF?
>>
>> I'm sure that can be arranged in Anaheim.
>> (Does anyone have an implementation with them here in Hiroshima?)
>>
>> Gruesse, Carsten
>>
>>
>> _______________________________________________
>> 6lowpan mailing list
>> 6lowpan@ietf.org
>> https://www.ietf.org/mailman/listinfo/6lowpan
>
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>
>Zach Shelby
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