Re: [6lowpan] Working Group Last call for draft-ietf-6lowpan-nd-15

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

Hi Carsten:

My main issue with ND 15 has to do with the role of the 'L'=='on-link'
flag. 

1) The text seems to indicate that the 'L' it determines whether
classical ND or ND registration per this draft should be used

"
   When a host has configured a non-link-local IPv6 address, it
   registers that address with one or more of its default routers using
   the Address Registration option (ARO) in an NS message.
"
I think that the 'L' bit can be reset in environments where ARO is not
wanted. Further, I think that registration is useful in many
environments, even Ethernet, where you do want to set the 'L' bit.
As a consequence, I think 6LowPAN ND should define a new PIO 'W' bit to
indicate whether ARO should be used or not, regardless of whether a node
may look up another node on-link or not.


2) The text also indicates that if there are PIOs with and without 'L'
set, then reset wins. 
That's an interesting rule but then, what if the PIO with 'L' set is
received before the L reset?
And BTW how does a host erroneously receive something? Like the postman
was too busy?
"
   Should the host erroneously receive a Prefix Information option with
   the 'L' (on-link) flag set, then that Prefix Information Option (PIO)
   MUST be ignored.
"
I think that the text should stay away from L bit. If a new 'W' bit is
defined, then I suggest that as soon as the  node receives a PIO with
the 'W' but then it MUST register all its addresses that are based on
that prefix.

Note on the side that RPL extends the meaning of 'L' bit when used
router to router in RPL's PIO, and that it is valid to set the 'L' bit
there.

Pascal
http://www.xtranormal.com/watch/7011357/


> -----Original Message-----
> From: [e-mail] [mailto:[e-mail]] On
> Behalf Of Carsten Bormann
> Sent: Thursday, February 17, 2011 4:58 PM
> To: 6lowpan
> Subject: [6lowpan] Working Group Last call for
draft-ietf-6lowpan-nd-15
> 
> In September/October, we had the first WGLC on 6LoWPAN-ND, which
> resulted in a number of detailed comments and two resulting
fine-tuning
> iterations of the draft.
> 
> draft-ietf-6lowpan-nd-15.txt has been out for two months now.
> I understand it has taken part in several interops with multiple
> implementations in this period; no issues came up.
> 
> We now start the Working Group Last Call on:
> 
>    http://tools.ietf.org/html/draft-ietf-6lowpan-nd-15
> 
> The document is planned to be submitted by this Working Group to the
IESG
> for publication as a Standards-Track Document.
> 
> This is a two-week Working-Group Last-Call, ending on Thursday,
> 2011-03-03 at 2359 UTC.
> 
> Please review the changes to the document carefully once more, and
send
> your comments to the 6lowpan list.  Please also do indicate to the
list if you
> are all-OK with the document.
> 
> Gruesse, Carsten
> 
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