Re: 6MAN WG Adoption Call: draft-nordmark-6man-rs-refresh-01

On 4/21/15 9:44 AM, 神明達哉 wrote:
> At Tue, 21 Apr 2015 10:35:15 +0900,
> Lorenzo Colitti <lorenzo@google.com> wrote:
>
>> I think the root of my objections to this draft is that it proposes what is
>> in effect a substantial change to the current configuration model in IPv6
>> networks without saying so explicitly.
> [...]
>> If I am incorrect and the document is not proposing such a model, then it
>> should not mention this as a possibility. But then we need to understand
>> where the power savings are.
> I'm not sure if these points are too critical to adopt the document,
> but I guess it may be related to the higher-level question that I
> asked in response to this call:
> http://www.ietf.org/mail-archive/web/ipv6/current/msg22411.html
> (and that hasn't been answered).
Jinmei,

Your email had some editorial corrections, which will be applied.

The question seemed to be addressed to the WG and not the authors, which 
is a sad excuse for not responding.
Your question was:

I think it's worth discussing so I support the adoption.  But I have
one higher level question: did we agree that we need some enhancements
to ND to address the concern of multicast overhead?  It's quite
possible that I missed something in previous discussions, but I
thought there was not a clear consensus for the need for protocol
level changes while we generally saw potential issues in this area.

It is up to the WG chairs to gauge consensus, and I don't think there 
has been any explicit call on whether we need work to reduce ND 
multicast in general. (There are various techniques which can already be 
used such as setting O=0 to avoid multicast NS from hosts, and adjust 
timers, etc).

My personal take is that we don't need any open-ended protocol work 
here, but it would useful to have some (v6ops?) documents with 
operational recommendations e.g. for WiFi networks. Others have 
expressed concerns that for WiFI vendors are busy implementing various 
forms of filtering of multicast, and it isn't clear to what extent those 
solutions/hacks (depending on your point of view) will cause problems in 
the future. Hence some recommendations would be helpful.

One separate output of the efficient-nd design team is that we need to 
ask the WG whether there is interest in improving DAD, but that is more 
about DAD robustness than efficiency. I had that question on the slides 
in Dallas, but the question wasn't asked of the room. Bob and Ole 
suggested we do that question on the mailing list.

>
> I was not sure if we had agreed on sufficient need for making
> non-trivial (if not substantial) changes to a core part of the
> protocol.  If what Lorenzo was trying to say is a different form of
> what I tried to ask, I tend to agree with part of his argument.
> Although I'm not necessarily opposed to adopting the document just
> because of that, I think it's reasonable to request clarifying the
> problem statement and expected goal.

Please send text on what you would want to see as (part of) PS and goals.

Thanks,
    Erik

>
> --
> JINMEI, Tatuya
>
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