Re: 6man w.g. last call for <draft-ietf-6man-default-iids-11.txt>

[Alissa Cooper <[e-mail]>]

> On May 18, 2016, at 4:22 PM, 神明達哉 <[e-mail]> wrote:
> 
> At Tue, 17 May 2016 22:13:36 -0400,
> Fernando Gont <[e-mail]> wrote:
> 
>>> From this one, and your response to the next point, it seems you are
>>> saying the decision was to refuse to address that concern.  Am I
>>> understanding it correctly?
>> 
>> No. My take is that the concern is flawed. Please read
>> draft-gont-predictable-protocol-ids, and even RFC4941, which talks at
>> length about security and privacy issues regarding reusing identifiers
>> in different context, for different scopes, etc.
>> 
>> Let's call a lemon a lemon: Asking to embed a layer-2 identifier/address
>> in a layer-3 address is extremely bad.
> 
> I don't have a strong position on this matter itself, but my
> understanding of the sense of the wg is that this is controversial,
> and at least far from a clear consensus.  To repeat myself, *my*
> concern on this last call is that it's not even clear, at least to me,
> if this draft tries to say embedding a link-layer address is, whether
> it's randomized or not, "extremely bad" (and must therefore be
> prohibited).  If that's the intent, it should be clearly stated

The draft makes just about a clear a statement in this vein as is possible:

"By default, nodes SHOULD NOT employ IPv6 address generation schemes
   that embed the underlying link-layer address in the IID.”

Note that this statement does not prohibit anything, nor does it make a normative (in the moral sense) judgment. It just states the recommendation, which is the point of the document.

I appreciate that not everyone on the list agrees with this recommendation. But I find the claim that this recommendation is unclear to be difficult to understand. That is, I can’t think of a way to convey the same recommendation that would be clearer. If you can, please suggest text.

Alissa


> and
> backed by a clear consensus from the wg.  Right now I don't see either
> such a clear statement or clear wg consensus.
> 
> --
> JINMEI, Tatuya