Re: [v6ops] A proposal for draft-ietf-6man-rfc4291bis-07

[David Farmer <[e-mail]>]

On Wed, Mar 8, 2017 at 2:20 PM, james woodyatt <[e-mail]> wrote:

> On Mar 7, 2017, at 13:41, [e-mail] wrote:
>
> On 7 Mar 2017, at 22:22, james woodyatt <[e-mail]> wrote:
>
>
> In summary, there is a deficit of RFC 2119 keyword language here, and we
> have to make the case that the standards texts make a sufficiently strong
> implicit case rather than an explicit normative requirement.
>
> As explained above, it sure looks to me like a very fair reading of the
> implicit requirements language is that LwIP is within the limits of RFC
> 4291, RFC 4861 and RFC 4862 when it choose the option of ignoring PIO
> elements with invalid prefix length for IID on the underlying link type.
>
> Yes, the USGv6 and IPv6 Ready Logo tests are well within their rights to
> apply additional requirements beyond the IETF standards, but it seems like
> a strict interpretation of the standards allow for LwIP to claim
> conformance.
>
> How can we counter this argument?
>
>
> We're not writing law, we're specifying what it takes to have
> implementations of a specification interoperate.
>
>
> I agree, and I contend there's something missing here in what we’ve said
> it takes to interoperate.
>
> That implementation would fail to interoperate.
>
>
> As I wrote to the other participants in this exchange off list, I remain
> convinced that the interoperability issue here is due to system
> administrators ignoring the recommendation in RFC 4862 to always use a
> valid Prefix Length for the link type in PIO elements without also ensuring
> that all hosts on the link implement behavior that RFC 4861 implies is
> OPTIONAL for performing on-link determination.
>
> Here I will add that I’m not going to push for changes to LwIP either
> locally or upstream until I’m persuaded this interpretation of the existing
> text is wrong.
>

So one question, where in your mind do the standards say what is a valid
prefix for PIO on link? Or the conversely, where does it define invalid
prefixes for such?

Thanks

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