Re: Last Call: <draft-ietf-6man-rfc4941bis-10.txt> (Temporary Address Extensions for Stateless Address Autoconfiguration in IPv6) to Proposed Standard

[神明達哉 <[e-mail]>]

At Thu, 10 Sep 2020 20:18:33 -0300,
Fernando Gont <[e-mail]> wrote:

> > BTW, RFC4941 limits the length of IID of temporary addresses to 64
> > bits while noting the length is not a fixed constant:
[...]
> >     [...] Note that an IPv6 identifier does not
> >     necessarily have to be 64 bits in length, but the algorithm specified
> >     in this document is targeted towards 64-bit interface identifiers.
> > (I suspect "an IPv6 identifier" is a typo and should be "an interface
> > identifier")
> >
> > rfc4941bis now seems to remove this limitation, albeit maybe
> > implicitly.  Independently from the discussion on Section 3.3.1, I
> > guess this change should probably be noted in Section 5 ("Significant
> > Changes from RFC4941").
>
> RFC4291 notes that the IID length is specified in Link-specific RFCs,

Do you mean RFC4862?

> and refrains to specify the IID in the addressing architecture. THat's
> the same we do here. And is the same we do in RFC7217.
>
> So, if you want to implement rfc4941bis on Ethernet, you need to look at
> RFC2464, where you find that the IID is 64-bit long. This document
> (rfc4941bis) does not change or attempt to change that at all.

Right, and I have no problem with that.  But that's not my point.  I
just pointed out that RFC4941 only defined an algorithm with 64-bit
IIDs while rfc4941bis doesn't have that limitation, and that the
difference may be worth noting in the "changes from" section.  If I
were to offer some specific text, it might be something like this:

   Broadly speaking, this document introduces the following changes:
...
   o  Removes the explicit limitation of the length of interface
      identifiers: [RFC4941] is specifically targeted towards 64-bit
      interface identifiers, but this document simply refers to the
      more general specification in [RFC4862] regarding the length of
      interface identifiers.

(Here I assume rfc4941bis will adopt text like my proposal in Section
3.3.1).

That said, I wouldn't insist on having this bullet in Section 5.  If
the authors (and wg) think it's not a "significant" change, I'm okay
with not bothering to say it.

--
JINMEI, Tatuya