Re: Éric Vyncke's No Objection on draft-ietf-6man-icmp-limits-07: (with COMMENT)

[Tom Herbert <[e-mail]>]

On Fri, Mar 6, 2020 at 3:57 AM Éric Vyncke via Datatracker
<[e-mail]> wrote:
>
> Éric Vyncke has entered the following ballot position for
> draft-ietf-6man-icmp-limits-07: No Objection
>
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> The document, along with other ballot positions, can be found here:
> https://datatracker.ietf.org/doc/draft-ietf-6man-icmp-limits/
>
>
>
> ----------------------------------------------------------------------
> COMMENT:
> ----------------------------------------------------------------------
>
> Tom,
>
> Thank you for the work put into this document. It is short and easy to read
> while addressing a real problem in real deployments.
>
> ********************
> *  I was about to add a DISCUSS for not using the right BCP14 RFC 8174 template
> but please FIX this *       (as this is the first review, I would suggest to
> issue today a revised I-D with just this fix *       before other IESG
> reviews). * *  I was also about to ballot a DISCUSS on the comment in section
> 2.4...
> *******************
>
Okay.

> Please find below some non-blocking COMMENTs and NITs. An answer will be
> appreciated.
>
> I hope that this helps to improve the document,
>
Thanks for the review!

> Regards,
>
> -éric
>
> == COMMENTS ==
>
> -- Section 1.2 --
> Just wondering why the "aggregate header limits" has a section on its own. Feel
> free to keep it like it is but this looks weird.
>
It's distinctly different than the other errors. This error can be
applied to other packet headers than IPv6 whereas the rest are only
about IPv6 header or extension header. Hence we needed to use
Destination Unreachable with extended ICMP message instead of
Parameter Problem type.

> -- Section 2 --
> Strongly suggest to use TBA1, TBA2, ... in order to avoid mistakes done by the
> IANA.

Thanks, will do that.

>
> -- Section 2.2 --
> Why not using a new code for 'unrecognized header' by intermediate node ? I
> really wonder why: it can only be confusing to existing implementation.
>
I imagine the host response would be the same.

> Please also ensure what is meant by 'destination' here... I would prefer to
> avoid discussions when a routing-header is used (too many discussions around
> this in 6MAN already)
>
Will make that "final destination"

> -- Section 2.4 --
> How can the original source distinguish among the two potential causes ? Why
> not using two code points? Or am I missing something obvious? I was really
> about to issue a blocking DISCUSS on this one.
>
If the Pointer points to the first byte of an extension header then
the limit on extension headers is inferred. If it points to something
inside extension headers then the length is exceeded. Grant it, that's
not 100% accurate but I don't believe that fine granularity is needed
for host response.

> -- Section 3 --
> Some justifications on why using a different ICMPv6 format would really help
> the reader.
>
Okay, will add some text.

> -- Section 4.1 --
> The wording "1) Real error (existing codes)" looks weird because the code
> points in this documents will also be existing. Why not using "1) RFC 4443
> error codes" ?
>

Will fix.

> -- Section 5.2 --
> Is applicable to RFC 4443 in general, so, I wonder why it is in this document.
>
That was due to feedback from 6man WG to mention reliability of ICMP.

> == NITS ==
>
> -- Section 1.1 --
> If I was picky, then I would argue that "Extension Headers are placed between
> the IPv6 header and the Upper-Layer Header in a packet" is not always true: if
> Next-Header is 59 (No Next Header per RFC 8200 section 4.7) ;-)
>
That's from RFC8200.

> -- Section 2.1 + 3.1--
> s/IPv6 Fields:/IPv6 Header Fields:/

Will fix.
>
>
>