Re: [Last-Call] Opsdir last call review of draft-ietf-ippm-ioam-ipv6-options-08

[Shwetha Bhandari <[e-mail]>]

Hello Tianran,

Thank you for your review and feedback. Sorry for the late response. I am
revising the draft based on this, gen-art, sec-dir feedback.

Regarding your concern on the Increment Tracing option, it has a RemainingLen
field to restrict the length the option data can grow to.
This is elaborated in RFC 9197.
Will a new deployment consideration with the following text address your
concern:

C7       The IOAM Incremental Trace Option-Type expands the
            option length that may affect the processing of extension
            headers and options that follow IOAM options.
            Hence when IOAM Incremental Trace Option-Type is
            used in the deployment the RemainingLen field of the option
            must follow the guidance in RFC9197 and must
            be computed and set appropriately.

Thanks,
Shwetha

On Wed, Jul 13, 2022 at 12:39 PM Tianran Zhou via Datatracker <
[e-mail]> wrote:

> Reviewer: Tianran Zhou
> Review result: Has Issues
>
> I have reviewed this document as part of the Operational directorate's
> ongoing
> effort to review all IETF documents being processed by the IESG.  These
> comments were written with the intent of improving the operational aspects
> of
> the IETF drafts. Comments that are not addressed in last call may be
> included
> in AD reviews during the IESG review.  Document editors and WG chairs
> should
> treat these comments just like any other last call comments.
>
> It is good to describe the deployment consideration in section 5. However,
> I
> think there is an issue that the increamental tracing option will impact
> other
> IPv6 extension header processing, e.g. SRH. This is similar to the
> consideration about PMTU, which has many ways to detect. But it is
> different.
> The increamental option is encapsulated in HbH which is the first EH. As
> the
> option length expands, the intermedate node may not be able to process
> other
> EHs. Typically, SRH is used for TE. This will break the network service.
>
> Best,
> Tianran
>
>
>