IS-IS Application-Specific Link Attributes
draft-ietf-lsr-rfc8919bis-04

[Ballot comment]
Hi There,

Thanks for the document and for attempts to clarify things.  By way of one non-blocking comment, and just for my own understanding, I'd like to understand why the S-Bit (Segment Routing Policy) has been explicitly denoted dataplane independent.

This comment equally applies to draft-ietf-lsr-rfc8920bis

Thanks

Andrew

[Ballot comment]
# GEN AD review of draft-ietf-lsr-rfc8919bis-03

CC @larseggert

Thanks to Robert Sparks for the General Area Review Team (Gen-ART) review
(https://mailarchive.ietf.org/arch/msg/gen-art/LIVh0a3mn2tp9mWYXQ0QV8wgziA).

## Notes

This review is in the ["IETF Comments" Markdown format][ICMF], You can use the
[`ietf-comments` tool][ICT] to automatically convert this review into
individual GitHub issues. Review generated by the [`ietf-reviewtool`][IRT].

[ICMF]: https://github.com/mnot/ietf-comments/blob/main/format.md
[ICT]: https://github.com/mnot/ietf-comments
[IRT]: https://github.com/larseggert/ietf-reviewtool

[Ballot comment]
Thanks to John Scudder for the warning about revising only the diff, due to lack of time I will follow his guidance even if normally the IESG should review the whole document.

I am also sympathetic to Warren Kumari's ballot.

Thanks also to Christian Hopps for the shepherd's write-up.

[Ballot comment]
Thanks to the sponsoring AD John Scudder for providing context and the diff link in his Yes ballot and advertising this to the other ADs :)

[Ballot comment]
I initially wrote this up as a DISCUSS position, but made it NoObjection instead because it didn't strictly fit the DISCUSS criteria -- that said, I *do* think that it is important and would really appreciate it if you'd strongly consider addressing it (it's also IMO a trivial update!).

I reviewed this document on a plane, and had a bunch of comments... but it was only when I came to ballot that and I saw John Scudder's note of "Note that this document is a tightly-scoped update to RFC 8919. Prudent reviewers will focus on the diff vs. 8919 [1], and *not* try to do a detailed/full document review." - it would have been great to know that before reading the document!

Knowing what has changed in a -bis is really important - it lets the reader know if they actually have to bother reading the new document. This information *does* exist in this document, but it is buried in the RFC equivalent of the bottom of a locked filing cabinet stuck in a disused lavatory with a sign on the door saying 'Beware of the Leopard.” (Section 9, between Security Considerations and References)

Normally, in an "Updates" document we'd say (in the Abstract) something like "This document updates RFC 8919 by x and y and z". This is somewhat harder to do in a grammatically correct manner with Obsoletes, but perhaps something like: "This document obsoletes RFC 8919; the changes are documented in Section 9"?
(I'm planning on balloting the same on the OSPF version of this doc).

[Ballot comment]
Note that this document is a tightly-scoped update to RFC 8919. Prudent reviewers will focus on the diff vs. 8919 [1], and *not* try to do a detailed/full document review. Also, be aware that the registry name changes in the document reflect an earlier registry reorganization, between the publication of RFC 8919 and this bis document, the registry name changes are not being done by this document. Finally, be aware that there's a similar document, draft-ietf-lsr-rfc8920bis, that makes virtually the same changes, but with respect to RFC 8920 (OSPF) instead of RFC 8919 (IS-IS). I suggest reviewing them at the same time.

[1] https://author-tools.ietf.org/iddiff?url1=rfc8919&url2=draft-ietf-lsr-rfc8919bis&difftype=--html

(Via drafts-lastcall@iana.org): IESG/Authors/WG Chairs:

The IANA Functions Operator has completed its review of draft-ietf-lsr-rfc8919bis-01. If any part of this review is inaccurate, please let us know.

The IANA Functions Operator has questions about each of the actions requested in the IANA Considerations section of this document.

The IANA Functions Operator understands that, upon approval of this document, there are five actions which we must complete.

First, in the IS-IS Sub-TLVs for TLVs Advertising Neighbor Information registry on the IS-IS TLV Codepoints registry page located at:

https://www.iana.org/assignments/isis-tlv-codepoints/

the existing registration for Sub-TLV type:

Type: 16
Description: Application-Specific Link Attributes

will remain unchanged.

IANA Question --> Should [ RFC-to-be ] be added to or replace the reference for this registration?

Second, in the IS-IS Top-Level TLV Codepoints registry also on the IS-IS TLV Codepoints registry page located at:

https://www.iana.org/assignments/isis-tlv-codepoints/

the existing registration for TLV:

Value: 238
Description: Application-Specific SRLG

will remain unchanged.

IANA Question --> Should [ RFC-to-be ] be added to or replace the reference for this registration?

Third, Section 7.3 of the current draft describes (Table 5) the existing IS-IS Sub-sub-TLV Codepoints for Application-Specific Link Attributes registry also on the IS-IS TLV Codepoints registry page located at:

https://www.iana.org/assignments/isis-tlv-codepoints/

IANA notes that the early registration for Type: 17 is not included in Section 7.3.

IANA Question --> Are there any changes to the existing registry required other than continuing with the early registration requested in [draft-ietf-lsr-flex-algo-bw-con-05, Section 2.1]?

Fourth, Section 7.4 of the current draft describes (Table 6) the existing Link Attribute Application Identifiers registry on the Interior Gateway Protocol (IGP) Parameters registry page located at:

https://www.iana.org/assignments/igp-parameters/

IANA Question --> Section 7.4 omits:

Bit: 3
Name: Flexible Algorithm (X-bit)
Reference: [RFC9350, Section 12]

Do the authors intend for this bit to remain registered? Are there any changes to the existing registry required by the approval of the current draft?

Fifth, Section 7.5 of the current draft describes (Table 7) the IS-IS Sub-TLVs for Application-Specific SRLG TLV registry on the IS-IS TLV Codepoints registry page located at:

https://www.iana.org/assignments/isis-tlv-codepoints/

IANA Question --> Are there any changes to the existing registry required by the approval of the current draft?

The IANA Functions Operator understands that these are the only actions required to be completed upon approval of this document.

Note:  The actions requested in this document will not be completed until the document has been approved for publication as an RFC. This message is meant only to confirm the list of actions that will be performed.

For definitions of IANA review states, please see:

https://datatracker.ietf.org/help/state/draft/iana-review

Thank you,

David Dong
IANA Services Specialist

The following Last Call announcement was sent out (ends 2023-05-03):

From: The IESG
To: IETF-Announce
CC: chopps@chopps.org, draft-ietf-lsr-rfc8919bis@ietf.org, jgs@juniper.net, lsr-chairs@ietf.org, lsr@ietf.org
Reply-To: last-call@ietf.org
Sender:
Subject: Last Call:  (IS-IS Application-Specific Link Attributes) to Proposed Standard


The IESG has received a request from the Link State Routing WG (lsr) to
consider the following document: - 'IS-IS Application-Specific Link
Attributes'
  as Proposed Standard

The IESG plans to make a decision in the next few weeks, and solicits final
comments on this action. Please send substantive comments to the
last-call@ietf.org mailing lists by 2023-05-03. Exceptionally, comments may
be sent to iesg@ietf.org instead. In either case, please retain the beginning
of the Subject line to allow automated sorting.

Abstract


  Existing traffic-engineering-related link attribute advertisements
  have been defined and are used in RSVP-TE deployments.  Since the
  original RSVP-TE use case was defined, additional applications (e.g.,
  Segment Routing Policy and Loop-Free Alternates) that also make use
  of the link attribute advertisements have been defined.  In cases
  where multiple applications wish to make use of these link
  attributes, the current advertisements do not support application-
  specific values for a given attribute, nor do they support indication
  of which applications are using the advertised value for a given
  link.  This document introduces new link attribute advertisements
  that address both of these shortcomings.

  This document obsoletes RFC 8919.




The file can be obtained via
https://datatracker.ietf.org/doc/draft-ietf-lsr-rfc8919bis/



No IPR declarations have been submitted directly on this I-D.

# Document Shepherd Write-Up for Group Documents

*This version is dated 4 July 2022.*

Thank you for your service as a document shepherd. Among the responsibilities is
answering the questions in this write-up to give helpful context to Last Call
and Internet Engineering Steering Group ([IESG][1]) reviewers, and your
diligence in completing it is appreciated. The full role of the shepherd is
further described in [RFC 4858][2]. You will need the cooperation of the authors
and editors to complete these checks.

Note that some numbered items contain multiple related questions; please be sure
to answer all of them.

## Document History

This document is a clarifying update to the base document, it is based on
errata submitted to the WG.

    1. Does the working group (WG) consensus represent the strong concurrence of
      a few individuals, with others being silent, or did it reach broad
      agreement?

Broad agreement.

    2. Was there controversy about particular points, or were there decisions
      where the consensus was particularly rough?

No controversy, one person expressed dislike for the base document; however, that was deemed out-of-scope as this is a simple clarifying document update.

    3. Has anyone threatened an appeal or otherwise indicated extreme
      discontent? If so, please summarize the areas of conflict in separate
      email messages to the responsible Area Director. (It should be in a
      separate email because this questionnaire is publicly available.)

No.

    4. For protocol documents, are there existing implementations of the
    contents of the document? Have a significant number of potential
    implementers indicated plans to implement? Are any existing implementations
    reported somewhere, either in the document itself (as [RFC 7942][3]
    recommends) or elsewhere (where)?

Implementations of the base document exist.

    ## Additional Reviews

    5. Do the contents of this document closely interact with technologies in
      other IETF working groups or external organizations, and would it
      therefore benefit from their review? Have those reviews occurred? If yes,
      describe which reviews took place.

No.

    6. Describe how the document meets any required formal expert review
      criteria, such as the MIB Doctor, YANG Doctor, media type, and URI type
      reviews.

There are no MIB, YANG, media type or URI concerns with this document update.

    7. If the document contains a YANG module, has the final version of the
      module been checked with any of the [recommended validation tools][4] for
      syntax and formatting validation? If there are any resulting errors or
      warnings, what is the justification for not fixing them at this time?
      Does the YANG module comply with the Network Management Datastore
      Architecture (NMDA) as specified in [RFC 8342][5]?

Does not contain a YANG module.

    8. Describe reviews and automated checks performed to validate sections of
      the final version of the document written in a formal language, such as
      XML code, BNF rules, MIB definitions, CBOR's CDDL, etc.

None required.

    ## Document Shepherd Checks

    9. Based on the shepherd's review of the document, is it their opinion that
      this document is needed, clearly written, complete, correctly designed,
      and ready to be handed off to the responsible Area Director?

Yes to all of these.

    10. Several IETF Areas have assembled [lists of common issues that their
        reviewers encounter][6]. For which areas have such issues been
        identified and addressed? For which does this still need to happen in
        subsequent reviews?

N/A

    11. What type of RFC publication is being requested on the IETF stream
        ([Best Current Practice][12], [Proposed Standard, Internet
        Standard][13], [Informational, Experimental or Historic][14])? Why is
        this the proper type of RFC? Do all Datatracker state attributes
        correctly reflect this intent?

Proposed Standard. This is the same track as the base document this one updates.

    12. Have reasonable efforts been made to remind all authors of the
        intellectual property rights (IPR) disclosure obligations described in
        [BCP 79][7]? To the best of your knowledge, have all required
        disclosures been filed? If not, explain why. If yes, summarize any
        relevant discussion, including links to publicly-available messages when
        applicable.

Yes.

    13. Has each author, editor, and contributor shown their willingness to be
        listed as such? If the total number of authors and editors on the front
        page is greater than five, please provide a justification.

Yes.

    14. Document any remaining I-D nits in this document. Simply running the
        [idnits tool][8] is not enough; please review the ["Content Guidelines"
        on authors.ietf.org][15]. (Also note that the current idnits tool
        generates some incorrect warnings; a rewrite is underway.)

No outstanding or unexpected NITS.

    15. Should any informative references be normative or vice-versa? See the
        [IESG Statement on Normative and Informative References][16].

No.

    16. List any normative references that are not freely available to anyone.
        Did the community have sufficient access to review any such normative
        references?

ISO 10589 - The IS-IS base standard document. Community had sufficient time to
review.

    17. Are there any normative downward references (see [RFC 3967][9] and [BCP
        97][10]) that are not already listed in the [DOWNREF registry][17]? If
        so, list them.

No.

    18. Are there normative references to documents that are not ready to be
        submitted to the IESG for publication or are otherwise in an unclear
        state? If so, what is the plan for their completion?

No.

    19. Will publication of this document change the status of any existing
        RFCs? If so, does the Datatracker metadata correctly reflect this and
        are those RFCs listed on the title page, in the abstract, and discussed
        in the introduction? If not, explain why and point to the part of the
        document where the relationship of this document to these other RFCs is
        discussed.

This will update and obsolete the existing base document.

    20. Describe the document shepherd's review of the IANA considerations
        section, especially with regard to its consistency with the body of the
        document. Confirm that all aspects of the document requiring IANA
        assignments are associated with the appropriate reservations in IANA
        registries. Confirm that any referenced IANA registries have been
        clearly identified. Confirm that each newly created IANA registry
        specifies its initial contents, allocations procedures, and a reasonable
        name (see [RFC 8126][11]).

No changes in this area to review.

    21. List any new IANA registries that require Designated Expert Review for
        future allocations. Are the instructions to the Designated Expert clear?
        Please include suggestions of designated experts, if appropriate.

No changes in this area to review.

    [1]: https://www.ietf.org/about/groups/iesg/ [2]:
    https://www.rfc-editor.org/rfc/rfc4858.html [3]:
    https://www.rfc-editor.org/rfc/rfc7942.html [4]:
    https://trac.ietf.org/trac/ops/wiki/yang-review-tools [5]:
    https://www.rfc-editor.org/rfc/rfc8342.html [6]:
    https://trac.ietf.org/trac/iesg/wiki/ExpertTopics [7]:
    https://www.rfc-editor.org/info/bcp79 [8]:
    https://www.ietf.org/tools/idnits/ [9]:
    https://www.rfc-editor.org/rfc/rfc3967.html [10]:
    https://www.rfc-editor.org/info/bcp97 [11]:
    https://www.rfc-editor.org/rfc/rfc8126.html [12]:
    https://www.rfc-editor.org/rfc/rfc2026.html#section-5 [13]:
    https://www.rfc-editor.org/rfc/rfc2026.html#section-4.1 [14]:
    https://www.rfc-editor.org/rfc/rfc2026.html#section-4.2 [15]:
    https://authors.ietf.org/en/content-guidelines-overview [16]:
    https://www.ietf.org/about/groups/iesg/statements/normative-informative-references/
    [17]: https://datatracker.ietf.org/doc/downref/

# Document Shepherd Write-Up for Group Documents

*This version is dated 4 July 2022.*

Thank you for your service as a document shepherd. Among the responsibilities is
answering the questions in this write-up to give helpful context to Last Call
and Internet Engineering Steering Group ([IESG][1]) reviewers, and your
diligence in completing it is appreciated. The full role of the shepherd is
further described in [RFC 4858][2]. You will need the cooperation of the authors
and editors to complete these checks.

Note that some numbered items contain multiple related questions; please be sure
to answer all of them.

## Document History

This document is a clarifying update to the base document, it is based on
errata submitted to the WG.

    1. Does the working group (WG) consensus represent the strong concurrence of
      a few individuals, with others being silent, or did it reach broad
      agreement?

Broad agreement.

    2. Was there controversy about particular points, or were there decisions
      where the consensus was particularly rough?

No controversy, one person expressed dislike for the base document; however, that was deemed out-of-scope as this is a simple clarifying document update.

    3. Has anyone threatened an appeal or otherwise indicated extreme
      discontent? If so, please summarize the areas of conflict in separate
      email messages to the responsible Area Director. (It should be in a
      separate email because this questionnaire is publicly available.)

No.

    4. For protocol documents, are there existing implementations of the
    contents of the document? Have a significant number of potential
    implementers indicated plans to implement? Are any existing implementations
    reported somewhere, either in the document itself (as [RFC 7942][3]
    recommends) or elsewhere (where)?

Implementations of the base document exist.

    ## Additional Reviews

    5. Do the contents of this document closely interact with technologies in
      other IETF working groups or external organizations, and would it
      therefore benefit from their review? Have those reviews occurred? If yes,
      describe which reviews took place.

No.

    6. Describe how the document meets any required formal expert review
      criteria, such as the MIB Doctor, YANG Doctor, media type, and URI type
      reviews.

There are no MIB, YANG, media type or URI concerns with this document update.

    7. If the document contains a YANG module, has the final version of the
      module been checked with any of the [recommended validation tools][4] for
      syntax and formatting validation? If there are any resulting errors or
      warnings, what is the justification for not fixing them at this time?
      Does the YANG module comply with the Network Management Datastore
      Architecture (NMDA) as specified in [RFC 8342][5]?

Does not contain a YANG module.

    8. Describe reviews and automated checks performed to validate sections of
      the final version of the document written in a formal language, such as
      XML code, BNF rules, MIB definitions, CBOR's CDDL, etc.

None required.

    ## Document Shepherd Checks

    9. Based on the shepherd's review of the document, is it their opinion that
      this document is needed, clearly written, complete, correctly designed,
      and ready to be handed off to the responsible Area Director?

Yes to all of these.

    10. Several IETF Areas have assembled [lists of common issues that their
        reviewers encounter][6]. For which areas have such issues been
        identified and addressed? For which does this still need to happen in
        subsequent reviews?

N/A

    11. What type of RFC publication is being requested on the IETF stream
        ([Best Current Practice][12], [Proposed Standard, Internet
        Standard][13], [Informational, Experimental or Historic][14])? Why is
        this the proper type of RFC? Do all Datatracker state attributes
        correctly reflect this intent?

Proposed Standard. This is the same track as the base document this one updates.

    12. Have reasonable efforts been made to remind all authors of the
        intellectual property rights (IPR) disclosure obligations described in
        [BCP 79][7]? To the best of your knowledge, have all required
        disclosures been filed? If not, explain why. If yes, summarize any
        relevant discussion, including links to publicly-available messages when
        applicable.

Yes.

    13. Has each author, editor, and contributor shown their willingness to be
        listed as such? If the total number of authors and editors on the front
        page is greater than five, please provide a justification.

Yes.

    14. Document any remaining I-D nits in this document. Simply running the
        [idnits tool][8] is not enough; please review the ["Content Guidelines"
        on authors.ietf.org][15]. (Also note that the current idnits tool
        generates some incorrect warnings; a rewrite is underway.)

No outstanding or unexpected NITS.

    15. Should any informative references be normative or vice-versa? See the
        [IESG Statement on Normative and Informative References][16].

No.

    16. List any normative references that are not freely available to anyone.
        Did the community have sufficient access to review any such normative
        references?

ISO 10589 - The IS-IS base standard document. Community had sufficient time to
review.

    17. Are there any normative downward references (see [RFC 3967][9] and [BCP
        97][10]) that are not already listed in the [DOWNREF registry][17]? If
        so, list them.

No.

    18. Are there normative references to documents that are not ready to be
        submitted to the IESG for publication or are otherwise in an unclear
        state? If so, what is the plan for their completion?

No.

    19. Will publication of this document change the status of any existing
        RFCs? If so, does the Datatracker metadata correctly reflect this and
        are those RFCs listed on the title page, in the abstract, and discussed
        in the introduction? If not, explain why and point to the part of the
        document where the relationship of this document to these other RFCs is
        discussed.

This will update and obsolete the existing base document.

    20. Describe the document shepherd's review of the IANA considerations
        section, especially with regard to its consistency with the body of the
        document. Confirm that all aspects of the document requiring IANA
        assignments are associated with the appropriate reservations in IANA
        registries. Confirm that any referenced IANA registries have been
        clearly identified. Confirm that each newly created IANA registry
        specifies its initial contents, allocations procedures, and a reasonable
        name (see [RFC 8126][11]).

No changes in this area to review.

    21. List any new IANA registries that require Designated Expert Review for
        future allocations. Are the instructions to the Designated Expert clear?
        Please include suggestions of designated experts, if appropriate.

No changes in this area to review.

    [1]: https://www.ietf.org/about/groups/iesg/ [2]:
    https://www.rfc-editor.org/rfc/rfc4858.html [3]:
    https://www.rfc-editor.org/rfc/rfc7942.html [4]:
    https://trac.ietf.org/trac/ops/wiki/yang-review-tools [5]:
    https://www.rfc-editor.org/rfc/rfc8342.html [6]:
    https://trac.ietf.org/trac/iesg/wiki/ExpertTopics [7]:
    https://www.rfc-editor.org/info/bcp79 [8]:
    https://www.ietf.org/tools/idnits/ [9]:
    https://www.rfc-editor.org/rfc/rfc3967.html [10]:
    https://www.rfc-editor.org/info/bcp97 [11]:
    https://www.rfc-editor.org/rfc/rfc8126.html [12]:
    https://www.rfc-editor.org/rfc/rfc2026.html#section-5 [13]:
    https://www.rfc-editor.org/rfc/rfc2026.html#section-4.1 [14]:
    https://www.rfc-editor.org/rfc/rfc2026.html#section-4.2 [15]:
    https://authors.ietf.org/en/content-guidelines-overview [16]:
    https://www.ietf.org/about/groups/iesg/statements/normative-informative-references/
    [17]: https://datatracker.ietf.org/doc/downref/