Post-Stack MPLS Network Action (MNA) Header Specification
draft-ietf-mpls-mna-ps-hdr-09

IESG/Authors/WG Chairs:

IANA has completed its review of draft-ietf-mpls-mna-ps-hdr-08. If any part of this review is inaccurate, please let us know.

IANA understands that the third action requested in the IANA Considerations section of this document is dependent upon the approval of and completion of IANA Actions in another document:

[I-D.ietf-mpls-mna-hdr]

We also have a question about the second action requested.

IANA understands that, upon approval of this document, there are three actions that we must complete.

First, in the Post-Stack First Nibble registry located at:

https://www.iana.org/assignments/post-stack-first-nibble/

a single new registration is to be made as follows:

Protocol: MPLS
Value: 0x0
Description: Post-Stack MPLS Header
Reference: [ RFC-to-be ]

Second, a new registry is to be created called the Post-Stack MPLS Header Types registry.

IANA QUESTION -> Where should this new registry be located? Is it to be in a new registry group or a registry in an existing registry group? If it to be a new registry in an existing registry group, in which registry group should it be contained?

The registration procedure for the new registry is as follows:

0: Reserved
1-65520: IETF Review
65521-65524: Experimental Use
65525-65535: Private Use

There are initial registrations in the new registry as follows:

Type Description Reference
0 Reserved [ RFC-to-be ]
1 Post-Stack MPLS Header Type For MNA [ RFC-to-be ]

Third, in the Network Action Opcodes registry to be created upon approval of [ietf-mpls-mna-hdr], two actions are required:

1. Assign two code points for network actions defined in this document.
2. Add a new column to indicate whether network action opcodes may be used In-Stack or Post-Stack.

The resulting registry will be as follows:

Opcode: 0
Description: Reserved
In-Stack Only, Post-Stack Only, In-Stack and Post-Stack: Not applicable
Reference: [I-D.ietf-mpls-mna-hdr]

Opcode: 1
Description: Flag-Based Network Action Indicators without AD
In-Stack Only, Post-Stack Only, In-Stack and Post-Stack: In-Stack Only
Reference: [I-D.ietf-mpls-mna-hdr]

Opcode: 2
Description: No operation Opcode
In-Stack Only, Post-Stack Only, In-Stack and Post-Stack: In-Stack and Post-Stack
Reference: [I-D.ietf-mpls-mna-hdr]

Opcode: [ TBD-at-Registration ]
Description: Offset of Start of Post-Stack MPLS Header
In-Stack Only, Post-Stack Only, In-Stack and Post-Stack: In-Stack Only
Reference: [ RFC-to-be ]

Opcode: [ TBD-at-Registration ]
Description: Offset of End of Post-Stack MPLS Header
In-Stack Only, Post-Stack Only, In-Stack and Post-Stack: In-Stack Only
Reference: [ RFC-to-be ]

Opcode: 127
Description: Opcode Range Extension Beyond 127
In-Stack Only, Post-Stack Only, In-Stack and Post-Stack: In-Stack and Post-Stack
Reference: [I-D.ietf-mpls-mna-hdr]

We understand 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 Sr. Specialist

The following Last Call announcement was sent out (ends 2026-06-09):

From: The IESG
To: IETF-Announce
CC: adrian@olddog.co.uk, draft-ietf-mpls-mna-ps-hdr@ietf.org, james.n.guichard@futurewei.com, mpls-chairs@ietf.org, mpls@ietf.org
Reply-To: last-call@ietf.org
Sender:
Subject: Last Call:  (Post-Stack MPLS Network Action (MNA) Header Specification) to Proposed Standard


The IESG has received a request from the Multiprotocol Label Switching WG
(mpls) to consider the following document: - 'Post-Stack MPLS Network Action
(MNA) Header Specification'
  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 2026-06-09. 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


  This document defines the Post-Stack MPLS Network Action (MNA) Header
  Specification for carrying Network Actions encodings and Ancillary
  Data after the MPLS label stack, based on the In-Stack MNA
  Specification defined in "MPLS Network Action (MNA) Sub-Stack
  Specification."  MPLS Network Actions can be used to influence packet
  forwarding decisions, carry additional Operations, Administration,
  and Maintenance information in the MPLS packet, or perform user-
  defined operations.  This document follows the framework specified in
  RFC 9789.




The file can be obtained via
https://datatracker.ietf.org/doc/draft-ietf-mpls-mna-ps-hdr/


The following IPR Declarations may be related to this I-D:

  https://datatracker.ietf.org/ipr/5994/
  https://datatracker.ietf.org/ipr/6549/

Shepherd writeup for draft-ietf-mpls-mna-ps-hdr
"Post-Stack MPLS Network Action (MNA) Header Specification"
Document shepherd: Adrian Farrel

= Document History

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

  The first WG last call attracted only 4 responses (2 from authors),
  so the chairs held a second last call which had to be extended with a
  prompt to the WG to pay attention. Finally there were enough responses
  to be able to say that there is consensus for publication.

  It may be said that there is not overwhelming enthusiasm in the WG for
  this draft.

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

  There were three points of note:
  - The first arose from draft-ietf-mpls-mna-hdr and concerned how the
    MNA Header should indicate whether post-stack data was in use or a
    post-stack header was present. This debate almost derailed that
    other draft, but the issues were resolved.
  - The second issue concerned whether the same MNA Opcodes should be
    used for actions that could be encoded either in-stack or post-
    stack. The conclusion was to have a shared registry (defined in
    draft-ietf-mpls-mna-hdr, but updated with an additional column in
    this document).
  - The third topic of debate was whether there was any need for this
    post-stack work at all. specific use cases that demanded the
    mechanism are thin on the ground, however, the original
    requirements work set out that post-stack should be made available,
    and in the end it was agreed that this document should proceed to
    make the tool available.

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 appeals promissed.

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 recommends) or elsewhere
(where)?

  There are no implementations reported.
  There are six I-Ds (one is a WG I-D) that make normative reference
  to this document.

= Additional Reviews

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.

  This is pure MPLS. No other WGs need be involved.

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

  No formal reviews needed.

If the document contains a YANG module, has the final version of the module
been checked with any of the recommended validation tools 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?

  No YANG.

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.

  No formal language.

= Document Shepherd Checks

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?

  The shepherd's review (at revision -01) raised penty of issues and nits.
  It took several subsequent revisions to address all of the points.
  The document is now (after additional RTG-Dir reviews) ready for
  publication.

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

  The document has been checked against the list for the RTG Area.

  Sadly, the document oes not contain an Operational Considerations
  section, and I believe a check against the OPS Area list might find
  it deficient. Unfortunately, two requests for OPS-Dir reviews failed
  to deliver.

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

  Publication is requested on the Standards Track.
  This is indicated:
  - in the document header
  - in the Datatracker

Have reasonable efforts been made to remind all authors of the intellectual
property rights (IPR) disclosure obligations described in BCP 79? 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.

  An IPR poll was condicted before WG last call. See the thread at:
  https://mailarchive.ietf.org/arch/msg/mpls/5ISGADSRJtf50bcep6CBq5rgE98/
  All authors and the one conributor responded.

  There are two IPR disclosures against the document:
  https://datatracker.ietf.org/ipr/search/?submit=draft&id=draft-ietf-mpls-mna-ps-hdr

  Both disclosures were notified to the mailing list, and no discussion
  ensued.

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.

  There are just 5 front-page authors.
  All authors and the contributor have acknowledged their roles by dint
  of replying to the IPR poll. None objected.

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

  idnits runs cleanly on the latest revision.
  No other nits noticed.

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

  The balance of normative and informative references looks right.

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

  All normative references emanate from the IETF.

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

  No Downrefs.

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?

  draft-ietf-mpls-mna-hdr is a normative reference, but it is ahead of
  this document in the processing cycle and so will not be a problem.

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.

  No status changes.

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).

  The document shepherd's review led to significant changes in the IANA
  considerations. This appears to be correct now, although it is
  dependent on draft-ietf-mpls-mna-hdr.

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 new registries.

Shepherd writeup for draft-ietf-mpls-mna-ps-hdr
"Post-Stack MPLS Network Action (MNA) Header Specification"
Document shepherd: Adrian Farrel

= Document History

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

  The first WG last call attracted only 4 responses (2 from authors),
  so the chairs held a second last call which had to be extended with a
  prompt to the WG to pay attention. Finally there were enough responses
  to be able to say that there is consensus for publication.

  It may be said that there is not overwhelming enthusiasm in the WG for
  this draft.

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

  There were three points of note:
  - The first arose from draft-ietf-mpls-mna-hdr and concerned how the
    MNA Header should indicate whether post-stack data was in use or a
    post-stack header was present. This debate almost derailed that
    other draft, but the issues were resolved.
  - The second issue concerned whether the same MNA Opcodes should be
    used for actions that could be encoded either in-stack or post-
    stack. The conclusion was to have a shared registry (defined in
    draft-ietf-mpls-mna-hdr, but updated with an additional column in
    this document).
  - The third topic of debate was whether there was any need for this
    post-stack work at all. specific use cases that demanded the
    mechanism are thin on the ground, however, the original
    requirements work set out that post-stack should be made available,
    and in the end it was agreed that this document should proceed to
    make the tool available.

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 appeals promissed.

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 recommends) or elsewhere
(where)?

  There are no implementations reported.
  There are six I-Ds (one is a WG I-D) that make normative reference
  to this document.

= Additional Reviews

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.

  This is pure MPLS. No other WGs need be involved.

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

  No formal reviews needed.

If the document contains a YANG module, has the final version of the module
been checked with any of the recommended validation tools 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?

  No YANG.

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.

  No formal language.

= Document Shepherd Checks

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?

  The shepherd's review (at revision -01) raised penty of issues and nits.
  It took several subsequent revisions to address all of the points.
  The document is now (after additional RTG-Dir reviews) ready for
  publication.

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

  The document has been checked against the list for the RTG Area.

  Sadly, the document oes not contain an Operational Considerations
  section, and I believe a check against the OPS Area list might find
  it deficient. Unfortunately, two requests for OPS-Dir reviews failed
  to deliver.

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

  Publication is requested on the Standards Track.
  This is indicated:
  - in the document header
  - in the Datatracker

Have reasonable efforts been made to remind all authors of the intellectual
property rights (IPR) disclosure obligations described in BCP 79? 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.

  An IPR poll was condicted before WG last call. See the thread at:
  https://mailarchive.ietf.org/arch/msg/mpls/5ISGADSRJtf50bcep6CBq5rgE98/
  All authors and the one conributor responded.

  There are two IPR disclosures against the document:
  https://datatracker.ietf.org/ipr/search/?submit=draft&id=draft-ietf-mpls-mna-ps-hdr

  Both disclosures were notified to the mailing list, and no discussion
  ensued.

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.

  There are just 5 front-page authors.
  All authors and the contributor have acknowledged their roles by dint
  of replying to the IPR poll. None objected.

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

  idnits runs cleanly on the latest revision.
  No other nits noticed.

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

  The balance of normative and informative references looks right.

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

  All normative references emanate from the IETF.

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

  No Downrefs.

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?

  draft-ietf-mpls-mna-hdr is a normative reference, but it is ahead of
  this document in the processing cycle and so will not be a problem.

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.

  No status changes.

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).

  The document shepherd's review led to significant changes in the IANA
  considerations. This appears to be correct now, although it is
  dependent on draft-ietf-mpls-mna-hdr.

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 new registries.

Closed request for Early review by OPSDIR with state 'Withdrawn': Happy to have a review as this document progresses with the AD, but cannot wait any longer in the working group