Network Time Protocol Version 4 (NTPv4) Extension Fields
draft-ietf-ntp-extension-field-07

[Ballot comment]
Thank you for writing this much clarifying document!

I want to recommend its approval with a 'Yes' position, but before that I had two issues / question which I believe would benefit from some discussion:

Issue 1:

Suresh Krishnan's Gen-ART review raised a number of comments, and I thought fixing this was important:

> I could not find the text in RFC5905 Section 7.5 that this draft says it is
> replacing. Specifically the following "OLD:" text does not exist in RFC5905

Can the authors comment on this and make any changes that might be needed?

Issue 2:

Section 7.5.1.2 says:

  If an NTP packet is received with two or more extension fields that
  require a MAC with different algorithms, the packet MUST be
  discarded.

However, Section 7.5 already said earlier:

  If a host receives an
  extension field with an unknown Field Type, the host SHOULD ignore
  the extension field and MAY drop the packet altogether if policy
  requires it.

This leaves me wondering how the MUST-drop-packet-with-fields-with-different-algs can be implemented. Did you perhaps mean:

  If an NTP packet is received with two or more extension fields that
  this receiver recognises and those fields require a MAC with
  different algorithms, the packet MUST be discarded.

Or maybe something else? Can you clarify?

[Ballot discuss]
Suresh Krishnan's Gen-ART review raised a number of comments, and I thought fixing this was important:

> I could not find the text in RFC5905 Section 7.5 that this draft says it is
> replacing. Specifically the following "OLD:" text does not exist in RFC5905

Can the authors comment on this and make any changes that might be needed?

[Ballot comment]

If you do revisit the MACing setup, (as indicated
in the response to the secdir review [1]), I hope
you maybe consider taking some input on this from
security folk - having a scheme where essentially
random parts of the packet are/are-not protected
by a MAC isn't necessarily a good way to go. I do
totally agree that getting away from depending on
the length to figure out the algorithm is a thing
that definitely should be done, and moving to use
modern ciphers as well of course;-)

  [1] https://www.ietf.org/mail-archive/web/secdir/current/msg06329.html

[Ballot comment]
Thank you for writing this much clarifying document!

I want to recommend its approval with a 'Yes' position, but before that I had one question which I believe would benefit from some discussion:

Section 7.5.1.2 says:

  If an NTP packet is received with two or more extension fields that
  require a MAC with different algorithms, the packet MUST be
  discarded.

However, Section 7.5 already said earlier:

  If a host receives an
  extension field with an unknown Field Type, the host SHOULD ignore
  the extension field and MAY drop the packet altogether if policy
  requires it.

This leaves me wondering how the MUST-drop-packet-with-fields-with-different-algs can be implemented. Did you perhaps mean:

  If an NTP packet is received with two or more extension fields that
  this receiver recognises and those fields require a MAC with
  different algorithms, the packet MUST be discarded.

Or maybe something else? Can you clarify?

[Ballot discuss]
Thank you for writing this much clarifying document!

I want to recommend its approval with a 'Yes' position shortly, but before that I had one question which I believe would benefit from some discussion:

Section 7.5.1.2 says:

  If an NTP packet is received with two or more extension fields that
  require a MAC with different algorithms, the packet MUST be
  discarded.

However, Section 7.5 already said earlier:

  If a host receives an
  extension field with an unknown Field Type, the host SHOULD ignore
  the extension field and MAY drop the packet altogether if policy
  requires it.

This leaves me wondering how the MUST-drop-packet-with-fields-with-different-algs can be implemented. Did you perhaps mean:

  If an NTP packet is received with two or more extension fields that
  this receiver recognises and those fields require a MAC with
  different algorithms, the packet MUST be discarded.

Or maybe something else? Can you clarify?

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

IANA has reviewed draft-ietf-ntp-extension-field-04, which is currently in Last Call, and has the following comments:

We understand that this document doesn't require any IANA actions.

While it's often helpful for a document's IANA Considerations section to remain in place upon publication even if there are no actions, if the authors strongly prefer to remove it, IANA does not object.

If this assessment is not accurate, please respond as soon as possible.

The following Last Call announcement was sent out:

From: The IESG
To: IETF-Announce
CC:
Reply-To: ietf@ietf.org
Sender:
Subject: Last Call:  (The Network Time Protocol Version 4 (NTPv4) Extension Fields) to Proposed Standard


The IESG has received a request from the Network Time Protocol WG (ntp)
to consider the following document:
- 'The Network Time Protocol Version 4 (NTPv4) Extension Fields'
  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
ietf@ietf.org mailing lists by 2015-09-01. 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


  The Network Time Protocol Version 4 (NTPv4) defines the optional
  usage of extension fields. An extension field, defined in RFC5905, is
  an optional field that resides at the end of the NTP header, and can
  be used to add optional capabilities or additional information that
  is not conveyed in the standard NTP header. This document updates
  RFC5905 by clarifying some points regarding NTP extension fields and
  their usage with Message Authentication Codes (MAC).




The file can be obtained via
https://datatracker.ietf.org/doc/draft-ietf-ntp-extension-field/

IESG discussion can be tracked via
https://datatracker.ietf.org/doc/draft-ietf-ntp-extension-field/ballot/


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

(1) What type of RFC is being requested (BCP, Proposed Standard, Internet Standard, Informational, Experimental, or Historic)? Why is this the proper type of RFC? Is this type of RFC indicated in the title page header?

This document is being requested for publication as a Proposed Standard. It updates RFC5905, which is a standards track RFC, and therefore it belongs in the standards track. The intended status is shown on the title page. 

(2) The IESG approval announcement includes a Document Announcement Write-Up. Please provide such a Document Announcement Write-Up. Recent examples can be found in the "Action" announcements for approved documents. The approval announcement contains the following sections:

Technical Summary:

The Network Time Protocol Version 4 (NTPv4) [RFC5905] defines the optional usage of extension fields in NTP packets. The current document updates RFC5905 by clarifying some points regarding the usage of the NTP extension fields.

Working Group Summary:

The document has clear working group consensus for publication, and has been reviewed by several WG participants since its initial adoption as a working group item. Since the publication of NTPv4, various questions were raised on the WG mailing list regarding the correct usage of extension fields. These questions and discussions triggered the publication of the current document.

Document Quality:

This document has been reviewed and revised many times. There were no specific external expert reviews conducted. The WGLC notification was sent to the TICTOC working group in addition to the NTP working group

Personnel:

Karen O'Donoghue is acting as the Document Shepherd.  Brian Haberman is the Responsible Area Director.

(3) Briefly describe the review of this document that was performed by the Document Shepherd. If this version of the document is not ready for publication, please explain why the document is being forwarded to the IESG.

The document shepherd has followed the working group process and reviewed the final document and feels this document is ready for IESG review.

(4) Does the document Shepherd have any concerns about the depth or breadth of the reviews that have been performed?

The document shepherd does not have any concerns about the reviews that were performed.

(5) Do portions of the document need review from a particular or from broader perspective, e.g., security, operational complexity, AAA, DNS, DHCP, XML, or internationalization? If so, describe the review that took place.

This document does not require any special reviews beyond those planned during the IESG review process.

(6) Describe any specific concerns or issues that the Document Shepherd has with this document that the Responsible Area Director and/or the IESG should be aware of? For example, perhaps he or she is uncomfortable with certain parts of the document, or has concerns whether there really is a need for it. In any event, if the WG has discussed those issues and has indicated that it still wishes to advance the document, detail those concerns here.

The Document Shepherd is comfortable with this document as an update to RFC 5905 regarding the NTP extension fields. The documents represent the consensus of the working group.

(7) Has each author confirmed that any and all appropriate IPR disclosures required for full conformance with the provisions of BCP 78 and BCP 79 have already been filed. If not, explain why?

The authors have confirmed that they have dealt with all appropriate IPR disclosures.

(8) Has an IPR disclosure been filed that references this document? If so, summarize any WG discussion and conclusion regarding the IPR disclosures.

No IPR disclosures have been filed that reference this document.

(9) How solid is the WG consensus behind this document? Does it represent the strong concurrence of a few individuals, with others being silent, or does the WG as a whole understand and agree with it?

The document represents strong WG consensus.

(10) 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.

There have been no threats of anyone appealing the documents.

(11) Identify any ID nits the Document Shepherd has found in this document. (See http://www.ietf.org/tools/idnits/ and the Internet-Drafts Checklist). Boilerplate checks are not enough; this check needs to be thorough.

* There is a comment regarding non-compliant IPv4 addresses. ID nits mistakenly parses some of the section numbers as IP addresses.
* Since the document updates RFC 5905, the following warning is shown:
The document seems to lack a disclaimer for pre-RFC5378 work, but may have content which was first submitted before 10 November 2008….
* There are two comments about problematic references. It appears that two references to RFC errata have not been formatted correctly.

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

There are no formal review criteria for this document.

(13) Have all references within this document been identified as either normative or informative?

All references are tagged as normative or informative.

(14) Are there normative references to documents that are not ready for advancement or are otherwise in an unclear state? If such normative references exist, what is the plan for their completion?

All normative references are completed.

(15) Are there downward normative references (see RFC 3967)? If so, list these downward references to support the Area Director in the Last Call procedure.

There is a normative reference to an erratum of RFC 5905, which is a standard track document.

[RFC5905Err]  RFC 5905 Technical Erratum 3627, May 2014.


(16) Will publication of this document change the status of any existing RFCs? Are those RFCs listed on the title page header, listed in the abstract, and discussed in the introduction? If the RFCs are not listed in the Abstract and Introduction, explain why, and point to the part of the document where the relationship of this document to the other RFCs is discussed. If this information is not in the document, explain why the WG considers it unnecessary.

This document updates RFC 5905. The title page specifies that the current draft updates RFC 5905.

(17) 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 protocol extensions that the document makes are associated with the appropriate reservations in IANA registries. Confirm that any referenced IANA registries have been clearly identified. Confirm that newly created IANA registries include a detailed specification of the initial contents for the registry, that allocations procedures for future registrations are defined, and a reasonable name for the new registry has been suggested (see RFC 5226).

There are no new IANA considerations contained in this document.

(18) List any new IANA registries that require Expert Review for future allocations. Provide any public guidance that the IESG would find useful in selecting the IANA Experts for these new registries.

There are no new IANA considerations contained in this document.

(19) Describe reviews and automated checks performed by the Document Shepherd to validate sections of the document written in a formal language, such as XML code, BNF rules, MIB definitions, etc.

There are no formal language sections in this document.