(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?
Proposed standard. The RFC type is indicated on the title page header.
This document updates RFC5905, replacing text from RFC5095 to recommend the use
of transport-protocol ephemeral port randomization for NTP modes where use of
the service port is not required. Thus, it requires a Standards Track document.
(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:
Relevant content can frequently be found in the abstract and/or introduction of
the document. If not, this may be an indication that there are deficiencies in
the abstract or introduction.
The Network Time Protocol can operate in several modes. Some of these modes
are based on the receipt of unsolicited packets, and therefore require the use
of a well-known port as the local port number. However, in the case of NTP
modes where the use of a well-known port is not required, employing such
well-known port unnecessarily increases the ability of attackers to perform
blind/off-path attacks. This document formally updates RFC5905, recommending
the use of transport-protocol ephemeral port randomization for those modes
where use of the NTP well-known port is not required.
Working Group Summary:
Was there anything in WG process that is worth noting? For example, was there
controversy about particular points or were there decisions where the consensus
was particularly rough?
There was nothing particularly noteworthy in the WG process.
Are there existing implementations of the protocol? Have a significant number
of vendors indicated their plan to implement the specification? Are there any
reviewers that merit special mention as having done a thorough review, e.g.,
one that resulted in important changes or a conclusion that the document had no
substantive issues? If there was a MIB Doctor, YANG Doctor, Media Type or other
expert review, what was its course (briefly)? In the case of a Media Type
review, on what date was the request posted?
There are multiple implementations of the document. They are discussed in
Section 5, entitled "Implementation Status".
Who is the Document Shepherd? Who is the Responsible Area Director?
Karen O'Donoghue is the Document Shepherd. Erik Kline is the Responsible Area
(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.
This document is an update of RFC5905. The document shepherd has reviewed the
proposed change to that document, and has performed a thorough read of the
(4) Does the document Shepherd have any concerns about the depth or breadth of
the reviews that have been 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.
(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.
There are no concerns.
(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?
All co-authors have confirmed conformance.
(8) Has an IPR disclosure been filed that references this document? If so,
summarize any WG discussion and conclusion regarding the IPR disclosures.
(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?
There is WG consensus behind the document.
(10) Has anyone threatened an appeal or otherwise indicated extreme discontent?
If so, please summarise 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.)
(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.
ID nits was run on 11 Feb 2021. The results at that time were:
Summary: 0 errors (**), 0 flaws (~~), 3 warnings (==), 2 comments (--).
These are minor issues that will be addressed during the next stage of
publication including the update of an outdated informative reference.
(12) Describe how the document meets any required formal review criteria, such
as the MIB Doctor, YANG Doctor, media type, and URI type reviews.
(13) Have all references within this document been identified as either
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?
(15) Are there downward normative references references (see RFC 3967)? If so,
list these downward references to support the Area Director in the Last Call
There are no downward references.
(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 RFC5905. This is listed on the title page header and the
abstract, and discussed in the introduction.
(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
There are no IANA considerations.
(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.
(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, YANG modules, etc.
(20) If the document contains a YANG module, has the module been checked with
any of the recommended validation tools
(https://trac.ietf.org/trac/ops/wiki/yang-review-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
This document does not contain a YANG module.