Shepherd writeup

As required by RFC 4858, this is the current template for the Document 
Shepherd Write-Up.

Changes are expected over time. This version is dated 24 February 2012.

(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. This is a product of the IETF Homenet Working Group. It is intended to be used as a normative reference by other network protocols, some likely to be Standards Track, which require this type of algorithm. Yes, the “Intended Status” in the RFC header is “Proposed Standard.”

(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

This document specifies a distributed algorithm for prefix assignment within a site. While developed primarily for IPv6, it is generic enough to be used for any prefix-based numbering space such as IPv4. In order to run, the algorithm requires that participating nodes share information through a flooding mechanism of some kind.  If the flooding mechanism ensures that all messages are propagated to all nodes faster than a given timing upper bound, the algorithm also ensures that all assigned prefixes used for networking operations (e.g., host configuration) remain unchanged, unless another node assigns an overlapping prefix with a higher assignment priority, or the topology changes and renumbering cannot be avoided.

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 

This algorithm began as an extension to OSPF as, at the time, the Homenet WG was heading down the path of using OSPF as a monolithic home network routing and configuration protocol. There was strong consensus against using OSPF in this manner in the WG, leading to the the standalone prefix-assignment document. As a modular piece of work, the algorithm has now been applied to OSPF, IS-IS, and HNCP.

RFC 7503 includes this text:

   “This new LSA is designated for information related to OSPFv3
   autoconfiguration and, in the future, could be used for other
   autoconfiguration information, e.g., global IPv6 prefixes.  However,
   this is beyond the scope of this document.”

While this document is not referenced directly above, the work in this document is what was in mind when RFC 7503 was written.

Document Quality

  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, 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?

Open source implementation:, 


  Who is the Document Shepherd? Who is the Responsible Area

Mark Townsley, Terry Manderson

(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.

Mark Townsley reviewed this document. The document is ready for advancement. 

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

Since the split from OSPF, the document was used for implementation and received at least four in-depth reviews (Jiazi Ji, Markus Stenberg, Steven Barth, Benjamin Patterson, etc…)

(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.

There are no “bits on the wire” aspects defined in this document for review. However, algorithm correctness is very important. In addition to implementation and testing, correctness was determined as part of an academic paper and formal proof by Benjamin Paterson in 2012 (available upon request, albeit not yet formally published outside of the university system where it was submitted).

(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.

No specific 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.

Email has been sent (April 17, 2015) to all authors from chairs asking for formal yes/no for this question.

2015/04/20 - confirmation received from Pierre and Benjamin - still waiting for Jari!

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

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?   

Whilst the subject material is not necessarily understood in detail by a large proportion of the WG participants, there is a substantive core that has reviewed this document without dissent.

(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.) 

No, not that we are aware of.

(11) Identify any ID nits the Document Shepherd has found in this
document. (See and the Internet-Drafts
Checklist). Boilerplate checks are not enough; this check needs to be

Yes, there is one warning in the current version that MAY need to be addressed:

  == The document seems to lack the recommended RFC 2119 boilerplate, even if
     it appears to use RFC 2119 keywords. 

     (The document does seem to have the reference to RFC 2119 which the
     ID-Checklist requires).

(12) Describe how the document meets any required formal review
criteria, such as the MIB 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 procedure. 

Only normative reference is BCP so, no.

(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.


(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).

No IANA actions required.

(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, etc.