Handling Unknown DHCPv6 Messages
RFC 7283

[Ballot comment]
was

.  Problem Statement

  When a relay agent receives a message, it decides to send the message
  either toward the server or toward the client.  However, RFC 3315
  does not explicitly describe how the relay agent can determine
  whether it should send a message toward the server or the client,
  although this is implied by the message definitions in RFC3315.

Imho this is untrue.

A relay agent receives two kinds of messages, messages it is configured to relay to a dhcpv6 server, e.g. because it is configured for a specific subnet, or because it is configured a relay for relays, replies or messages constructed with relay -replies contain the information necessary for them to be forwarded.

3315 section 20

The problem statement covers message routing however section 4. and later are not  in fact about message routing but rather about that handling of unknown message types which seems orthogonal to the problem statement. in fact it would seem better if the problem statement reflected the problem the draft is trying to address.

[Ballot discuss]
.  Problem Statement

  When a relay agent receives a message, it decides to send the message
  either toward the server or toward the client.  However, RFC 3315
  does not explicitly describe how the relay agent can determine
  whether it should send a message toward the server or the client,
  although this is implied by the message definitions in RFC3315.

Imho this is untrue.

A relay agent receives two kinds of messages, messages it is configured to relay to a dhcpv6 server, e.g. because it is configured for a specific subnet, or because it is configured a relay for relays, replies or messages constructed with relay -replies contain the information necessary for them to be forwarded.

3315 section 20

The problem statement covers message routing however section 4. and later are not  in fact about message routing but rather about that handling of unknown message types which seems orthogonal to the problem statement. in fact it would seem better if the problem statement reflected the problem the draft is trying to address.

[Ballot comment]

Two very nitty/minor comments. Feel free to ignore them.

Is it worth noting the potential for loops here? That'd need
a server to also re-tx a received message to a relay (who'd
send it back) or for the server to generate a new message
(or even better two new messages:-) in response to receiving
one from a relay. I doubt it'd happen so probably not worth
a mention unless there's some DHCP specific behaviour that
might trigger such a loop. (I know of none.)

In a similar vein, is there any DHCP mechanism where a relay
would send out the unknown message to two or more servers as
some form of load balancing?  If there were, then maybe it'd
be worth just sending unknown message types to one server
and not to all? If it went to all, and each server then
"occasionally" pinged the relay to see if had been updated
and each ping gets sent to all servers... Again probably not
worth a mention since I don't see it being a bad loop, so
just in case it rings a bell with you.

IESG/Authors/WG Chairs:

IANA has reviewed draft-ietf-dhc-dhcpv6-unknown-msg-05, which is currently in Last Call, and has the following comments:

We understand that, upon approval of this document, there are no IANA Actions that need completion. 

While it is helpful for the IANA Considerations section of the document to remain in place upon publication, if authors 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:  (Handling Unknown DHCPv6 Messages) to Proposed Standard


The IESG has received a request from the Dynamic Host Configuration WG
(dhc) to consider the following document:
- 'Handling Unknown DHCPv6 Messages'
  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 2014-02-18. 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


  DHCPv6 is not specific about handling messages with unknown types.
  This memo describes the problems and defines how a DHCPv6 server,
  client or relay agent should behave when receiving unknown DHCPv6
  messages.  This document also provides advice for authors of future
  documents defining new messages sent from DHCP servers to DHCP relay
  agents, and should be read by potential authors of such documents.
  This document updates RFC3315.




The file can be obtained via
http://datatracker.ietf.org/doc/draft-ietf-dhc-dhcpv6-unknown-msg/

IESG discussion can be tracked via
http://datatracker.ietf.org/doc/draft-ietf-dhc-dhcpv6-unknown-msg/ballot/


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

Document Writeup, template from IESG area on ietf.org, dated 6th January 2014.

draft-ietf-dhc-dhcpv6-unknown-message-04 write-up

(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 document defines the behavior of relay agents on handling
  unknown DHCPv6 messages, which requires standards track. The intended type is
  indicated in the document header.
 
(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 defines how a DHCPv6 server, client or relay agent should
  behave when receiving unknown DHCPv6 messages.

Working Group Summary:

  This document was called draft-csl-dhc-dhcpv6-unknown-msg-3315update prior to its
  adoption. There was unanimous support for it in favor of adoption and none
  against), so this document was adopted in April 2013. There was quite interest in
  this work posts since its adoption. There was never any opposition for this work.

Document Quality:

Personnel:

Who is the Document Shepherd? Who is the Responsible Area Director?

  Sheng Jiang is the document shepherd. Brian Haberman is the responsible AD.
 
(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.

  I thoroughly reviewed this document  (and had other minor
  comments in between):
 
  http://www.ietf.org/mail-archive/web/dhcwg/current/msg14951.html
 
  The issues raised in my last review were promptly addressed by authors
  in -04 version along with the comments from other DHC WG members. This
  document is ready for publication in my opinion.
 
(4) Does the document Shepherd have any concerns about the depth or breadth of
the reviews that have been performed?

  No.
 
(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.

  No. This document has been carefully reviewed by DHC WG.
 
(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 outstanding issues.

(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?

  Yes. The authors, Yong Cui, Qi Sun and Ted Lemon confirmed in writing that
  they are not aware of any IPR.
 
(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.
 
(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 was broad support for this document. It was reviewed by active WG
  participants. All changes were mostly minor.
 
(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. There was unanimous support for this work and nobody raised any objections.
 
(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.

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

  No MIB Doctor, media type, URI type or similar apply to this
  document.
 
(13) Have all references within this document been identified as either
normative or informative?

  Yes.

(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 published RFCs.
 
(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.

  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.

  It was discussed with co-chair and Internet area ADs that this
  document updates RFC3315 (DHCPv6). This document is an addition to RFC3315.
  The update information is clearly listed on the title page header, listed in
  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 RFC 5226).

  This document does not raise any 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.

  This document does not raise any IANA considerations.
 
(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 such parts to the document.

We believe this document has sufficient support to move forward and there were no objections.

The authors are requested to publish an updated draft with the reported issues and nits addressed, at which point publication will be requested.