Transmission and Processing of IPv6 Extension Headers
draft-ietf-6man-ext-transmit-05

[Ballot comment]
Converting the discuss to a comment on the assumption the proposed text will make it into the document under brian's watch.

If you need to find the transport header due to configured policy and you can't due to being unable to parse the extensions chain your configured action will be to drop. That perhaps weasels it's way through section 2.1 requirements but it's still quite ugly.

...
former discuss

This is a dicuss because I'd like to see if I'm in the rough in this.

Devices generally considered to be IP routers in fact are able to or find it necessary to forward on the basis of headers other than the IP header e.g. the transport header. By the definition applied in the problem statement all ipv6 capable routers in the internet that  I'm aware are or are capable of being middleboxes.

I would welcome the existence proof of an ipv6 capable router which is not capable of being a middlebox by the definition applied in the problem statement.

I'm not sure that's a glaring flaw in the document but it certainly is with our vocabulary around taxonomy if true.

[Ballot comment]
Comment:

In section 2.1, I think that it would be helpful to the reader to use the
option name, as well as the number.

[Ballot comment]
Could you provide any citations on the middle box behaviors, e.g., lack of support for all of 2460?

10 points to the INT area for the cite to Heller :)

"... Not just a failure to recognize such a header". 
Isn't this another Catch-22?  If a node doesn't recognize a header, how does it know if it's standard or not?  This also seems in contradiction to later guidance that unrecognized extensions may be dropped by default.

A flow chart or pseudo code might be useful in Section 2.1, like "if (known && standard) { /* policy */ }"

[Ballot comment]

- 2.1 says nodes SHOULD forward rfc4727 experimental
headers, but earlier said that its ok (nodes MAY) default
to not forwarding packets with experimental headers. I
think you need to add an "unless otherwise stated here"
to the statement about defaults for experimental headers.

- section 4: Is it wise to ask IANA to "redirect" users
from one (empty) registry to another? That could be the
start of a slippery slope turning IANA registries into a
miasma of hypertext;-) Maybe it'd be better to ask that
IANA mark that registry as having being replaced by this
new one. Also - what if someone else asks IANA to add an
entry to the currently empty registry but not the new one
- is it clear what should happen in that case?

[Ballot discuss]
This is a dicuss because I'd like to see if I'm in the rough in this.

Devices generally considered to be IP routers in fact are able to or find it necessary to forward on the basis of headers other than the IP header e.g. the transport header. By the definition applied in the problem statement all ipv6 capable routers in the internet that  I'm aware are or are capable of being middleboxes.

I would welcome the existence proof of an ipv6 capable router which is not capable of being a middlebox by the definition applied in the problem statement.

I'm not sure that's a glaring flaw in the document but it certainly is with our vocabulary around taxonomy if true.

[Ballot comment]
If you need to find the transport header due to configured policy and you can't due to being unable to parse the extensions chain your configured action will be to drop. That perhaps weasels it's way through section 2.1 requirements but it's still quite ugly.

[Ballot comment]
Thanks for the work on this document. I have no objection to its publication and just two minor observations.

---

Section 1.1

A couple of points about the following paragraph:

  In this document "standard" IPv6 extension headers are those
  specified in detail by IETF standards actions.  "Experimental"
  extension headers are those defined by any Experimental RFC, and the
  experimental extension header values 253 and 254 defined by [RFC3692]
  and [RFC4727].  "Defined" extension headers are the "standard"
  extension headers plus the "experimental" ones.

My reading of the IANA registry (http://www.iana.org/assignments/
protocol-numbers/protocol-numbers.xhtml) is that allocations can be made
by IESG Approval or Standards Action. I think both of those are covered
by what you call "standard".

I am not convinced that an experiment that uses an experimental code
point needs to be documented in an Experimental RFC.

Are 253 and 254 intended solely for experimental extension headers?
Couldn't the experiment be an experimental payload protocol?

---

I find myself in I-wouldn't-have-done-it-this-way land, so this is, of
course, just a Comment for you to chew on and accept or reject according
to how it strikes you...

It seems to me unwise to create a new registry that duplicates
information held in another registry. By adding a column to the
"Assigned Internet Protocol Numbers" registry you are making it
completely clear which are the IPv6 Extension Headers. Rather than risk
having this registry out of step with your new "IPv6 Extension Header
Types registry", I would have had the existing, empty "IPv6 Next Header
Types" registry redirect users to the "Assigned Internet Protocol
Numbers" registry and mention the existence of the specific column that
identifies extension headers.

[Ballot comment]
As "Catch 22" is one of my favourite books ( http://staringatemptypages.blogspot.com/2007/10/you-must-read-this.html ), it pleases me to know that there'll be an RFC with a reference to it.

-- Section 4 --

  Additionally, IANA is requested to make the existing empty IPv6 Next
  Header Types registry redirect users to a new IPv6 Extension Header
  Types registry.  It will contain only those protocol numbers which
  are also marked as IPv6 Extension Header types in the Assigned
  Internet Protocol Numbers registry.

Two small points here:

1. "It" in the second sentence is ambiguous: it could refer to either of the registries mentioned in the first sentence.  I suggest making it "The IPv6 Extension Header Types registry will contain...".

2. Is it your intent that the (empty) IPv6 Next Header Types registry also be closed to new registrations?  Whether or not, it would be best to make that clear.

IESG/Authors/WG Chairs:

IANA has reviewed draft-ietf-6man-ext-transmit-03.  Authors should review the comments and/or questions below.  Please report any inaccuracies and respond to any questions as soon as possible.

IANA's reviewer has the following comments/questions:

IANA has questions about some of the actions requested in the IANA Considerations section of this document.

IANA understands that, upon approval of this document, there are three actions which IANA needs to complete.

First, in the Assigned Internet Protocol Numbers registry in the Protocol Numbers page at

http://www.iana.org/assignments/protocol-numbers

a new column will be added to the registry to indicate whether or not the value is also IPv6 Extension Header types defined through IETF Action as defined in RFC 5226.

IANA Question -> What should the title of this column be?

IANA Question -> For which values in the Assigned Internet Protocol Numbers registry should there be an indication that the value is also IPv6 Extension Header types defined through IETF Action as defined in RFC 5226?

Second, the Next Header Types registry in the Internet Protocol Version 6 (IPv6) Parameters page will be removed completely from 

http://www.iana.org/assignments/ipv6-parameters

Third, a new registry called "IPv6 Extension Header Types" will be created in the Internet Protocol Version 6 (IPv6) Parameters page at

http://www.iana.org/assignments/ipv6-parameters

IANA Question -> using the definitions of RFC5226, how is this new registry to be managed?

There will be initial registrations in this registry, as follows:

Type Description Reference
------+---------------------------------------+----------------------
0 Hop-by-Hop Options [RFC2460]
43 Routing [RFC2460], [RFC5095]
44 Fragment [RFC2460]
50 Encapsulating Security Payload [RFC4303]
51 Authentication [RFC4302]
60 Destination Options [RFC2460]
135 MIPv6 [RFC6275]
139 experimental use, HIP [RFC5201]
140 shim6 [RFC5533]
253 experimental use [RFC3692], [RFC4727]
254 experimental use [RFC3692], [RFC4727]

IANA understands that these three actions are the only ones required 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 only to confirm what actions will be performed.

The following Last Call announcement was sent out:

From: The IESG
To: IETF-Announce
CC:
Reply-To: ietf@ietf.org
Sender:
Subject: Last Call:  (Transmission and Processing of IPv6 Extension Headers) to Proposed Standard


The IESG has received a request from the IPv6 Maintenance WG (6man) to
consider the following document:
- 'Transmission and Processing of IPv6 Extension Headers'
  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 2013-09-20. 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


  Various IPv6 extension headers have been standardised since the IPv6
  standard was first published.  This document updates RFC 2460 to
  clarify how intermediate nodes should deal with such extension
  headers and with any that are defined in future.  It also specifies
  how extension headers should be registered by IANA, with a
  corresponding minor update to RFC 2780.




The file can be obtained via
http://datatracker.ietf.org/doc/draft-ietf-6man-ext-transmit/

IESG discussion can be tracked via
http://datatracker.ietf.org/doc/draft-ietf-6man-ext-transmit/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?

  Proposed Standard.

  The type of RFC is indicated in the 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 updates RFC 2460 to clarify how intermediate nodes should
  deal with such extension headers and with any that are defined in
  future.  It also specifies how extension headers should be registered
  by IANA, with a corresponding minor update to RFC 2780.

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?

  No.


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?

  There was a good discussion in the working group and well as a detailed
  review by Fernando Gont.  The current draft resolves issues raised in
  the w.g. last call and detailed review. 

Personnel:

  Bob Hinden is 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.

  There was a good discussion in the working group and well as a detailed
  review by Fernando Gont.  The current draft resolves issues raised in
  the w.g. last call and detailed review.

  The chairs did a thorough review and discussed the draft during several
  phone conferences.


(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.

(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 issues to report.

(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, both authors have responded that they followed the BCPs and are
  not aware of any IPR relating to his document.

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

  No.

(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 WG consensus appears solid, with the whole WG behind it.

(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.

(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.

  Verified with the nits tool.

  One nit:  The document has a normative reference to an experimental
  protocol.  If this is an issue it can be fixed later or with a note to
  the RFC Editor.

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

N/A

(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?

  No.

(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.

  The document has a normative reference to an experimental
  protocol.  If this is an issue it can be fixed later or with a note to
  the RFC Editor.

(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.

  No.

(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).

  Reviewed the IANA considerations and think what is asked of IANA is
  clear and consistent with the 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.

  IANA is requested to replace the existing empty IPv6
  Next Header Types registry by an IPv6 Extension Header Types
  registry.  It will contain only those protocol numbers which are also
  marked as IPv6 Extension Header types in the Assigned Internet
  Protocol Numbers registry.  Experimental values will be marked as
  such. 

(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.

  None.