Keyed IPv6 Tunnel
draft-ietf-l2tpext-keyed-ipv6-tunnel-07

[Ballot discuss]
* Section 5
I am having a hard time seeing how fragmentation is expected to work

  It is NOT RECOMMENDED for routers implementing this specification to
  enable IPv6 fragmentation (as defined in section 4.5 of RFC2460) for
  keyed IP tunnels.  IP fragmentation issues for L2TPv3 are discussed
  in section 4.1.4 of RFC3931.

And that specific section of RFC3931 recommends using RFC2473 to tunnel the packets which again ends up using the RFC2460 fragment header that this draft is trying to forbid.

So, can you please clarify exactly what happens when the size of the packet to be tunneled exceeds the MTU?

[Ballot discuss]
* Section 5
I am having a hard time seeing how fragmentation is supposed to work

  It is NOT RECOMMENDED for routers implementing this specification to
  enable IPv6 fragmentation (as defined in section 4.5 of RFC2460) for
  keyed IP tunnels.  IP fragmentation issues for L2TPv3 are discussed
  in section 4.1.4 of RFC3931.

And that specific section of RFC3931 recommends using RFC2473 to tunnel the packets which again ends up using the RFC2460 fragment header that this draft is trying to forbid.

So, can you please clarify exactly what happens when the size of the packet to be tunneled exceeds the MTU?

[Ballot comment]
I have just a few minor comments:

- 1, 2nd paragraph: The first sentence is convoluterd; can it be simplified?

-- "upon receipt on each tunnel": on receipt of packets?

-6: Please expand OAM, MEP, and MIP on first mention.

-11.2: RFCs 1981, 4623, 4720, 5085. 5883, and 5885 are all cited in the context of 2119 language. They should probably be normative references. (In my opinion, even citations for optional features need normative references if they are needed to fully understand the features.)

[Ballot comment]
Two questions:

1) I assume this was in depth discussed in the wg but the given reasoning for the following MUST does still not justify a MUST for me:
"All packets MUST carry the 64-bit L2TPv3 cookie field."
I would assume that there are possible deployment scenarios e.g. within a single domain where other existing protection mechanisms might be sufficient already that you don't really need the cookie...?

2) Further this is not normative language and i wonder if it should be:
"However, for compatibility with existing RFC3931 implementations, the packets need to be sent with Session ID."
Again I assume that this could be a SHOULD because if you know that you don't have devices that (only) implement RFC3931, you could probably even neglect the session id...?

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

The IANA Services Operator has reviewed draft-ietf-l2tpext-keyed-ipv6-tunnel-07.txt, which is currently in Last Call, and has the following comments:

We understand that this document doesn't require any registry 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, we do not object.

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

Thank you,

Sabrina Tanamal
IANA Services Specialist
PTI

The following Last Call announcement was sent out:

From: The IESG
To: "IETF-Announce"
CC: cpignata@cisco.com, draft-ietf-l2tpext-keyed-ipv6-tunnel@ietf.org, l2tpext@ietf.org, db3546@att.com, draft-ietf-l2tpext-keyed-ipv6-tunnel.all@ietf.org, l2tpext-chairs@ietf.org
Reply-To: ietf@ietf.org
Sender:
Subject: Last Call:  (Keyed IPv6 Tunnel) to Proposed Standard


The IESG has received a request from the Layer Two Tunneling Protocol
Extensions WG (l2tpext) to consider the following document:
- 'Keyed IPv6 Tunnel'
  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 2016-10-28. 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


  This document describes an Ethernet over IPv6 tunnel encapsulation
  with mandatory 64-bit cookie for connecting L2 Ethernet attachment
  circuits identified by IPv6 addresses.  The encapsulation is based on
  L2TPv3 over IP and does not use the L2TPv3 control plane.





The file can be obtained via
https://datatracker.ietf.org/doc/draft-ietf-l2tpext-keyed-ipv6-tunnel/

IESG discussion can be tracked via
https://datatracker.ietf.org/doc/draft-ietf-l2tpext-keyed-ipv6-tunnel/ballot/


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

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.

Shepherd writeup for:

                          Keyed IPv6 Tunnel
                draft-ietf-l2tpext-keyed-ipv6-tunnel-04

(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?

The intended status is Proposed Standard in the Standards Track. This is clearly indicated in the title page header.

Initially, the document was targeting Informational status. However, it was moved to Standards Track as it is making normative recommendations on L2TPv3. This was prompted by an on-list review of the 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:

Technical Summary

  Keyed IPv6 Tunnel:

  This document describes a simple L2 Ethernet over IPv6 tunnel
  encapsulation with mandatory 64-bit cookie for connecting L2 Ethernet
  attachment circuits identified by IPv6 addresses.  The encapsulation
  is based on L2TPv3 over IP.

  Implementing L2TPv3 over IPv6 [RFC2460] provides the opportunity to
  utilize unique IPv6 addresses to identify Ethernet attachment
  circuits directly, leveraging the key property that IPv6 offers, a
  vast number of unique IP addresses.  In this case, processing of the
  L2TPv3 Session ID may be bypassed upon receipt as each tunnel has one
  and only one associated session.  This local optimization does not
  hinder the ability to continue supporting the multiplexing of
  circuits via the Session ID on the same router for other L2TPv3
  tunnels.

Working Group Summary

The WG process as it relates to this document has been smooth and without major controversies. One of the key goals of the WG has been to ensure compliance, compatibility and continued support of demultiplexing based on Session ID.

Document Quality

There are multiple interoperable implementations of the solution described in this document, among four major router vendors. These implementations are deployed and running in production. Further, there is additional interop done with other vendors, and implementations in Linux.

Significant cross-WG and cross-Area review were performed on this document.

Most notable, the 6MAN WG reviewed this document and posted review comments on the L2TPExt mailing list. Further, this document was presented in PWE3/PALS, and one of the PALS chairs provided also a most thorough review.

Personnel

  Carlos Pignataro is the Document Shepherd, Deborah Brungard 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.

The document shepherd has reviewed the draft numerous times, before adoption, during WG progress, and during and after WG LC, and finds that it is ready to advance to the IESG. All issues that were raised in the working group have been addressed.

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

No such concerns. See Document Quality above.

(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 such reviews needed.

(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 such concerns, all the outstanding issues have been resolved.

(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. Each author and contributor have provided an IPR disclosure confirmation.

(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 behind this document has been pretty stable and is strong.

(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.

No errors were found on the ID nits check.

(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.

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.

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).

The document requests no IANA actions.

(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.

N/A.

(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.

N/A.