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Shepherd writeup
draft-ietf-bfd-vxlan

: (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?

Informational.

: (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 describes the use of the Bidirectional Forwarding
Detection (BFD - RFC 5880) protocol in Virtual eXtensible Local Area Network
(VXLAN) overlay networks.

: Working Group Summary:

This document has received community review with opportunities to comment in
relevant working groups such as BFD, NVO3, and BESS.  It is of interest to
parties that operate VXLAN networks and wish to provide continuity checks for
tunnels interconnecting virtual machines in such networks.

: 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?

In spite of significant discussion prior to submitting this document to the
IESG, there was much commentary as part of IESG review.

A substantial amount of review commentary was generated by the original text
related to what VNI is being tested using this protocol extension.  The
majority of this commentary was the result of the security considerations
related to how a tenant VNI may benefit from this feature.  In particular,
how does the protocol attempt to avoid hijacking tenant MAC addresses and
necessary IP addressing of the encapsulated BFD packets.

As part of addressing this issue, the Working Group decided to reduce the
general scope of the feature in this document to validating reachability to
the management VNI.  This removed the related security considerations for
the more general mechanism in the proposal.  It should be noted that the
encapsulation format remains flexible enough that testing non-management
VNIs remains feasible, but is now out of scope for this document.

While VXLAN implementations appear to regularly have forms of "management
VNIs", this concept does not appear in the VXLAN architecture documents.
The consensus in this document is that VNI number 1 would be the default VNI
for the management VNI number.

Since the management VNI did not have a well known Destination MAC address,
the proposal in this document was that one would be allocated from the IANA
pool for unicast MAC addresses for this purpose.

The internal Destination IP address, using the ::ffff:127.0.0.0/104 network
in a fashion similar to the MPLS LSP Ping feature required extensive
discussion with the IESG.  While this usage is well understood in MPLS OAM
functionality, it was controversial with one of the reivewing Area Directors.  
However, that AD's DISCUSS was removed after long discussion. 

The TTL/Hop Limit value and the application of GTSM (RFC 5082) as per BFD
core procedural documents was discussed and the document moved to use that
procedure even in encapsulated traffic.

A final note is that issue tracking became challenging during this review
and that the IETF would be well served by re-tooling IESG commentary to
include an issue tracker as part of the core infrastructure.

: 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?

At the time of working group last call, there are two known implementations of
this mechanism.  No special reviewers were required for this document.

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

Document Shepherd: Jeffrey Haas, BFD co-chair.
Responsible Area Director: Martin Vigoreux.

: (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 has been through working group review and has received and
incorporated commentary.  Additionally, feedback was solicited within NVO3 and
BESS.  BESS feedback was suggested after WGLC had concluded at the
recommendation of one of the NVO3 reviewers, Anoop Ghanwani, since BESS
provides protocol extensions for provisioning networks related to this
mechanism.

: (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.

The Destination MAC address assignment still requires review from the IANA
Designated Experts.  Multiple attempts to reach them were made during
document review.

: (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 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?

Yes.

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

There exists an IPR disclosure, #3193, from Cisco.  This IPR was disclosed
prior to last call and is not seen as an obstacle to document publication.

: (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 feedback on the document was solid.  Core participants of the working group
provided feedback on this document.  Additionally, it received review from
parties that normally do not provide last call feedback. 

: (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 nits.

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

The IANA considerations requesting a unicast MAC will require Expert Review as
part of IANA assignment.

: (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.  

Previously, when the document was targeted for Proposed Standard, there was
an issue with the core VXLAN documents having Informational status.
However, it was the consensus of the Working Group to change the status of
this proposal to match it as Informational.

: (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 has one request to IANA for assignment of a unicast MAC
address. This request requires review from a Designated Expert.

: (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.

None.

: (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

-- Jeff Haas
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