Shepherd writeup

: Document 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.  The draft meets the criteria in RFC 2026, Sec. 4.1.1.
The type is properly indicated in the title page 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 memo defines an portion of the Management Information Base (MIB)
   for use with network management protocols in the Internet community.
   In particular, it describes managed objects to configure and/or
   monitor Bi-Directional Forwarding Detection for [RFC5880], [RFC5881]
   and [RFC5883], BFD versions 0 and/or 1, on devices supporting this

This document also includes writable SNMP objects.  While such objects have been recommended to be discontinued in IETF MIBs by the IESG, BFD represents a low-level components where configuration of such functionality may be appropriate for some scenarios.  Additionally, write-access has already been implemented by some vendors.  

A further review comment brought up during review is with regards to BFD version 0.  This MIB does not provide a specific conformance statement for that protocol profile for two reasons: BFD Version 0 never made it to RFC status due to a critical failure in the design of its state machine.  In the field, pretty much every vendor has moved to BFD version 1.  The second reason is that the only MIB impacting change is the IANAbfdSessStateTC impacting a single state that is otherwise not present in BFD 1.  The authors of the MIB made a brief comment in the text noting that BFD v0 is historical and that is as much as should be done in the context of a MIB.  I am of the opinion that any other document in the RFC series describing this history given the lack of publication of version 0 as an RFC, is probably excessive.

Working Group Summary

   This document received commentary from multiple individuals that have had
   prior SNMP MIB authoring and implementation experience.  The document was
   also reviewed in the context of additional BFD work besides providing
   base MIB functionality for the above RFCs.  This includes BFD
   multi-point, BFD over LAG.  It also has been reviewed as being the basis
   MIB for the BFD MPLS MIB.

Document Quality

   As is typical with MIB documents, several vendors implement the contents
   of the BFD MIB in various enterprise MIBs with greater or lesser
   attention paid to the exact structure of this document.  MIBs are seldom
   fully finished at vendors until the publication of the MIB as an RFC
   wherein all the code points are finalized with IANA and other

   In particular, the Textual-Convention draft covers various TCs that do
   not share consistent implementations across the vendors.  By publishing
   an RFC, these code points will become normalized across the vendors.

   Being a MIB document, review by the MIB doctors is always appreciated.


  Document Shepherd: Jeffrey Haas <>
  Responsible AD: Adrian Farrel <>

: (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 reviewed the MIB documents for structural and language content multiple
times throughout their life cycle.  Additionally, I also requested targeted
review of the contents and structure with interested reviewers at the Berlin

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

No concerns.

: (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.

While there has been a general distancing of MIBs from write-capable
behaviors within the IETF routing area, this MIB does contain objects that
are read-create.  Unlike other far more complex protocols, basic BFD is
simple enough from a data modeling standpoint that the MIB can potentially
be used to provision BFD using SNMP.  As such, this does warrant additional
review from both a security and operational complexity perspective.

As is typical with routing protocol components, particularly those used for
OAM functionality, BFD is not terribly useful in a standalone environment.
It is thus expected that while the protocol can be provisioned using the
read-create objects within the MIB that many environments would not be able
to fully take advantage of such a provisioning system due inter-protocol,
and thus inter-MIB table dependencies.  This, however, is not a deficiency
of this MIB but rather a well known issue of the MIB ecosystem.

: (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.

I have no ongoing 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.

All 3 authors have positively affirmed that they have done all necessary IPR
disclosures - there are none.

: (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 has been filed and all authors affirm there is no IPR attached to
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?   

For a MIB, this document has received substantial review by the working group.

The WG has consensus that this document should be published.

: (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 appeals have been threatened and discontent has been confined to minor
concerns about future MIBs that may need to be based upon this base MIB.
Those concerns appear to have been addressed as partof WGLC comments.

: (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
: thorough.

The ID-nits tool has run clean on the MIB drafts.

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

MIB Doctor review has not yet been done.

: (13) Have all references within this document been identified as
: either normative or informative?

They have.

: (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 currently published RFCs.  For the base BFD
MIB, the remaining normative reference is the TC MIB, also being submitted
for publication with the base MIB.

: (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. 


: (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).

The documents were reviewed after WGLC to request IANA to adopt these as
IANA maintained MIBs.  An additional short WGLC-bis was requested to double
check the resulting object and TC renames.

: (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.

In the base BFD MIB, no additional registries are requested.

For the BFD TC MIB, there is a desire to publish the TC MIB as an IANA
maintained MIB.  

: (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.

Per the mib-review-tools, the drafts pass smilint.  I do not have access to