Multipoint LDP (mLDP) Node Protection
draft-ietf-mpls-mldp-node-protection-08

[Ballot comment]

Thanks for adding the new security consideration text.

If you change again please consider this tweak:

s/(a PLR or a MPT)/(e.g., a PLR or a MPT)/

[Ballot discuss]

The MUST in para 2 section 3 seems to me to create a possibly
new DoS enabler. The ability of N to cause this kind of ripple
effect, (setting up then pushing traffic to a bunch of new
LSPs), is what may be new. Exactly where in the referenced RFCs
is that covered? Or am I wrong that this is a new threat? (BTW:
Answering that this new threat is no worse than other existing
threats if one has access to the internals of a node.... is a
non-answer:-)

[Ballot comment]

While it is fine to re-use text, it is increasingly hard to
believe that almost nothing done since RFC5920 (dated in 2010)
has any new security considerations.  Put another way, who is
really helped by a 2 line security considerations section that
points at 6388 which points at 5036 (etc)?

[Ballot comment]
The shepherd writup says that there has been no explicit discussion of the two IPR disclosures. It's probably too late to worry about that for this draft, and both disclosures have the fairly common "we won't assert if you don't" terms. But I think we should encourage working groups to have more explicit discussion for IPR disclosures.

-- 2.3, last paragraph: "Along with the PLR MP Status a MP FEC TLV MUST be included"
Does that mean that both MUST be included, or if the first is included, the second MUST also be?

-- 4.1.3, last paragraph:
Just “recommended”? Is link flapping a minor enough that it doesn't justify a MUST?

-- 6:
It would be nice to show your work a bit more in the security considerations. This draft adds new protocol elements and procedures. If the working group has determined that those new bits add no new security concerns, it would be good to say why.

Editorial and Nits:

A (probably first) paragraph in the intro that defined exactly what the draft means by "protection" would be helpful. (The existing first paragraph talks about how you provide protection, but one must infer what this protects _against_.

-- 1, 2nd paragraph: Lots of the terms here could use (informative) citations.

-- 2.1, first paragraph: Consider s/"we are describing"/"we describe"
-- 2.1, last paragraph, 2nd to last sentence, "See section 5":
unbalanced parentheses.

-- 2.2, 1st paragraph:
s/"we are describing"/"we describe"

-- 2.2, last paragraph:
"protection mechanism don’t" -- Noun/verb disagreement (singular/plural)
s/ help restoring/help restore

-- 2.3, 2nd to last paragraph:
I suggest the “A node N” phrase be moved to the first mention of N in this paragraph.

"Removing a PLR address is likely due to a link failure, see the procedures as documented in Section 4.1. ":
Comma splice. Consider a semicolon.

"MUST encode PLR Status Value Element": Missing article.

-- 3, 2nd paragraph:
"Ln that was assigned to N via the normal mLDP procedures, and Label Lpx that was assigned for PLR (LSR1) for the purpose of node protecting MP LSP via node N."
I can’t parse this sentence. (Incomplete sentence?)

-- 3, 3rd paragraph: "For this reason, the FEC Label Mapping (FEC  : Lpx) sent by the MPT over the tLDP session to the PLR MUST include a Status TLV with
  MP Status including a new LDP MP status Value Element called the "Protected Node Status Value Element"."
Convoluted sentence. Consider breaking into multiple, simpler sentences.

-- 5, 1st sentence:
s/we are organizing/we organize/

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

IANA has completed its review of draft-ietf-mpls-mldp-node-protection-05. If any part of this review is inaccurate, please let us know.

IANA understands that, upon approval of this document, there are two actions which IANA must complete.

First, in the LDP MP Status Value Element type subregistry of the Label Distribution Protocol (LDP) Parameters registry located at:

https://www.iana.org/assignments/ldp-namespaces/

two, new element types will be registered as follows:

Value: [ TBD-at-Registration ]
Name: PLR Status Value Element
Reference: [ RfC-to-be ]

Value: [ TBD-at-Registration ]
Name: Protected Node Status Value Element
Reference: [ RfC-to-be ]

Second, in the TLV Type Name Space also in the Label Distribution Protocol (LDP) Parameters registry located at:

https://www.iana.org/assignments/ldp-namespaces/

a single, new TLV will be registered as follows:

Value: [ TBD-at-Registration ]
Description: MP Node Protection Capability
Reference: [ RFC-to-be ]

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:  (mLDP Node Protection) to Proposed Standard


The IESG has received a request from the Multiprotocol Label Switching WG
(mpls) to consider the following document:
- 'mLDP Node Protection'
  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 2015-09-08. 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 procedures to support node protection for
  Point-to-Multipoint and Multipoint-to-Multipoint Label Switched Paths
  (MP LSPs) that has been built by "Multipoint Label Distribution
  Protocol"(mLDP).  In order to protect a node N, the Point of Local
  Repair (PLR) LSR of N must learn the Merge Point (MPT) LSR(s) of node
  N such that traffic can be redirected to them in case node N fails.
  Redirecting the traffic around the failed node N depends on existing
  P2P LSPs.  The pre-established LSPs originate from the PLR LSR and
  terminate on the MPT LSRs while bypassing LSR N.




The file can be obtained via
https://datatracker.ietf.org/doc/draft-ietf-mpls-mldp-node-protection/

IESG discussion can be tracked via
https://datatracker.ietf.org/doc/draft-ietf-mpls-mldp-node-protection/ballot/


The following IPR Declarations may be related to this I-D:

  https://datatracker.ietf.org/ipr/2116/
  https://datatracker.ietf.org/ipr/1727/

The MPLS working group requests that

                                  mLDP Node Protection
                draft-ietf-mpls-mldp-node-protection-05

is published as an RFC on the standards track!


(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?

  We request that the document is published as a Proposed Standard. This is the
  right type of RFC since the document both specifies protocol procedures and
  protocol elements. The document says Standard Tracks.

(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 procedures to support node protection for
  P2P and MP2MP LSPs built by  mLDP.  In order to protect a node N,
  the Point of Local Repair (PLR) of N must learn the Merge Point (MPT)
  LSR(s) of node N to be able to redirected traffic if node N fails.  Redirecting
  the traffic around the failed node N depends on existing P2P LSPs
  from the PLRto the MPTs bypassing node N.
  The procedures to setup these P2P LSPs are outside the scope of
  this document, but one could use RSVP-TE or LDP LFA based
  techniques to accomplish this.

  The solution described in this document signals the MPT LSR(s) to the
  PLR LSR(s) via a Targeted LDP (tLDP) session [RFC5036].  By having a
  tLDP session with the PLR, most of the mLDP features currently
  defined should just work, like Make-Before-Break (MBB), Graceful
  Restart (GR), Typed Wildcard FEC support, etc.  All this is achieved
  at the expense of having an additional tLDP session between an MPT
  and PLR.

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?

  Nothing worth noting, the progress through the working group, from the adoption
  poll to the wglc has been smooth.
  The working group is behind the idea that different a full set of tools for
  different protection scenarios, this draft is one of them.

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?

  We do not currently know any implementations, but an implementation
  poll has been sent to the working group mailing list and the Write-up will
  be updated as soon as we receive more information.

Personnel

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

  Loa Andersson is the document shepherd
  Adrian Farrel 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 doucment was reviewed by the shepherd when if was first posted to the
    working group, in preparation for the working group adoption poll, when
  preparing the wglc and while writing the Shepherds Write-up.

  The Shepherd believes that the document is ready for publication.

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

  No such 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.

  No such reviews necessary.

(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!

(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 authors have stated on the MPLS wg mailing list that they are unaware
  of any other IPRs than those already disclosed.

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

  There are two IPRs disclosed against this document, the working has been
  notified (at wg poll and wglc), but there has been no explicit discussion.
  The working group chair take this to mean that the working group are
  comfortable with the disclosed IPRs.

(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 working group as a whole support this document.

(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 such threats.

(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.

    The document passes the nits tool clean.

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

    No formal reviews needed.

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

    Yes the references are correctly identified as normative and informative.

(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 references (even informative) are to existing 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 downward references.

(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.

    The publication will not change status of any existing RFC.


(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 Shepherd first reviewed the IANA section when this was on individual
    document, and proposed substantial changes. The IANA section has not
    really changed since then.

    The document does not create any new registries.

(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.

    No new IANA registries, so no registries that needs Expert Review.

(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.

    No automated reviews, except the nits-tool is necessary.