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Loop-Free Alternate (LFA) Applicability in Service Provider (SP) Networks
RFC 6571

Revision differences

Document history

Date Rev. By Action
2020-07-29
06 (System) Received changes through RFC Editor sync (removed Errata tag (all errata rejected))
2015-10-14
06 (System) Notify list changed from rtgwg-chairs@ietf.org, draft-ietf-rtgwg-lfa-applicability@ietf.org to (None)
2012-08-22
06 (System) post-migration administrative database adjustment to the Yes position for Adrian Farrel
2012-06-12
06 (System) RFC published
2012-01-19
06 Cindy Morgan State changed to RFC Ed Queue from Approved-announcement sent.
2012-01-18
06 (System) IANA Action state changed to No IC
2012-01-18
06 Cindy Morgan IESG state changed to Approved-announcement sent
2012-01-18
06 Cindy Morgan IESG has approved the document
2012-01-18
06 Cindy Morgan Closed "Approve" ballot
2012-01-18
06 Cindy Morgan Approval announcement text regenerated
2012-01-18
06 Cindy Morgan Ballot writeup text changed
2012-01-18
06 (System) New version available: draft-ietf-rtgwg-lfa-applicability-06.txt
2012-01-11
05 (System) New version available: draft-ietf-rtgwg-lfa-applicability-05.txt
2012-01-06
06 Suresh Krishnan Request for Telechat review by GENART Completed. Reviewer: Suresh Krishnan.
2012-01-05
06 Samuel Weiler Request for Telechat review by SECDIR Completed. Reviewer: Shawn Emery.
2012-01-05
06 Cindy Morgan Removed from agenda for telechat
2012-01-05
06 Cindy Morgan State changed to Approved-announcement to be sent::Point Raised - writeup needed from IESG Evaluation.
2012-01-05
06 Dan Romascanu
[Ballot comment]
I would normally enter a DISCUSS on these two issues if the document was standards track. As it is informational I will just …
[Ballot comment]
I would normally enter a DISCUSS on these two issues if the document was standards track. As it is informational I will just mention the issues, in the hope that the authors would agree to consider them before publication.

1. The document is very dense and not easy reading, and one of the reasons is the lack of context explanation. The reader familiarity with the types of networks and the algorithms is assumed. Even the term Service Provider needs an explanation, there are many kinds of SPs and SP networks. Other example - you need to read through section 4 until you encounter for the first time the term MPLS.

2. There is very little information on the operational impact of deploying and activating LFAs. Section 6 only makes some claims of reduced complexity without much substantiation. There are no manageability considerations at all. If these are desscribed in another document please specify where.
2012-01-05
06 Dan Romascanu [Ballot Position Update] New position, No Objection, has been recorded
2012-01-05
06 Pete Resnick [Ballot comment]
I agree wholeheartedly with Peter's comments.
2012-01-05
06 Pete Resnick [Ballot Position Update] New position, No Objection, has been recorded
2012-01-05
06 Russ Housley
[Ballot comment]
The Security Considerations say: " This document does not introduce
  any new security considerations."  I am sure this is true, but it …
[Ballot comment]
The Security Considerations say: " This document does not introduce
  any new security considerations."  I am sure this is true, but it
  does not really help the reader.  Please add a sentence pointing the
  reader to security considerations from IP/MPLS.

  The late Gen-ART Review by Suresh Krishnan on 4-Jan-2012 includes a
  good suggestion.  Suresh suggests:

  This draft needs an informative reference to RFC5286. Without this
  reference it is very difficult to get the context required to
  understand this draft. Please consider adding the reference.
2012-01-05
06 Jari Arkko [Ballot comment]
Nice doc!
2012-01-05
06 Jari Arkko [Ballot Position Update] New position, No Objection, has been recorded
2012-01-04
06 Peter Saint-Andre
[Ballot comment]
Personally I found this document to be nearly impenetrable, but that's probably because the air is so thin up here at the application …
[Ballot comment]
Personally I found this document to be nearly impenetrable, but that's probably because the air is so thin up here at the application layer. :) I am balloting "No Objection" on the assumption that our Routing ADs have performed up to their usual high standard of excellence.
2012-01-04
06 Peter Saint-Andre
[Ballot comment]
Personally I found this document to be nearly impenetrable, but that's probably because the air is so thin up here at the application …
[Ballot comment]
Personally I found this document to be nearly impenetrable, but that's probably because the air is so thin up here at the application layer. :)  I am balloting "No Objection" on the assumption that our Routing ADs have performed up to their usual high standard of excellence.
2012-01-04
06 Peter Saint-Andre [Ballot Position Update] New position, No Objection, has been recorded
2012-01-04
06 Robert Sparks [Ballot Position Update] New position, No Objection, has been recorded
2012-01-04
06 Adrian Farrel
[Ballot comment]
I have cleared my Discuss and moved to a Yes ballot.

Thanks for addressing some of my comments.

I still wish the I-D …
[Ballot comment]
I have cleared my Discuss and moved to a Yes ballot.

Thanks for addressing some of my comments.

I still wish the I-D would spend more time looking at the security (are rpf checks commonly used in the topologies that are discussed, and if so what will be done to improve security when rpf checks are disabled) and management (what will be the consequences for management of turning on LFAs in the topologies discussed). But I don't think this is a blocking concern.

---

Section 2 starts with...

  In this document, we assume that all links to be protected are point-
  to-point.

The introduction has not mentioned the need to protect any links (nor
what the concept of a protected link is).

---

ISIS and OSPF should have references in Section 2.
2012-01-04
06 Adrian Farrel [Ballot Position Update] Position for Adrian Farrel has been changed to Yes from Discuss
2012-01-04
06 Stewart Bryant Ballot writeup text changed
2012-01-04
06 Stewart Bryant Ballot writeup text changed
2012-01-03
06 Russ Housley
[Ballot comment]
The Security Considerations say: " This document does not introduce
  any new security considerations."  I am sure this is true, but it …
[Ballot comment]
The Security Considerations say: " This document does not introduce
  any new security considerations."  I am sure this is true, but it
  does not really help the reader.  Please add a sentence pointing the
  reader to security considerations from IP/MPLS.
2012-01-03
06 Russ Housley [Ballot Position Update] New position, No Objection, has been recorded
2012-01-03
06 Sean Turner [Ballot Position Update] New position, No Objection, has been recorded
2012-01-02
06 Wesley Eddy
[Ballot comment]
In Section 3.8, under "Intra Area Destinations", the Node Protection evaluations use "Full" rather than "yes", which is inconsistent with the explanation of …
[Ballot comment]
In Section 3.8, under "Intra Area Destinations", the Node Protection evaluations use "Full" rather than "yes", which is inconsistent with the explanation of terms at the beginning of the section and with the terms used for the next subsection for "Inter Area Destinations".
2012-01-02
06 Wesley Eddy [Ballot Position Update] New position, No Objection, has been recorded
2012-01-02
06 Ron Bonica [Ballot Position Update] New position, No Objection, has been recorded
2012-01-02
06 Adrian Farrel
[Ballot comment]
Please show "(LFA)" as the acronym for "LoopFree Alternate" at the top
of the Introduction.

---
              …
[Ballot comment]
Please show "(LFA)" as the acronym for "LoopFree Alternate" at the top
of the Introduction.

---
                                                   
Section 1 could really use a reference to RFC 5714 to establish what LFA
actually means. I would suggest a new five-line paragraph summarising
LFAs.

---

Section 2 starts with...

  In this document, we assume that all links to be protected are point-
  to-point.

The introduction has not mentioned the need to protect any links (nor
what the concept of a protected link is).

---

ISIS and OSPF should have references in Section 2.
2012-01-02
06 Adrian Farrel
[Ballot discuss]
I would like to ballot "Yes" on this document, but I think the Security
Considerations are lacking. Although, of course, this document cannot …
[Ballot discuss]
I would like to ballot "Yes" on this document, but I think the Security
Considerations are lacking. Although, of course, this document cannot
introduce any security issues, I believe it should discuss the security
implications of LFAs. Can they be leveraged to swamp the network or do
other forms of DoS? Can they provide a way in that would normally not be
available?

At the very least there should be an explanation of why applying LFAs
does not make any difference to the security model for
routing/forwarding.

---

I should have liked to see some discussion of the management
implications of LFAs. Both in terms of what needs to be
configured/managed at a router that applies LFAs, and in terms of how
diagnostics are impacted at a neighboring router.
2012-01-02
06 Adrian Farrel [Ballot Position Update] New position, Discuss, has been recorded
2012-01-01
06 Stephen Farrell [Ballot Position Update] New position, No Objection, has been recorded
2011-12-30
06 Mary Barnes Request for Telechat review by GENART is assigned to Suresh Krishnan
2011-12-30
06 Mary Barnes Request for Telechat review by GENART is assigned to Suresh Krishnan
2011-12-30
06 Stewart Bryant State changed to IESG Evaluation from AD Evaluation::AD Followup.
2011-12-22
06 Stewart Bryant Ballot has been issued
2011-12-21
06 Samuel Weiler Request for Telechat review by SECDIR is assigned to Shawn Emery
2011-12-21
06 Samuel Weiler Request for Telechat review by SECDIR is assigned to Shawn Emery
2011-12-21
06 Stewart Bryant Placed on agenda for telechat - 2012-01-05
2011-12-21
06 Stewart Bryant [Ballot Position Update] New position, Yes, has been recorded for Stewart Bryant
2011-12-21
06 Stewart Bryant Ballot has been issued
2011-12-21
06 Stewart Bryant Created "Approve" ballot
2011-12-21
06 Stewart Bryant State changed to AD Evaluation::AD Followup from Last Call Requested.
2011-12-21
06 Stewart Bryant Last Call was requested
2011-12-21
06 Stewart Bryant State changed to Last Call Requested from AD Evaluation::AD Followup.
2011-12-21
06 Stewart Bryant Last Call text changed
2011-12-08
06 (System) Sub state has been changed to AD Follow up from New Id Needed
2011-12-08
04 (System) New version available: draft-ietf-rtgwg-lfa-applicability-04.txt
2011-10-20
06 Amanda Baber We understand that this document doesn't require any IANA actions.
2011-10-07
06 Stewart Bryant State changed to AD Evaluation::Revised ID Needed from In Last Call.
2011-10-07
06 Amy Vezza Last call sent
2011-10-07
06 Amy Vezza
State changed to In Last Call from Last Call Requested.

The following Last Call Announcement was sent out:

From: The IESG <iesg-secretary@ietf.org>
To: …
State changed to In Last Call from Last Call Requested.

The following Last Call Announcement was sent out:

From: The IESG <iesg-secretary@ietf.org>
To: IETF-Announce <ietf-announce@ietf.org>
CC: <rtgwg@ietf.org>
Reply-To: ietf@ietf.org
Subject: Last Call: <draft-ietf-rtgwg-lfa-applicability-03.txt> (LFA applicability in SP networks) to Informational RFC


The IESG has received a request from the Routing Area Working Group WG
(rtgwg) to consider the following document:
- 'LFA applicability in SP networks'
  <draft-ietf-rtgwg-lfa-applicability-03.txt> as an Informational RFC

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 2011-10-21. 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


  In this draft, we analyze the applicability of LoopFree Alternates in
  both core and access parts of Service Provider networks.  We provide
  design guides to favor their applicability where relevant, typically
  in the access part of the network.




The file can be obtained via
http://datatracker.ietf.org/doc/draft-ietf-rtgwg-lfa-applicability/

IESG discussion can be tracked via
http://datatracker.ietf.org/doc/draft-ietf-rtgwg-lfa-applicability/


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


2011-10-07
06 Stewart Bryant Ballot writeup text changed
2011-10-07
06 Stewart Bryant Ballot writeup text changed
2011-10-07
06 Stewart Bryant Last Call was requested
2011-10-07
06 Stewart Bryant State changed to Last Call Requested from Publication Requested.
2011-10-07
06 Stewart Bryant Last Call text changed
2011-10-07
06 (System) Ballot writeup text was added
2011-10-07
06 (System) Last call text was added
2011-10-07
06 (System) Ballot approval text was added
2011-09-27
06 Cindy Morgan
(1.a) Who is the Document Shepherd for this document? Has the
Document Shepherd personally reviewed this version of the
document and, in particular, does he …
(1.a) Who is the Document Shepherd for this document? Has the
Document Shepherd personally reviewed this version of the
document and, in particular, does he or she believe this
version is ready for forwarding to the IESG for publication?

Document Shepherd: Alvaro Retana (alvaro.retana@hp.com)

I have reviewed the document and believe that the current version (-03) is ready for publication.

(1.b) Has the document had adequate review both from key WG members
and from key non-WG members? Does the Document Shepherd have
any concerns about the depth or breadth of the reviews that
have been performed?

The document has been discussed in the rtgwg WG (both on the mailing list and during in-person meetings).

No concerns about the reviews.


(1.c) Does the Document Shepherd have concerns that the document
needs more review from a particular or broader perspective,
e.g., security, operational complexity, someone familiar with
AAA, internationalization or XML?

No need for specialized review.


(1.d) Does the Document Shepherd have any specific concerns or
issues 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. Has an IPR disclosure related to this document
been filed? If so, please include a reference to the
disclosure and summarize the WG discussion and conclusion on
this issue.

No additional concerns about the content.

No related IPR statements.


(1.e) 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 document has been active for a long time. In general, there hasn't been any opposition at all -- the WG understands and agrees with the document. OTOH, given that this is an informational document that analyzes the use of LFAs through a number of examples with significant detail, the support voices have not been overwhelming.


(1.f) 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
entered into the ID Tracker.)

No.


(1.g) Has the Document Shepherd personally verified that the
document satisfies all ID nits? (See the Internet-Drafts Checklist
and http://tools.ietf.org/tools/idnits/). Boilerplate checks are
not enough; this check needs to be thorough. Has the document
met all formal review criteria it needs to, such as the MIB
Doctor, media type and URI type reviews?

Yes.


(1.h) Has the document split its references into normative and
informative? 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
strategy for their completion? Are there normative references
that are downward references, as described in [RFC3967]? If
so, list these downward references to support the Area
Director in the Last Call procedure for them [RFC3967].

There's only one reference (total), and it is informative.


(1.i) Has the Document Shepherd verified that the document IANA
consideration section exists and is consistent with the body
of the document? If the document specifies protocol
extensions, are reservations requested in appropriate IANA
registries? Are the IANA registries clearly identified? If
the document creates a new registry, does it define the
proposed initial contents of the registry and an allocation
procedure for future registrations? Does it suggest a
reasonable name for the new registry? See [RFC5226]. If the
document describes an Expert Review process has Shepherd
conferred with the Responsible Area Director so that the IESG
can appoint the needed Expert during the IESG Evaluation?

Yes, the section is consistent; there is no IANA action required.

(1.j) Has the Document Shepherd verified that sections of the
document that are written in a formal language, such as XML
code, BNF rules, MIB definitions, etc., validate correctly in
an automated checker?

N/A

(1.k) 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

In this document, the applicability of LoopFree Alternates
in both core and access parts of Service Provider networks is analyzed.
Design guides are provided to favor their applicability where relevant,
typically in the access part of the network.


Working Group Summary

There is consensus in the WG to publish this document.

Document Quality

This document analyzes the applicability and provides design and
deployment guidance for LFAs (as defined in RFC 5714 - IP Fast Reroute
Framework). There are no changes suggested to the original framework.

Personnel

Document Shepherd: Alvaro Retana
Responsible AD: Stewart Bryant
2011-09-27
06 Cindy Morgan Draft added in state Publication Requested
2011-09-27
06 Cindy Morgan [Note]: 'Alvaro Retana (alvaro.retana@hp.com) is the document shepherd.' added
2011-09-27
06 Alvaro Retana Changed protocol writeup
2011-09-27
06 Alvaro Retana Document Write-Up sent to AD and iesg-secretary.
2011-09-27
06 Alvaro Retana IETF state changed to Submitted to IESG for Publication from WG Consensus: Waiting for Write-Up
2011-09-27
06 Alvaro Retana Document Write-Up sent to AD and iesg-secretary.
2011-09-27
06 Alvaro Retana Annotation tag Doc Shepherd Follow-Up Underway cleared.
2011-09-20
06 Alvaro Retana IETF state changed to WG Consensus: Waiting for Write-Up from WG Document
2011-09-20
06 Alvaro Retana Official Process Start for RFC publication
2011-09-20
06 Alvaro Retana Annotation tag Doc Shepherd Follow-Up Underway set.
2011-08-17
03 (System) New version available: draft-ietf-rtgwg-lfa-applicability-03.txt
2011-05-04
02 (System) New version available: draft-ietf-rtgwg-lfa-applicability-02.txt
2011-03-12
01 (System) New version available: draft-ietf-rtgwg-lfa-applicability-01.txt
2011-03-03
06 (System) Document has expired
2010-08-30
00 (System) New version available: draft-ietf-rtgwg-lfa-applicability-00.txt