Transparent Interconnection of Lots of Links (TRILL): Appointed Forwarders
draft-ietf-trill-rfc6439bis-05

[Ballot discuss]
Section 2.4 (Overload and Appointed Forwarders) talks about potential Appointed Forwarders which are overloaded.  In IS-IS, a node with the overload bit set "shall not" (ISO 10589) be considered for transit.  However, the use of "SHOULD NOT appoint an RBridge in overload" and "SHOULD re-assign VLANs from the overloaded RBridge" leaves a potential hole in the proper forwarding of TRILL data packers.  Why aren't MUST NOT/MUST used?  Is there something in the specific use of IS-IS by TRILL that I am missing?

I think this should be an easy DISCUSS to clear; either point to the piece I'm missing, or don't use an overloaded node.

[Ballot discuss]
I think this should be an easy DISCUSS to clear; either point to the piece I'm missing, or don't use an overloaded node.

Section 2.4 (Overload and Appointed Forwarders) talks about potential Appointed Forwarders which are overloaded.  In IS-IS, a node with the overload bit set "shall not" (ISO 10589) be considered for transit.  However, the use of "SHOULD NOT appoint an RBridge in overload" and "SHOULD re-assign VLANs from the overloaded RBridge" leaves a potential hole in the proper forwarding of TRILL data packers.  Why aren't MUST NOT/MUST used?  Is there something in the specific use of IS-IS by TRILL that I am missing?

[Ballot discuss]
I would like to see a resolution to Dan Romascanu's OPS DIR concern.
https://datatracker.ietf.org/doc/review-ietf-trill-rfc6439bis-04-opsdir-telechat-romascanu-2017-01-12/
Note that the discussion is under way with Donald Eastlake

[Ballot comment]
I had trouble parsing "output it to or queue it for" (this occurs twice in the sentence).

  However, it does not output it to or queue it for that link,
  although, if appropriate (for example, the frame is multi-
  destination), it may output it to or queue it for other links.

I don't think the text is incorrect, just awkward. Perhaps commas would help?

In these three subsection titles,

  3.2.1 Change Optimization One

  3.2.2 Change Optimization Two

  3.2.3 Settling Detection Optimization

I found the title for 3.2.3 helpful, but not 3.2.1 or 3.2.2. Is it possible to come up with more descriptive titles?

I found

  For robustness, a TRILL switch sends a number of copies of a Port-
  Shutdown messages configurable from one to three, which defaults to
  two copies, at a configurable interval, which defaults to 20
  milliseconds (see Section 6.6).

difficult to parse. Perhaps

  For robustness, a TRILL switch sends a configurable number of copies
  of Port-Shutdown messages separated by a configurable interval. The default
  number of copies is two, although this can be configured as one copy
  or as three copies, and the default interval is 20 milliseconds
  (see Section 6.6).

?

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

The IANA Services Operator has completed its review of draft-ietf-trill-rfc6439bis-03.txt. If any part of this review is inaccurate, please let us know.

The IANA Services Operator understands that, upon approval of this document, there are three actions which we must complete.

First, in the TRILL APPsub-TLV Types under IS-IS TLV 251 Application Identifier 1 subregistry of the Transparent Interconnection of Lots of Links (TRILL) Parameters registry located at:

https://www.iana.org/assignments/trill-parameters/

four new TLV Types are to be registered as follows:

Type: [ TBD-at-registration ]
Name: AppointmentBitmap
Reference: [ RFC-to-be ]

Type: [ TBD-at-registration ]
Name: AppointmentList
Reference: [ RFC-to-be ]

Type: [ TBD-at-registration ]
Name: FGL-VLAN-Bitmap
Reference: [ RFC-to-be ]

Type: [ TBD-at-registration ]
Name: FGL-VLAN-Pairs
Reference: [ RFC-to-be ]

Second, in the RBridge Channel Protocols subregistry also in the Transparent Interconnection of Lots of Links (TRILL) Parameters registry located at:

https://www.iana.org/assignments/trill-parameters/

a single, new protocol will be registered from the Standards Action range as follows:

Protocol: [ TBD-at-registration ]
Description: Port Shut-Down
Reference: [ RFC-to-be ]

Third, in the PORT-TRILL-VER Sub-TLV Capability Flags also in the Transparent Interconnection of Lots of Links (TRILL) Parameters registry located at:

https://www.iana.org/assignments/trill-parameters/

the entry for value 0 (Hello reduction support) will have its reference changed from RFC 7780 to [ RFC-to-be ].

We understand that sections 10.2 through 10.5 represent documentation of data structures related to Appointed Forwarders in TRILL and not actions for the IANA Services Operator.

The IANA Services Operator understands that these three actions are the only ones required to be completed upon approval of this document.

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.

Thank you,

Sabrina Tanamal
IANA Services Specialist
PTI

The following Last Call announcement was sent out:

From: The IESG
To: "IETF-Announce"
CC: "Susan Hares" , shares@ndzh.com., akatlas@gmail.com, trill-chairs@ietf.org, trill@ietf.org, draft-ietf-trill-rfc6439bis@ietf.org
Reply-To: ietf@ietf.org
Sender:
Subject: EXTENSION OF Last Call:  (TRILL: Appointed Forwarders) to Proposed Standard


The IESG has received a request from the Transparent Interconnection of
Lots of Links WG (trill) to consider the following document:
- 'TRILL: Appointed Forwarders'
  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 2017-01-10. 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


  TRILL supports multi-access LAN (Local Area Network) links where a
  single link can have multiple end stations and TRILL switches
  attached.  Where multiple TRILL switches are attached to a link,
  native traffic to and from end stations on that link is handled by a
  subset of those TRILL switches called "Appointed Forwarders", with
  the intent that native traffic in each VLAN be handled by at most one
  TRILL switch.  This document clarifies and updates the Appointed
  Forwarder mechanism. It updates RFC 6325, updates RFC 7177, and
  obsoletes RFC 6439.





The file can be obtained via
https://datatracker.ietf.org/doc/draft-ietf-trill-rfc6439bis/

IESG discussion can be tracked via
https://datatracker.ietf.org/doc/draft-ietf-trill-rfc6439bis/ballot/

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

  https://datatracker.ietf.org/ipr/2585/
  https://datatracker.ietf.org/ipr/2685/

The following Last Call announcement was sent out:

From: The IESG
To: "IETF-Announce"
CC: "Susan Hares" , shares@ndzh.com., akatlas@gmail.com, trill-chairs@ietf.org, trill@ietf.org, draft-ietf-trill-rfc6439bis@ietf.org
Reply-To: ietf@ietf.org
Sender:
Subject: Last Call:  (TRILL: Appointed Forwarders) to Proposed Standard


The IESG has received a request from the Transparent Interconnection of
Lots of Links WG (trill) to consider the following document:
- 'TRILL: Appointed Forwarders'
  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 2017-01-03. 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


  TRILL supports multi-access LAN (Local Area Network) links where a
  single link can have multiple end stations and TRILL switches
  attached.  Where multiple TRILL switches are attached to a link,
  native traffic to and from end stations on that link is handled by a
  subset of those TRILL switches called "Appointed Forwarders", with
  the intent that native traffic in each VLAN be handled by at most one
  TRILL switch.  This document clarifies and updates the Appointed
  Forwarder mechanism. It updates RFC 6325, updates RFC 7177, and
  obsoletes RFC 6439.





The file can be obtained via
https://datatracker.ietf.org/doc/draft-ietf-trill-rfc6439bis/

IESG discussion can be tracked via
https://datatracker.ietf.org/doc/draft-ietf-trill-rfc6439bis/ballot/

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

  https://datatracker.ietf.org/ipr/2585/
  https://datatracker.ietf.org/ipr/2685/

write-up format: refer to RFC 4858 for template,  version 02/24/2012.

(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?
type: Protocol standard
Why: Obsoletes RFC6439 on TRILL appointed forwarders. 
on title page: yes

(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

    TRILL supports multi-access LAN (Local Area Network) links where a
  single link can have multiple end stations and TRILL switches
  attached.  Where multiple TRILL switches are attached to a link,
  native traffic to and from end stations on that link is handled by a
  subset of those TRILL switches called "Appointed Forwarders", with
  the intent that native traffic in each VLAN be handled by at most one
  TRILL switch.  This document clarifies and updates the Appointed
  Forwarder mechanism. It updates RFC 6325, updates RFC 7177, and
  obsoletes RFC 6439.

Working Group Summary

WG has discussed this for 2 years. 
The consensus seemed reasonable.

WG LC:
https://www.ietf.org/mail-archive/web/trill/current/msg07305.html


Document Quality

  Are there existing implementations of the protocol?

  No.
 
  Have a significant number of vendors indicated their plan to
  implement the specification?

Huawei plans to implement this draft.

  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?

RTG-DIR reviewer:
RTG-DIR Reviewer: Joel Halpern 
https://www.ietf.org/mail-archive/web/trill/current/msg07382.html


No mib doctor, yang doctor, Media type or other expert review.
Personnel
  Document shephered: Susan Hares
  WG chairs: Jon Hudson and Susan Hares
  Responsible AD: Alia Atlas
  RTG-DIR reviewer: Joel Halpern

(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.

Shepherd reviewed the latest document, check WG IPR, Nits.

(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.

sec-dir might review the security considerations for "Port-Shutdown messages"
in section 9 - Security Considerations.  But this review will come as
part of the sec-dir 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.

IPR:
Donald Eastlake:
https://www.ietf.org/mail-archive/web/trill/current/msg07251.html
Yizhou Li
https://www.ietf.org/mail-archive/web/trill/current/msg07523.html

Fangwei Hu
4/20/2016, reposted on 8/26/2016
https://mailarchive.ietf.org/arch/msg/trill/xzuwX1tOEjjzLa9SxH_tBqrUmxc


Mohammed Umnair
https://www.ietf.org/mail-archive/web/trill/current/msg07252.html
Ayan Banerjee
https://www.ietf.org/mail-archive/web/trill/current/msg07253.html


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

2 IPR disclosures where made prior to WG LC (9/28/2015, 4/27/2015). 
https://datatracker.ietf.org/ipr/search/?submit=draft&id=draft-ietf-trill-rfc6439bis

(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? 

Light, but reasonable for this stage of WG.  The WG has discussed these changes over 18 months
so the whole WG seems to agree.

WG LC:
https://www.ietf.org/mail-archive/web/trill/current/msg07305.html

(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.)

Two possible downrefs:
  -- Obsolete informational reference (is this intentional?): RFC 7180
    (Obsoleted by RFC 7780)

(11) Identify any ID nits the Document Shepherd has found in this
document. (See https://www.ietf.org/tools/idnits/ and the Internet-Drafts
Checklist). Boilerplate checks are not enough; this check needs to be
thorough.

[remove once this is fixed]
- Obsolete informational reference (is this intentional?): RFC 7180
    (Obsoleted by RFC 7780)


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

no MIB, media, yang, or URI reviews needed.

(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 normative references. 

(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 ref normative references.
Two informative references fixes:  RFC7180 replaced by RFC7880.

[ChannelTunnel] - D. Eastlake, M. Umair, Y. Li, draft-ietf-trill-
        channel-tunnel, work in progress.
-- has been submitted to IESG.

(16) Will publication of this document change the status of any
existing RFCs?

Obsoletes RFC6439.

Are those RFCs listed on the title page header, listed
in the abstract, and discussed in the introduction?

Yes.


(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).

IANA - section has the definitions of additional PDUs.

(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 registries.

(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 XML, BNF, MIB or yang in the document.