Extensions to IS-IS for Layer-2 Systems
draft-ietf-isis-layer2-11

[Ballot comment]
Extraordinarily pedantic nit: MAC address in section 2.1 is not to scale; suggested


  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+...+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  |                          MAC (1)    (6 bytes)                |
  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+...+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  |                  .................                          |
  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+...+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  |                          MAC (N)    (6 bytes)                |
  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+...+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

[Ballot discuss]
The OPS-DIR review by Menachem Dodge (posted in the tracker) raised a number of issues which I believe require clarification and edits. As the authors of the document answered that they will deal with the comments in a revised version of the document I am holding a DISCUSS until the comments are resolved by edits or detailed clarification answers.

OPS-DIR review by Menachem Dodge raised the issues below relative to version 09. The authors replied that they will address the issues in a revised version of the document.

I have reviewed the document draft-ietf-isis-layer2-09 for its operational impact.



This document describes generic layer 2 TLV additions to the IS-IS link state routing protocol.



I have no operational issues with this draft but I have a number of comments.



In section 2.1 the "MAC-Reachability" (MAC-RI) TLV is described, while in section 2.2 the "Multi Topology aware Port Capability" (MT-PORT-CAP) TLV is described. The layout of the diagram showing the format of these 2 TLVs is different and I suggest that the same layout be used for both TLVs.



I wish to query whether only for the MT-PORT-CAP there are 4 reserved bits between the "Length" and the "Topology Identifier" but not for the MAC-RI TLV. Isn't the Topology Identifier always 12 bits in length?



In these two sections 2.1 and 2.2 which are defining the new TLV Types shouldn't a comment be added for the IANA to fill in the value (147 / 143)? If these values are already known then there is no need for the two "[TBD]" indications in section 2.2. A comment should be added so that these are removed before the document is published.







The tool has found the following nits:



Checking references for intended status: Proposed Standard

  ----------------------------------------------------------------------------



    (See RFCs 3967 and 4897 for information about using normative references

    to lower-maturity documents in RFCs)



  == Missing Reference: 'RFC1195' is mentioned on line 73, but not

    defined

    'protocol, specifically IS-IS [IS-IS] [RFC1195], to provide true l...'



  == Missing Reference: 'TBD' is mentioned on line 170, but not defined

    'o  Type: TLV Type, set to MT-PORT-CAP TLV 143 [TBD]....'



  == Missing Reference: 'RFC5305' is mentioned on line 182, but not

    defined

    'TLVs formatted as described in [RFC5305].  They are defined in...'



  == Unused Reference: 'RFC 1195' is defined on line 220, but no explicit

    reference was found in the text

    '[RFC 1195] Callon, R., "Use of OSI IS-IS for Routing in TCP/IP and D...'



  -- Possible downref: Non-RFC (?) normative reference: ref. 'IS-IS'



  == Outdated reference: A later version (-01) exists of draft-hasmit-otv-00


-----------

(follow-up comment)

Just clarifying again the MAC-RI TLV Topology Identifier / Nickname field.



Is it correct that the field is sometimes used as a Nickname (16 bits) and sometimes used as a Topology Identifier (12 bits)?



If so:

1.      Would it be better to show 2 diagrams one showing the format with the Topology Identifier and 4 reserved bits and another diagram with the Nickname?

2.      There doesn't seem to be an indication in the message that indicates whether the field is used as a Topology Identifier or a Nickname.

[Ballot comment]
2.2.  Multi Topology aware Port Capability TLV

  o  Topology Identifier: MT ID is a 12-bit field containing the MT ID
      of the topology being announced.  This field when set to zero
      implies that it is being used to carry base topology information.

Excuse my ignorance, but is this description actually sufficient for interoperability? Which values are valid here and where are they coming from?


Also I don't think specifying exact values before they are assigned by IANA is a good idea.

IANA has a question about the IANA Actions in this document.

Upon approval of this document, IANA understands that there is a single
IANA Action that needs to be completed.

In the IS-IS TLV Codepoints registry located at:

http://www.iana.org/assignments/isis-tlv-codepoints/isis-tlv-codepoints.xhtml

two new codepoints need to be registered as follows:

IIH LSP SNP
MAC-RI TLV (tbd) - X -
MT-Port-Cap-TLV (tbd) X - -

The reference for each of the codepoints will be [RFC-to-be].

IANA QUESTION: The authors suggest the values 141 for the MAC-RI TLV and
143 for the MT-Port-Cap-TLV. the value 141 is already used for another
codepoint in the TLV registry. Should IANA simply use the next two
available, unassigned codepoints for MAC-RI TLV and MT-Port-Cap-TLV?

State changed to In Last Call from Last Call Requested.

The following Last Call Announcement was sent out:

To: IETF-Announce 
From: The IESG
Reply-to: ietf@ietf.org
CC:
Subject: Last Call: draft-ietf-isis-layer2 (Extensions to IS-IS for Layer-2 Systems) to Proposed Standard

The IESG has received a request from the IS-IS for IP Internets WG (isis)
to consider the following document:

- 'Extensions to IS-IS for Layer-2 Systems '
    as a 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 2010-12-14. 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.

The file can be obtained via
http://www.ietf.org/internet-drafts/draft-ietf-isis-layer2-08.txt


IESG discussion can be tracked via
https://datatracker.ietf.org/public/pidtracker.cgi?command=view_id&dTag=18360&rfc_flag=0

(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?

David Ward. Yes, the document 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?

Yes.


(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.

(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.

(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?

Very solid.

(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.)

N/A

(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].

Yes.

(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.

(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?

Yes.

(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

This document specifies the IS-IS extensions necessary to support
link state routing to any protocols running directly over layer 2.
While supporting this concept involves several pieces, this document
only describes extensions to IS-IS. Furthermore, the TLVs described
in this document are generic layer 2 additions and specific ones as
needed are defined in the IS-IS technology specific extensions.

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?

Issues arose as this document, isis-trill and isis-aq were originally one document. It was felt during review that -trill and -aq were sufficiently different that there needs to be a "base" document (this one) and two separate technology documents. It is unfortunate that there could not be one solution for layer2 routing in ISIS but, this decision was made before the ISIS WG was involved.

Document Quality

There are multiple, interoperable implementations.