Advertising Layer 2 Bundle Member Link Attributes in IS-IS
draft-ietf-isis-l2bundles-07

[Ballot comment]
I support the various DISCUSS points concerning the security considerations.

I note that the remaining authors have made their IPR statements, so that discussion is moot.

I share some of the discomfort concerning the shepherd report. I'm willing to accept that the shepherd is in the rough, but it would be nice to have stronger evidence of that, perhaps in the form of an opinion from the other chair. To quote a wise area director: I leave it to the responsible AD to do the right thing, whatever that might be.

[Ballot discuss]
[removed issue regarding author IPR declarations based on  and ]

Blocking Issue: This document is at odds with BCP 72, and is inappropriate for publication with its current security considerations section.

[Ballot discuss]
I agree that there needs to be security considerations and have the following suggestions to help fill in that section. I think I caught the added considerations, but please expand on it if I've missed something.

The draft seems to enable methods to gather information on connected links and the available bandwidth. That should be mentioned as a vulnerability, exposing path information (connections/links and bandwidth).  This is a consideration in other IS-IS RFCs and is specific to the TLVS and subTLVs of this draft as well as far as I can tell, but please correct me if I am missing something.

The use of the Sub-TLV identifiers provide path information that should be a security consideration in the write up:
  o  IPv4 Interface Address (sub-TLV 6 defined in [RFC5305])

  o  IPv6 Interface Address (sub-TLV 12 defined in [RFC6119])

  o  Link Local/Remote Identifiers (sub-TLV 4 defined in [RFC5307])

Within a single operator environment, the concerns are mitigated, but not eliminated since it does not appear that encryption is used.

The following text from RFC7917 seems like a useful addition to these security considerations along with an explanation of what is possibly exposed with this draft (above):
  Security concerns for IS-IS are already addressed in [ISO10589],
  [RFC5304], and [RFC5310] and are applicable to the mechanisms
  described in this document.  Extended authentication mechanisms
  described in [RFC5304] or [RFC5310] SHOULD be used in deployments
  where attackers have access to the physical networks, because nodes
  included in the IS-IS domain are vulnerable.

[Ballot comment]

The main motivation (from the Introduction) for this extension seems to be to provide information to "entities external to IS-IS such as Path Computation Elements".  I would like to see some discussion related to the "interface" with these external entities.  [Note: I am not asking for a comparison with other potential solutions like BGP-LS.]  I would also like to see the conversation with the OPS DIR reviewer reflected in the document.

I also support the DISCUSS points about the Security Considerations.

About other potential or protocol agnostic solutions...  I read the related discussion [1] that took place before the WG adoption of the document, and trust that the subsequent adoption and WGLC reflect the consensus of the WG.  As has been put in evidence by the development of multiple routing protocols and other solutions, one size doesn't always fit all.

[1] https://mailarchive.ietf.org/arch/msg/isis-wg/cK6dBtjvFZgNnZsQGZBgrpGG8jc/?qid=0a77495659ebc27956fe54d200bf3f33

[Ballot comment]
(1) I support Adam and Ekr's DISCUSSes about the security considerations.

(2) I also agree that this document should not go forward until Clarence confirms that all appropriate IPR disclosures have been filed.

(3) Given the point raised by the shepherd about protocol-agnosticism, it seems like the existence of single mail (all I could find, but maybe there is more?) from another WG participant who works for the same vendor as several of the authors saying that he believes the encodings are adaptable to OSPF is not quite sufficient justification for putting the shepherd's concerns aside. OTOH, perhaps there is more context that is not present in the ballot text, list archives, and minutes I reviewed, so just flagging this in case there is further explanation that could be provided to the IESG (don't think this would imply changes to the draft).

[Ballot comment]
1. "IPR declarations from Clarence Filsfils and Ebben Aries are missing.". Adam is right. That's a showstopper.

2. Reading the write-up:

    (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.

    An operational review on the question how should management of L3 bundles
    be handled would be a good recommendation.

This is exactly what Mahesh's OPS DIR feedback is about: https://datatracker.ietf.org/doc/review-ietf-isis-l2bundles-04-opsdir-telechat-jethanandani-2017-04-20/
I've seen Les' answers. I believe those should be documented in the draft.

[Ballot comment]
* I would like to suggest rewriting the examples with IPv4 addresses from the documentation block(s) defined in RFC5737 instead of using random IP addresses.

* It would have been nice to include an example with IPv6 addresses.

* Appendix A: The length value for "L2 Bundle Attribute Descriptors" under "TLV for Adjacency #2" is wrong. It says 29 but it needs to be 32

* I would like to see Adam's DISCUSS points addressed as well.

[Ballot discuss]
I agree with Adam's discuss and in particular the point about Security Considerations. I am holding this discuss independently so I can review those when they exist.

[Ballot discuss]
Blocking Issue 1: I am truly concerned that the shepherd's write up implies that there has been a failure by some authors to comply with IETF IPR rules laid out in BCP 79. I do not believe the IETF can publish a document under such circumstances.

Blocking Issue 2: This document is at odds with BCP 72, and is inappropriate for publication with its current security considerations section.

[Ballot comment]
If the Discuss objections I lay out can be addressed, I plan to abstain for the many of the same reasons Mirja cites in her abstention. I find the shepherd's write-up to contain an alarming number of red flags indicating a lack of WG consensus and, lack of proper review by parties who should be involved, claims that operator input has been ignored (for a routing protocol no less), and indication that IPR disclosures have not apparently been brought to the WG's attention.

These overarching process problems seem large enough that any comments I may have on actual content -- such as an apparent lack of IPv6 support (or, at least, a complete omission of IPv6 from the examples) -- would seem like rearranging deck chairs on the Titanic.

[Ballot comment]
The shepherd raises multiple concerns about this document including the need for additional discussions in rtgwg, more operator feedback, technical concerns, and no discussion about the filed IPR. Further, the security considerations section only says 'None' which also seems not appropriate. I didn't follow the working group, nor am I an expert on this work, therefore I abstain. However, for me this document does not seems to fulfill the needed processing requirements to be published but I'll leave the judgement to the responsible AD.

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

The IANA Services Operator has completed its review of draft-ietf-isis-l2bundles-04.txt. If any part of this review is inaccurate, please let us know.

The IANA Services Operator has a question about one of the actions requested in the IANA Considerations section of this document.

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

First, in the TLV Codepoints registry on the IS-IS TLV Codepoints registry page located at:

https://www.iana.org/assignments/isis-tlv-codepoints/

a single, new codepoint will be registered as follows:

Value: [ TBD-at-Registration ]
Name: L2 Bundle Member Attributes
IIH:
LSP:
SNP:
Purge:
Status/Reference: [ RFC-to-be ]

We note that the authors have suggested a value of 25 for this codepoint.

Because this registry requires Expert Review [RFC5226] for registration, we've contacted the IESG-designated expert in a separate ticket to request approval. Expert review should be completed before your document can be approved for publication as an RFC.

IANA Question --> What are the values for IIH, LSP, SNP and Purge for this new registration?

Second, the name of the Sub-TLVs for TLVs 22, 23, 141, 222, and 223 subregistry also on the IS-IS TLV Codepoints registry page located at:

https://www.iana.org/assignments/isis-tlv-codepoints/

will be changed to Sub-TLVs for TLVs 22, 23, 25, 141, 222, and 233 subregistry.

In the newly renamed registry an additional column is to be added to the registry to indicate which sub-TLVs may appear in the new L2 Bundle Member Attributes TLV. The column for TLV 25 has one of the following three values:

y - sub-TLV may appear in TLV 25 but MUST NOT be shared by multiple
L2 Bundle Members
y(s) - sub-TLV may appear in TLV 25 and MAY be shared by multiple
L2 Bundle Members
n - sub-TLV MUST NOT appear in TLV 25

The following table indicates the appropriate settings for all currently defined sub-TLVs as regards their use in the new L2 Bundle Member Attributes TLV:
Type Description 25
----+---------------------------------------------------+--------
3 Administrative group (color) y(s)
4 Link Local/Remote Identifiers y(s)
6 IPv4 interface address y(s)
8 IPv4 neighbor address y(s)
9 Maximum link bandwidth y(s)
10 Maximum reservable link bandwidth y(s)
11 Unreserved bandwidth y(s)
12 IPv6 Interface Address y(s)
13 IPv6 Neighbor Address y(s)
14 Extended Administrative Group y(s)
18 TE Default metric y(s)
19 Link-attributes y(s)
20 Link Protection Type y(s)
21 Interface Switching Capability Descriptor y(s)
22 Bandwidth Constraints y(s)
23 Unconstrained TE LSP Count y(s)
24 Remote AS number n
25 IPv4 remote ASBR Identifier n
26 IPv6 remote ASBR Identifier n
27 Interface Adjustment Capability Descriptor (IACD) y(s)
28 MTU n
29 SPB-Metric y(s)
30 SPB-A-OALG y(s)

Third, in the newly renamed subregistry for sub-TLVs for TLVs 22, 23, 25, 141, 222, and 223 two new values are to be registered as follows:

Value: [ TBD-at-registration ]
Description: L2 Bundle Member Adj-SID
22: n
23: n
25: y
141: n
222: n
223: n
Reference: [ RFC-to-be ]

We note that the authors request the value 41 for this registration.

Value: [ TBD-at-registration ]
Description: L2 Bundle Member LAN Adj-SID
22: n
23: n
25: y
141: n
222: n
223: n
Reference: [ RFC-to-be ]

We note that the authors request the value 42 for this registration.

Because this registry requires Expert Review [RFC5226] for registration, we've contacted the IESG-designated expert in a separate ticket to request approval. Expert review should be completed before your document can be approved for publication as an RFC.

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: hannes@gredler.at, isis-chairs@ietf.org, isis-wg@ietf.org, draft-ietf-isis-l2bundles@ietf.org, akatlas@gmail.com
Reply-To: ietf@ietf.org
Sender:
Subject: Last Call:  (Advertising L2 Bundle Member Link Attributes in IS-IS) to Proposed Standard


The IESG has received a request from the IS-IS for IP Internets WG (isis)
to consider the following document:
- 'Advertising L2 Bundle Member Link Attributes in IS-IS'
  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 2017-05-17. 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


  There are deployments where the Layer 3 interface on which IS-IS
  operates is a Layer 2 interface bundle.  Existing IS-IS
  advertisements only support advertising link attributes of the Layer
  3 interface.  If entities external to IS-IS wish to control traffic
  flows on the individual physical links which comprise the Layer 2
  interface bundle link attribute information about the bundle members
  is required.

  This document introduces the ability for IS-IS to advertise the link
  attributes of layer 2 (L2) bundle members.





The file can be obtained via
https://datatracker.ietf.org/doc/draft-ietf-isis-l2bundles/

IESG discussion can be tracked via
https://datatracker.ietf.org/doc/draft-ietf-isis-l2bundles/ballot/

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

  https://datatracker.ietf.org/ipr/2793/

Request for posting confirmation emailed to previous authors: Stefano Previdi , Ahmed Bashandy , isis-chairs@ietf.org, Les Ginsberg , Ebben Aries , Mohan Nanduri , Clarence Filsfils

Request for posting confirmation emailed to previous authors: isis-chairs@ietf.org, "Clarence Filsfils" , " (Unknown)" , "Les Ginsberg" , "Stefano Previdi" , "Mohan Nanduri" , "Ebben Aries"