BGP Link-State Shortest Path First (SPF) Routing
draft-ietf-lsvr-bgp-spf-29

Notification list changed to Gunter Van de Velde <gunter.van_de_velde@nokia.com>, aretana.ietf@gmail.com, victor@jvknet.com, ketant.ietf@gmail.com from Gunter Van de Velde <gunter.van_de_velde@nokia.com>, aretana.ietf@gmail.com, victor@jvknet.com because the document shepherd was set

- Abstract:

Change layer 3 routing to "layer-3 routing" as typically it is hyphenated. Also used in the introduction so change throughout the document.

- Introduction:

BGP-LS [I-D.ietf-idr-rfc7752bis] protocols -> change to 'protocol' (BGP-LS is a single protocol not a suite of protocols as the sentence suggests).

- Section 2:

First paragraph text "any error handling defined in the [RFC4271] and [RFC7606]" - remove "the" in this sentence.

Third paragraph text "Section 9 of [RFC4271] defines the decision process" - it is actually Section 9.1

- Section 3:

  The rules for setting the NLRI next-hop path attribute for the BGP-
  LS-SPF SAFI follow the BGP-LS SAFI as specified in section 3.4 of
  [I-D.ietf-idr-rfc7752bis].

There is no section 3.4 in ietf-idr-rfc7752bis. Please correct this reference. Should it be section 5.5?

- Section 4.1:

Second paragraph text "advertising the BGP-LS Link NLRI for to peer" - sentence does not make grammatical sense please correct the end of the sentence.

- Section 5.1.1:

  If a mandatory TLV is not specified, the NLRI is
  not used in the BGP SPF route calculation.  All the other TLVs are
  considered as an optional TLVs.

If a mandatory TLV is not specificed then would this be considered a misconfiguration or implementation bug? I would like to understand how that might happen and also what is the router supposed to do other than not consider the NLRI in the SPF route calculation?

- Section 5.1.2:

This attribute
  is an optional, non-transitive BGP attribute that is used to carry
  link, node, and prefix properties and attributes.

if this is non-transitive it means it cannot be sent (flooded) to eBGP peers and yet the deployment models specifically allow the use of eBGP and iBGP. Is the intent to
redefine the transitive nature of the BGP-LS attribute and if so, this needs to be specifically stated.

- Section 5.2:

For Node NLRI and Link NLRI, this MUST be the direct protocol
  (4)

It might be clearer to put "For Node NLRI and link NLRI, this MUST be the direct protocol (value: 4)".

- Section 5.2.1.1:

An implementation MAY
  optionally log detection of a BGP node that has either not advertised
  the SPF capability TLV or is advertising the SPF capability TLV with
  an algorithm type other than 0.

The SPF capability TLV seems to be mandatory although the text does not specifically say it but implies it by saying "attribute TLV MUST be included". Please
clarify and add mandatory if necessary. Also, shouldn't the MAY be a MUST as otherwise, you could be calculating SPF without a node that you expect to be
included in the calculation?

- Section 5.2.1.2:

Third paragraph text "A BGP SPF speaker receiving a BGP Update containing a SPF Status TLV in the BGP-LS attribute [I-D.ietf-idr-rfc7752bis] with a value that is undefined values SHOULD.." - remove "values" from end of sentence (redundant text).

- Section 5.2.2:

Fourth paragraph text "MUST consider the received NLRI as a malformed.." - remove "a" from text.

- Section 5.2.2.1:

Third paragraph text "The maximum prefix-length is 32 bits for an IPv4 Prefix-Length TLV A prefix-length field and 128 bits for an IPv6 Prefix-Length TLV." looks malformed should "A prefix-length field" text in sentence be removed?

Third paragraph second sentence "A prefix-length field indicating a larger value is in error and the the corresponding.." - remove extra "the" in sentence.

Third paragraph third sentence " An implementation MAY log." - remove text as next sentence replaces it.

- Section 5.2.4:

  A BGP-LS Attribute TLV of the BGP-LS-SPF NLRI types is defined to
  assure the most recent version of a given NLRI is used in the SPF
  computation.  The Sequence-Number TLV is mandatory for BGP-LS-SPF
  NLRI.

Is this mandatory for all NLRI types or just Node NLRI?

- Section 5.2.4:

Add colon after "Sequence Number" in description of TLV.

- Section 6.1.1:

  *  If self-originated NLRI is received and the sequence number is
      more recent (i.e., greater than the local node's sequence number
      for the NLRI), the NLRI sequence number is advanced to one greater
      than the received sequence number and the NLRI is readvertised to
      all peers.

If the sequence number is higher than the local nodes sequence number then shouldn't this be treated as an error as someone (not the local node) has increased the sequence number - they should not be
doing that. If there is a reason why the sequence number CAN legitimately increase then that should be stated (I cannot think of an example where this is valid). Is this related to cold-start? If so please
make that clearer.

  *  If self-originated NLRI is received and the sequence number is the
      same as the local node's sequence number but the attributes
      differ, the NLRI sequence number is advanced to one greater than
      the received sequence number and the NLRI is readvertised to all
      peers.

How is it possible for the attributes of a self-originated NLRI to change? if this is valid then an example should be provided.

- Section 6.3:

      The CAN-LIST is typically implemented as a heap but other data
      structures have been used.

Probably better to say that other data structures MAY be used.

- Section 9:

The BGP-LS-SPF SAFI NLRI described in this document are
  typically advertised between EBGP or IBGP speakers under a single
  administrative domain.

how based on iBGP advertisement rules? how can an iBGP speaker flood NLRI to another iBGP speaker unless they are a route reflector?

Several editorial nits to be fixed please.

- Abstract:

Change layer 3 routing to "layer-3 routing" as typically it is hyphenated. Also used in introduction so change throughout document.

- Introduction:

BGP-LS [I-D.ietf-idr-rfc7752bis] protocols -> change to protocol (BGP-LS is a single protocol not a suite of protocols as the sentence suggests).

- Section 2:

- First paragraph text "any error handling defined in the [RFC4271] and [RFC7606]" - remove "the" in this sentence.
- Third paragraph text "Section 9 of [RFC4271] defines the decision process" - it is actually Section 9.1

- Section 4.1:

- Second paragraph text "advertising the BGP-LS Link NLRI for to peer" - sentence does not make grammatical sense please correct end of sentence.

- Section 4.3:

- reference to ietf-lsvr-applicability - should that document be processed at the same time as this one (?)

- Section 5.2.1.2:

- Third paragraph text "A BGP SPF speaker receiving a BGP Update containing a SPF Status TLV in the BGP-LS attribute [I-D.ietf-idr-rfc7752bis] with a
value that is undefined values SHOULD.." - remove "values" from end of sentence (redundant text).

- Section 5.2.2:

- Fourth paragraph text "MUST consider the received NLRI as a malformed.." - remove "a" from text.

- Section 5.2.2.1:

- Third paragraph text "The maximum prefix-length is 32 bits for an IPv4 Prefix-Length TLV A prefix-length field and 128 bits for an IPv6 Prefix-Length
TLV." looks malformed should "A prefix-length field" text in sentence be removed?
- Third paragraph second sentence "A prefix-length field indicating a larger value is in error and the the corresponding.." - remove extra "the" in sentence.
- Third paragraph third sentence " An implementation MAY log." - remove text as next sentence replaces it.

- Section 5.2.4:

- Add colon after "Sequence Number" in description of TLV.

As required by RFC 4858, this is the current template for the Document
Shepherd Write-Up. Changes are expected over time.

This version is dated 15 February 2022.

(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?

Proposed Standard

(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:

1. Technical Summary:
Many Massively Scaled Data Centers (MSDCs) have converged on simplified layer 3 routing.  Furthermore, requirements for operational simplicity have led many of these MSDCs to converge on BGP as their single routing protocol for intra-fabric routing, inter-fabric routing and Data Center Interconnect (DCI) routing.  This draft describes a solution which leverages BGP Link-State distribution and the Shortest Path First (SPF) algorithm like Internal Gateway Protocols (IGPs) such as OSPF.
How is this done?

This document augments BGP-LS [RFC7752] by replacing its use of the existing Decision Process.  Rather than reusing the BGP-LS SAFI, the BGP-LS-SPF SAFI is introduced to insure backward compatibility.  The BGP Phase 1 and 2 decision functions of the Decision Process are replaced with the Shortest Path First (SPF) algorithm also known as the Dijkstra algorithm.  The BGP Phase 3 decision function is also simplified since it is no longer dependent on the previous phases.  This solution avails the benefits of both BGP and SPF-based IGPs.  These include TCP based flow-control, no periodic link-state refresh, and completely incremental NLRI advertisement.  These advantages can reduce the overhead in MSDCs where there is a high degree of Equal Cost Multi-Path (ECMPs) and the topology is very stable.  Additionally, using an SPF-based computation can support fast convergence and the computation of Loop-Free Alternatives (LFAs) [RFC5286] in the event of link failures.  Furthermore, a BGP based solution lends itself to multiple peering models including those incorporating route-reflectors [RFC4456] or controllers.

2. Review and Consensus
The LSVR WG enjoyed a turbulent startup period. The IDR WG and LSR WG handle routing for interdomain and intradomain, while LSVR is using foundational technology of both BGP and SPF based routing protocols. The IETF face-2-face meetings avoided timing overlap to allow IDR and LSR WG participants to voice the depths of their experience and technology authority. This contributed to develop and provide feedback upon the draft draft-ietf-lsvr-bgp-spf.

The draft went through few iterations of volunteer review cycles that have been tracked within the WG email list. In addition, the draft went through early directorate reviews. The original (2019) OPSDIR review executed upon an early version went well (state: READY), while RTGDIR (state: HAS ISSUES) review caused additional technology discussion resulting in the draft to be updated upon the feedback provided (See: https://mailarchive.ietf.org/arch/msg/lsvr/9z_KGdwqHlmhnzD5HWrarmlSroU/ ).  The document was re-reviewed in June 2021 with some additional concerns for consideration before publication.  These issues identified in the RTGDIR were addressed in the most recent version of publication.
The document went through a third WGLC in 2021 (May – June) and completed on June 17, 2021.

In addition, the LSVR chairs asked expert reviewers to provide feedback on the document, and those have been included and discussed on the WG mailing list.
The document went through three cycles of WGLC to finally result into current documentation status:

WGLC#1 on draft-ietf-lsvr-bgp-spf-03
Date: 3 December 2018 to 17 December 2018
Reference: https://mailarchive.ietf.org/arch/msg/lsvr/-7zKGZ-PIXCNnpmxfEjHVSEUqXc/
WGLC#2 on draft-ietf-lsvr-bgp-spf-05
Date: 23 September 2019 – 7 October 2019
Reference: https://mailarchive.ietf.org/arch/msg/lsvr/A066U6av_6--WDo7BRFswOtMea4/
WGLC#3 on draft-ietf-lsvr-bgp-spf-13
Date: 20 May 2021 – 17 June 2021
Reference: https://mailarchive.ietf.org/arch/browse/lsvr/?gbt=1&index=aQ9Ud_FjwiFpO7OGJnhcXgY0A4U
Current Implementations: https://datatracker.ietf.org/doc/html/draft-psarkar-lsvr-bgp-spf-impl-00
• Arrcus (March 2019): https://mailarchive.ietf.org/arch/msg/lsvr/OPB6pO_aKU8ty0A3PspSBTQyqXg/
• FRR Plans (June 2020): https://mailarchive.ietf.org/arch/msg/lsvr/wCXxSObjSy0Vih5SRS2PPbfacz8/

3. Intellectual Property
During the WGLC IPR calls were performed. No claims for IPR awareness were mentioned by WG members and neither by any of the participating document authors.

4. Other Points
No downward references
Request IANA to assign the BGP-LS/BGP-LS-SPF (AFI 16388 / SAFI TBD1) as described in [RFC4760].
From safi range [1-63] standards action: https://www.iana.org/assignments/safi-namespace/safi-namespace.xhtml
When this registry is modified, the YANG module [iana-routing-types] must be updated as defined in [RFC8294].
This draft also defines five attribute TLVs for BGP-LS NLRI from the "BGP-LS Node Descriptor, Link Descriptor, Prefix Descriptor, and Attribute TLVs" Registry
Expert review suggested by IANA:
https://www.iana.org/assignments/bgp-ls-parameters/bgp-ls-parameters.xhtml
The draft request IANA to assign types for the
• SPF capability TLV
• Sequence Number TLV
• IPv4 Link Prefix-Length TLV
• IPv6 Link Prefix-Length TLV
• SPF Status TLV.

WG Yang draft in progress found here - https://datatracker.ietf.org/doc/draft-ietf-lsvr-bgp-ls-yang/00/

5. Checklist
• This applicability for bgp-spf (https://www.ietf.org/id/draft-ietf-lsvr-bgp-spf-09.txt) draft is progressed in parallel with 'I-D.ietf-lsvr-applicability'

As required by RFC 4858, this is the current template for the Document
Shepherd Write-Up. Changes are expected over time.

This version is dated 15 February 2022.

(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?

Proposed Standard

(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:

1. Technical Summary:
Many Massively Scaled Data Centers (MSDCs) have converged on simplified layer 3 routing.  Furthermore, requirements for operational simplicity have led many of these MSDCs to converge on BGP as their single routing protocol for intra-fabric routing, inter-fabric routing and Data Center Interconnect (DCI) routing.  This draft describes a solution which leverages BGP Link-State distribution and the Shortest Path First (SPF) algorithm like Internal Gateway Protocols (IGPs) such as OSPF.
How is this done?

This document augments BGP-LS [RFC7752] by replacing its use of the existing Decision Process.  Rather than reusing the BGP-LS SAFI, the BGP-LS-SPF SAFI is introduced to insure backward compatibility.  The BGP Phase 1 and 2 decision functions of the Decision Process are replaced with the Shortest Path First (SPF) algorithm also known as the Dijkstra algorithm.  The BGP Phase 3 decision function is also simplified since it is no longer dependent on the previous phases.  This solution avails the benefits of both BGP and SPF-based IGPs.  These include TCP based flow-control, no periodic link-state refresh, and completely incremental NLRI advertisement.  These advantages can reduce the overhead in MSDCs where there is a high degree of Equal Cost Multi-Path (ECMPs) and the topology is very stable.  Additionally, using an SPF-based computation can support fast convergence and the computation of Loop-Free Alternatives (LFAs) [RFC5286] in the event of link failures.  Furthermore, a BGP based solution lends itself to multiple peering models including those incorporating route-reflectors [RFC4456] or controllers.

2. Review and Consensus
The LSVR WG enjoyed a turbulent startup period. The IDR WG and LSR WG handle routing for interdomain and intradomain, while LSVR is using foundational technology of both BGP and SPF based routing protocols. The IETF face-2-face meetings avoided timing overlap to allow IDR and LSR WG participants to voice the depths of their experience and technology authority. This contributed to develop and provide feedback upon the draft draft-ietf-lsvr-bgp-spf.

The draft went through few iterations of volunteer review cycles that have been tracked within the WG email list. In addition, the draft went through early directorate reviews. The original (2019) OPSDIR review executed upon an early version went well (state: READY), while RTGDIR (state: HAS ISSUES) review caused additional technology discussion resulting in the draft to be updated upon the feedback provided (See: https://mailarchive.ietf.org/arch/msg/lsvr/9z_KGdwqHlmhnzD5HWrarmlSroU/ ).  The document was re-reviewed in June 2021 with some additional concerns for consideration before publication.  These issues identified in the RTGDIR were addressed in the most recent version of publication.
The document went through a third WGLC in 2021 (May – June) and completed on June 17, 2021.

In addition, the LSVR chairs asked expert reviewers to provide feedback on the document, and those have been included and discussed on the WG mailing list.
The document went through three cycles of WGLC to finally result into current documentation status:

WGLC#1 on draft-ietf-lsvr-bgp-spf-03
Date: 3 December 2018 to 17 December 2018
Reference: https://mailarchive.ietf.org/arch/msg/lsvr/-7zKGZ-PIXCNnpmxfEjHVSEUqXc/
WGLC#2 on draft-ietf-lsvr-bgp-spf-05
Date: 23 September 2019 – 7 October 2019
Reference: https://mailarchive.ietf.org/arch/msg/lsvr/A066U6av_6--WDo7BRFswOtMea4/
WGLC#3 on draft-ietf-lsvr-bgp-spf-13
Date: 20 May 2021 – 17 June 2021
Reference: https://mailarchive.ietf.org/arch/browse/lsvr/?gbt=1&index=aQ9Ud_FjwiFpO7OGJnhcXgY0A4U
Current Implementations: https://datatracker.ietf.org/doc/html/draft-psarkar-lsvr-bgp-spf-impl-00
• Arrcus (March 2019): https://mailarchive.ietf.org/arch/msg/lsvr/OPB6pO_aKU8ty0A3PspSBTQyqXg/
• FRR Plans (June 2020): https://mailarchive.ietf.org/arch/msg/lsvr/wCXxSObjSy0Vih5SRS2PPbfacz8/

3. Intellectual Property
During the WGLC IPR calls were performed. No claims for IPR awareness were mentioned by WG members and neither by any of the participating document authors.

4. Other Points
No downward references
Request IANA to assign the BGP-LS/BGP-LS-SPF (AFI 16388 / SAFI TBD1) as described in [RFC4760].
From safi range [1-63] standards action: https://www.iana.org/assignments/safi-namespace/safi-namespace.xhtml
When this registry is modified, the YANG module [iana-routing-types] must be updated as defined in [RFC8294].
This draft also defines five attribute TLVs for BGP-LS NLRI from the "BGP-LS Node Descriptor, Link Descriptor, Prefix Descriptor, and Attribute TLVs" Registry
Expert review suggested by IANA:
https://www.iana.org/assignments/bgp-ls-parameters/bgp-ls-parameters.xhtml
The draft request IANA to assign types for the
• SPF capability TLV
• Sequence Number TLV
• IPv4 Link Prefix-Length TLV
• IPv6 Link Prefix-Length TLV
• SPF Status TLV.

WG Yang draft in progress found here - https://datatracker.ietf.org/doc/draft-ietf-lsvr-bgp-ls-yang/00/

5. Checklist
• This applicability for bgp-spf (https://www.ietf.org/id/draft-ietf-lsvr-bgp-spf-09.txt) draft is progressed in parallel with 'I-D.ietf-lsvr-applicability'

Notification list changed to Gunter Van de Velde <gunter.van_de_velde@nokia.com>, aretana.ietf@gmail.com, victor@jvknet.com from Gunter Van de Velde <gunter.van_de_velde@nokia.com>, aretana.ietf@gmail.com because the document shepherd was set

As required by RFC 4858, this is the current template for the Document
Shepherd Write-Up. Changes are expected over time.

This version is dated 1 November 2019.

(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?

Proposed Standard

(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:

Many Massively Scaled Data Centers (MSDCs) have converged on simplified layer 3 routing.  Furthermore, requirements for operational simplicity have led many of these MSDCs to converge on BGP as their single routing protocol for both their fabric routing and their Data Center Interconnect (DCI) routing.  This draft describes a solution which leverages BGP Link-State distribution and the Shortest Path First (SPF) algorithm like Internal Gateway Protocols (IGPs) such as OSPF.
How is this done?
This document augments BGP-LS [RFC7752] by replacing its use of the existing Decision Process.  Rather than reusing the BGP-LS SAFI, the BGP-LS-SPF SAFI is introduced to insure backward compatibility.  The BGP Phase 1 and 2 decision functions of the Decision Process are replaced with the Shortest Path First (SPF) algorithm also known as the Dijkstra algorithm.  The BGP Phase 3 decision function is also simplified since it is no longer dependent on the previous phases.  This solution avails the benefits of both BGP and SPF-based IGPs.  These include TCP based flow-control, no periodic link-state refresh, and completely incremental NLRI advertisement.  These advantages can reduce the overhead in MSDCs where there is a high degree of Equal Cost Multi-Path (ECMPs) and the topology is very stable.  Additionally, using an SPF-based computation can support fast convergence and the computation of Loop-Free Alternatives (LFAs) [RFC5286] in the event of link failures.  Furthermore, a BGP based solution lends itself to multiple peering models including those incorporating route-reflectors [RFC4456] or controllers.


Working Group Summary:

The LSVR WG enjoyed a turbulent startup period. The IDR WG and LSR WG handle routing for interdomain and intradomain. LSVR is using foundational technology from both BGP and SPF based routing protocols. The IETF face-2-face meetings included IDR and LSR WG participants to voice the depths of their experience and technology authority. This contributed to develop and provide feedback upon the draft draft-ietf-lsvr-bgp-spf.
The draft went through few iterations of volunteer review cycles that have been tracked within the WG email list. In addition, the draft went through early directorate reviews. The OPSDIR review executed upon an early version went well (state: READY), while RTGDIR (state: HAS ISSUES) review caused additional technology discussion resulting in the draft to be updated upon the feedback provided (See: https://mailarchive.ietf.org/arch/msg/lsvr/9z_KGdwqHlmhnzD5HWrarmlSroU/ ).
In addition, the LSVR chairs asked expert reviewers to provide feedback on the document, and those have been included and discussed on the WG mailing list.

The document went through two cycles of WGLC to finally result into current documentation status:

WGLC#1 on draft-ietf-lsvr-bgp-spf-03
Date: 3 December 208 to 17 December 2018
Reference: https://mailarchive.ietf.org/arch/msg/lsvr/-7zKGZ-PIXCNnpmxfEjHVSEUqXc/
WGLC#2 on draft-ietf-lsvr-bgp-spf-05
Date: 23 September 2019 – 7 October 2019
Reference: https://mailarchive.ietf.org/arch/msg/lsvr/A066U6av_6--WDo7BRFswOtMea4/


Document Quality:

Arrcus (March 2019): https://mailarchive.ietf.org/arch/msg/lsvr/OPB6pO_aKU8ty0A3PspSBTQyqXg/
FRR (Plans to support): https://mailarchive.ietf.org/arch/msg/lsvr/wCXxSObjSy0Vih5SRS2PPbfacz8/


Personnel:

Document Shepherd: Gunter Van de Velde
Responsible Area Director: Alvaro Retana

(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.

Document went through few iterations of review. This 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?

Review cycle was contributed by experts, and working implementation exists.

(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

(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 specific 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?

Yes, all authors responded on the list about IPR ( there is no IPR awareness.
No other WG member responded with any IPRdisclosure when WGLC was initiated.

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

No

(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?

Document went through 2 WGLCs
Document has been presented at each IETF LSVr WG meeting to inform about updates and changes
Feedback has been promptly incorporated by the document authors

(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 threatening for an appeal on this document

(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.

When going trough the idnit check 12 missing document references were found.
However, those references for proposed standard are referenced in the informational section of the draft
One informational draft [Missing Reference: 'I-D.ietf-lsvr-applicability'] is progressed in parallel with this draft and describe how to apply the technology in a network environment.

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

No such components included.
YANG is to progressed in a separate LSVR WG document

(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?

Yes, the draft [ietf-idr-bgpls-segment-routing-epe]

(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

(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.

No

(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 8126).

IANA section document the request of IANA code points
no indications for code-point have been provided

(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.

Request IANA to assign the BGP-LS/BGP-LS-SPF (AFI 16388 / SAFI TBD1) as described in [RFC4760].
From safi range [1-63] standards action: https://www.iana.org/assignments/safi-namespace/safi-namespace.xhtml
When this registry is modified, the YANG module [iana-routing-types] must be updated as defined in [RFC8294].

This draft also defines five attribute TLVs for BGP-LS NLRI from the "BGP-LS Node Descriptor, Link Descriptor, Prefix Descriptor, and Attribute TLVs" Registry
Expert review suggested by IANA:

https://www.iana.org/assignments/bgp-ls-parameters/bgp-ls-parameters.xhtml
The draft request IANA to assign types for the

  * SPF capability TLV
  * Sequence Number TLV
  * IPv4 Link Prefix-Length TLV
  * IPv6 Link Prefix-Length TLV
  * SPF Status TLV.

(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, YANG modules, etc.

YANG definition is to be defined in a seperate LSVR WG document.
This work has not been initiated by the LSVR WG.

(20) If the document contains a YANG module, has the module been checked with any of the recommended validation tools (https://trac.ietf.org/trac/ops/wiki/yang-review-tools) for syntax and formatting validation? If there are any resulting errors or warnings, what is the justification for not fixing them at this time? Does the YANG module comply with the Network Management Datastore Architecture (NMDA) as specified in RFC8342?

No YANG module included

As required by RFC 4858, this is the current template for the Document
Shepherd Write-Up. Changes are expected over time.

This version is dated 1 November 2019.

(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?

Proposed Standard

(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:

Many Massively Scaled Data Centers (MSDCs) have converged on simplified layer 3 routing.  Furthermore, requirements for operational simplicity have led many of these MSDCs to converge on BGP as their single routing protocol for both their fabric routing and their Data Center Interconnect (DCI) routing.  This draft describes a solution which leverages BGP Link-State distribution and the Shortest Path First (SPF) algorithm like Internal Gateway Protocols (IGPs) such as OSPF.
How is this done?
This document augments BGP-LS [RFC7752] by replacing its use of the existing Decision Process.  Rather than reusing the BGP-LS SAFI, the BGP-LS-SPF SAFI is introduced to insure backward compatibility.  The BGP Phase 1 and 2 decision functions of the Decision Process are replaced with the Shortest Path First (SPF) algorithm also known as the Dijkstra algorithm.  The BGP Phase 3 decision function is also simplified since it is no longer dependent on the previous phases.  This solution avails the benefits of both BGP and SPF-based IGPs.  These include TCP based flow-control, no periodic link-state refresh, and completely incremental NLRI advertisement.  These advantages can reduce the overhead in MSDCs where there is a high degree of Equal Cost Multi-Path (ECMPs) and the topology is very stable.  Additionally, using an SPF-based computation can support fast convergence and the computation of Loop-Free Alternatives (LFAs) [RFC5286] in the event of link failures.  Furthermore, a BGP based solution lends itself to multiple peering models including those incorporating route-reflectors [RFC4456] or controllers.


Working Group Summary:

The LSVR WG enjoyed a turbulent startup period. The IDR WG and LSR WG handle routing for interdomain and intradomain. LSVR is using foundational technology from both BGP and SPF based routing protocols. The IETF face-2-face meetings included IDR and LSR WG participants to voice the depths of their experience and technology authority. This contributed to develop and provide feedback upon the draft draft-ietf-lsvr-bgp-spf.
The draft went through few iterations of volunteer review cycles that have been tracked within the WG email list. In addition, the draft went through early directorate reviews. The OPSDIR review executed upon an early version went well (state: READY), while RTGDIR (state: HAS ISSUES) review caused additional technology discussion resulting in the draft to be updated upon the feedback provided (See: https://mailarchive.ietf.org/arch/msg/lsvr/9z_KGdwqHlmhnzD5HWrarmlSroU/ ).
In addition, the LSVR chairs asked expert reviewers to provide feedback on the document, and those have been included and discussed on the WG mailing list.

The document went through two cycles of WGLC to finally result into current documentation status:

WGLC#1 on draft-ietf-lsvr-bgp-spf-03
Date: 3 December 208 to 17 December 2018
Reference: https://mailarchive.ietf.org/arch/msg/lsvr/-7zKGZ-PIXCNnpmxfEjHVSEUqXc/
WGLC#2 on draft-ietf-lsvr-bgp-spf-05
Date: 23 September 2019 – 7 October 2019
Reference: https://mailarchive.ietf.org/arch/msg/lsvr/A066U6av_6--WDo7BRFswOtMea4/


Document Quality:

Arrcus (March 2019): https://mailarchive.ietf.org/arch/msg/lsvr/OPB6pO_aKU8ty0A3PspSBTQyqXg/
FRR (Plans to support): https://mailarchive.ietf.org/arch/msg/lsvr/wCXxSObjSy0Vih5SRS2PPbfacz8/


Personnel:

Document Shepherd: Gunter Van de Velde
Responsible Area Director: Alvaro Retana

(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.

Document went through few iterations of review. This 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?

Review cycle was contributed by experts, and working implementation exists.

(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

(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 specific 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?

Yes, all authors responded on the list about IPR ( there is no IPR awareness.
No other WG member responded with any IPRdisclosure when WGLC was initiated.

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

No

(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?

Document went through 2 WGLCs
Document has been presented at each IETF LSVr WG meeting to inform about updates and changes
Feedback has been promptly incorporated by the document authors

(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 threatening for an appeal on this document

(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.

When going trough the idnit check 12 missing document references were found.
However, those references for proposed standard are referenced in the informational section of the draft
One informational draft [Missing Reference: 'I-D.ietf-lsvr-applicability'] is progressed in parallel with this draft and describe how to apply the technology in a network environment.

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

No such components included.
YANG is to progressed in a separate LSVR WG document

(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?

Yes, the draft [ietf-idr-bgpls-segment-routing-epe]

(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

(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.

No

(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 8126).

IANA section document the request of IANA code points
no indications for code-point have been provided

(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.

Request IANA to assign the BGP-LS/BGP-LS-SPF (AFI 16388 / SAFI TBD1) as described in [RFC4760].
From safi range [1-63] standards action: https://www.iana.org/assignments/safi-namespace/safi-namespace.xhtml
When this registry is modified, the YANG module [iana-routing-types] must be updated as defined in [RFC8294].

This draft also defines five attribute TLVs for BGP-LS NLRI from the "BGP-LS Node Descriptor, Link Descriptor, Prefix Descriptor, and Attribute TLVs" Registry
Expert review suggested by IANA:

https://www.iana.org/assignments/bgp-ls-parameters/bgp-ls-parameters.xhtml
The draft request IANA to assign types for the

  * SPF capability TLV
  * Sequence Number TLV
  * IPv4 Link Prefix-Length TLV
  * IPv6 Link Prefix-Length TLV
  * SPF Status TLV.

(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, YANG modules, etc.

YANG definition is to be defined in a seperate LSVR WG document.
This work has not been initiated by the LSVR WG.

(20) If the document contains a YANG module, has the module been checked with any of the recommended validation tools (https://trac.ietf.org/trac/ops/wiki/yang-review-tools) for syntax and formatting validation? If there are any resulting errors or warnings, what is the justification for not fixing them at this time? Does the YANG module comply with the Network Management Datastore Architecture (NMDA) as specified in RFC8342?

No YANG module included

Waiting for all authors/contributors to comment on IPR awareness
Waiting for confirmation that document addressed all routing directorate issues identified
Waiting for authors to confirm that comments during WGLC have been sufficiently addressed in the draft