Shepherd writeup

Template date:  1 November 2019.
Date of Shepherd's report: 5/26/2021

(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?  BGP-LS additions to BGP. 
Is this type of RFC indicated in the title page header?  yes 

(2) The IESG approval announcement includes a Document Announcement Write-Up. 
Technical Summary:

   Segment Routing (SR) over IPv6 (SRv6) allows for a flexible
   definition of end-to-end paths within various topologies by encoding
   paths as sequences of topological or functional sub-paths, called
   "segments".  These segments are advertised by the various protocols
   such as BGP, IS-IS and OSPFv3.

   BGP Link-state (BGP-LS) address-family solution for SRv6 is similar
   to BGP-LS for SR for MPLS data-plane.  This draft defines extensions
   to the BGP-LS to advertise SRv6 Segments along with their behaviors
   and other attributes via BGP.

Working Group Summary:
WG LC occurred on 11/1/2020 to 11/16/2020).  
WG support has strong for draft-ietf-idr-bgpls-srv6-ext-07.txt.  
This draft is a part of the BGP-LS work for SRv6.  
Four implementations of this draft exist (Cisco IOS-Xr, Huawei VRP, GoBGP, GoBMP)

Document Quality:

Are there existing implementations of the protocol? 
There are 4 implementations of the protocol.  The specific details of the implementations can be found at:

MIB doctor review: None  required 
Early Reviews requested:  (5/25/2021)  
BGP-LS for SRv6 is key technology so extra reviews were requested.  
Shepherd received targeted Haibo Wang (implementer, deployer, standards person) review so the shepherd is confident in reviews performed. 

 1) RTG- DIR -  awaiting assignment (Tentatively Eric Gray) 
 2) OPS-DIR - awaiting assignment 
 3) INT-DIR - awaiting assignment. 
4) SEC-DIR - awaiting assignment. 

Who is the Document Shepherd? Susan Hares 
Who is the Responsible Area Director? Alvaro Retana 
IDR chairs:  Keyur Patel, Jeff Haas, Susan Hares 

(3) Briefly describe the review of this document that was performed by the Document Shepherd. 

1) Extensive review and discussion with authors on Text

Version 7 addressed all the known issues. 
2) NITS review - no nits  
3) IPR review 
4) Requested specific BGP-LS expert to review
Wanghaibo (Rainsword) <>

See input to shepherd's review:

Summary of Comments from Haibo Wang:   Addressed by 

1. chapter 4.2 SRv6 LAN End.X SID TLV  need clarifiications -  Clarifications made to -07
2. SRv6 SID NLRI - BGP EPE Peer node is advertised with SRv6 SID NLRI, can cause disadvantages to SR-MPLS. 
   [comment - Clarifications made to -07.txt 

3. Figure 12: SRv6 BGP Peer Node SID TLV Format  
   Figure 13: SRv6 BGP Peer End.X SID TLV Flags Format - clarifications made to -07. 

If this version of the document is not ready for publication, please explain why the document is being forwarded to the IESG. 

(4) Does the document Shepherd have any concerns about the depth or breadth of the reviews that have been performed? 

(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? 
No broader review required.  

Early reviews requested for OPS-DIR, RTG-DIR, INT-DIR, and SEC-DIR.
Reason: Key technology such as BGP-LS for SRV6 should be reviewed by as many eyes as possible. 
I am confident in IDR reviews for BGP technology, but wider issues should be examined by Directorates. 

(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?

No issues with current text.  
SRv6 is important technology to variety of Carriers and Data Center support. 
INT-DIR request is to validate the SRv6 given the tunnel technology.  

(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 statements from Authors:  (All Authors have given IPR,  Not all contributors)
Guarav Dawra:

Clarence Filsfils

Ketan Talaulikar

Mach Chen

Daniel Bernier

Bruno Decraene

James Uttaro - missing 

Hani Elmalky [Ericsson]  (missing) 

Arjun Sreekantiah  (missing)

Les Ginsberg (Cisco) (missing) 

Shuwan Zhuang:

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

IPR disclosures: 
Cisco: filed 10/1/2019
Huawei: filed 11/13/2020

Note:  Cisco IPR filed after adoption, but no concerns with 
Note: Huawei IPR filed prior close of WG LC. 
No objections in WG LC for Huawei and Cisco WG LC. 
Recall during status reports (5/26 - 6/7) 

(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? 


Solid consensus with active comments 

(10) Has anyone threatened an appeal or otherwise indicated extreme discontent?

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

Ran detailed IP-NITs - nothing found. 

(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 additional reviews 

(13) Have all references within this document been identified as either normative or informative? 

(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? 

WG draft: (unclear timeline for advancement) 

Submitted to IESG for publication: 

Normative references in RFC editor's queue: 

(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. 

WG draft: 

Submitted to IESG for publication: 

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

No changes to RFCs.  New work on BGP-LS for SRV6. 

(17) Describe the Document Shepherd's review of the IANA considerations section, especially with regard to its consistency with the body of the document. 

All Allocation of the BGP-LS NLRI (section 9.1) and BGP-LS TLVs were assigned for early allocation.   These allocation are correct. 

No new registries. 

(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 regist ries. 

(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.

No XML, BNF, MIB, or Yang modules.  No review needed. 

(20) If the document contains a YANG module, has the module been checked with any of the recommended validation 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