Skip to main content

Shepherd writeup

Draft Title: BGP MPLS Based Ethernet VPN
Draft Name: draft-ietf-l2vpn-evpn-07

(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?

Standards Track.

This is the proper type of RFC as this is the base protocol draft for EVPN, which is at 
the core of most of the new L2VPN work.  The type of RFC is indicated in the title page 

(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:

   This document describes procedures for BGP MPLS based Ethernet VPNs (EVPN), 
   which are intended to meet the requirements specified in RFC7209.  EVPN requires 
   extensions to existing IP/MPLS protocols as described in this document, but also 
   uses several building blocks from existing MPLS technologies.

Working Group Summary:

   This document is an L2VPN Working Group document, and has been reviewed in 
   the working group through multiple iterations of the draft.

Document Quality:

   The document is long (50 pages) and detailed, however this is due to the inherent 
   complexity of the problem which EVPN solves - namely the provision of scalable 
   E-LAN services with support for active/active attachment (i.e. the ability for CE 
   devices to load balance across multiple PEs).  The document has been through 
   multiple revisions and is now sufficiently stable to progress to RFC, and more 
   importantly to be used as a reference for creating interoperable implementations.


   Document Shepherd: Giles Heron (
   Area Director: Adrian Farrell (

(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.

The Document Shepherd did a thorough review of the text of version -06 of the draft, 
leading to the authors issuing version -07 with a large number of fixes.  The Document 
Shepherd did a scan through the mail archives and previous IETF meeting minutes to 
review debates on the draft.

(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? If so, describe the review that took place.

No.  From a security perspective the solution inherits the characteristics of VPLS 
(RFC4761/RFC4762) and of IP-VPN (RFC4364).  Additional considerations are 
addressed in the security section - and will no doubt be reviewed as part of the IESG 
process.   From an operational complexity perspective the document shepherd has 
actively sought comments from service providers, and indeed there are service 
providers amongst the author list for the draft.  Again no doubt this aspect will be 
discussed as part of the IESG process.

(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?


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

Yes, IPR has been filed by Juniper, Cisco and Alcatel-Lucent (ID #1751, 1910, 2362 
and 2363).

The IPR issue was raised by the chairs on the WG list, specifically due to the Alcatel-
Lucent IPR having been disclosed rather late in the process (due to having initially 
been disclosed against the individual ID that preceded the WG draft).  There was no 
comment by anyone on the list relating to this late IPR - the only "discussion" 
consisted of authors indicating that they were unware of any undisclosed IPR.

(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?

WG consensus is extremely solid.  over 20 individuals supported the draft during WG 
LC, with nobody giving a differing opinion.

(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.)


(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.

There are multiple nits due to references to drafts which have become RFCs during 
the authoring of the document, and which were fixed at the end of the document but 
not in the text.  These can be resolved as part of the publication process.  the 
copyright year also needs to be fixed to 2014.

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

No formal review required.

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

Yes.  The Document Shepherd checked all this as part of the document review.

(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 - all normative references are to RFCs.

(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 - all normative references are upward.

(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 - no impact on status of existing RFCs.

(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).

The IANA considerations notes that IANA has already assigned a SAFI of 70, within 
the L2VPN AFI or 25, to be used for the EVPN NLRI and carried in BGP using 
multiprotocol extensions.  This SAFI assignment can be found at

(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 sections written in a formal language.