(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, as indicated on the title page. This document
updates the TRILL distribution tree construction algorithm currently
specified in Proposed Standard RFC 6325.
(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
The TRILL base protocol facilitates loop free connectivity to
non-TRILL networks via choice of an Appointed Forwarder for a set of
VLANs. Appointed Forwarders provides load sharing based on VLAN with
an active-standby model. High performance operations require an
active-active load sharing model with rapid fail over and load
spreading on a per flow basis. Active-Active load sharing can be
accomplished by representing any given non-TRILL network with a single
virtual RBridge. Virtual representation of the non-TRILL network with
a single RBridge poses serious challenges in multi-destination RPF
(Reverse Path Forwarding) check calculations. This document specifies
required enhancements to build Coordinated Multicast Trees (CMT)
within the TRILL campus to solve RPF related issues.
Working Group Summary:
This draft was developed by the WG over a two year period. There has
been relatively little controversy over the technical content of the
draft. It has good WG support.
This document is of good quality. CMT is implemented in the Cisco
Nexus product line.
Document Shepherd: Donald Eastlake, 3rd
Responsible Area Director: Alia Atlas
(3) Briefly describe the review of this document that was performed
by the Document Shepherd.
The Shepherd provided some technical review and input to this
draft. The most recent Shepherd review is shown here:
(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.
(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 special 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
Yes, see https://datatracker.ietf.org/ipr/2225/ by Dell Computer which
provides for non-assertion on a reciprocal basis and is believed to
relate to published patent application US20140071987 A1 "Systems and
methods providing reverse path forwarding compliance for a multihoming
virtual routing bridge". This IPR disclosure was not noted in the
first WG Last Call on this draft and a 2nd WG Last Call was
specifically held due to that oversight. There were no objections.
(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?
Many members of the WG have been involved in the development of
strategies to provide active-active support at the TRILL edge
[RFC7379] and support this draft with a reasonably broad consensus.
(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.
(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.
No nit errors.
(12) Describe how the document meets any required formal review
criteria, such as the MIB Doctor, media type, and URI type
No formal review required.
(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?
(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, although there are references to standards documents of other
organizations which the nits checker finds as possible downrefs.
(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?
This draft updates RFC 6325 because implementation of CMT changes the
mandatory distribution tree construction algorithm in RFC 6325. This
update is indicated on the title page.
(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.
No IANA actions are required because the Affinity TLV was assigned by
(18) List any new IANA registries that require Expert Review for
No new IANA registries are created.
(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.