Registration Extensions for IPv6 over Low-Power Wireless Personal Area Network (6LoWPAN) Neighbor Discovery
draft-ietf-6lo-rfc6775-update-21

[Ballot comment]

I found this document quite challenging to read. It would be very
helpful if it started with a description of the failings of 6775 and a
brief overview of how it solves those. At the risk of self-citing, the
techniques of RFC 4101 might be helpful here.

In addition, I recognize that some of the guarantees here depend on
draft-ietf-6lo-ap-nd. I have not yet thoroughly reviewed that
document, but it is not yet clear to me precisely what guarantees it
in fact provides.



  This specification introduces the Extended Address Registration
  Option (EARO) based on the ARO as defined [RFC6775].  A 'T' flag is

Can you describe here the problem that ARO has that this solves?

  that this specification avoids the Duplicate Address message flow for
  Link-Local Addresses in a Route-Over [RFC6606] topology.

This sentence is not really maximally clear. Why does it avoid it?

  o  The address that is being registered with an NS with an EARO is
      now the Target Address, as opposed to the Source Address as

This would read better, I think if you said

"The address that is being registered is set to the target address in the NS containing
the EARO,as opposed to..."

                  denoting a ROVR size of 128, 192 and 256 bits
                  respectively.
  Status:        8-bit unsigned integer.  Indicates the status of a

It took me a minute to realize that this is the length of the *entire* option and so it's 1 larger than the length of the ROVR. Some text might help here.

                  registration of a particular IPv6 Address and it
                  cannot be used to correlate registrations of
                  different addresses.

"cannot" doesn't seem quite right. I.e., if you use the same EUI-64, someone could use it for that. Perhaps you mean "must not"

  rightmost bit and place the result in the EDAR message to maintain
  compatibility.  This way, the support of DAD is preserved.

Is there a reason for the rightmost bits? I see that https://tools.ietf.org/html/draft-ietf-6lo-ap-nd-06 uses the leftmost bits for Crypto-ID.

  Networks" [I-D.ietf-6lo-ap-nd], which guarantees the ownership of the
  Registered Address using a cryptographic ROVR.

I'm a little unsure how to read this text. It seems like the techniques you are discussing are about whether a node behaves incorrectly, but 6775 says that the first trust model of 3756 applies, and *that* says:

A model where all authenticated nodes trust each other to behave
      correctly at the IP layer and not to send any ND or RD messages
      that contain false information.  This model is thought to
      represent a situation where the nodes are under a single
      administration and form a closed or semi-closed group.  A
      corporate intranet is a good example.

So in that setting why do you need ownership guarantees? Is this just belt and suspenders?

      address, but a stronger identification (e.g., by security
      credentials) is RECOMMENDED.  When that maximum is reached, the
      router should use a Least-Recently-Used (LRU) algorithm to clean

What would these security credentials be?

[Ballot comment]
I believe this document would have been easier to read for me if section 6 would have been before section 4; however, I guess that's a matter of taste.

On the TID in section 6.1: Should this field be zero if the T flag is not set? I guess you should at least say that the field should be ignored if the T flag is not set.

[Ballot comment]
§3, last paragraph: The MUST seems like a statement of fact.

§12.1: There are normative downrefs to RFC 4919, RFC 6606, RFC 7102, RFC 7228 that were not mentioned in the IETF LC announcement, nor are they in the downref registry.

[Ballot comment]
Section 6.1 has:

  Registration Ownership Verifier (ROVR):  Enables the correlation
                  between multiple attempts to register a same IPv6
                  Address.  This can be a unique ID of the Registering
                  Node, such as the EUI-64 address of an interface.
                  This can also be a token obtained with cryptographic
                  methods and used as proof of ownership of the
                  registration.  [...]

I understand that the actual crypto is (currently) in draft-ietf-6lo-ap-nd, but from the point
of view of this document, the ROVR token (or "crypto-ID" in the terminology of 6lo-ap-nd)
behaves as a bearer token.  That is, I include it with my EARO and my registration request
is authenticated and associated with that "identity"; there is not anything in this document
that ties the crypto-ID to the EARO.  From a very quick read of the other document, it sounds
like the 6LR can optionally request validation that the 6LN using the crypto-ID actually has control
of the associated private key, and is expected to do so on the first exchange, and so arguably the
transport key+LLA are what associates the crypto-ID with the EARO.

The conclusion from the above would be that this sort of ROVR is not itself proof of ownership of
anything, so it might be better to have text like "this can also be a token obtained with cryptographic
methods which can be used in additional protocol exchanges to associate a cryptographic identity
(key) with this registration".


In several places in section 7 it is indicated that implementations that support this spec should
always use the new data structures even when talking to RFC6775-only peers; this generally seems
fine due to the way that reserved fields are used.  I was not entirely sure if the same holds for the
use of new status codes in the EARO, though -- do things work out okay if (e.g.) "Moved" or "Removed"
are interpreted as a generic error?


In general the Security and Privacy Considerations seem well thought-out (in the model where
Layer-2 security is already in place), thank you!  (Key distribution remains a hard problem, of course,
and sharing such keys across groups does reduce the security properties of the system, but this
is not the right place to go into detail on such issues.)

One final nit: what is the "port" involved in the Binding?  It does not sound like it is an IP port...

[Ballot comment]
Thank you for a very readable document - this is not a simple process, but the document was clear and understandable.
Also, thank you for addressing Jürgen Schönwälder's OpsDir comments (I have not personally checked that each was incorporated, but the authors said that they would, and I'm trusting them).

Issues:
"In IPv6 ND [RFC4861], a router needs enough storage to hold NCEs for all the addresses to which it can currently forward packets." -- I do not believe that this is correct and am not quite sure how to fix it.
Can you point where in RFC4861 it says this? I'd agree that *to be efficient* a router should have enough space to hold an NCE for all locally attached subnets, but a constrained device *could* presumably age out and relearn old entries. Apart from that somewhat pathological case, if I'm a router and get a transit packet (not for a directly connected interface), I don't need to have a neighbor entry for it (otherwise "core" routers would need to build NCEs for every IP on the Internet :-P). Perhaps "for all directly connected subnets." or "for all directly connected addresses to which it can currently forward packets."?

I'm somewhat uncomfortable with the uppercase MUST in:
"A network administrator MUST deploy updated 6LR/6LBRs to support the number and type of devices in their network, ..."
Having an uppercase MUST driving operators' design decisions stuff feels weird. I'd be perfectly fine with something like "In order to deploy this, network administrators MUST..." or "Network Administrators need to ensure that 6LR/6LBRs support the number and..."


Nits:
Section 4.2.1.  Comparing TID values
"In order to keep this document self-contained and yet compatible, the text below is an exact copy from section 7.2.  "Sequence Counter Operation" of [RFC6550].""
I think that it would be helpful to delimit the copied text (perhaps by indenting it) -- it was unclear to me where the copied text started and ended, and so I had to go read RFC6550 (which kind of defeats the purpose of copying it).

Section 4.3.  Registration Ownership Verifier
"An RFC6775-only will confuse the name-spaces,"
Missing a word - perhaps "device", "6LoWPAN Router" or "implementation"?

Section 7.3.  RFC6775-only 6LoWPAN Router
"But if RFC6775-only and updated 6LRs
  coexist temporarily in a network, then it makes sense for an
  administrator to install a policy that allows so, and the capability
  to install such a policy should be configurable in a 6LBR though it
  is out of scope for this document."
s/that allows so/that allows this/ -- readability (purely a nit).


Section Appendix B.  Requirements (Not Normative)
"This section lists requirements that were discussed discussed by the 6lo WG..."
I guess that they were discussed at length? :-P

Section B.1.  Requirements Related to Mobility
" Due to the unstable nature of LLN links, even in an LLN of immobile nodes a 6LN may change"
s/of immobile nodes a/of immobile nodes, a/ (add comma -- also a nitty nit).

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 24 February 2012.

(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

  This specification updates RFC 6775 - 6LoWPAN Neighbor Discovery, to
  clarify the role of the protocol as a registration technique,
  simplify the registration operation in 6LoWPAN routers, as well as to
  provide enhancements to the registration capabilities and mobility
  detection for different network topologies.

Working Group Summary

There has been plenty of discussion about these extensions in the working group. This document started in Oct. 2016 as an individual submission, but ideas were discussed even previous to that, including a requirements document (draft-thubert-6lo-rfc6775-update-reqs) which fed into this document, 6775bis. There have been 10 revisions based on implementation experience. Initially, it was a controversial document since it affects how IPv6 ND works in certain networks. This prompted some concern from IPv6 folks (e.g., Lorenzo Colitti) concerned that these modifications were not generally applicable to all link layers or situations. In response, the authors made changes to clarify the scope of the extensions. Section 2, in particular was modified as a result of these debates and exchanges.

Document Quality

These extensions have been implemented in open source (OpenWSN, Cisco IOS) and has been tested in 6TiSCH/6lo ETSI Plugtest.

Personnel

  Who is the Document Shepherd? Who is the Responsible Area
  Director?

Shepherd: Gabriel Montenegro
AD: Suresh Krishnan

(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.

I have reviewed the document and identified several editorial issues, but these should not block IESG review and can be addressed as part of IETF LC  and IESG comments.

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

This document has received in-depth reviews. No concerns.

(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.

This documents will benefit from operational and privacy review, but nothing beyond the normal.

(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.

(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.

Authors have confirmed that they have no knowledge of relevant IPR.

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

No disclosure.

(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? 

At this point, it is solid. There was a point when it was very controversial as noted above.

(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.

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

  == Outdated reference: A later version (-05) exists of
    draft-ietf-6lo-backbone-router-04

  == Outdated reference: A later version (-09) exists of draft-ietf-6lo-nfc-08

  == Outdated reference: draft-ietf-bier-architecture has been published as
    RFC 8279

Note: there are also two ignorable warnings about non-existent references which do exist. Idnits just does not expect to find them in an "Exernal Informative References" section.


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

Not applicable.

(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?

Not applicable.

(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.

Only RFC8126 (Guidance IANA Considerations), which shouldn't be an issue.
Alternatively, this could be moved to informational.


(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.

Per the header of the document:
"Updates: 6775 (if approved) "

(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).

Looks good.

(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.

Nothing new under expert review.


(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.

Not applicable.

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

The IANA Services Operator has completed its review of draft-ietf-6lo-rfc6775-update-11. 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 five actions which we must complete.

First, a new registry is to be created called the ARO Flags registry. The new reistry will be located in the Internet Control Message Protocol version 6 (ICMPv6) Parameters registry page located at:

https://www.iana.org/assignments/icmpv6-parameters/

the new registry will be managed via IETF Review as defined by RFC 8126. There are eight bits in the registry and there are initial registrations as follows:

ARO
Status Description Refernce
-------+-----------------------------+---------------
0 - 6 Unassigned
7 "T" Flag [ RFC-to-be ]

Second, a new subregistry of the ICMPv6 "Code" Fields registry also on the Internet Control Message Protocol version 6 (ICMPv6) Parameters registry page located at:

https://www.iana.org/assignments/icmpv6-parameters/

The new subregistry is for Duplicate Address Request and is as follows:

Type 157 - Duplicate Address Request
Registration Procedure: Standards Action or IESG Approval
Reference: [ RFC-to-be ]

Code Name Reference
--------+------------------------+----------------
0 Original DAR message RFC 6775
1 Extended DAR message [ RFC-to-be ]

Third, a new subregistry of the ICMPv6 "Code" Fields registry also on the Internet Control Message Protocol version 6 (ICMPv6) Parameters registry page located at:

https://www.iana.org/assignments/icmpv6-parameters/

The new subregistry is for Duplicate Address Confirmation and is as follows:

Type 158 - Duplicate Address Confirmation
Registration Procedure: Standards Action or IESG Approval
Reference: [ RFC-to-be ]

Code Name Reference
--------+------------------------+----------------
0 Original DAC message RFC 6775
1 Extended DAC message [ RFC-to-be ]

Fourth, in the Address Registration Option Status Values registry also on the Internet Control Message Protocol version 6 (ICMPv6) Parameters registry page located at:

https://www.iana.org/assignments/icmpv6-parameters/

a series of new registrations will be made as follows:

+------------+------------------------------------+----------------+
| ARO Status | Description | Reference |
+------------+------------------------------------+----------------+
| 3 | Moved | [ RFC-to-be ] |
| | | |
| 4 | Removed | [ RFC-to-be ] |
| | | |
| 5 | Validation Requested | [ RFC-to-be ] |
| | | |
| 6 | Duplicate Source Address | [ RFC-to-be ] |
| | | |
| 7 | Invalid Source Address | [ RFC-to-be ] |
| | | |
| 8 | Registered Address topologically | [ RFC-to-be ] |
| | incorrect | |
| | | |
| 9 | 6LBR registry saturated | [ RFC-to-be ] |
| | | |
| 10 | Validation Failed | [ RFC-to-be ] |
+------------+------------------------------------+----------------+

Fifth, in the 6LoWPAN capability Bits registry also on the Internet Control Message Protocol version 6 (ICMPv6) Parameters registry page located at:

https://www.iana.org/assignments/icmpv6-parameters/

a series of new registrations will be made as follows:

+-----------------+----------------------+----------------+
| Capability Bit | Description | Document |
+-----------------+----------------------+----------------+
| 11 | 6LR capable (L bit) | [ RFC-to-be ] |
| | | |
| 12 | 6LBR capable (B bit) | [ RFC-to-be ] |
| | | |
| 13 | 6BBR capable (P bit) | [ RFC-to-be ] |
| | | |
| 14 | EARO support (E bit) | [ RFC-to-be ] |
+-----------------+----------------------+----------------+

IANA Question --> Are there any other places on the Internet Control Message Protocol version 6 (ICMPv6) Parameters registry page located at:

https://www.iana.org/assignments/icmpv6-parameters/

where the references should be changed from RFC 6775 to [ RFC-to-be ]?

The IANA Services Operator understands that these are the only actions 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 meant only to confirm the list of actions that will be performed.


Thank you,

Sabrina Tanamal
Senior IANA Services Specialist

instead. In either case, please retain the beginning of
the Subject line to allow automated sorting.

Abstract


  This specification updates RFC 6775 - 6LoWPAN Neighbor Discovery, to
  clarify the role of the protocol as a registration technique,
  simplify the registration operation in 6LoWPAN routers, as well as to
  provide enhancements to the registration capabilities and mobility
  detection for different network topologies including the backbone
  routers performing proxy Neighbor Discovery in a low power network.




The file can be obtained via
https://datatracker.ietf.org/doc/draft-ietf-6lo-rfc6775-update/

IESG discussion can be tracked via
https://datatracker.ietf.org/doc/draft-ietf-6lo-rfc6775-update/ballot/


No IPR declarations have been submitted directly on this I-D.

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 24 February 2012.

(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

  Relevant content can frequently be found in the abstract
  and/or introduction of the document. If not, this may be
  an indication that there are deficiencies in the abstract
  or introduction.

  This specification updates RFC 6775 - 6LoWPAN Neighbor Discovery, to
  clarify the role of the protocol as a registration technique,
  simplify the registration operation in 6LoWPAN routers, as well as to
  provide enhancements to the registration capabilities and mobility
  detection for different network topologies.

Working Group Summary

  Was there anything in WG process that is worth noting? For
  example, was there controversy about particular points or
  were there decisions where the consensus was particularly
  rough?

There has been plenty of discussion about these extensions in the working group. This document started in Oct. 2016 as an individual submission, but ideas were discussed even previous to that, including a requirements document (draft-thubert-6lo-rfc6775-update-reqs) which fed into this document, 6775bis. There have been 10 revisions based on implementation experience. Initially, it was a controversial document since it affects how IPv6 ND works in certain networks. This prompted some concern from IPv6 folks (e.g., Lorenzo Colitti) concerned that these modifications were not generally applicable to all link layers or situations. In response, the authors made changes to clarify the scope of the extensions. Section 2, in particular was modified as a result of these debates and exchanges.

Document Quality

  Are there existing implementations of the protocol? Have a
  significant number of vendors indicated their plan to
  implement the specification? Are there any reviewers that
  merit special mention as having done a thorough review,
  e.g., one that resulted in important changes or a
  conclusion that the document had no substantive issues? If
  there was a MIB Doctor, Media Type or other expert review,
  what was its course (briefly)? In the case of a Media Type
  review, on what date was the request posted?

These extensions have been implemented in open source (OpenWSN, Cisco IOS) and has been tested in 6TiSCH/6lo ETSI Plugtest.

Personnel

  Who is the Document Shepherd? Who is the Responsible Area
  Director?

Shepherd: Gabriel Montenegro
AD: Suresh Krishnan

(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.

I have reviewed the document and identified several editorial issues, but these should not block IESG review and can be addressed as part of IETF LC  and IESG comments.

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

This document has received in-depth reviews. No concerns.

(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.

This documents will benefit from operational and privacy review, but nothing beyond the normal.

(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.

(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.

Authors have confirmed that they have no knowledge of relevant IPR.

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

No disclosure.

(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? 

At this point, it is solid. There was a point when it was very controversial as noted above.

(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.

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

  == Outdated reference: A later version (-05) exists of
    draft-ietf-6lo-backbone-router-04

  == Outdated reference: A later version (-09) exists of draft-ietf-6lo-nfc-08

  == Outdated reference: draft-ietf-bier-architecture has been published as
    RFC 8279

Note: there are also two ignorable warnings about non-existent references which do exist. Idnits just does not expect to find them in an "Exernal Informative References" section.


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

Not applicable.

(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?

Not applicable.

(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.

Only RFC8126 (Guidance IANA Considerations), which shouldn't be an issue.
Alternatively, this could be moved to informational.


(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.

Per the header of the document:
"Updates: 6775 (if approved) "

(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).

Looks good.

(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.

Nothing new under expert review.


(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.

Not applicable.