IPv4, IPv6, and IPv4-IPv6 Coexistence: Updates for the IP Performance Metrics (IPPM) Framework
draft-ietf-ippm-2330-ipv6-06

[Ballot discuss]
* Section 4

Since this behavior is clearly forbidden in RFC8200 there is no need to add a special case for this (as middleboxes perform any number of transformations that not standards compliant). Given that safe header insertion/deletion is a hard problem that has not been solved, I would remove this text or significantly augment it to describe potential issues that may occur due to header insertion/deletion (similar to the sections related to 6lowpan and translation).

  o  Extension Header insertion or deletion: Although such behavior is
      not endorsed by current standards, it is possible that Extension
      Headers could be added to, or removed from the header chain.  The
      resulting packet may be standard-formed, with a corresponding
      Type-P.

[Ballot comment]
* Section 3

Please add RFC6398 as the reference for Router Alert as it provides significant guidelines regarding usage similar to what RFC7045 does for hop-by-hop options. 

* Section 4

I think this text should be removed

  [RFC8250] endorses the use of IPv6 extension headers for measurement
  purposes, consistent with other approved IETF specifications.

as RFC8250 uses a destination option and defining new extension headers has been explicitly recommended against by section 4.8 of RFC8200.


* Minor

=> The reference for 6lowpan is wrong throughout the document (typo?). It should be RFC4944 instead of RFC4494 (which is a crypto spec).

[Ballot comment]
I'm glad to see that the "class C" potential confusion is already being addressed.  Even having
seen that previous discussion, I was still struck by how my mind jumped to "address class" when
reading it.

The Abstract claims that this document " deprecates the definition of minimum standard-formed packet",
but the body text refers only to a "minimal IP packet".

A couple of nits:

Section 4

  Two mechanisms require some discussion in the context of standard-
  formed packets, namely IPv6 over Low-Power Wireless Area Networks
  (6LowPAN, [RFC4494]) and Robust Header Compression (ROHC, [RFC3095]).
  IPv6 over Low-Power Wireless Area Networks (6LowPAN), as defined in
  [RFC4494] and updated by [RFC6282] with header compression and
  [RFC6775] with neighbor discovery optimizations proposes solutions
  for using IPv6 in resource-constrained environments.

Please put a comma before "proposes"

Maybe I should leave this one for the RFC Editor, but this document uses "exemplary"
twice when I think "example" is more appropriate -- to me, "exemplary" means something
like "best in class" and specifically has a positive connotation, whereas these usages are
for things that have ambivalent or negative connotations.

[Ballot comment]
Rich version of this review at:
https://mozphab-ietf.devsvcdev.mozaws.net/D6118

Thank you for writing this. Note that I'm using a new tool for
balloting, apologies in advance if it goes Boom!
Also apologies for the terseness / tone, still getting use to the
tooling, and not sure what shows up where.

COMMENTS
S 1.
>      aspects of IP packets can influence its processing during transfer
>      across the network.
>
>      In Section 15 of [RFC2330], the notion of a "standard-formed" packet
>      is defined.  However, the definition was never updated to include
>      IPv6, as the original authors planned.

Nit: This is slightly ambiguous - it is unclear if "As the authors
intended, it was not updated", or if the authors planned to update it,
and never did.


S 3.
>      This suggests we devise a metric or suite of metrics that attempt to
>      determine C.
>
>      Load balancing over parallel paths is one particular example where
>      such a class C would be more complex to determine in IPPM
>      measurements.  Load balancers often use flow identifiers, computed as

I think you might want "load balancers and routers" here. Generally a
load-balancer is used to mean something which chooses a server (or
cluster of servers) to direct a packet / transaction to. Hashing to
choose amongst parallel paths is more likely to be a router (yes, the
terminology gets squishy - a router doing this is in fact load-
balancing amongst links / paths, but...)



S 3.
>      fields that are used for the forwarding decision, are not known when
>      measuring the path as a black-box.  Potential assessment scenarios
>      include the measurement of one of the parallel paths, and the
>      measurement of all available parallel paths that the load balancer
>      can use.  Knowledge of a load balancer's flow definition
>      (alternatively: its class C specific treatment in terms of header

I realize that RFC2330 also used this term, but it was less jarring
there (it is also only used once)  - I think that you might want to
clarify that "class C" is used here in a different way to "class C
addresses".

I don't have any text to suggest though...


S 4.
>      o  Its total length as given in the IPv4 header corresponds to the
>        size of the IPv4 header plus the size of the payload.
>
>      o  Either the packet possesses sufficient TTL to travel from the
>        Source to the Destination if the TTL is decremented by one at each
>        hop, or it possesses the maximum TTL of 255.

I'm confused here - why do you need to add the "or 255 bit"?

Are you saying that a IPv4 packet that has a TTL of 255 sent to a
destination that is 300 hops away is still "standard-formed"? (not
that that would work anyway!)

Surely just saying "Either the packet possesses sufficient TTL to
travel from the Source to the Destination" is enough? (255, as used by
some protocols is more than sufficient for their single hop).

This feels like over specifying, leading to confusion.


S 4.
>        the packet, and the headers appear in the standard-conforming
>        order (Next Header).
>
>      o  All parameters used in the header and Extension Headers are found
>        in the IANA Registry of Internet Protocol Version 6 (IPv6)
>        Parameters, partly specified in [IANA-6P].

I'm confused again -- this says that all parameters must be in the
"IANA Registry of Internet Protocol Version 6 (IPv6)
Parameters". Ok, cool.
But which part of that registry isn't specified by
https://www.iana.org/assignments/ipv6-parameters/ipv6-parameters.xhtml?

(why the "partly")?

[Ballot comment]
Rich version of this review at:
https://mozphab-ietf.devsvcdev.mozaws.net/D6118

Thank you for writing this. Note that I'm using a new tool for
balloting, apologies in advance if it goes Boom!

COMMENTS
S 1.
>      aspects of IP packets can influence its processing during transfer
>      across the network.
>
>      In Section 15 of [RFC2330], the notion of a "standard-formed" packet
>      is defined.  However, the definition was never updated to include
>      IPv6, as the original authors planned.

Nit: This is slightly ambiguous - it is unclear if "As the authors
intended, it was not updated", or if the authors planned to update it,
and never did.


S 3.
>      This suggests we devise a metric or suite of metrics that attempt to
>      determine C.
>
>      Load balancing over parallel paths is one particular example where
>      such a class C would be more complex to determine in IPPM
>      measurements.  Load balancers often use flow identifiers, computed as

I think you might want "load balancers and routers" here. Generally a
load-balancer is used to mean something which chooses a server (or
cluster of servers) to direct a packet / transaction to. Hashing to
choose amongst parallel paths is more likely to be a router (yes, the
terminology gets squishy - a router doing this is in fact load-
balancing amongst links / paths, but...)



S 3.
>      fields that are used for the forwarding decision, are not known when
>      measuring the path as a black-box.  Potential assessment scenarios
>      include the measurement of one of the parallel paths, and the
>      measurement of all available parallel paths that the load balancer
>      can use.  Knowledge of a load balancer's flow definition
>      (alternatively: its class C specific treatment in terms of header

I realize that RFC2330 also used this term, but it was less jarring
there (it is also only used once)  - I think that you might want to
clarify that "class C" is used here in a different way to "class C
addresses".

I don't have any text to suggest though...


S 4.
>      o  Its total length as given in the IPv4 header corresponds to the
>        size of the IPv4 header plus the size of the payload.
>
>      o  Either the packet possesses sufficient TTL to travel from the
>        Source to the Destination if the TTL is decremented by one at each
>        hop, or it possesses the maximum TTL of 255.

I'm confused here - why do you need to add the "or 255 bit"?

Are you saying that a IPv4 packet that has a TTL of 255 sent to a
destination that is 300 hops away is still "standard-formed"? (not
that that would work anyway!)

Surely just saying "Either the packet possesses sufficient TTL to
travel from the Source to the Destination" is enough? (255, as used by
some protocols is more than sufficient for their single hop).

This feels like over specifying, leading to confusion.


S 4.
>        the packet, and the headers appear in the standard-conforming
>        order (Next Header).
>
>      o  All parameters used in the header and Extension Headers are found
>        in the IANA Registry of Internet Protocol Version 6 (IPv6)
>        Parameters, partly specified in [IANA-6P].

I'm confused again -- this says that all parameters must be in the
"IANA Registry of Internet Protocol Version 6 (IPv6)
Parameters". Ok, cool.
But which part of that registry isn't specified by
https://www.iana.org/assignments/ipv6-parameters/ipv6-parameters.xhtml?

(why the "partly")?

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

The IANA Services Operator has reviewed draft-ietf-ippm-2330-ipv6-04, which is currently in Last Call, and has the following comments:

We understand that this document doesn't require any registry actions.

While it's often helpful for a document's IANA Considerations section to remain in place upon publication even if there are no actions, if the authors strongly prefer to remove it, we do not object.

If this assessment is not accurate, please respond as soon as possible.

Thank you,

Sabrina Tanamal
Senior IANA Services Specialist

The following Last Call announcement was sent out (ends 2018-04-25):

From: The IESG
To: IETF-Announce
CC: Nevil Brownlee , ippm-chairs@ietf.org, draft-ietf-ippm-2330-ipv6@ietf.org, ippm@ietf.org, Brian Trammell , n.brownlee@auckland.ac.nz, spencerdawkins.ietf@gmail.com
Reply-To: ietf@ietf.org
Sender:
Subject: Last Call:  (IPv6, IPv4 and Coexistence Updates for IPPM's Active Metric Framework) to Informational RFC


The IESG has received a request from the IP Performance Measurement WG (ippm)
to consider the following document: - 'IPv6, IPv4 and Coexistence Updates for
IPPM's Active Metric Framework'
  as Informational RFC

The IESG plans to make a decision in the next few weeks, and solicits final
comments on this action. Please send substantive comments to the
ietf@ietf.org mailing lists by 2018-04-25. Exceptionally, comments may be
sent to iesg@ietf.org instead. In either case, please retain the beginning of
the Subject line to allow automated sorting.

Abstract


  This memo updates the IP Performance Metrics (IPPM) Framework RFC
  2330 with new considerations for measurement methodology and testing.
  It updates the definition of standard-formed packets in RFC 2330 to
  include IPv6 packets, deprecates the definition of minimum standard-
  formed packet, and augments distinguishing aspects of packets,
  referred to as Type-P for test packets in RFC 2330.  This memo
  identifies that IPv4-IPv6 co-existence can challenge measurements
  within the scope of the IPPM Framework.  Exemplary use cases include,
  but are not limited to IPv4-IPv6 translation, NAT, protocol
  encapsulation, IPv6 header compression, or use of IPv6 over Low-Power
  Wireless Area Networks (6LoWPAN).





The file can be obtained via
https://datatracker.ietf.org/doc/draft-ietf-ippm-2330-ipv6/

IESG discussion can be tracked via
https://datatracker.ietf.org/doc/draft-ietf-ippm-2330-ipv6/ballot/


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

Document Writeup for draft-ietf-ippm-2330-ipv6-03

(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?

Informational, as shown in its title page header.  This draft updates 2330, which is also Informational.  Although 7312 updates 2330, it does not update 2330 in every area.  The updates proposed in this draft reference sections that are not mentioned in 7312, so the WG had no choice but to update 2330.

(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 memo updates the IP Performance Metrics (IPPM) Framework, RFC 2330, with new considerations for measurement methodology and testing.  It updates the definition of standard-formed packets in RFC 2330 to include IPv6 packets, deprecates the definition of minimum standard-formed packet, and augments distinguishing aspects of packets, referred to as Type-P for test packets in RFC 2330.  This memo identifies that IPv4-IPv6 co-existence can challenge measurements within the scope of the IPPM Framework.  Exemplary use cases include, but are not limited to IPv4-IPv6 translation, NAT, protocol encapsulation, IPv6 header compression, or use of IPv6 over Low-Power Wireless Area Networks (6LoWPAN).

Working Group Summary:

The need for this draft was raised by Brian Carpenter early in 2015.  It had three versions as an individual draft before being adopted by the IPPM Working Group in July 2016.  It's now in its third (-02) version.  Discussion within the WG has not been contentious, it's simply been aimed at improving the quality and completeness of this draft.

Document Quality:

This draft simply describes the aspects of IP Performance Measurement affected by the change from IPv4 to IPv6.  These changes are well understood within the IPPM WG, RFC 8259 is a clear example if this.
Fred Baker and Marius Georgescu's review appear in the IPPM WG archive.  There were other comments at meetings.  Brian Carpenter reviewed  an early version of the draft.  See the ACKS.

Personnel:

Shepherd: Nevil Brownlee.  Responsible AD: Spencer Dawkins.

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

I have read the draft carefully, it is clear and well-written, therefore ready for submission to IESG.

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

No.

(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, this draft is only of interest within the IPPM WG.

(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 problems or 'uncomfortable' feelings about it.

(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?

This draft simply explores the changes needed for IPv6 Performance Measurement, it references the relevant RFCs for that.  It has no IPR disclosures, it doesn't need any.

(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?

Strong concurrence, well understood by th WG.

(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.

No.

(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.

None.

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

No such reviews are needed.

(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?

No.

(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 5226).

"This memo makes no requests of IANA."

(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.

None.

(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.

None.

Cheers, Nevil Brownlee