Dynamic Allocation of Shared IPv4 Addresses
draft-ietf-dhc-dynamic-shared-v4allocation-09

[Ballot comment]
In section 10.1, how could preserving port randomization
become "less" difficult?Presumably the assigned port
range will never be larger than "all the ports".

[Fixed in update]

[Ballot discuss]
Section 2 (Applicability Statement) says that “this extension is only suitable for specific architectures based on the Address plus Port model (A+P) [RFC6346]”, which I take to mean that the components of the solution in RFC6346 must be present (PRR, for example).  In fact, if the functionality described in RFC6346 is not present, then the forwarding won’t work as standard destination-based protocols may not deliver the packets to the right place.  I think that RFC6346 should be a Normative Reference, which then results in a DOWNREF to an Experimental RFC.

IOW, if the functionality in RFC6346 is needed (which I think it is), then the status of this document should not be Standards Track.

[Ballot comment]
I have many of the same questions as Stephen, so I support his discuss and comments.  In particular, I'd like to see text int he security considerations about sending traffic to the wrong host and how that is prevented as well as risks.  Stephen hits on this in his comments and I'd like to see it addressed in the security considerations section.  Since that's the point of the draft (multiple hosts using the same IPs), it is a major consideration.

[Ballot comment]
In section 10.1, how could preserving port randomization become "less" difficult?
Presumably the assigned port range will never be larger than "all the ports".

[Ballot comment]
In section 10.1, how could preserving port randomization become "less" difficult? Presumably the assigned port range will never be larger than "all the ports".

[Ballot discuss]

section 6: Why is client identifier option a MUST?  Surely the
PSID has to end up as a unique identifier for the client for the
duration of the lease or else stuff will be broken. (And I don't
see any real use of the client identifier in section 8.) So
requiring the client identifier seems like something counter to
data minimisation. Requiring that also seems to conflict with
possible future privacy friendly dhcp profiles, which might want
to use this as e.g. with some cleverness in source port
randomisation, the public Internet might get less trackable
evidence than would otherwise be the case. I'd argue that you
might be better off here to make the client identifier a SHOULD
NOT and to point out that including it may break a privacy
friendly profile such as defined in [1] should that end up being
standardised, which is presumably likely now that [1] is a dhc
wg draft (though note that I'm not sure the treatment of client
identifier in [1]-02 is what'll end up there in the end.)

  [1] https://tools.ietf.org/html/draft-ietf-dhc-anonymity-profile-00

[Ballot comment]

- section 2: s/mediums/media/? I also wondered if cable is
considered shared here or not? (I assume Ethernet and WiFi are
considered shared.)

- What if 1 of N of the devices with that IP operates a server,
how do we ensure that clients of that server talk to the right
one?

- I have some questions about ports. Can I ask for port 546 or
547? Why is that ever allowed?  Would port 443 be very popular I
wonder?  Can I ask for other well known ports in the hopes of
successful typosquatting sending me traffic?  What if mptcp is
used?

- section 6, step 3: I'm not sure I get how there can be many
DHCPOFFER messages from which to choose (in the nominal case).
Are you envisaging that two DHCP relays/servers on the same
subnet would be handing out different PSIDs?

- section 6, step 6: Could I "release" ports that had not been
assigned to me? Where's it say to watch out for that.

- section 9: PSID-len - the description of that isn't clear to
me sorry. I've not followed the references though so I assume it
would be if I had.

- section 10: [I-D.bajko-pripaddrassign] is odd - that was
replaced by stuff that was replaced by stuff that was replaced
by stuff that's still in-work in the dhc wg. I think you need to
explain why you refer to the archaic thing and not the WG
document.

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

IANA has reviewed draft-ietf-dhc-dynamic-shared-v4allocation-06.  Please report any inaccuracies and respond to any questions as soon as possible.

IANA's reviewer has the following comments:

IANA understands that, upon approval of this document, there is a single action which IANA must complete.

In the BOOTP Vendor Extensions and DHCP Options registry under the Dynamic Host Configuration Protocol (DHCP) and Bootstrap Protocol (BOOTP) Parameters heading at

https://www.iana.org/assignments/bootp-dhcp-parameters/

a new option code will be registered as follows:

Tag: [ TBD-AT-REGISTRATION ]
Name: OPTION_V4_PORTPARAMS
Data Length: 4
Meaning: This option is used to configure a set of ports bound to a shared IPv4 address.
Reference: [ RFC-to-be ]

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 only to confirm what actions will be performed.

The following Last Call announcement was sent out:

From: The IESG
To: IETF-Announce
CC:
Reply-To: ietf@ietf.org
Sender:
Subject: Last Call:  (Dynamic Allocation of Shared IPv4 Addresses) to Proposed Standard


The IESG has received a request from the Dynamic Host Configuration WG
(dhc) to consider the following document:
- 'Dynamic Allocation of Shared IPv4 Addresses'
  as Proposed
Standard

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 2015-05-06. 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 describes the dynamic allocation of shared IPv4 addresses
  to clients using DHCPv4.  Address sharing allows a single IPv4
  address to be allocated to multiple active clients simultaneously,
  each client being differentiated by a unique set of transport layer
  source port numbers.  The necessary changes to existing DHCPv4 client
  and server behavior are described and a new DHCPv4 option for
  provisioning clients with shared IPv4 addresses is included.

  Due to the nature of IP address sharing, some limitations to its
  applicability are necessary.  This memo describes these limitations
  and recommends suitable architectures and technologies where address
  sharing may be utilized.




The file can be obtained via
http://datatracker.ietf.org/doc/draft-ietf-dhc-dynamic-shared-v4allocation/

IESG discussion can be tracked via
http://datatracker.ietf.org/doc/draft-ietf-dhc-dynamic-shared-v4allocation/ballot/


The following IPR Declarations may be related to this I-D:

  http://datatracker.ietf.org/ipr/2502/
  http://datatracker.ietf.org/ipr/1102/
  http://datatracker.ietf.org/ipr/1119/

Write up for draft-ietf-dhc-dynamic-shared-v4allocation(-05).txt:

(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 because this document specifies
a mechanism for DHCPv4, when used over DHCPv6 (see RFC 7341), to obtain
a shared portion of an IPv4 address (see RFC 6346). This is also related
to the Softwire WG MAP work. The type is indicated in the title page
header.

(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 specifies a mechanism for obtaining shared IPv4 address
and IPv4 configuration information dynamically via DHCPv4 (over
DHCPv6).


Working Group Summary:

This work is an extension to DHCPv4 to allow for a shared IPv4 address
to be allocated and renewed by a client.

Document Quality:

This document has had thorough reviews by many interested and
knowledgeable folks (beyond those mentioned in the acknowledgements
section). There were no significant points of difficulty or
controversy with the contents of the document.

Personnel:

Bernie Volz is the document shepherd. Ted Lemon is the responsible AD.

(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 read the document thoroughly, and submitted editorial and technical
suggestions to the authors, which they implemented. I believe it is
ready for publication.

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

No, the document has had a good deal of careful review.

(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 is strictly a DHCP document, and has had sufficient review from
DHCP experts. And, some of those involved also are active in the
Softwire 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.

I think the document is good as written, and serves a useful purpose.
See section (3) above for a minor nit.

(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?

Yes. However, please see (8).


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

Yes. There are 3 IPR statements (one directly associated with this
document and 2 indirectly from earlier related efforts).

The directly associated IPR was late (after the WGLC) as the ones from
the earlier documents did not get properly associated with this new
work. The DHC WG was notified of this issue and there were no
objections to proceeding with this work because of the 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?

There is a strong consensus behind this document and in particular from
very active WG participants (i.e. "DHCP experts").

(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 http://www.ietf.org/tools/idnits/ and the
    Internet-Drafts Checklist). Boilerplate checks are not enough;
    this check needs to be thorough.

The document passes the idnits tool. There is one warning regarding
a non-RFC5737-complaint IPv4 address, but that is on purpose since
it is referencing the auto-configuration address range
(169.254.0.0/16), see RFC 6890 (Table 5).

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

The DHCPv4 option defined by this document uses the same format for
the port parameters as used by draft-ietf-softwire-map-dhcp (see
section 4.5) and both of these follow RFC 7227 (Guidelines for
Creating New DHCPv6 Options).

(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?

There are two drafts referenced, draft-ietf-softwire-map-12 and
draft-ietf-softwire-lw4over6-13, which are both flagged as
"Approved-announcement to be sent" as of 02/13/2015 as they
received enough positions to pass.


(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 downward normative references.

(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).

I reviewed the IANA Considerations section and it is fine and clear; the
actions are to define a new DHCPv4 option and the appropriate
registry is clearly identified to 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.

There are no new IANA registries requested by this draft.

(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.

There are no such parts to the document.

Hi all,

This message starts the DHC working group last call to advance "Dynamic Allocation of Shared IPv4 Addresses", draft-ietf-dhc-dynamic-shared-v4allocation-02, document as a Standards Track (Proposed Standard) RFC. The authors believe that this version is ready.

The draft is available here:
http://tools.ietf.org/html/draft-ietf-dhc-dynamic-shared-v4allocation-02

Please send your comments by October 27th, 2014. If you do not feel this document should advance, please state your reasons why.

There are no IPR claims reported at this time.

Bernie Volz is (tentatively) the assigned shepherd for this document.

- Tomek & Bernie