Host Multihoming with the Host Identity Protocol
draft-ietf-hip-multihoming-12

[Ballot comment]

- I think section 6 ought note the privacy issue that
was relatively recently with WebRTC and ICE where a
client might not want all of it's IP addresses
exposed, as doing so could expose the fact that the
client e.g. is using Tor or another VPN service. The
issue being that in some locations, that information
may be quite sensitive.  4.2 notes this but in a quite
opaque way, ("may be held back") but it'd be better to
say some more. 5.1 is also relevant maybe in that it
says one "SHOULD avoid" sending info about virtual
interfaces. Anyway, I think it'd be good to add some
recognition of this privacy issue to section 6. I am
not arguing that this draft ought specify the one true
way to avoid this problem, but only that it be
recognised.

- 4.11: what's the concern about anti-replay windows?
I didn't get that fwiw, not sure if that just my
relative ignorance of HIP or if more needs to be said
in the document.

[Ballot comment]
I'm wondering if split-tunneling should be listed as a security consideration.  I see the following in section 4.1 that might be used to help prevent split tunneling:
  In the outbound direction, as a result of SPD processing, when
  an outbound SA is selected, the correct IP destination address for
  the peer must also be assigned.

Then also the entirety of section 4.3.

I read this as split tunneling could be an issue in some circumstances depending on policy and it might be good to mention this in the security considerations section.  Or let me know if I am missing some background that would prevent split tunneling so implementers don't need to be made aware of this consideration.

Thanks.

[Ballot comment]
One big general comment:

The split between this document and draft-ietf-hip-rfc5206-bis-13 (still) seems a little artificial. draft-ietf-hip-rfc5206-bis-13 describes some general parts that actually covers both use cases. I guess it would be at least nice to spell out clearly in this document which parts of draft-ietf-hip-rfc5206-bis-13 are required to read (section 4 and parts of section 5) if that's is somehow clearly separately.

E.g. I believe the following should be in draft-ietf-hip-rfc5206-bis-13 and not in this doc:
"Hosts MUST NOT announce broadcast or multicast addresses in
  LOCATOR_SETs. "
I this is more relevant for the case described in this document but is true for the general case. draft-ietf-hip-rfc5206-bis-13 stated the following but that's not the same because it only describes the peer side:
"  For
  each locator listed in the LOCATOR_SET parameter, check that the
  address therein is a legal unicast or anycast address.  That is, the
  address MUST NOT be a broadcast or multicast address."

What worries me more is that I believe that one would need to always read both documents to implement the peer functionality correctly. E.g. this documents says the following:
"An Initiator MAY include one or more LOCATOR_SET parameters in the I2
  packet, independent of whether or not there was a LOCATOR_SET
  parameter in the R1.  These parameters MUST be protected by the I2
  signature.  Even if the I2 packet contains LOCATOR_SET parameters,
  the Responder MUST still send the R2 packet to the source address of
  the I2."
However, when I read draft-ietf-hip-rfc5206-bis-13, it is not clear that there are specifications in this document that are important for a correct implementation.

Smaller comments:
1) Regarding the following sentence:
"In summary, whether and how a host decides to leverage additional
  addresses in a load-balancing or fault-tolerant manner is outside the
  scope of the specification."
I agree that it is out of scope for this doc. But maybe it would be useful to provide pointers to existng work. The scheduling problem is well know and e.g. basically the same for MPTCP.

2) Regarding the following recommendation:
"Although the protocol may allow for configurations in which there is
  an asymmetric number of SAs between the hosts (e.g., one host has two
  interfaces and two inbound SAs, while the peer has one interface and
  one inbound SA), it is RECOMMENDED that inbound and outbound SAs be
  created pairwise between hosts.  When an ESP_INFO arrives to rekey a
  particular outbound SA, the corresponding inbound SA should be also
  rekeyed at that time."
I believe I agree but why?

3) I (again) would find it easier to have section 4.9, 4.10, and 4.11 before 4.2-4.8. However, I guess that's a matter of taste. Alternatively maybe have most of the text from 4.2-4.8 in a separate supersection first and call it 'usage scenarios' or something like this, while summerizing the protocol actions in one subsection in the 'protocol overview' section because it seems that the actions are actually quite similar for all use cases, no?

4) Maybe indicate clearly what is recommendated in draft-ietf-hip-rfc5206-bis the following way:
OLD
"[I-D.ietf-hip-rfc5206-bis]
  recommends that a host should send a LOCATOR_SET whenever it
  recognizes a change of its IP addresses in use on an active HIP
  association, and assumes that the change is going to last at least
  for a few seconds. "
NEW
"[I-D.ietf-hip-rfc5206-bis]
  recommends that "a host should send a LOCATOR_SET whenever it
  recognizes a change of its IP addresses in use on an active HIP
  association, and assumes that the change is going to last at least
  for a few seconds. ""

5) How does a host know about this? Can you give examples?
"The grouping should consider also whether middlebox
  interaction requires sending the same LOCATOR_SET in separate UPDATEs
  on different paths."

[Ballot comment]
One big general comment:

The split between this document and draft-ietf-hip-rfc5206-bis-13 (still) seems a little artificial. draft-ietf-hip-rfc5206-bis-13 describes some general parts that actually covers both use case. I guess it would be at least nice to spell out clearly in this document which parts on draft-ietf-hip-rfc5206-bis-13 are needed (section 4 and parts of section 5) if that's is somehow clearly separately.

E.g. I believe the following should be in draft-ietf-hip-rfc5206-bis-13 and not in this doc:
"Hosts MUST NOT announce broadcast or multicast addresses in
  LOCATOR_SETs. "
I this is more relevant for the case described in this document but is true for the general case. draft-ietf-hip-rfc5206-bis-13 stated the following but that's not the same because it only describes the peer side:
"  For
  each locator listed in the LOCATOR_SET parameter, check that the
  address therein is a legal unicast or anycast address.  That is, the
  address MUST NOT be a broadcast or multicast address."

What worries more more is that I believe that one would need to always read both documents to implement the peer functionality correctly. E.g. this documents says the following:
"An Initiator MAY include one or more LOCATOR_SET parameters in the I2
  packet, independent of whether or not there was a LOCATOR_SET
  parameter in the R1.  These parameters MUST be protected by the I2
  signature.  Even if the I2 packet contains LOCATOR_SET parameters,
  the Responder MUST still send the R2 packet to the source address of
  the I2."
However, when I read draft-ietf-hip-rfc5206-bis-13, it is not clear that there are specification in this document that are important for a correct implementation.

Smaller comments:
1) Regarding the following sentence:
"In summary, whether and how a host decides to leverage additional
  addresses in a load-balancing or fault-tolerant manner is outside the
  scope of the specification."
I agree that it is out of scope for this doc. But maybe it would be useful to provide pointer to existng work. The scheduling problem is well know and e.g. basically the same for MPTCP.

2) Regarding the following recommendation:
"Although the protocol may allow for configurations in which there is
  an asymmetric number of SAs between the hosts (e.g., one host has two
  interfaces and two inbound SAs, while the peer has one interface and
  one inbound SA), it is RECOMMENDED that inbound and outbound SAs be
  created pairwise between hosts.  When an ESP_INFO arrives to rekey a
  particular outbound SA, the corresponding inbound SA should be also
  rekeyed at that time."
I believe I agree but why?

3) I (again) would find it easier to have section 4.9, 4.10, and 4.11 before 4.2-4.8. However, I guess that's a matter of taste. Alternatively maybe have most of the text from 4.2-4.8 in a separate supersection first and call it 'usage scenarios' or something like this, while summerizing the protocol action in one subsection in the 'protocol overview' section because it seems that the actions are actually quite similar for all use cases, no?

4) Maybe indicate clearly what is recommendated in draft-ietf-hip-rfc5206-bis the following way:
OLD
"[I-D.ietf-hip-rfc5206-bis]
  recommends that a host should send a LOCATOR_SET whenever it
  recognizes a change of its IP addresses in use on an active HIP
  association, and assumes that the change is going to last at least
  for a few seconds. "
NEW
"[I-D.ietf-hip-rfc5206-bis]
  recommends that "a host should send a LOCATOR_SET whenever it
  recognizes a change of its IP addresses in use on an active HIP
  association, and assumes that the change is going to last at least
  for a few seconds. ""

5) How does a host know about this? Can you give examples?
"The grouping should consider also whether middlebox
  interaction requires sending the same LOCATOR_SET in separate UPDATEs
  on different paths."

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

IANA has reviewed draft-ietf-hip-multihoming-10.txt, which is currently in Last Call, and has the following comments:

We understand that this document doesn't require any IANA 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, IANA does not object.

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

Thank you,

Sabrina Tanamal
IANA Specialist
ICANN

The following Last Call announcement was sent out:

From: The IESG
To: "IETF-Announce"
CC: hipsec@ietf.org, gonzalo.camarillo@ericsson.com, "Gonzalo Camarillo" , hip-chairs@ietf.org, draft-ietf-hip-multihoming@ietf.org, terry.manderson@icann.org
Reply-To: ietf@ietf.org
Sender:
Subject: Last Call:  (Host Multihoming with the Host Identity Protocol) to Proposed Standard


The IESG has received a request from the Host Identity Protocol WG (hip)
to consider the following document:
- 'Host Multihoming with the Host Identity Protocol'
  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 2016-08-25. 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 document defines host multihoming extensions to the Host
  Identity Protocol (HIP), by leveraging protocol components defined
  for host mobility.




The file can be obtained via
https://datatracker.ietf.org/doc/draft-ietf-hip-multihoming/

IESG discussion can be tracked via
https://datatracker.ietf.org/doc/draft-ietf-hip-multihoming/ballot/


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

PROTO Writeup: draft-ietf-hip-multihoming-09

(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 header (i.e., Standards
  Track).
 

(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 defines host multihoming extensions to the Host
  Identity Protocol (HIP), by leveraging protocol components defined
  for host mobility.


Working Group Summary:

  There was WG consensus behind this document.


Document Quality:

  As discussed in RFC 6538, there are several implementations of the
  Experimental HIP specs. At least HIP for Linux and OpenHIP will be
  updated to comply with the new standards-track specs like this one.


Personnel:

  Gonzalo Camarillo is the documetn shepherd. Terry Manderson is the
  responsible area director.


(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 reviewed revision 09 of this document, which
  was ready for publication.


(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.
 

(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 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?

  Yes.

(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?

  The whole WG understands the document and agree with it. Note that
  this is the revision of a part of an existing RFC. In particular,
  this document revises the multihoming part of RFC 5206 (the mobility
  part is being revised by draft-ietf-hip-rfc5206-bis).
 

(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 contains no nits.
 

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

  No formal 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).

  The IANA Considerations Section is a no-op.
 

(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 experts are required.
 

(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 such checks were needed.