Title : Generation of IPv6 Atomic Fragments Considered Harmful
Authors : Fernando Gont
Filename : draft-ietf-6man-deprecate-atomfrag-generation-05.txt
Pages : 10
Date : 2016-01-20
(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
This is correct as it describes the reasons to deprecate the generation
of atomic fragments that has been included in draft-ietf-rfc2460bis.
(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:
RFC2460 requires that when a host receives an ICMPv6 "Packet Too Big"
message reporting an MTU smaller than 1280 bytes, the host includes a
Fragment Header in all subsequent packets sent to that destination,
without reducing the assumed Path-MTU. The simplicity with which
ICMPv6 "Packet Too Big" messages can be forged means that an attacker
can leverage this functionality (the generation of IPv6 atomic
fragments) to trigger the use of fragmentation for any arbitrary IPv6
flow, and subsequently perform any fragmentation-based attack. This
document discusses the security implications of the generation of
IPv6 atomic fragments and a number of interoperability issues
associated with IPv6 atomic fragments, and concludes that the
aforementioned functionality is undesirable, thus documenting the
motivation for removing this functionality in the revision of the
core IPv6 protocol specification in draft-ietf-6man-rfc2460bis.
Working Group Summary
The document was developed and adopted in the 6MAN w.g. and the
deprecating of the remaining case of atomic fragment generation was
included in draft-ietf-6man-rfc2460bis based on an earlier standards
track version of this draft. After this was done the authors agree to
remove the RFC2460 update and change the status of this document as
There is wide support for this document and the relevant changes in
draft-ietf-6man-rfc2460bis. The document has had extensive review in
the w.g. including reviews by the w.g. chairs. There are no open
technical issues. A few editorial issues have been identified that can
be dealt with in later versions.
Bob Hinden is the document shepherd. Brain Haberman is the responsible
area director. This is expected to move to 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
Reviewed the current version of the document and identified a few
editorial changes. The document is ready for publication.
(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
(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 interested community 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.
None of the authors are aware of any IPR on this document.
(8) Has an IPR disclosure been filed that references this document? If
so, summarize any discussion and conclusion regarding the IPR
(9) How solid is the consensus of the interested community behind this
document? Does it represent the strong concurrence of a few individuals,
with others being silent, or does the interested community as a whole
understand and agree with it?
(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.)
(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
No serious ID nits. The only issues identified are editorial (remove
reference from abstract and a few references that aren't used)
(12) Describe how the document meets any required formal review criteria,
such as the MIB Doctor, media type, and URI type reviews.
(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? If such normative
references exist, what is the plan for their completion?
(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.
(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
interested community considers it unnecessary.
(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).
No IANA considerations.
(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.
(19) Describe reviews and automated checks performed by to validate
sections of the document written in a formal language, such as XML code,
BNF rules, MIB definitions, etc.