[ipv6hackers] Security Implications of Predictable IPv6 Fragment Identification values (rev'ed IETF I-D)

Fernando Gont fgont at si6networks.com
Sun Mar 4 01:07:47 CET 2012


We have published a revision of the aforementioned IETF Internet-Draft.
The revised document is available at:

A diff from the previous version is available at:

This version incorporates lots of detailed feedback sent by Ivan Arce
(Thanks Ivan!).

Any comments will be welcome.

Best regards,

-------- Original Message --------
Subject: New Version Notification for
Date: Sat, 03 Mar 2012 15:02:10 -0800
From: internet-drafts at ietf.org
To: fgont at si6networks.com

A new version of I-D, draft-gont-6man-predictable-fragment-id-01.txt has
been successfully submitted by Fernando Gont and posted to the IETF

Filename:	 draft-gont-6man-predictable-fragment-id
Revision:	 01
Title:		 Security Implications of Predictable Fragment Identification Values
Creation date:	 2012-03-03
WG ID:		 Individual Submission
Number of pages: 21

   IPv6 specifies the Fragment Header, which is employed for the
   fragmentation and reassembly mechanisms.  The Fragment Header
   contains an "Identification" field which, together with the
   Source Address and the IPv6 Destination Address of the packet,
   identifies fragments that correspond to the same original datagram,
   such that they can be reassembled together at the receiving host.
   The only requirement for setting the "Identification" value
is that
   it must be different than that of any other fragmented packet sent
   recently with the same Source Address and Destination Address.  Some
   implementations simply use a global counter for setting the Fragment
   Identification field, thus leading to predictable values.  This
   document analyzes the security implications of predictable
   Identification values, and updates RFC 2460 specifying additional
   requirements for setting the Fragment Identification, such that the
   aforementioned security implications are mitigated.

The IETF Secretariat

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