RFC 6946: Processing of IPv6 "Atomic" Fragments
In plain English — editorial summary, not part of the RFC
The IPv6 specification allows packets to contain a Fragment Header without the packet being actually fragmented into multiple pieces (we refer to these packets as "atomic fragments"). Such packets are typically sent by hosts that have received an ICMPv6 "Packet Too Big" error message that advertises a Next-Hop MTU smaller than 1280 bytes, and are currently processed by some implementations as normal "fragmented traffic" (i.e., they are "reassembled" with any other queued fragments that supposedly correspond to the same original packet). Thus, an attacker can cause hosts to employ atomic fragments by forging ICMPv6 "Packet Too Big" error messages, and then launch any fragmentation-based attacks against such traffic. This document discusses the generation of the aforementioned atomic fragments and the corresponding security implications. Additionally, this document formally updates RFC 2460 and RFC 5722, such that IPv6 atomic fragments are processed independently of any other fragments, thus completely eliminating the aforementioned attack vector.
Document record
- Document ID
- RFC6946
- Published
- May 2013
- Authors
- F. Gont
- Status
- PROPOSED STANDARD
- Stream
- IETF
- Area
- int
- Pages
- 9
- Also known as
- —
Topics
Related documents
Ranked automatically by shared keywords, IETF area and stream — not by editorial selection.
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August 2013
- RFC 7588A Widely Deployed Solution to the Generic Routing Encapsulation (GRE) Fragmentation ProblemCurrent
July 2015
- RFC 8724SCHC: Generic Framework for Static Context Header Compression and FragmentationUpdated
April 2020
- RFC 8824Static Context Header Compression (SCHC) for the Constrained Application Protocol (CoAP)Current
June 2021
- RFC 8900IP Fragmentation Considered FragileCurrent
September 2020
- RFC 9011Static Context Header Compression and Fragmentation (SCHC) over LoRaWANCurrent
April 2021
- RFC 9363A YANG Data Model for Static Context Header Compression (SCHC)Updated
March 2023
- RFC 9391Static Context Header Compression over Narrowband Internet of ThingsCurrent
April 2023
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The document record above — title, authors, date, status, stream, area, relationships, DOI and errata — is imported verbatim from the public RFC Editor index. The “in plain English” section is editorial: written by The metasystema editorial team, not part of the RFC. Where the two differ, the RFC text governs.
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