IPv6 Oversized Packets Analysis
draft-vasilenko-v6ops-ipv6-oversized-analysis-00

Document Type Active Internet-Draft (individual)
Authors Eduard V  , XiPeng Xiao  , Dmitriy Khaustov 
Last updated 2021-03-19
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IPv6 Operations (v6ops) Working Group                      E. Vasilenko
Internet Draft                                                  X. Xiao
Intended status: Informational                      Huawei Technologies
Expires: September 2021                                     D. Khaustov
                                                             Rostelecom
                                                         March 19, 2021

                     IPv6 Oversized Packets Analysis
             draft-vasilenko-v6ops-ipv6-oversized-analysis-00

Abstract

   The IETF has many new initiatives relying on IPv6 Enhanced Headers
   added in transit: SRv6, SFC, BIERv6, iOAM. Additionally, some recent
   developments are overlays (SRv6, VxLAN) over IPv6. It could create
   oversized packets that need to be dealt with. This document analyzes
   available standards for the resolution of oversized packet drops.

Status of this Memo

   This Internet-Draft is submitted in full conformance with the
   provisions of BCP 78 and BCP 79.

   Internet-Drafts are working documents of the Internet Engineering
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   reference material or to cite them other than as "work in progress."

   This Internet-Draft will expire on September 2021.

Copyright Notice

   Copyright (c) 2021 IETF Trust and the persons identified as the
   document authors. All rights reserved.

   This document is subject to BCP 78 and the IETF Trust's Legal
   Provisions Relating to IETF Documents
   (http://trustee.ietf.org/license-info) in effect on the date of
   publication of this document. Please review these documents

Vasilenko             Expires September 19, 2021               [Page 1]
Internet-Draft            Oversized Analysis                 March 2021

   carefully, as they describe your rights and restrictions with
   respect to this document. Code Components extracted from this
   document must include Simplified BSD License text as described in
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Table of Contents

   1. Terminology and pre-requisite..................................2
   2. Problem statement..............................................3
   3. Solutions......................................................5
      3.1. Provision links with big enough MTU.......................5
      3.2. Frugal usage of Extension Headers.........................7
      3.3. Fragmentation and reassembly at the tunnel ends...........8
      3.4. PMTUD by original packet source..........................12
      3.5. Packetization Layer MTU Discovery........................14
   4. Conclusion....................................................15
   5. Security Considerations.......................................15
   6. IANA Considerations...........................................15
   7. References....................................................16
      7.1. Normative References.....................................16
      7.2. Informative References...................................18
   8. Acknowledgments...............................................19

1. Terminology and pre-requisite

   We do assume good knowledge or frequent references to [PMTUD] and
   [IPv6 Tunneling]. Terminology is inherited from [PMTUD].

  Link MTU - the maximum transmission unit, i.e., maximum packet size
            in octets that can be conveyed over a link.

  Path MTU (PMTU) - the minimum link MTU of all links in a path
            between a source node and a destination node.

  Path MTU Discovery (PMTUD) - the process by which a node learns the
            PMTU of a path.

  EMTU_S - Effective MTU for sending; used by upper-layer protocols to
            limit the size of IP packets they queue for sending.

  EMTU_R - Effective MTU for receiving; the largest packet that can be
            reassembled at the receiver.

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  Packetization Layer - the layer of the network stack that segments
            data into packets.

  PLPMTUD - Packetization Layer Path MTU Discovery, the method of
            detecting path MTU at packetization layer, which is an
            extension of classical PMTU Discovery.

  PTB (Packet Too Big) message - an ICMPv6 message reporting that an
            IPv6 packet is too large to forward through some link.
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