RFC 2406 (rfc2406) - Page 1 of 22


IP Encapsulating Security Payload (ESP)



Alternative Format: Original Text Document



Network Working Group                                            S. Kent
Request for Comments: 2406                                      BBN Corp
Obsoletes: 1827                                              R. Atkinson
Category: Standards Track                                  @Home Network
                                                           November 1998


                IP Encapsulating Security Payload (ESP)

Status of this Memo

   This document specifies an Internet standards track protocol for the
   Internet community, and requests discussion and suggestions for
   improvements.  Please refer to the current edition of the "Internet
   Official Protocol Standards" (STD 1) for the standardization state
   and status of this protocol.  Distribution of this memo is unlimited.

Copyright Notice

   Copyright (C) The Internet Society (1998).  All Rights Reserved.

Table of Contents

   1. Introduction..................................................2
   2. Encapsulating Security Payload Packet Format..................3
      2.1  Security Parameters Index................................4
      2.2  Sequence Number .........................................4
      2.3  Payload Data.............................................5
      2.4  Padding (for Encryption).................................5
      2.5  Pad Length...............................................7
      2.6  Next Header..............................................7
      2.7  Authentication Data......................................7
   3. Encapsulating Security Protocol Processing....................7
      3.1  ESP Header Location......................................7
      3.2  Algorithms..............................................10
         3.2.1  Encryption Algorithms..............................10
         3.2.2  Authentication Algorithms..........................10
      3.3  Outbound Packet Processing..............................10
         3.3.1  Security Association Lookup........................11
         3.3.2  Packet Encryption..................................11
         3.3.3  Sequence Number Generation.........................12
         3.3.4  Integrity Check Value Calculation..................12
         3.3.5  Fragmentation......................................13
      3.4  Inbound Packet Processing...............................13
         3.4.1  Reassembly.........................................13
         3.4.2  Security Association Lookup........................13
         3.4.3  Sequence Number Verification.......................14
         3.4.4  Integrity Check Value Verification.................15



Kent & Atkinson             Standards Track