Internet Key Exchange Protocol Version 2 (IKEv2) Notification Status Types for IPv4/IPv6 Coexistence
RFC 8983

Document Type RFC - Proposed Standard (February 2021; No errata)
Updates RFC 7296
Author Mohamed Boucadair 
Last updated 2021-02-12
Replaces draft-boucadair-ipsecme-ipv6-ipv4-codes
Stream Internent Engineering Task Force (IETF)
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Stream WG state Submitted to IESG for Publication (wg milestone: Dec 2019 - The internal address... )
Document shepherd Yoav Nir
Shepherd write-up Show (last changed 2020-02-11)
IESG IESG state RFC 8983 (Proposed Standard)
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Consensus Boilerplate Yes
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Responsible AD Benjamin Kaduk
Send notices to David Waltermire <>, Yoav Nir <>
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Internet Engineering Task Force (IETF)                      M. Boucadair
Request for Comments: 8983                                        Orange
Updates: 7296                                              February 2021
Category: Standards Track                                               
ISSN: 2070-1721

  Internet Key Exchange Protocol Version 2 (IKEv2) Notification Status
                    Types for IPv4/IPv6 Coexistence


   This document specifies new Internet Key Exchange Protocol Version 2
   (IKEv2) notification status types to better manage IPv4 and IPv6
   coexistence by allowing the responder to signal to the initiator
   which address families are allowed.

   This document updates RFC 7296.

Status of This Memo

   This is an Internet Standards Track document.

   This document is a product of the Internet Engineering Task Force
   (IETF).  It represents the consensus of the IETF community.  It has
   received public review and has been approved for publication by the
   Internet Engineering Steering Group (IESG).  Further information on
   Internet Standards is available in Section 2 of RFC 7841.

   Information about the current status of this document, any errata,
   and how to provide feedback on it may be obtained at

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
   ( in effect on the date of
   publication of this document.  Please review these documents
   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 Section 4.e of
   the Trust Legal Provisions and are provided without warranty as
   described in the Simplified BSD License.

Table of Contents

   1.  Introduction
   2.  Terminology
   4.  IP6_ALLOWED and IP4_ALLOWED Status Types
   5.  Update to RFC 7296
   6.  Security Considerations
   7.  IANA Considerations
   8.  References
     8.1.  Normative References
     8.2.  Informative References
   Author's Address

1.  Introduction

   As described in [RFC7849], if the subscription data or network
   configuration allows only one IP address family (IPv4 or IPv6), the
   cellular host must not request a second PDP-Context (Section 3.2 of
   [RFC6459]) to the same Access Point Name (APN) for the other IP
   address family (AF).  The Third Generation Partnership Project (3GPP)
   network informs the cellular host about allowed Packet Data Protocol
   (PDP) types by means of Session Management (SM) cause codes.  In
   particular, the following cause codes can be returned:

   cause #50 "PDP type IPv4 only allowed":  This cause code is used by
      the network to indicate that only PDP type IPv4 is allowed for the
      requested Public Data Network (PDN) connectivity.

   cause #51 "PDP type IPv6 only allowed":  This cause code is used by
      the network to indicate that only PDP type IPv6 is allowed for the
      requested PDN connectivity.

   cause #52 "single address bearers only allowed":  This cause code is
      used by the network to indicate that the requested PDN
      connectivity is accepted with the restriction that only single IP
      version bearers are allowed.

   If the requested IPv4v6 PDP-Context is not supported by the network
   but IPv4 and IPv6 PDP types are allowed, then the cellular host will
   be configured with an IPv4 address or an IPv6 prefix by the network.
   It must initiate another PDP-Context activation of the other address
   family in addition to the one already activated for a given APN.  The
   purpose of initiating a second PDP-Context is to achieve dual-stack
   connectivity (that is, IPv4 and IPv6 connectivity) by means of two

   When the User Equipment (UE) attaches to the 3GPP network using a
   non-3GPP access network (e.g., Wireless Local Area Network (WLAN)),
   there are no equivalent IKEv2 capabilities [RFC7296] notification
   codes for the 3GPP network to inform the UE why an IP address family
   is not assigned or whether that UE should retry with another address

   This document fills that void by introducing new IKEv2 notification
   status types for the sake of deterministic UE behaviors (Section 4).

   These notification status types are not specific to 3GPP
   architectures but can be used in other deployment contexts.  Cellular
   networks are provided as an illustration example.

2.  Terminology

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
   "OPTIONAL" in this document are to be interpreted as described in
   BCP 14 [RFC2119] [RFC8174] when, and only when, they appear in all
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