IPv6-Only-Preferred Option for DHCPv4
draft-ietf-dhc-v6only-08

Document Type Active Internet-Draft (dhc WG)
Last updated 2020-08-25 (latest revision 2020-08-13)
Replaces draft-link-dhc-v6only
Stream IETF
Intended RFC status Proposed Standard
Formats plain text xml pdf htmlized (tools) htmlized bibtex
Reviews
Stream WG state Submitted to IESG for Publication
Document shepherd Bernie Volz
Shepherd write-up Show (last changed 2020-06-01)
IESG IESG state RFC Ed Queue
Consensus Boilerplate Yes
Telechat date
Responsible AD √Čric Vyncke
Send notices to Bernie Volz <volz@cisco.com>
IANA IANA review state IANA OK - Actions Needed
IANA action state RFC-Ed-Ack
RFC Editor RFC Editor state RFC-EDITOR
Details
Dynamic Host Configuration                                    L. Colitti
Internet-Draft                                                J. Linkova
Updates: 2563 (if approved)                                       Google
Intended status: Standards Track                           M. Richardson
Expires: February 14, 2021                                     Sandelman
                                                            T. Mrugalski
                                                                     ISC
                                                         August 13, 2020

                 IPv6-Only-Preferred Option for DHCPv4
                        draft-ietf-dhc-v6only-08

Abstract

   This document specifies a DHCPv4 option to indicate that a host
   supports an IPv6-only mode and is willing to forgo obtaining an IPv4
   address if the network provides IPv6 connectivity.  It also updates
   RFC2563 to specify the DHCPv4 server behavior when the server
   receives a DHCPDISCOVER not containing the Auto-Configure option but
   containing the new option defined in this document.

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
   Task Force (IETF).  Note that other groups may also distribute
   working documents as Internet-Drafts.  The list of current Internet-
   Drafts is at https://datatracker.ietf.org/drafts/current/.

   Internet-Drafts are draft documents valid for a maximum of six months
   and may be updated, replaced, or obsoleted by other documents at any
   time.  It is inappropriate to use Internet-Drafts as reference
   material or to cite them other than as "work in progress."

   This Internet-Draft will expire on February 14, 2021.

Copyright Notice

   Copyright (c) 2020 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
   (https://trustee.ietf.org/license-info) in effect on the date of
   publication of this document.  Please review these documents

Colitti, et al.         Expires February 14, 2021               [Page 1]
Internet-Draft    IPv6-Only-Preferred Option for DHCPv4      August 2020

   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
     1.1.  Requirements Language . . . . . . . . . . . . . . . . . .   3
     1.2.  Terminology . . . . . . . . . . . . . . . . . . . . . . .   4
   2.  Reasons to Signal IPv6-Only Support in DHCPv4 Packets . . . .   5
   3.  IPv6-Only Preferred Option  . . . . . . . . . . . . . . . . .   5
     3.1.  Option format . . . . . . . . . . . . . . . . . . . . . .   6
     3.2.  DHCPv4 Client Behavior  . . . . . . . . . . . . . . . . .   6
     3.3.  DHCPv4 Server Behavior  . . . . . . . . . . . . . . . . .   8
       3.3.1.  Interaction with RFC2563  . . . . . . . . . . . . . .   9
     3.4.  Constants and Configuration Variables . . . . . . . . . .  10
   4.  IPv6-Only Transition Technologies Considerations  . . . . . .  10
   5.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .  11
   6.  Security Considerations . . . . . . . . . . . . . . . . . . .  12
   7.  Acknowledgements  . . . . . . . . . . . . . . . . . . . . . .  12
   8.  References  . . . . . . . . . . . . . . . . . . . . . . . . .  12
     8.1.  Normative References  . . . . . . . . . . . . . . . . . .  12
     8.2.  Informative References  . . . . . . . . . . . . . . . . .  13
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  14

1.  Introduction

   One of the biggest challenges of deploying IPv6-only LANs is that
   such networks might contain rather heterogeneous collection of hosts.
   While some hosts are capable of operating in IPv6-only mode (either
   because the OS and all applications are IPv6-only capable or because
   the host has some form of 464XLAT [RFC6877] deployed), others might
   still have IPv4 dependencies and need IPv4 addresses to operate
   properly.  To incrementally rollout IPv6-only, network operators
   might need to provide IPv4 on demand whereby a host receives an IPv4
   address if it needs it, while IPv6-only capable hosts (such as modern
   mobile devices) are not allocated IPv4 addresses.  Traditionally that
   goal is achieved by placing IPv6-only capable devices into a
   dedicated IPv6-only network segment or WiFi SSID, while dual-stack
   devices reside in another network with IPv4 and DHCPv4 enabled.
   However such an approach has a number of drawbacks, including but not
Show full document text