File: rfc8983.html

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<!DOCTYPE html>
<html lang="en" class="RFC">
<head>
<meta charset="utf-8">
<meta content="Common,Latin" name="scripts">
<meta content="initial-scale=1.0" name="viewport">
<title>RFC 8983: Internet Key Exchange Protocol Version 2 (IKEv2) Notification Status Types for IPv4/IPv6 Coexistence</title>
<meta content="Mohamed Boucadair" name="author">
<meta content="
       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. 
    " name="description">
<meta content="xml2rfc 3.5.0" name="generator">
<meta content="IPv4 service continuity" name="keyword">
<meta content="VoLTE" name="keyword">
<meta content="Handover" name="keyword">
<meta content="Service continuity" name="keyword">
<meta content="3GPP" name="keyword">
<meta content="IPv6 transition" name="keyword">
<meta content="TS.24302" name="keyword">
<meta content="PDP context" name="keyword">
<meta content="PDP type" name="keyword">
<meta content="8983" name="rfc.number">
<!-- Generator version information:
  xml2rfc 3.5.0
    Python 3.6.10
    appdirs 1.4.4
    ConfigArgParse 1.2.3
    google-i18n-address 2.3.5
    html5lib 1.0.1
    intervaltree 3.0.2
    Jinja2 2.11.2
    kitchen 1.2.6
    lxml 4.4.2
    pycairo 1.19.0
    pycountry 19.8.18
    pyflakes 2.1.1
    PyYAML 5.3.1
    requests 2.22.0
    setuptools 40.6.2
    six 1.14.0
    WeasyPrint 51
-->
<link href="rfc8983.xml" rel="alternate" type="application/rfc+xml">
<link href="#copyright" rel="license">
<style type="text/css">/*

  NOTE: Changes at the bottom of this file overrides some earlier settings.

  Once the style has stabilized and has been adopted as an official RFC style,
  this can be consolidated so that style settings occur only in one place, but
  for now the contents of this file consists first of the initial CSS work as
  provided to the RFC Formatter (xml2rfc) work, followed by itemized and
  commented changes found necssary during the development of the v3
  formatters.

*/

/* fonts */
@import url('https://fonts.googleapis.com/css?family=Noto+Sans'); /* Sans-serif */
@import url('https://fonts.googleapis.com/css?family=Noto+Serif'); /* Serif (print) */
@import url('https://fonts.googleapis.com/css?family=Roboto+Mono'); /* Monospace */

@viewport {
  zoom: 1.0;
  width: extend-to-zoom;
}
@-ms-viewport {
  width: extend-to-zoom;
  zoom: 1.0;
}
/* general and mobile first */
html {
}
body {
  max-width: 90%;
  margin: 1.5em auto;
  color: #222;
  background-color: #fff;
  font-size: 14px;
  font-family: 'Noto Sans', Arial, Helvetica, sans-serif;
  line-height: 1.6;
  scroll-behavior: smooth;
}
.ears {
  display: none;
}

/* headings */
#title, h1, h2, h3, h4, h5, h6 {
  margin: 1em 0 0.5em;
  font-weight: bold;
  line-height: 1.3;
}
#title {
  clear: both;
  border-bottom: 1px solid #ddd;
  margin: 0 0 0.5em 0;
  padding: 1em 0 0.5em;
}
.author {
  padding-bottom: 4px;
}
h1 {
  font-size: 26px;
  margin: 1em 0;
}
h2 {
  font-size: 22px;
  margin-top: -20px;  /* provide offset for in-page anchors */
  padding-top: 33px;
}
h3 {
  font-size: 18px;
  margin-top: -36px;  /* provide offset for in-page anchors */
  padding-top: 42px;
}
h4 {
  font-size: 16px;
  margin-top: -36px;  /* provide offset for in-page anchors */
  padding-top: 42px;
}
h5, h6 {
  font-size: 14px;
}
#n-copyright-notice {
  border-bottom: 1px solid #ddd;
  padding-bottom: 1em;
  margin-bottom: 1em;
}
/* general structure */
p {
  padding: 0;
  margin: 0 0 1em 0;
  text-align: left;
}
div, span {
  position: relative;
}
div {
  margin: 0;
}
.alignRight.art-text {
  background-color: #f9f9f9;
  border: 1px solid #eee;
  border-radius: 3px;
  padding: 1em 1em 0;
  margin-bottom: 1.5em;
}
.alignRight.art-text pre {
  padding: 0;
}
.alignRight {
  margin: 1em 0;
}
.alignRight > *:first-child {
  border: none;
  margin: 0;
  float: right;
  clear: both;
}
.alignRight > *:nth-child(2) {
  clear: both;
  display: block;
  border: none;
}
svg {
  display: block;
}
.alignCenter.art-text {
  background-color: #f9f9f9;
  border: 1px solid #eee;
  border-radius: 3px;
  padding: 1em 1em 0;
  margin-bottom: 1.5em;
}
.alignCenter.art-text pre {
  padding: 0;
}
.alignCenter {
  margin: 1em 0;
}
.alignCenter > *:first-child {
  border: none;
  /* this isn't optimal, but it's an existence proof.  PrinceXML doesn't
     support flexbox yet.
  */
  display: table;
  margin: 0 auto;
}

/* lists */
ol, ul {
  padding: 0;
  margin: 0 0 1em 2em;
}
ol ol, ul ul, ol ul, ul ol {
  margin-left: 1em;
}
li {
  margin: 0 0 0.25em 0;
}
.ulCompact li {
  margin: 0;
}
ul.empty, .ulEmpty {
  list-style-type: none;
}
ul.empty li, .ulEmpty li {
  margin-top: 0.5em;
}
ul.compact, .ulCompact,
ol.compact, .olCompact {
  line-height: 100%;
  margin: 0 0 0 2em;
}

/* definition lists */
dl {
}
dl > dt {
  float: left;
  margin-right: 1em;
}
/* 
dl.nohang > dt {
  float: none;
}
*/
dl > dd {
  margin-bottom: .8em;
  min-height: 1.3em;
}
dl.compact > dd, .dlCompact > dd {
  margin-bottom: 0em;
}
dl > dd > dl {
  margin-top: 0.5em;
  margin-bottom: 0em;
}

/* links */
a {
  text-decoration: none;
}
a[href] {
  color: #22e; /* Arlen: WCAG 2019 */
}
a[href]:hover {
  background-color: #f2f2f2;
}
figcaption a[href],
a[href].selfRef {
  color: #222;
}
/* XXX probably not this:
a.selfRef:hover {
  background-color: transparent;
  cursor: default;
} */

/* Figures */
tt, code, pre, code {
  background-color: #f9f9f9;
  font-family: 'Roboto Mono', monospace;
}
pre {
  border: 1px solid #eee;
  margin: 0;
  padding: 1em;
}
img {
  max-width: 100%;
}
figure {
  margin: 0;
}
figure blockquote {
  margin: 0.8em 0.4em 0.4em;
}
figcaption {
  font-style: italic;
  margin: 0 0 1em 0;
}
@media screen {
  pre {
    overflow-x: auto;
    max-width: 100%;
    max-width: calc(100% - 22px);
  }
}

/* aside, blockquote */
aside, blockquote {
  margin-left: 0;
  padding: 1.2em 2em;
}
blockquote {
  background-color: #f9f9f9;
  color: #111; /* Arlen: WCAG 2019 */
  border: 1px solid #ddd;
  border-radius: 3px;
  margin: 1em 0;
}
cite {
  display: block;
  text-align: right;
  font-style: italic;
}

/* tables */
table {
  width: 100%;
  margin: 0 0 1em;
  border-collapse: collapse;
  border: 1px solid #eee;
}
th, td {
  text-align: left;
  vertical-align: top;
  padding: 0.5em 0.75em;
}
th {
  text-align: left;
  background-color: #e9e9e9;
}
tr:nth-child(2n+1) > td {
  background-color: #f5f5f5;
}
table caption {
  font-style: italic;
  margin: 0;
  padding: 0;
  text-align: left;
}
table p {
  /* XXX to avoid bottom margin on table row signifiers. If paragraphs should
     be allowed within tables more generally, it would be far better to select on a class. */
  margin: 0;
}

/* pilcrow */
a.pilcrow {
  color: #666; /* Arlen: AHDJ 2019 */
  text-decoration: none;
  visibility: hidden;
  user-select: none;
  -ms-user-select: none;
  -o-user-select:none;
  -moz-user-select: none;
  -khtml-user-select: none;
  -webkit-user-select: none;
  -webkit-touch-callout: none;
}
@media screen {
  aside:hover > a.pilcrow,
  p:hover > a.pilcrow,
  blockquote:hover > a.pilcrow,
  div:hover > a.pilcrow,
  li:hover > a.pilcrow,
  pre:hover > a.pilcrow {
    visibility: visible;
  }
  a.pilcrow:hover {
    background-color: transparent;
  }
}

/* misc */
hr {
  border: 0;
  border-top: 1px solid #eee;
}
.bcp14 {
  font-variant: small-caps;
}

.role {
  font-variant: all-small-caps;
}

/* info block */
#identifiers {
  margin: 0;
  font-size: 0.9em;
}
#identifiers dt {
  width: 3em;
  clear: left;
}
#identifiers dd {
  float: left;
  margin-bottom: 0;
}
#identifiers .authors .author {
  display: inline-block;
  margin-right: 1.5em;
}
#identifiers .authors .org {
  font-style: italic;
}

/* The prepared/rendered info at the very bottom of the page */
.docInfo {
  color: #666; /* Arlen: WCAG 2019 */
  font-size: 0.9em;
  font-style: italic;
  margin-top: 2em;
}
.docInfo .prepared {
  float: left;
}
.docInfo .prepared {
  float: right;
}

/* table of contents */
#toc  {
  padding: 0.75em 0 2em 0;
  margin-bottom: 1em;
}
nav.toc ul {
  margin: 0 0.5em 0 0;
  padding: 0;
  list-style: none;
}
nav.toc li {
  line-height: 1.3em;
  margin: 0.75em 0;
  padding-left: 1.2em;
  text-indent: -1.2em;
}
/* references */
.references dt {
  text-align: right;
  font-weight: bold;
  min-width: 7em;
}
.references dd {
  margin-left: 8em;
  overflow: auto;
}

.refInstance {
  margin-bottom: 1.25em;
}

.references .ascii {
  margin-bottom: 0.25em;
}

/* index */
.index ul {
  margin: 0 0 0 1em;
  padding: 0;
  list-style: none;
}
.index ul ul {
  margin: 0;
}
.index li {
  margin: 0;
  text-indent: -2em;
  padding-left: 2em;
  padding-bottom: 5px;
}
.indexIndex {
  margin: 0.5em 0 1em;
}
.index a {
  font-weight: 700;
}
/* make the index two-column on all but the smallest screens */
@media (min-width: 600px) {
  .index ul {
    -moz-column-count: 2;
    -moz-column-gap: 20px;
  }
  .index ul ul {
    -moz-column-count: 1;
    -moz-column-gap: 0;
  }
}

/* authors */
address.vcard {
  font-style: normal;
  margin: 1em 0;
}

address.vcard .nameRole {
  font-weight: 700;
  margin-left: 0;
}
address.vcard .label {
  font-family: "Noto Sans",Arial,Helvetica,sans-serif;
  margin: 0.5em 0;
}
address.vcard .type {
  display: none;
}
.alternative-contact {
  margin: 1.5em 0 1em;
}
hr.addr {
  border-top: 1px dashed;
  margin: 0;
  color: #ddd;
  max-width: calc(100% - 16px);
}

/* temporary notes */
.rfcEditorRemove::before {
  position: absolute;
  top: 0.2em;
  right: 0.2em;
  padding: 0.2em;
  content: "The RFC Editor will remove this note";
  color: #9e2a00; /* Arlen: WCAG 2019 */
  background-color: #ffd; /* Arlen: WCAG 2019 */
}
.rfcEditorRemove {
  position: relative;
  padding-top: 1.8em;
  background-color: #ffd; /* Arlen: WCAG 2019 */
  border-radius: 3px;
}
.cref {
  background-color: #ffd; /* Arlen: WCAG 2019 */
  padding: 2px 4px;
}
.crefSource {
  font-style: italic;
}
/* alternative layout for smaller screens */
@media screen and (max-width: 1023px) {
  body {
    padding-top: 2em;
  }
  #title {
    padding: 1em 0;
  }
  h1 {
    font-size: 24px;
  }
  h2 {
    font-size: 20px;
    margin-top: -18px;  /* provide offset for in-page anchors */
    padding-top: 38px;
  }
  #identifiers dd {
    max-width: 60%;
  }
  #toc {
    position: fixed;
    z-index: 2;
    top: 0;
    right: 0;
    padding: 0;
    margin: 0;
    background-color: inherit;
    border-bottom: 1px solid #ccc;
  }
  #toc h2 {
    margin: -1px 0 0 0;
    padding: 4px 0 4px 6px;
    padding-right: 1em;
    min-width: 190px;
    font-size: 1.1em;
    text-align: right;
    background-color: #444;
    color: white;
    cursor: pointer;
  }
  #toc h2::before { /* css hamburger */
    float: right;
    position: relative;
    width: 1em;
    height: 1px;
    left: -164px;
    margin: 6px 0 0 0;
    background: white none repeat scroll 0 0;
    box-shadow: 0 4px 0 0 white, 0 8px 0 0 white;
    content: "";
  }
  #toc nav {
    display: none;
    padding: 0.5em 1em 1em;
    overflow: auto;
    height: calc(100vh - 48px);
    border-left: 1px solid #ddd;
  }
}

/* alternative layout for wide screens */
@media screen and (min-width: 1024px) {
  body {
    max-width: 724px;
    margin: 42px auto;
    padding-left: 1.5em;
    padding-right: 29em;
  }
  #toc {
    position: fixed;
    top: 42px;
    right: 42px;
    width: 25%;
    margin: 0;
    padding: 0 1em;
    z-index: 1;
  }
  #toc h2 {
    border-top: none;
    border-bottom: 1px solid #ddd;
    font-size: 1em;
    font-weight: normal;
    margin: 0;
    padding: 0.25em 1em 1em 0;
  }
  #toc nav {
    display: block;
    height: calc(90vh - 84px);
    bottom: 0;
    padding: 0.5em 0 0;
    overflow: auto;
  }
  img { /* future proofing */
    max-width: 100%;
    height: auto;
  }
}

/* pagination */
@media print {
  body {

    width: 100%;
  }
  p {
    orphans: 3;
    widows: 3;
  }
  #n-copyright-notice {
    border-bottom: none;
  }
  #toc, #n-introduction {
    page-break-before: always;
  }
  #toc {
    border-top: none;
    padding-top: 0;
  }
  figure, pre {
    page-break-inside: avoid;
  }
  figure {
    overflow: scroll;
  }
  h1, h2, h3, h4, h5, h6 {
    page-break-after: avoid;
  }
  h2+*, h3+*, h4+*, h5+*, h6+* {
    page-break-before: avoid;
  }
  pre {
    white-space: pre-wrap;
    word-wrap: break-word;
    font-size: 10pt;
  }
  table {
    border: 1px solid #ddd;
  }
  td {
    border-top: 1px solid #ddd;
  }
}

/* This is commented out here, as the string-set: doesn't
   pass W3C validation currently */
/*
.ears thead .left {
  string-set: ears-top-left content();
}

.ears thead .center {
  string-set: ears-top-center content();
}

.ears thead .right {
  string-set: ears-top-right content();
}

.ears tfoot .left {
  string-set: ears-bottom-left content();
}

.ears tfoot .center {
  string-set: ears-bottom-center content();
}

.ears tfoot .right {
  string-set: ears-bottom-right content();
}
*/

@page :first {
  padding-top: 0;
  @top-left {
    content: normal;
    border: none;
  }
  @top-center {
    content: normal;
    border: none;
  }
  @top-right {
    content: normal;
    border: none;
  }
}

@page {
  size: A4;
  margin-bottom: 45mm;
  padding-top: 20px;
  /* The follwing is commented out here, but set appropriately by in code, as
     the content depends on the document */
  /*
  @top-left {
    content: 'Internet-Draft';
    vertical-align: bottom;
    border-bottom: solid 1px #ccc;
  }
  @top-left {
    content: string(ears-top-left);
    vertical-align: bottom;
    border-bottom: solid 1px #ccc;
  }
  @top-center {
    content: string(ears-top-center);
    vertical-align: bottom;
    border-bottom: solid 1px #ccc;
  }
  @top-right {
    content: string(ears-top-right);
    vertical-align: bottom;
    border-bottom: solid 1px #ccc;
  }
  @bottom-left {
    content: string(ears-bottom-left);
    vertical-align: top;
    border-top: solid 1px #ccc;
  }
  @bottom-center {
    content: string(ears-bottom-center);
    vertical-align: top;
    border-top: solid 1px #ccc;
  }
  @bottom-right {
      content: '[Page ' counter(page) ']';
      vertical-align: top;
      border-top: solid 1px #ccc;
  }
  */

}

/* Changes introduced to fix issues found during implementation */
/* Make sure links are clickable even if overlapped by following H* */
a {
  z-index: 2;
}
/* Separate body from document info even without intervening H1 */
section {
  clear: both;
}


/* Top align author divs, to avoid names without organization dropping level with org names */
.author {
  vertical-align: top;
}

/* Leave room in document info to show Internet-Draft on one line */
#identifiers dt {
  width: 8em;
}

/* Don't waste quite as much whitespace between label and value in doc info */
#identifiers dd {
  margin-left: 1em;
}

/* Give floating toc a background color (needed when it's a div inside section */
#toc {
  background-color: white;
}

/* Make the collapsed ToC header render white on gray also when it's a link */
@media screen and (max-width: 1023px) {
  #toc h2 a,
  #toc h2 a:link,
  #toc h2 a:focus,
  #toc h2 a:hover,
  #toc a.toplink,
  #toc a.toplink:hover {
    color: white;
    background-color: #444;
    text-decoration: none;
  }
}

/* Give the bottom of the ToC some whitespace */
@media screen and (min-width: 1024px) {
  #toc {
    padding: 0 0 1em 1em;
  }
}

/* Style section numbers with more space between number and title */
.section-number {
  padding-right: 0.5em;
}

/* prevent monospace from becoming overly large */
tt, code, pre, code {
  font-size: 95%;
}

/* Fix the height/width aspect for ascii art*/
pre.sourcecode,
.art-text pre {
  line-height: 1.12;
}


/* Add styling for a link in the ToC that points to the top of the document */
a.toplink {
  float: right;
  margin-right: 0.5em;
}

/* Fix the dl styling to match the RFC 7992 attributes */
dl > dt,
dl.dlParallel > dt {
  float: left;
  margin-right: 1em;
}
dl.dlNewline > dt {
  float: none;
}

/* Provide styling for table cell text alignment */
table td.text-left,
table th.text-left {
  text-align: left;
}
table td.text-center,
table th.text-center {
  text-align: center;
}
table td.text-right,
table th.text-right {
  text-align: right;
}

/* Make the alternative author contact informatio look less like just another
   author, and group it closer with the primary author contact information */
.alternative-contact {
  margin: 0.5em 0 0.25em 0;
}
address .non-ascii {
  margin: 0 0 0 2em;
}

/* With it being possible to set tables with alignment
  left, center, and right, { width: 100%; } does not make sense */
table {
  width: auto;
}

/* Avoid reference text that sits in a block with very wide left margin,
   because of a long floating dt label.*/
.references dd {
  overflow: visible;
}

/* Control caption placement */
caption {
  caption-side: bottom;
}

/* Limit the width of the author address vcard, so names in right-to-left
   script don't end up on the other side of the page. */

address.vcard {
  max-width: 30em;
  margin-right: auto;
}

/* For address alignment dependent on LTR or RTL scripts */
address div.left {
  text-align: left;
}
address div.right {
  text-align: right;
}

/* Provide table alignment support.  We can't use the alignX classes above
   since they do unwanted things with caption and other styling. */
table.right {
 margin-left: auto;
 margin-right: 0;
}
table.center {
 margin-left: auto;
 margin-right: auto;
}
table.left {
 margin-left: 0;
 margin-right: auto;
}

/* Give the table caption label the same styling as the figcaption */
caption a[href] {
  color: #222;
}

@media print {
  .toplink {
    display: none;
  }

  /* avoid overwriting the top border line with the ToC header */
  #toc {
    padding-top: 1px;
  }

  /* Avoid page breaks inside dl and author address entries */
  .vcard {
    page-break-inside: avoid;
  }

}
/* Tweak the bcp14 keyword presentation */
.bcp14 {
  font-variant: small-caps;
  font-weight: bold;
  font-size: 0.9em;
}
/* Tweak the invisible space above H* in order not to overlay links in text above */
 h2 {
  margin-top: -18px;  /* provide offset for in-page anchors */
  padding-top: 31px;
 }
 h3 {
  margin-top: -18px;  /* provide offset for in-page anchors */
  padding-top: 24px;
 }
 h4 {
  margin-top: -18px;  /* provide offset for in-page anchors */
  padding-top: 24px;
 }
/* Float artwork pilcrow to the right */
@media screen {
  .artwork a.pilcrow {
    display: block;
    line-height: 0.7;
    margin-top: 0.15em;
  }
}
/* Make pilcrows on dd visible */
@media screen {
  dd:hover > a.pilcrow {
    visibility: visible;
  }
}
/* Make the placement of figcaption match that of a table's caption
   by removing the figure's added bottom margin */
.alignLeft.art-text,
.alignCenter.art-text,
.alignRight.art-text {
   margin-bottom: 0;
}
.alignLeft,
.alignCenter,
.alignRight {
  margin: 1em 0 0 0;
}
/* In print, the pilcrow won't show on hover, so prevent it from taking up space,
   possibly even requiring a new line */
@media print {
  a.pilcrow {
    display: none;
  }
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<table class="ears">
<thead><tr>
<td class="left">RFC 8983</td>
<td class="center">IPv4/IPv6 Notification Status Types</td>
<td class="right">February 2021</td>
</tr></thead>
<tfoot><tr>
<td class="left">Boucadair</td>
<td class="center">Standards Track</td>
<td class="right">[Page]</td>
</tr></tfoot>
</table>
<div id="external-metadata" class="document-information"></div>
<div id="internal-metadata" class="document-information">
<dl id="identifiers">
<dt class="label-stream">Stream:</dt>
<dd class="stream">Internet Engineering Task Force (IETF)</dd>
<dt class="label-rfc">RFC:</dt>
<dd class="rfc"><a href="https://www.rfc-editor.org/rfc/rfc8983" class="eref">8983</a></dd>
<dt class="label-updates">Updates:</dt>
<dd class="updates">
<a href="https://www.rfc-editor.org/rfc/rfc7296" class="eref">7296</a> </dd>
<dt class="label-category">Category:</dt>
<dd class="category">Standards Track</dd>
<dt class="label-published">Published:</dt>
<dd class="published">
<time datetime="2021-02" class="published">February 2021</time>
    </dd>
<dt class="label-issn">ISSN:</dt>
<dd class="issn">2070-1721</dd>
<dt class="label-authors">Author:</dt>
<dd class="authors">
<div class="author">
      <div class="author-name">M. Boucadair</div>
<div class="org">Orange</div>
</div>
</dd>
</dl>
</div>
<h1 id="rfcnum">RFC 8983</h1>
<h1 id="title">Internet Key Exchange Protocol Version 2 (IKEv2) Notification Status Types for IPv4/IPv6 Coexistence</h1>
<section id="section-abstract">
      <h2 id="abstract"><a href="#abstract" class="selfRef">Abstract</a></h2>
<p id="section-abstract-1">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.<a href="#section-abstract-1" class="pilcrow">¶</a></p>
<p id="section-abstract-2">This document updates RFC 7296.<a href="#section-abstract-2" class="pilcrow">¶</a></p>
</section>
<div id="status-of-memo">
<section id="section-boilerplate.1">
        <h2 id="name-status-of-this-memo">
<a href="#name-status-of-this-memo" class="section-name selfRef">Status of This Memo</a>
        </h2>
<p id="section-boilerplate.1-1">
            This is an Internet Standards Track document.<a href="#section-boilerplate.1-1" class="pilcrow">¶</a></p>
<p id="section-boilerplate.1-2">
            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.<a href="#section-boilerplate.1-2" class="pilcrow">¶</a></p>
<p id="section-boilerplate.1-3">
            Information about the current status of this document, any
            errata, and how to provide feedback on it may be obtained at
            <span><a href="https://www.rfc-editor.org/info/rfc8983">https://www.rfc-editor.org/info/rfc8983</a></span>.<a href="#section-boilerplate.1-3" class="pilcrow">¶</a></p>
</section>
</div>
<div id="copyright">
<section id="section-boilerplate.2">
        <h2 id="name-copyright-notice">
<a href="#name-copyright-notice" class="section-name selfRef">Copyright Notice</a>
        </h2>
<p id="section-boilerplate.2-1">
            Copyright (c) 2021 IETF Trust and the persons identified as the
            document authors. All rights reserved.<a href="#section-boilerplate.2-1" class="pilcrow">¶</a></p>
<p id="section-boilerplate.2-2">
            This document is subject to BCP 78 and the IETF Trust's Legal
            Provisions Relating to IETF Documents
            (<span><a href="https://trustee.ietf.org/license-info">https://trustee.ietf.org/license-info</a></span>) 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.<a href="#section-boilerplate.2-2" class="pilcrow">¶</a></p>
</section>
</div>
<div id="toc">
<section id="section-toc.1">
        <a href="#" onclick="scroll(0,0)" class="toplink">▲</a><h2 id="name-table-of-contents">
<a href="#name-table-of-contents" class="section-name selfRef">Table of Contents</a>
        </h2>
<nav class="toc"><ul class="compact ulEmpty toc">
<li class="compact ulEmpty toc" id="section-toc.1-1.1">
            <p id="section-toc.1-1.1.1" class="keepWithNext"><a href="#section-1" class="xref">1</a>.  <a href="#name-introduction" class="xref">Introduction</a><a href="#section-toc.1-1.1.1" class="pilcrow">¶</a></p>
</li>
          <li class="compact ulEmpty toc" id="section-toc.1-1.2">
            <p id="section-toc.1-1.2.1" class="keepWithNext"><a href="#section-2" class="xref">2</a>.  <a href="#name-terminology" class="xref">Terminology</a><a href="#section-toc.1-1.2.1" class="pilcrow">¶</a></p>
</li>
          <li class="compact ulEmpty toc" id="section-toc.1-1.3">
            <p id="section-toc.1-1.3.1" class="keepWithNext"><a href="#section-3" class="xref">3</a>.  <a href="#name-why-not-internal_address_fa" class="xref">Why Not INTERNAL_ADDRESS_FAILURE?</a><a href="#section-toc.1-1.3.1" class="pilcrow">¶</a></p>
</li>
          <li class="compact ulEmpty toc" id="section-toc.1-1.4">
            <p id="section-toc.1-1.4.1"><a href="#section-4" class="xref">4</a>.  <a href="#name-ip6_allowed-and-ip4_allowed" class="xref">IP6_ALLOWED and IP4_ALLOWED Status Types</a><a href="#section-toc.1-1.4.1" class="pilcrow">¶</a></p>
</li>
          <li class="compact ulEmpty toc" id="section-toc.1-1.5">
            <p id="section-toc.1-1.5.1"><a href="#section-5" class="xref">5</a>.  <a href="#name-update-to-rfc-7296" class="xref">Update to RFC 7296</a><a href="#section-toc.1-1.5.1" class="pilcrow">¶</a></p>
</li>
          <li class="compact ulEmpty toc" id="section-toc.1-1.6">
            <p id="section-toc.1-1.6.1"><a href="#section-6" class="xref">6</a>.  <a href="#name-security-considerations" class="xref">Security Considerations</a><a href="#section-toc.1-1.6.1" class="pilcrow">¶</a></p>
</li>
          <li class="compact ulEmpty toc" id="section-toc.1-1.7">
            <p id="section-toc.1-1.7.1"><a href="#section-7" class="xref">7</a>.  <a href="#name-iana-considerations" class="xref">IANA Considerations</a><a href="#section-toc.1-1.7.1" class="pilcrow">¶</a></p>
</li>
          <li class="compact ulEmpty toc" id="section-toc.1-1.8">
            <p id="section-toc.1-1.8.1"><a href="#section-8" class="xref">8</a>.  <a href="#name-references" class="xref">References</a><a href="#section-toc.1-1.8.1" class="pilcrow">¶</a></p>
<ul class="compact ulEmpty toc">
<li class="compact ulEmpty toc" id="section-toc.1-1.8.2.1">
                <p id="section-toc.1-1.8.2.1.1"><a href="#section-8.1" class="xref">8.1</a>.  <a href="#name-normative-references" class="xref">Normative References</a><a href="#section-toc.1-1.8.2.1.1" class="pilcrow">¶</a></p>
</li>
              <li class="compact ulEmpty toc" id="section-toc.1-1.8.2.2">
                <p id="section-toc.1-1.8.2.2.1"><a href="#section-8.2" class="xref">8.2</a>.  <a href="#name-informative-references" class="xref">Informative References</a><a href="#section-toc.1-1.8.2.2.1" class="pilcrow">¶</a></p>
</li>
            </ul>
</li>
          <li class="compact ulEmpty toc" id="section-toc.1-1.9">
            <p id="section-toc.1-1.9.1"><a href="#section-appendix.a" class="xref"></a><a href="#name-acknowledgements" class="xref">Acknowledgements</a><a href="#section-toc.1-1.9.1" class="pilcrow">¶</a></p>
</li>
          <li class="compact ulEmpty toc" id="section-toc.1-1.10">
            <p id="section-toc.1-1.10.1"><a href="#section-appendix.b" class="xref"></a><a href="#name-authors-address" class="xref">Author's Address</a><a href="#section-toc.1-1.10.1" class="pilcrow">¶</a></p>
</li>
        </ul>
</nav>
</section>
</div>
<section id="section-1">
      <h2 id="name-introduction">
<a href="#section-1" class="section-number selfRef">1. </a><a href="#name-introduction" class="section-name selfRef">Introduction</a>
      </h2>
<p id="section-1-1">As described in <span>[<a href="#RFC7849" class="xref">RFC7849</a>]</span>, 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 (<span><a href="https://www.rfc-editor.org/rfc/rfc6459#section-3.2" class="relref">Section 3.2</a> of [<a href="#RFC6459" class="xref">RFC6459</a>]</span>) 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:<a href="#section-1-1" class="pilcrow">¶</a></p>
<span class="break"></span><dl class="dlParallel" id="section-1-2">
        <dt id="section-1-2.1">cause #50 "PDP type IPv4 only allowed":
</dt>
        <dd style="margin-left: 1.5em" id="section-1-2.2">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.<a href="#section-1-2.2" class="pilcrow">¶</a>
</dd>
        <dd class="break"></dd>
<dt id="section-1-2.3">cause #51 "PDP type IPv6 only allowed":
</dt>
        <dd style="margin-left: 1.5em" id="section-1-2.4">This cause code is used by the network to indicate that only PDP type IPv6
is allowed for the requested PDN connectivity.<a href="#section-1-2.4" class="pilcrow">¶</a>
</dd>
        <dd class="break"></dd>
<dt id="section-1-2.5">cause #52 "single address bearers only allowed":
</dt>
        <dd style="margin-left: 1.5em" id="section-1-2.6">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.<a href="#section-1-2.6" class="pilcrow">¶</a>
</dd>
      <dd class="break"></dd>
</dl>
<p id="section-1-3">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 PDP-Contexts.<a href="#section-1-3" class="pilcrow">¶</a></p>
<p id="section-1-4">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 <span>[<a href="#RFC7296" class="xref">RFC7296</a>]</span> 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 family.<a href="#section-1-4" class="pilcrow">¶</a></p>
<p id="section-1-5">This document fills that void by introducing new IKEv2 notification
      status types for the sake of deterministic UE behaviors (<a href="#new" class="xref">Section 4</a>).<a href="#section-1-5" class="pilcrow">¶</a></p>
<p id="section-1-6">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.<a href="#section-1-6" class="pilcrow">¶</a></p>
</section>
<div id="notation">
<section id="section-2">
      <h2 id="name-terminology">
<a href="#section-2" class="section-number selfRef">2. </a><a href="#name-terminology" class="section-name selfRef">Terminology</a>
      </h2>
<p id="section-2-1">
    The key words "<span class="bcp14">MUST</span>", "<span class="bcp14">MUST NOT</span>",
    "<span class="bcp14">REQUIRED</span>", "<span class="bcp14">SHALL</span>", "<span class="bcp14">SHALL NOT</span>", "<span class="bcp14">SHOULD</span>", "<span class="bcp14">SHOULD NOT</span>",
    "<span class="bcp14">RECOMMENDED</span>", "<span class="bcp14">NOT RECOMMENDED</span>",
    "<span class="bcp14">MAY</span>", and "<span class="bcp14">OPTIONAL</span>" in this document are
    to be interpreted as described in BCP 14 <span>[<a href="#RFC2119" class="xref">RFC2119</a>]</span>
        <span>[<a href="#RFC8174" class="xref">RFC8174</a>]</span> when, and only when, they appear in all capitals,
    as shown here.<a href="#section-2-1" class="pilcrow">¶</a></p>
<p id="section-2-2">This document makes use of the terms defined in <span>[<a href="#RFC7296" class="xref">RFC7296</a>]</span>. In particular, readers should be familiar with
      "initiator" and "responder" terms used in that document.<a href="#section-2-2" class="pilcrow">¶</a></p>
</section>
</div>
<section id="section-3">
      <h2 id="name-why-not-internal_address_fa">
<a href="#section-3" class="section-number selfRef">3. </a><a href="#name-why-not-internal_address_fa" class="section-name selfRef">Why Not INTERNAL_ADDRESS_FAILURE?</a>
      </h2>
<p id="section-3-1">The following address assignment failures may be encountered when an
      initiator requests assignment of IP addresses/prefixes:<a href="#section-3-1" class="pilcrow">¶</a></p>
<ul class="normal">
<li class="normal" id="section-3-2.1">An initiator asks for IPvx, but IPvx address assignment is not
          supported by the responder.<a href="#section-3-2.1" class="pilcrow">¶</a>
</li>
        <li class="normal" id="section-3-2.2">An initiator requests both IPv4 and IPv6 addresses, but only IPv4
          address assignment is supported by the responder.<a href="#section-3-2.2" class="pilcrow">¶</a>
</li>
        <li class="normal" id="section-3-2.3">An initiator requests both IPv4 and IPv6 addresses, but only IPv6
          prefix assignment is supported by the responder.<a href="#section-3-2.3" class="pilcrow">¶</a>
</li>
        <li class="normal" id="section-3-2.4">An initiator asks for both IPv4 and IPv6 addresses, but only one
          address family can be assigned by the responder for policy
          reasons.<a href="#section-3-2.4" class="pilcrow">¶</a>
</li>
      </ul>
<p id="section-3-3">
      <span><a href="https://www.rfc-editor.org/rfc/rfc7296#section-3.15.4" class="relref">Section 3.15.4</a> of [<a href="#RFC7296" class="xref">RFC7296</a>]</span> defines a
      generic notification error type (INTERNAL_ADDRESS_FAILURE) that is
      related to a failure to handle an address assignment request. The
      responder sends INTERNAL_ADDRESS_FAILURE only if no addresses can be
      assigned. This behavior does not explicitly allow an initiator to
      determine why a given address family is not assigned, nor whether it
      should try using another address family. INTERNAL_ADDRESS_FAILURE is a
      catch-all error type when an address-related issue is encountered by an
      IKEv2 responder.<a href="#section-3-3" class="pilcrow">¶</a></p>
<p id="section-3-4">INTERNAL_ADDRESS_FAILURE does not provide sufficient hints to the
      IKEv2 initiator to adjust its behavior.<a href="#section-3-4" class="pilcrow">¶</a></p>
</section>
<div id="new">
<section id="section-4">
      <h2 id="name-ip6_allowed-and-ip4_allowed">
<a href="#section-4" class="section-number selfRef">4. </a><a href="#name-ip6_allowed-and-ip4_allowed" class="section-name selfRef">IP6_ALLOWED and IP4_ALLOWED Status Types</a>
      </h2>
<p id="section-4-1">IP6_ALLOWED and IP4_ALLOWED notification status types (see <a href="#sec-IANA" class="xref">Section 7</a>) are defined to inform the initiator about the
      responder's address family assignment support capabilities and to
      report to the initiator the reason why an address assignment failed.
      These notification status types are used by the initiator to adjust its
      behavior accordingly (<a href="#update" class="xref">Section 5</a>).<a href="#section-4-1" class="pilcrow">¶</a></p>
<p id="section-4-2">No data is associated with these notifications.<a href="#section-4-2" class="pilcrow">¶</a></p>
</section>
</div>
<div id="update">
<section id="section-5">
      <h2 id="name-update-to-rfc-7296">
<a href="#section-5" class="section-number selfRef">5. </a><a href="#name-update-to-rfc-7296" class="section-name selfRef">Update to RFC 7296</a>
      </h2>
<p id="section-5-1">If the initiator is dual stack (i.e., supports both IPv4 and IPv6),
      it <span class="bcp14">MUST</span> include configuration attributes for both address
      families in its configuration request (absent explicit
      policy/configuration otherwise).  More details about IPv4 and IPv6
      configuration attributes are provided in <span><a href="https://www.rfc-editor.org/rfc/rfc7296#section-3.15" class="relref">Section 3.15</a> of [<a href="#RFC7296" class="xref">RFC7296</a>]</span>. These attributes are used to infer
      the requested/assigned AFs listed in <a href="#notification_status" class="xref">Table 1</a>.<a href="#section-5-1" class="pilcrow">¶</a></p>
<p id="section-5-2">The responder <span class="bcp14">MUST</span> include the IP6_ALLOWED and/or IP4_ALLOWED
      notification status type in a response to an address assignment request
      as indicated in <a href="#notification_status" class="xref">Table 1</a>.<a href="#section-5-2" class="pilcrow">¶</a></p>
<span id="name-returned-notification-statu"></span><div id="notification_status">
<table class="center" id="table-1">
        <caption>
<a href="#table-1" class="selfRef">Table 1</a>:
<a href="#name-returned-notification-statu" class="selfRef">Returned Notification Status Types</a>
        </caption>
<thead>
          <tr>
            <th class="text-left" rowspan="1" colspan="1">Requested AF(s) (Initiator)</th>
            <th class="text-left" rowspan="1" colspan="1">Supported AF(s) (Responder)</th>
            <th class="text-left" rowspan="1" colspan="1">Assigned AF(s) (Responder)</th>
            <th class="text-left" rowspan="1" colspan="1">Returned Notification Status Type(s) (Responder)</th>
          </tr>
        </thead>
        <tbody>
          <tr>
            <td class="text-left" rowspan="1" colspan="1">IPv4</td>
            <td class="text-left" rowspan="1" colspan="1">IPv6</td>
            <td class="text-left" rowspan="1" colspan="1">None</td>
            <td class="text-left" rowspan="1" colspan="1">IP6_ALLOWED</td>
          </tr>
          <tr>
            <td class="text-left" rowspan="1" colspan="1">IPv4</td>
            <td class="text-left" rowspan="1" colspan="1">IPv4</td>
            <td class="text-left" rowspan="1" colspan="1">IPv4</td>
            <td class="text-left" rowspan="1" colspan="1">IP4_ALLOWED</td>
          </tr>
          <tr>
            <td class="text-left" rowspan="1" colspan="1">IPv4</td>
            <td class="text-left" rowspan="1" colspan="1">IPv4 and IPv6</td>
            <td class="text-left" rowspan="1" colspan="1">IPv4</td>
            <td class="text-left" rowspan="1" colspan="1">IP4_ALLOWED, IP6_ALLOWED</td>
          </tr>
          <tr>
            <td class="text-left" rowspan="1" colspan="1">IPv6</td>
            <td class="text-left" rowspan="1" colspan="1">IPv6</td>
            <td class="text-left" rowspan="1" colspan="1">IPv6</td>
            <td class="text-left" rowspan="1" colspan="1">IP6_ALLOWED</td>
          </tr>
          <tr>
            <td class="text-left" rowspan="1" colspan="1">IPv6</td>
            <td class="text-left" rowspan="1" colspan="1">IPv4</td>
            <td class="text-left" rowspan="1" colspan="1">None</td>
            <td class="text-left" rowspan="1" colspan="1">IP4_ALLOWED</td>
          </tr>
          <tr>
            <td class="text-left" rowspan="1" colspan="1">IPv6</td>
            <td class="text-left" rowspan="1" colspan="1">IPv4 and IPv6</td>
            <td class="text-left" rowspan="1" colspan="1">IPv6</td>
            <td class="text-left" rowspan="1" colspan="1">IP4_ALLOWED, IP6_ALLOWED</td>
          </tr>
          <tr>
            <td class="text-left" rowspan="1" colspan="1">IPv4 and IPv6</td>
            <td class="text-left" rowspan="1" colspan="1">IPv4</td>
            <td class="text-left" rowspan="1" colspan="1">IPv4</td>
            <td class="text-left" rowspan="1" colspan="1">IP4_ALLOWED</td>
          </tr>
          <tr>
            <td class="text-left" rowspan="1" colspan="1">IPv4 and IPv6</td>
            <td class="text-left" rowspan="1" colspan="1">IPv6</td>
            <td class="text-left" rowspan="1" colspan="1">IPv6</td>
            <td class="text-left" rowspan="1" colspan="1">IP6_ALLOWED</td>
          </tr>
          <tr>
            <td class="text-left" rowspan="1" colspan="1">IPv4 and IPv6</td>
            <td class="text-left" rowspan="1" colspan="1">IPv4 and IPv6</td>
            <td class="text-left" rowspan="1" colspan="1">IPv4 and IPv6</td>
            <td class="text-left" rowspan="1" colspan="1">IP4_ALLOWED, IP6_ALLOWED</td>
          </tr>
          <tr>
            <td class="text-left" rowspan="1" colspan="1">IPv4 and IPv6</td>
            <td class="text-left" rowspan="1" colspan="1">IPv4 or IPv6 (policy based)</td>
            <td class="text-left" rowspan="1" colspan="1">IPv4 or IPv6</td>
            <td class="text-left" rowspan="1" colspan="1">IP4_ALLOWED, IP6_ALLOWED</td>
          </tr>
        </tbody>
      </table>
</div>
<p id="section-5-4">If the initiator only receives one single IP4_ALLOWED
 or IP6_ALLOWED notification from the responder, the initiator <span class="bcp14">MUST NOT</span> send a subsequent request for an alternate address family
 not supported by the responder.<a href="#section-5-4" class="pilcrow">¶</a></p>
<p id="section-5-5">If a dual-stack initiator requests only an IPv6 prefix (or an IPv4
 address) but only receives an IP4_ALLOWED (or IP6_ALLOWED)
 notification status type from the responder, the initiator
 <span class="bcp14">MUST</span> send a request for IPv4 address(es) (or IPv6
 prefix(es)).<a href="#section-5-5" class="pilcrow">¶</a></p>
<p id="section-5-6">If a dual-stack initiator requests both an IPv6 prefix and an IPv4
 address but receives an IPv6 prefix (or an IPv4 address) only with
 both IP4_ALLOWED and IP6_ALLOWED notification status types from the
 responder, the initiator <span class="bcp14">MAY</span> send a request for the
 other AF (i.e., IPv4 address (or IPv6 prefix)).

In such case, the initiator <span class="bcp14">MUST</span> create a new IKE Security
Association (SA) and request another address family using the new IKE
SA.<a href="#section-5-6" class="pilcrow">¶</a></p>
<p id="section-5-7">For other address-related error cases that have not been covered by
 the aforementioned notification status types, the responder/initiator
 <span class="bcp14">MUST</span> follow the procedure defined in <span><a href="https://www.rfc-editor.org/rfc/rfc7296#section-3.15.4" class="relref">Section 3.15.4</a> of [<a href="#RFC7296" class="xref">RFC7296</a>]</span>.<a href="#section-5-7" class="pilcrow">¶</a></p>
</section>
</div>
<div id="Security">
<section id="section-6">
      <h2 id="name-security-considerations">
<a href="#section-6" class="section-number selfRef">6. </a><a href="#name-security-considerations" class="section-name selfRef">Security Considerations</a>
      </h2>
<p id="section-6-1">Since the IPv4/IPv6 capabilities of a node are readily determined
 from the traffic it generates, this document does not introduce any
 new security considerations compared to the ones described in <span>[<a href="#RFC7296" class="xref">RFC7296</a>]</span>, which continue to apply.<a href="#section-6-1" class="pilcrow">¶</a></p>
</section>
</div>
<div id="sec-IANA">
<section id="section-7">
      <h2 id="name-iana-considerations">
<a href="#section-7" class="section-number selfRef">7. </a><a href="#name-iana-considerations" class="section-name selfRef">IANA Considerations</a>
      </h2>
<p id="section-7-1">IANA has updated the "IKEv2 Notify Message Types
 - Status Types" registry (available at 
 <span>&lt;<a href="https://www.iana.org/assignments/ikev2-parameters/">https://www.iana.org/assignments/ikev2-parameters/</a>&gt;</span>)
 with the following status types:<a href="#section-7-1" class="pilcrow">¶</a></p>
<span id="name-updates-to-ikev2-notify-mes"></span><div id="iana">
<table class="center" id="table-2">
        <caption>
<a href="#table-2" class="selfRef">Table 2</a>:
<a href="#name-updates-to-ikev2-notify-mes" class="selfRef">Updates to "IKEv2 Notify Message Types - Status Types" Registry</a>
        </caption>
<thead>
          <tr>
            <th class="text-left" rowspan="1" colspan="1">Value</th>
            <th class="text-left" rowspan="1" colspan="1">NOTIFY MESSAGES - STATUS TYPES</th>
            <th class="text-left" rowspan="1" colspan="1">Reference</th>
          </tr>
        </thead>
        <tbody>
          <tr>
            <td class="text-left" rowspan="1" colspan="1">16439</td>
            <td class="text-left" rowspan="1" colspan="1">IP4_ALLOWED</td>
            <td class="text-left" rowspan="1" colspan="1">RFC 8983</td>
          </tr>
          <tr>
            <td class="text-left" rowspan="1" colspan="1">16440</td>
            <td class="text-left" rowspan="1" colspan="1">IP6_ALLOWED</td>
            <td class="text-left" rowspan="1" colspan="1">RFC 8983</td>
          </tr>
        </tbody>
      </table>
</div>
</section>
</div>
<section id="section-8">
      <h2 id="name-references">
<a href="#section-8" class="section-number selfRef">8. </a><a href="#name-references" class="section-name selfRef">References</a>
      </h2>
<section id="section-8.1">
        <h3 id="name-normative-references">
<a href="#section-8.1" class="section-number selfRef">8.1. </a><a href="#name-normative-references" class="section-name selfRef">Normative References</a>
        </h3>
<dl class="references">
<dt id="RFC2119">[RFC2119]</dt>
        <dd>
<span class="refAuthor">Bradner, S.</span>, <span class="refTitle">"Key words for use in RFCs to Indicate Requirement Levels"</span>, <span class="seriesInfo">BCP 14</span>, <span class="seriesInfo">RFC 2119</span>, <span class="seriesInfo">DOI 10.17487/RFC2119</span>, <time datetime="1997-03" class="refDate">March 1997</time>, <span>&lt;<a href="https://www.rfc-editor.org/info/rfc2119">https://www.rfc-editor.org/info/rfc2119</a>&gt;</span>. </dd>
<dd class="break"></dd>
<dt id="RFC7296">[RFC7296]</dt>
        <dd>
<span class="refAuthor">Kaufman, C.</span><span class="refAuthor">, Hoffman, P.</span><span class="refAuthor">, Nir, Y.</span><span class="refAuthor">, Eronen, P.</span><span class="refAuthor">, and T. Kivinen</span>, <span class="refTitle">"Internet Key Exchange Protocol Version 2 (IKEv2)"</span>, <span class="seriesInfo">STD 79</span>, <span class="seriesInfo">RFC 7296</span>, <span class="seriesInfo">DOI 10.17487/RFC7296</span>, <time datetime="2014-10" class="refDate">October 2014</time>, <span>&lt;<a href="https://www.rfc-editor.org/info/rfc7296">https://www.rfc-editor.org/info/rfc7296</a>&gt;</span>. </dd>
<dd class="break"></dd>
<dt id="RFC8174">[RFC8174]</dt>
      <dd>
<span class="refAuthor">Leiba, B.</span>, <span class="refTitle">"Ambiguity of Uppercase vs Lowercase in RFC 2119 Key Words"</span>, <span class="seriesInfo">BCP 14</span>, <span class="seriesInfo">RFC 8174</span>, <span class="seriesInfo">DOI 10.17487/RFC8174</span>, <time datetime="2017-05" class="refDate">May 2017</time>, <span>&lt;<a href="https://www.rfc-editor.org/info/rfc8174">https://www.rfc-editor.org/info/rfc8174</a>&gt;</span>. </dd>
<dd class="break"></dd>
</dl>
</section>
<section id="section-8.2">
        <h3 id="name-informative-references">
<a href="#section-8.2" class="section-number selfRef">8.2. </a><a href="#name-informative-references" class="section-name selfRef">Informative References</a>
        </h3>
<dl class="references">
<dt id="RFC6459">[RFC6459]</dt>
        <dd>
<span class="refAuthor">Korhonen, J., Ed.</span><span class="refAuthor">, Soininen, J.</span><span class="refAuthor">, Patil, B.</span><span class="refAuthor">, Savolainen, T.</span><span class="refAuthor">, Bajko, G.</span><span class="refAuthor">, and K. Iisakkila</span>, <span class="refTitle">"IPv6 in 3rd Generation Partnership Project (3GPP) Evolved Packet System (EPS)"</span>, <span class="seriesInfo">RFC 6459</span>, <span class="seriesInfo">DOI 10.17487/RFC6459</span>, <time datetime="2012-01" class="refDate">January 2012</time>, <span>&lt;<a href="https://www.rfc-editor.org/info/rfc6459">https://www.rfc-editor.org/info/rfc6459</a>&gt;</span>. </dd>
<dd class="break"></dd>
<dt id="RFC7849">[RFC7849]</dt>
      <dd>
<span class="refAuthor">Binet, D.</span><span class="refAuthor">, Boucadair, M.</span><span class="refAuthor">, Vizdal, A.</span><span class="refAuthor">, Chen, G.</span><span class="refAuthor">, Heatley, N.</span><span class="refAuthor">, Chandler, R.</span><span class="refAuthor">, Michaud, D.</span><span class="refAuthor">, Lopez, D.</span><span class="refAuthor">, and W. Haeffner</span>, <span class="refTitle">"An IPv6 Profile for 3GPP Mobile Devices"</span>, <span class="seriesInfo">RFC 7849</span>, <span class="seriesInfo">DOI 10.17487/RFC7849</span>, <time datetime="2016-05" class="refDate">May 2016</time>, <span>&lt;<a href="https://www.rfc-editor.org/info/rfc7849">https://www.rfc-editor.org/info/rfc7849</a>&gt;</span>. </dd>
<dd class="break"></dd>
</dl>
</section>
</section>
<section id="section-appendix.a">
      <h2 id="name-acknowledgements">
<a href="#name-acknowledgements" class="section-name selfRef">Acknowledgements</a>
      </h2>
<p id="section-appendix.a-1">Many thanks to <span class="contact-name">Christian Jacquenet</span> for the review.<a href="#section-appendix.a-1" class="pilcrow">¶</a></p>
<p id="section-appendix.a-2">Thanks to <span class="contact-name">Paul Wouters</span>, <span class="contact-name">Yaov       Nir</span>, <span class="contact-name">Valery Smyslov</span>, <span class="contact-name">Daniel       Migault</span>, <span class="contact-name">Tero Kivinen</span>, and <span class="contact-name">Michael Richardson</span> for the comments and review.<a href="#section-appendix.a-2" class="pilcrow">¶</a></p>
<p id="section-appendix.a-3">Thanks to <span class="contact-name">Benjamin Kaduk</span> for the AD review.<a href="#section-appendix.a-3" class="pilcrow">¶</a></p>
<p id="section-appendix.a-4">Thanks to <span class="contact-name">Murray Kucherawy</span>, <span class="contact-name">Éric Vyncke</span>, and <span class="contact-name">Robert Wilton</span> for
      the IESG review.<a href="#section-appendix.a-4" class="pilcrow">¶</a></p>
</section>
<div id="authors-addresses">
<section id="section-appendix.b">
      <h2 id="name-authors-address">
<a href="#name-authors-address" class="section-name selfRef">Author's Address</a>
      </h2>
<address class="vcard">
        <div dir="auto" class="left"><span class="fn nameRole">Mohamed Boucadair</span></div>
<div dir="auto" class="left"><span class="org">Orange</span></div>
<div dir="auto" class="left">
<span class="postal-code">35000</span> <span class="locality">Rennes</span>
</div>
<div dir="auto" class="left"><span class="country-name">France</span></div>
<div class="email">
<span>Email:</span>
<a href="mailto:mohamed.boucadair@orange.com" class="email">mohamed.boucadair@orange.com</a>
</div>
</address>
</section>
</div>
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