<html xmlns:o="urn:schemas-microsoft-com:office:office" xmlns:w="urn:schemas-microsoft-com:office:word" xmlns:m="http://schemas.microsoft.com/office/2004/12/omml" xmlns="http://www.w3.org/TR/REC-html40">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<meta name="Generator" content="Microsoft Word 15 (filtered medium)">
<style><!--
/* Font Definitions */
@font-face
{font-family:"Cambria Math";
panose-1:2 4 5 3 5 4 6 3 2 4;}
@font-face
{font-family:Calibri;
panose-1:2 15 5 2 2 2 4 3 2 4;}
@font-face
{font-family:Verdana;
panose-1:2 11 6 4 3 5 4 4 2 4;}
@font-face
{font-family:Baskerville;
panose-1:2 2 5 2 7 4 1 2 3 3;}
@font-face
{font-family:"Times New Roman \(Body CS\)";
panose-1:2 11 6 4 2 2 2 2 2 4;}
/* Style Definitions */
p.MsoNormal, li.MsoNormal, div.MsoNormal
{margin:0cm;
font-size:12.0pt;
font-family:"Calibri",sans-serif;
mso-fareast-language:EN-US;}
a:link, span.MsoHyperlink
{mso-style-priority:99;
color:#0563C1;
text-decoration:underline;}
span.EmailStyle17
{mso-style-type:personal-compose;
font-family:"Baskerville",serif;
color:windowtext;}
span.apple-converted-space
{mso-style-name:apple-converted-space;}
.MsoChpDefault
{mso-style-type:export-only;
font-size:12.0pt;
font-family:"Calibri",sans-serif;
mso-fareast-language:EN-US;}
@page WordSection1
{size:612.0pt 792.0pt;
margin:72.0pt 72.0pt 72.0pt 72.0pt;}
div.WordSection1
{page:WordSection1;}
--></style>
</head>
<body lang="EN-IN" link="#0563C1" vlink="#954F72" style="word-wrap:break-word">
<div class="WordSection1">
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Baskerville",serif">Hi,<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Baskerville",serif"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Baskerville",serif">I have a question regarding INITIAL_CONTACT in IKEv2.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Baskerville",serif"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Baskerville",serif;color:black">I have found the following text in StrongSwan's documentation (<a href="https://wiki.strongswan.org/projects/strongswan/wiki/Swanctlconf">https://wiki.strongswan.org/projects/strongswan/wiki/Swanctlconf</a>):</span><span style="color:black"><o:p></o:p></span></p>
<p class="MsoNormal" style="caret-color: rgb(0, 0, 0);font-variant-caps: normal;orphans: auto;text-align:start;widows: auto;-webkit-text-size-adjust: auto;-webkit-text-stroke-width: 0px;word-spacing:0px">
<span style="font-family:"Baskerville",serif;color:black"> </span><span style="color:black"><o:p></o:p></span></p>
<p class="MsoNormal" style="caret-color: rgb(0, 0, 0);font-variant-caps: normal;orphans: auto;text-align:start;widows: auto;-webkit-text-size-adjust: auto;-webkit-text-stroke-width: 0px;word-spacing:0px">
<span style="font-family:"Baskerville",serif;color:black"> </span><span style="color:black"><o:p></o:p></span></p>
<table class="MsoNormalTable" border="0" cellspacing="0" cellpadding="0" style="background:white;border-collapse:collapse;caret-color: rgb(0, 0, 0);orphans: auto;widows: auto;-webkit-text-size-adjust: auto;-webkit-text-stroke-width: 0px;background-position:initial initial;background-repeat:initial initial;word-spacing:0px">
<tbody>
<tr>
<td style="border:solid #BBBBBB 1.0pt;background:#F0F0F0;padding:3.0pt 3.0pt 3.0pt 3.0pt;background-position:initial initial;background-repeat:initial initial">
<p class="MsoNormal" style="margin-bottom:12.0pt"><span style="font-size:8.0pt;font-family:"Verdana",sans-serif;color:#36000C">connections.<conn>.unique</span><o:p></o:p></p>
</td>
<td style="border:solid #BBBBBB 1.0pt;border-left:none;padding:3.0pt 3.0pt 3.0pt 3.0pt">
<p class="MsoNormal" style="margin-bottom:12.0pt"><span style="font-size:8.0pt;font-family:"Verdana",sans-serif;color:#36000C">Default => no</span><o:p></o:p></p>
</td>
</tr>
<tr>
<td colspan="2" style="border:solid #BBBBBB 1.0pt;border-top:none;padding:3.0pt 3.0pt 3.0pt 24.0pt">
<p class="MsoNormal" style="margin-bottom:12.0pt"><span style="font-size:8.0pt;font-family:"Verdana",sans-serif;color:#36000C">Connection uniqueness policy to enforce. To avoid multiple connections from the same user, a uniqueness policy can be enforced. The
value <i>never</i> does never enforce such a policy, even if a peer included INITIAL_CONTACT notification messages, whereas <i>no</i> replaces existing connections for the same identity if a new one has the INITIAL_CONTACT notify. <i>keep</i> rejects new connection
attempts if the same user already has an active connection, <i>replace</i> deletes any existing connection if a new one for the same user gets established.<br>
To compare connections for uniqueness, the remote IKE identity is used. If EAP or XAuth authentication is involved, the EAP-Identity or XAuth username is used to enforce the uniqueness policy instead.<br>
<span style="background:yellow">On initiators this setting specifies whether an INITIAL_CONTACT notify is sent during IKE_AUTH if no existing connection is found with the remote peer (determined by the identities of the first authentication round). Unless set
to <i>never</i> the client will send a notify</span></span><o:p></o:p></p>
</td>
</tr>
</tbody>
</table>
<p class="MsoNormal" style="caret-color: rgb(0, 0, 0);font-variant-caps: normal;orphans: auto;text-align:start;widows: auto;-webkit-text-size-adjust: auto;-webkit-text-stroke-width: 0px;word-spacing:0px">
<span style="font-family:"Baskerville",serif;color:black"> </span><span style="color:black"><o:p></o:p></span></p>
<p class="MsoNormal" style="caret-color: rgb(0, 0, 0);font-variant-caps: normal;orphans: auto;text-align:start;widows: auto;-webkit-text-size-adjust: auto;-webkit-text-stroke-width: 0px;word-spacing:0px">
<span style="font-family:"Baskerville",serif;color:black"> </span><span style="color:black"><o:p></o:p></span></p>
<p class="MsoNormal" style="caret-color: rgb(0, 0, 0);font-variant-caps: normal;orphans: auto;text-align:start;widows: auto;-webkit-text-size-adjust: auto;-webkit-text-stroke-width: 0px;word-spacing:0px">
<span style="font-family:"Baskerville",serif;color:black">This text seems to indicate that StrongSwan sends out INITIAL_CONTACT when it is acting as an initiator unless the above option is set to 'never'.<span class="apple-converted-space"> <o:p></o:p></span></span></p>
<p class="MsoNormal"><span class="apple-converted-space"><span style="font-family:"Baskerville",serif;color:black"><o:p> </o:p></span></span></p>
<p class="MsoNormal"><span class="apple-converted-space"><span style="font-family:"Baskerville",serif;color:black"><o:p> </o:p></span></span></p>
<p class="MsoNormal"><span class="apple-converted-space"><span style="font-family:"Baskerville",serif;color:black">My question is if this has been the behaviour of StrongSwan's implementation since day-1? If a device is using an older version of StrongSwan's
implementation, will the above documented behaviour hold true?<o:p></o:p></span></span></p>
<p class="MsoNormal"><span class="apple-converted-space"><span style="font-family:"Baskerville",serif;color:black"><o:p> </o:p></span></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Baskerville",serif"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Baskerville",serif"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Baskerville",serif;mso-fareast-language:EN-GB">Thanks,<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Baskerville",serif;mso-fareast-language:EN-GB">Mohit<o:p></o:p></span></p>
<p class="MsoNormal"><o:p> </o:p></p>
</div>
</body>
</html>