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<p class="MsoNormal">Hi,<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal"> I hope someone can help me with a problem I am having setting up IPsec transport mode between two CentOS 7 hosts. I have two hosts on the same subnet. Both are using the same ipsec.conf:<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal"><span style="font-family:"Courier New"">config setup<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Courier New""> protostack=netkey<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Courier New""> dumpdir=/var/run/pluto/<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Courier New""> nat_traversal=yes<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Courier New"">conn %default<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Courier New""> auto=start<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Courier New""> type=transport<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Courier New""> forceencaps=yes<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Courier New""> authby=secret<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Courier New""> ike=aes256-sha2;dh23<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Courier New""> phase2=esp<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Courier New""> phase2alg=aes256-sha2;dh23<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Courier New""> ikev2=insist<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Courier New""> failureshunt=drop<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Courier New""> ikelifetime=24h<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Courier New""> salifetime=12h<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Courier New""> rekey=yes<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Courier New""> rekeyfuzz=20%<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Courier New""> dpddelay=120<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Courier New""> dpdtimeout=120<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Courier New""> dpdaction=restart<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Courier New""><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Courier New"">include /etc/ipsec.d/*.conf<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Courier New""><o:p> </o:p></span></p>
<p class="MsoNormal">Then, in <span style="font-family:"Courier New"">/etc/ipsec.d/nodes.conf
</span>on Host A:<o:p></o:p></p>
<p class="MsoNormal"><span style="font-family:"Courier New"">conn node172.31.28.54<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Courier New""> left=172.31.28.53<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Courier New""> right=172.31.28.54<o:p></o:p></span></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">And on Host B:<o:p></o:p></p>
<p class="MsoNormal"><span style="font-family:"Courier New"">conn node172.31.28.53<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Courier New""> left=172.31.28.54<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Courier New""> right=172.31.28.53<o:p></o:p></span></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">When I first start the two hosts, I cannot connect to Host B from Host A, or vice versa (I test using ssh). However, if I first try to connect from Host A to Host B (which fails), and then from Host B to Host A, the connection from B to
A succeeds, and subsequent connections from A to B also work. Going in the opposite order produces the same result. The connections start working once I have initiated a connection from each host.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">My understanding was that it would be sufficient to set <span style="font-family:"Courier New"">
auto=start</span> to ensure the tunnels were up on startup.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">These hosts are both in an AWS VPC, with a Security Group permitting UDP 500 and 4500.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">I would appreciate any suggestions you could offer. Thanks! Dmitri<o:p></o:p></p>
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