The roadwarriors <b>carol</b> and <b>dave</b> set up a connection to gateway <b>moon</b>.
At the outset the gateway authenticates itself to the clients by sending
an IKEv2 <b>digital signature</b> accompanied by an X.509 certificate.
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Next the clients use the GSM <i>Subscriber Identity Module</i> (<b>EAP-SIM</b>)
method of the <i>Extensible Authentication Protocol</i> to authenticate themselves.
In this scenario triplets from the file <b>/etc/ipsec.d/triplets.dat</b> are used
instead of a physical SIM card.
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The gateway forwards all EAP messages to the RADIUS server <b>alice</b>
which also uses static triplets.
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The roadwarrior <b>dave</b> sends wrong EAP-SIM triplets. As a consequence
the RADIUS server <b>alice</b> returns an <b>Access-Reject</b> message
and the gateway <b>moon</b> sends back <b>EAP_FAILURE</b>.