<p>The roadwarriors <b>carol</b> and <b>dave</b> set up a connection each
to gateway <b>moon</b>. The authentication is based on <b>X.509 certificates</b>.
To authorize clients, <b>moon</b> expects attribute certificates sent inline in
IKEv2 CERT payloads. <b>Carol</b> provides a valid attribute certificate for
the group <i>sales</i>, but <b>dave</b> offers two invalid attribute
certificates: One is not for the <i>sales</i> group, and the other is issued by
an AA that has been expired.</p>
<p>Upon the successful establishment of the IPsec tunnels, <b>leftfirewall=yes</b>
automatically inserts iptables-based firewall rules that let pass the tunneled traffic.
In order to test both tunnel and firewall, both <b>carol</b> and <b>dave</b> try
to ping the client <b>alice</b> behind the gateway <b>moon</b>, but dave fails
to do so.</p>
