The roadwarriors <b>carol</b> and <b>dave</b> set up an IPv6 connection each 
to gateway <b>moon</b>. The authentication is based on <b>X.509 certificates</b>.
Upon the successful establishment of the IPv6 ESP tunnels, automatically inserted
ip6tables-based firewall rules let pass the tunneled traffic.
In order to test both tunnel and firewall, both <b>carol</b> and <b>dave</b> send
an IPv6 ICMP request to the client <b>alice</b> behind the gateway <b>moon</b>
using the ping6 command.
