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>.
Upon the successful establishment of the IPsec tunnels, the updown script
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> ping
the client <b>alice</b> behind the gateway <b>moon</b>.
