A connection between the subnets behind the gateways <b>moon</b> and <b>sun</b> is set up.
The authentication is based on <b>X.509 certificates</b>. Upon the successful
establishment of the IPsec tunnel, automatically inserted iptables-based firewall rules
let pass the tunneled traffic. In order to test both tunnel and firewall, client <b>alice</b>
behind gateway <b>moon</b> pings client <b>bob</b> located behind gateway <b>sun</b>.
