A connection between the subnets behind the gateways moon and sun is set up. The authentication is based on raw RSA keys loaded in PKCS#1 format.
Upon the successful establishment of the IPsec tunnel, leftfirewall=yes automatically inserts iptables-based firewall rules that let pass the tunneled traffic. In order to test both tunnel and firewall, client alice behind gateway moon pings client bob located behind gateway sun.