The roadwarriors carol and dave set up a connection each
to gateway moon. The authentication is based on raw RSA public keys
with ID_RFC822_ADDR and ID_FQDN identities for the roadwarriors and
gateway, respectively.
Upon the successful establishment of the IPsec tunnels, automatically inserted
iptables-based firewall rules let pass the tunneled traffic.
In order to test both tunnel and firewall, both carol and dave ping
the client alice behind the gateway moon.