The gateway moon uses a 3072 bit RSA private key protected by AES-128
encryption whereas the roadwarriors carol and dave have an
AES-192 and AES-256 envelope, respectively.
The X.509 certificate of the gateway moon uses a SHA-224 hash in
its signature whereas the certificates of the roadwarriors carol
and dave use SHA-384 and SHA-512, respectively.
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 carol and dave ping
the client alice behind the gateway moon.