The roadwarrior <b>carol</b> and the gateway <b>moon</b> use the <b>Crypto API</b>
of the Linux kernel via the <b>af_alg</b> userland interface for all symmetric
encryption and hash functions whereas roadwarrior <b>dave</b> uses <b>openssl</b>
as the default <b>strongSwan</b> cryptographical plugin.
<p>
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 tunnel automatically iptables-based
firewall rules are inserted which 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>.

