The roadwarriors <b>carol</b> and <b>dave</b> set up a connection to gateway <b>moon</b>.
The authentication is based on Pre-Shared Keys (<b>PSK</b>) followed by extended
authentication (<b>XAUTH</b>) of <b>carol</b> and <b>dave</b> based on user names and passwords.
<p>
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, <b>carol</b> and <b>dave</b> ping the client
<b>alice</b> behind the gateway <b>moon</b>.
