The roadwarriors <b>carol</b> and <b>dave</b> set up a connection each to gateway <b>moon</b> using <b>Blowfish</b> for both IKE and ESP encryption. Upon the successful establishment of the IPsec tunnels, <b>leftfirewall=yes</b> automatically inserts iptables-based firewall rules that 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>.