An IPv6 ESP connection between the hosts <b>moon</b> and <b>sun</b> is successfully set up.
-The authentication is based on X.509 certificates. In order to test the host-to-host tunnel
-<b>moon</b> sends an IPv6 ICMP request to <b>sun</b> using the ping6 command.
+The authentication is based on X.509 certificates. Upon the successful establishment of
+the IPsec tunnel, <b>leftfirewall=yes</b> automatically inserts ip6tables-based firewall
+rules that let pass the tunneled traffic. In order to test both the host-to-host tunnel
+and the firewall rules, <b>moon</b> sends an IPv6 ICMP request to <b>sun</b> using the ping6 command.