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. Upon the successful
establishment of the IPsec tunnel, automatically inserted ip6tables-based firewall
rules 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.
