A connection between the subnets behind the gateways <b>moon</b> and <b>sun</b> is set up
enabling IP-TFS (RFC 9347) to aggregate small packets into a single ESP packets and
fragment large packets across multiple ESP packets.
The authentication is based on <b>X.509 certificates</b>.
<p/>
Upon the successful establishment of the IPsec tunnel, the updown script automatically
inserts iptables-based firewall rules that let pass the tunneled traffic.
In order to test both tunnel and firewall, client <b>alice</b> behind gateway <b>moon</b>
sends several pings to client <b>bob</b> located behind gateway <b>sun</b>.
