The hosts <b>alice</b>, <b>venus</b>, <b>carol</b>, and <b>dave</b> set up tunnel connections
to gateway <b>moon</b> in a <b>hub-and-spoke</b> fashion. Each host requests a <b>virtual IP</b>
from gateway <b>moon</b> which assigns virtual IP addresses from a pool named <b>extpool</b>
[10.3.0.1..10.3.1.244] to hosts connecting to the <b>eth0</b> (PH_IP_MOON) interface and virtual
IP addresses from a pool named <b>intpool</b> [10.4.0.1..10.4.1.244] to hosts connecting to
the <b>eth1</b> (PH_IP_MOON1) interface.
Thus <b>carol</b> and <b>dave</b> are assigned <b>PH_IP_CAROL1</b> and <b>PH_IP_DAVE1</b>,
respectively, whereas <b>alice</b> and <b>venus</b> get <b>10.4.0.1</b> and <b>10.4.0.2</b>,
respectively.
<p>
By defining the composite traffic selector <b>10.3.0.0/16,10.4.0.0/16</b>, each of the four
spokes can securely reach any other spoke via the central hub <b>moon</b>. This is
demonstrated by <b>alice</b> and <b>dave</b> pinging the assigned virtual IP addresses
of <b>carol</b> and <b>venus</b>.
