The host <b>carol</b> sets up a tunnel connection to gateway <b>moon</b>. It requests
both an IPv4 and an IPv6 <b>virtual IP</b> via the IKEv2 configuration payload by using
<b>vips = 0.0.0.0,0::0</b>. Gateway <b>moon</b> assigns virtual IPs addresses
from two in-memory pools defined in the <b>pools</b> section. The established tunnel
carries both IPv4 and IPv6 in an IPv4 encapsulated tunnel.