18.3. Network Address Translation Mode

By default, virtual network switches operate in NAT mode. They use IP masquerading rather than SNAT (Source-NAT) or DNAT (Destination-NAT). IP masquerading enables connected guests to use the host physical machine IP address for communication to any external network. By default, computers that are placed externally to the host physical machine cannot communicate to the guests inside when the virtual network switch is operating in NAT mode, as shown in the following diagram:

If the switch is not running, you can set th public IP range for forward mode NAT in order to create a port masquerading range by running:

iptables -j SNAT --to-source [start]-[end]

# iptables -j SNAT --to-source [start]-[end]