Destination NAT (DNAT)
While SNAT changes the source address of packets, destination NAT (DNAT) changes the destination address of packets passing through the vRouter. DNAT is typically used when an external (public) host needs to initiate a session with an internal (private) host; for example, when a subscriber accesses a news service, as shown in the following figure. The source address of return packets is automatically translated back to the IP address of the source host.