Netopia R7100-C User Reference Manual page 82

9-2 User's Reference Guide
Network Address Translation works by remapping the source IP address of traffic from the LAN to a single static
or dynamically assigned IP address shown to the remote side of the router.
The feature can be implemented on a per–connection profile basis. The network router can use two or more
connection profiles simultaneously to connect to two or more networks. Each profile can have NAT enabled.
When NAT is enabled, the Netopia R7100 can use either a statically assigned IP address or one dynamically
assigned each time the router connects to the ISP. While a dynamically assigned IP address offers the ISP more
flexibility, it does have an important limitation: the router requires a static IP address to support Web, FTP, or
other services available to the WAN. To support these services with NAT enabled, a service can be associated
with only one machine on the LAN.
When connected to the Internet or some other large network using Network Address Translation, the individual
machines on your LAN are not directly accessible from the WAN. NAT provides an inherently secure method of
connection to the outside world.