Dell SonicWALL GX250 Manual page 27

The Use Network Address Translation (NAT) window verifies that the SonicWALL
has a registered IP address. To confirm this, click Next and go to Step 10.
Selecting Standard or NAT Enabled Mode
If you selected the Assigned you a single static IP Address option in Step 6, the
Optional-Network Address Translation window is displayed.
10. The Optional-Network Address Translation (NAT) window offers the ability
to enable NAT. Select Don't Use NAT if there are enough static IP addresses for
your SonicWALL, all PCs, and all network devices on your LAN. Selecting Don't
Use NAT enables the Standard mode. Select Use NAT if valid IP addresses are
in short supply or to hide all devices on your LAN behind the SonicWALL valid IP
address. Click Next to continue.
SonicWALL Internet Security Appliance Guide Page 27