Zoom X4 - Manual (Page 22)

22 X4 ADSL Modem User’s Manual
2.4 NAT Firewall
The X4’s built-in NAT (Network Address Translation) firewall
provides a good, but not perfect, level of protection from
unauthorized access. NAT keeps private a network’s internal IP
addresses and presents to the Internet a set of public IP addresses.
NAT’s more robust counterpart, NAPT (Network Address Port
Translation), replaces a network’s private IP addresses with a single
public IP address. Both NAPT and NAP are transparent to end
users.
Your X4’s NAT firewall is enabled by default; the default setting is
dynamic NAPT—everything is automatic. You shouldn’t need to
change this setting. However, if your service provider instructs you
to disable it (or change it), go to the Advanced Setup page and
click the NAT button.
NAT Default is NAPT. Options are Disable and NAT. You
should not need to change this setting, unless
advised to do so by your provider. Note: If you
select Disable, all your modem’s firewall capabilities
are turned off.
Session Name Only applicable to NAT; user-definable name to
differentiate between different NAT sessions,
different PPP sessions, and different PVCs.
User’s IP IP address of the client computer you want to add.
Action Choices are Add or Delete.