56 CHAPTER 4: BASIC SETTINGS OF THE F IREWALLChanging the BasicNetwork SettingsClick the Settings Tab from the Network Menu to display the NetworkSettings window (see Figure 24 below).Figure 24 Network Settings, Standard WindowSetting the NetworkAddressing ModeThe Network Addressing Mode drop-down list contains four modes:StandardChoose Standard if you have IP addresses allocated by your ISP for eachmachine that requires access to the Internet. When you select Standard,Network Address Translation (NAT) is disabled. All nodes on the LAN mustuse a valid public IP address.NAT EnabledChoose NAT Enabled if you want to use a single IP address for accessingthe Internet, or if you do not have an IP address allocated by your ISP foreach machine that requires access to the Internet. NAT providesanonymity to machines on the LAN by connecting the entire network tothe Internet using a single IP address. This is useful for two purposes: Additional security is provided because all the addresses on the LANare invisible to the outside world. In cases where a network uses invalid IP addresses or if addresses arein short supply, NAT can be used to connect the LAN to the Internetwithout changing the IP addresses of computers and other devices onthe LAN.Remote authenticated access is not possible with NAT enabled.DUA1611-0AAA02.book Page 56 Thursday, August 2, 2001 4:01 PM
