3Com 3C16111 - SuperStack 3 Firewall Web Site Filter, User Manual

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56 C
HAPTER
4: B
ASIC
S
ETTINGS OF THE
F
IREWALL
Changing the Basic
Network Settings
Click the Settings Tab from the Network Menu to display the Network
Settings window (see Figure 24 below).
Figure 24 Network Settings, Standard Window
Setting the Network
Addressing Mode
The Network Addressing Mode drop-down list contains four modes:
Standard
Choose Standard if you have IP addresses allocated by your ISP for each
machine that requires access to the Internet. When you select Standard ,
Network Address Translation (NAT) is disabled. All nodes on the LAN must
use a valid public IP address.
NAT Enabled
Choose NAT Enabled if you want to use a single IP address for accessing
the Internet, or if you do not have an IP address allocated by your ISP for
each machine that requires access to the Internet. NAT provides
anonymity to machines on the LAN by connecting the entire network to
the Internet using a single IP address. This is useful for two purposes:
■
Additional security is provided because all the addresses on the LAN
are invisible to the outside world.
■
In cases where a network uses invalid IP addresses or if addresses are
in short supply, NAT can be used to connect the LAN to the Internet
without changing the IP addresses of computers and other devices on
the LAN.
Remote authenticated access is not possible with NAT enabled.
DUA1611-0AAA02.book Page 56 Thursday, August 2, 2001 4:01 PM