Chapter 8
Neobit 1012VA-II ADSL Ethernet Router User’s Guide
52
disguised source port number. The Neobit 1012VAchanges the IP
address and source port number back to the original values (having
kept track of the changes it made earlier), and then routes the
packet to the originating computer.
NAT rules such as these provide several benefits:
They eliminate the need for purchasing multiple public IP
addresses for computers on your LAN. You can make up
your own private IP addresses at no cost, and then have
them translated to the public IP address when your
computers access the Internet.
They provide a measure of security for you LAN by
enabling you to assign private IP addresses and then have
these and the source port numbers swapped out before
your computers access the Internet.
The type of NAT function described above is called
network
address port translation
(napt). You can use other types, called
flavors
, of NAT for other purposes; for example, providing outside
access to your LAN or translating multiple private addresses to
multiple public addresses.
By default, NAT is enabled, with an napt rule configured that
translates any private address on the LAN side to your ISP-
assigned public IP address on the WAN side. (For a description of
napt rules, see page 58.)
Viewing NAT Global Settings and Statistics
To view your NAT settings, log into Configuration Manager, click the
Services tab. The NAT Configuration page displays by default, as
shown in Figure 16.
Figure 16. NAT Configuration Page
The NAT Configuration page contains the following elements:
The NAT Options drop-down list, which provides access to
the Global Information page (shown by default), the NAT
