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Chapter 14 NAT
NBG5715 User’s Guide
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The following table describes the labels in this screen.
14.3  The Port Forwarding Screen   
Use this screen to forward incoming service requests to the server(s) on your local network and set 
a default server. You may enter a single port number or a range of port numbers to be forwarded, 
and the local IP address of the desired server. The port number identifies a service; for example, 
web service is on port 80 and FTP on port 21. In some cases, such as for unknown services or 
where one server can support more than one service (for example both FTP and web service), it 
might be better to specify a range of port numbers.
In addition to the servers for specified services, NAT supports a default server. A service request 
that does not have a server explicitly designated for it is forwarded to the default server. If the 
default is not defined, the service request is simply discarded.
Note: Many residential broadband ISP accounts do not allow you to run any server 
processes (such as a Web or FTP server) from your location. Your ISP may 
periodically check for servers and may suspend your account if it discovers any 
active services at your location. If you are unsure, refer to your ISP.
Port forwarding allows you to define the local servers to which the incoming services will be 
forwarded. To change your NBG5715’s port forwarding settings, click Network > NAT > Port 
Forwarding
. The screen appears as shown.
Note: If you do not assign a Default Server, the NBG5715 discards all packets received 
for ports that are not specified in this screen or remote management.
Table 44   
Network > NAT > General
LABEL
DESCRIPTION
Network Address 
Translation (NAT)
Network Address Translation (NAT) allows the translation of an Internet protocol 
address used within one network (for example a private IP address used in a 
local network) to a different IP address known within another network (for 
example a public IP address used on the Internet). 
Select Enable to activate NAT. Select Disable to turn it off.
Max NAT/Firewall 
Session Per User
Specify the highest number of NAT sessions that the NBG5715 will permit a host 
to have at one time.
Apply
Click Apply to save your changes back to the NBG5715.
Cancel
Click Cancel to begin configuring this screen afresh.