ZyXEL Communications NBG-418N v2 User Manual
Chapter 10 Network Address Translation
NBG-418N v2 User’s Guide
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The following table describes the labels in this screen.
10.4 NAT Application Screen
Use the Application screen to forward incoming service requests to the server(s) on your local
network. 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.
network. 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.
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 NBG-418N v2’s port forwarding settings, click Network > NAT >
Application. The screen appears as shown.
forwarded. To change your NBG-418N v2’s port forwarding settings, click Network > NAT >
Application. The screen appears as shown.
Note: If you do not assign a Default Server IP address in the NAT > General screen,
the NBG-418N v2 discards all packets received for ports that are not specified in
this screen or remote management.
for port numbers commonly used for particular services.
Table 43
Network > NAT > General
LABEL
DESCRIPTION
NAT Setup
Network Address
Translation
Translation
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). This field displays whether the NAT is enabled or disabled.
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). This field displays whether the NAT is enabled or disabled.
Default Server Setup
Enable
Click the Enable check box to activate the default server.
Server IP
Address
In addition to the servers for specified services, NAT supports a default server. A default
server receives packets from ports that are not specified in the Application screen.
server receives packets from ports that are not specified in the Application screen.
If you do not assign a Default Server IP address, the NBG-418N v2 discards all packets
received for ports that are not specified in the Application screen or remote
management.
received for ports that are not specified in the Application screen or remote
management.
Apply
Click Apply to save your changes back to the NBG-418N v2.
Reset
Click Reset to begin configuring this screen afresh.