ZyXEL Communications NBG-419N User Manual page 127

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 NBG-419N'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-419N discards all packets received for ports that are not specified in this
screen or remote management.
Refer to Appendix E on page 251
Figure 95 Network > NAT > Application
The following table describes the labels in this screen.
Table 59 Network > NAT > Application
LABEL
Add Application Rule
Active
Service Name
NBG-419N User's Guide
for port numbers commonly used for particular services.
DESCRIPTION
Select the check box to enable this rule and the requested service can be
forwarded to the host with a specified internal IP address.
Clear the checkbox to disallow forwarding of these ports to an inside server
without having to delete the entry.
Type a name (of up to 31 printable characters) to identify this rule in the first
field next to Service Name. Otherwise, select a predefined service in the second
field next to Service Name. The predefined service name and port number(s)
will display in the Service Name and Port fields.
Chapter 15 Network Address Translation (NAT)
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