The Port Forwarding Screen - ZyXEL Communications NBG5715 User Manual

Chapter 14 NAT
The following table describes the labels in this screen.
Table 45 Network > NAT > General
LABEL
Network Address
Translation (NAT)
Max NAT/Firewall
Session Per User
Apply
Cancel

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.
Refer to Appendix E on page 237
102
DESCRIPTION
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.
Specify the highest number of NAT sessions that the NBG5715 will permit a host
to have at one time.
Click Apply to save your changes back to the NBG5715.
Click Cancel to begin configuring this screen afresh.
for port numbers commonly used for particular services.
NBG5715 User's Guide