User Manual

Advanced Settings
83
N600 Wireless Dual Band Gigabit Router WNDR3700v4
The destination address is replaced with 192.168.1.123.
Your router then sends this request message to your local network.
3. Y
our web server at 192.168.1.123 receives the request and composes a return message
with the requested web page data. Your web server then sends this reply message to
your router.
4. Y
our router performs NAT on the source IP address, and sends this request message
through the Internet to the remote computer, which displays the web page from
www.example.com.
To configure port forwarding, you need to know which in
bound ports the application needs.
Usually, you can determine this information by contacting the publisher of the application or
the relevant user groups or news groups.
How Port Forwarding Differs from Port Triggering
The following points summarize the differences between port forwarding and port triggering:
• Port triggering ca
n be used by any computer on your network, although only one
computer can use it at a time.
• Port forward
ing is configured for a single computer on your network.
• Port trig
gering does not require that you know the computer’s IP address in advance. The
IP address is captured automatically.
• Port forward
ing requires that you specify the computer’s IP address during configuration,
and the IP address can never change.
• Port triggering requ
ires specific outbound traffic to open the inbound ports, and the
triggered ports are closed after a period of no activity.
• Port forward
ing is always active and does not need to be triggered.
Set Up Port Forwarding to Local Servers
Using the port forwarding feature, you can allow certain types of incoming traffic to reach
servers on your local network. For example, you might want to make a local web server, FTP
server, or game server visible and available to the Internet.
Use the Port Forwarding screen to configure the rou
ter to forward specific incoming protocols
to computers on your local network. In addition to servers for specific applications, you can
also specify a default DMZ server to which all other incoming protocols are forwarded.
Before starting, determine which type of service, application, or game you want to provide.
F
ind out the local IP address of the computer that will provide the service. The server
computer has to always have the same IP address.