NETGEAR DG834v3 - ADSL Modem Router, Reference Manual

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Reference Manual for the ADSL Modem Router DG834
Protecting Your Network 4-7
v2.3, May 2007
Inbound Rules (Port Forwarding)
Because the DG834 v3 uses Network Address Translation (NAT), your network presents only one
IP address to the Internet, and outside users cannot directly address any of your local computers.
However, by defining an inbound rule you can make a local server (for example, a Web server or
game server) visible and available to the Internet. The rule tells the modem router to direct
inbound traffic for a particular service to one local server based on the destination port number.
This is also known as port forwarding.
Remember that allowing inbound services opens holes in your firewall. Only enable those ports
that are necessary for your network. Following are two application examples of inbound rules:
Inbound Rule Example: A Local Public Web Server
If you host a public Web server on your local network, you can define a rule to allow inbound Web
(HTTP) requests from any outside IP address to the IP address of your Web server at any time of
day. This rule is shown in
Figure 4-5 :
The parameters are:
Note: Some 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 the Acceptable Use
Policy of your ISP.
Figure 4-5