Wireless ADSL2+ Modem Router DG834Gv5 User Manual
3-6
Protecting Your Network
v1.0, March 2010
•
To edit an existing rule, select its button on the left side of the table and click
Edit
.
•
To delete an existing rule, select its button on the left side of the table and click
Delete
.
•
To move a rule to a different position in the table, select its button, and then click
Move
. At the
prompt, enter the number of the desired new position, and then click
OK
.
Inbound Rules (Port Forwarding)
Because the
modem router
uses Network Address Translation (NAT), your network presents only
one IP address to the Internet, and outside users cannot directly access 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. Enable only those ports
that are necessary for your network. Following are two application examples of inbound rules.
Figure 3-4
Note:
Some broadband ISP accounts do not allow you to run any server processes (such
as a Web or FTP server) from your location. Your ISP might periodically check for
servers and might suspend your account if it discovers any active services at your
location. If you are unsure, see the acceptable use policy of your ISP.
