Cusadmin Features
17
CG3000DCR Advanced Cable Modem Gateway
Port Configuration
You can set up port forwarding, port triggering, port blocking, and true static IP port
management.
To change the port configuration:
From the Main menu, select
Firewall
and click the
Port Configuration
tab.
Port Forwarding
A firewall has two default rules, one for inbound traffic (WAN to LAN) and one for outbound
traffic. Port forwarding affects the inbound rules. These rules restrict access from outsiders.
The default rule is to block all access from outside except responses to requests from the
LAN side. You can use port forwarding to add predefined or custom rules to specify
exceptions to the default rule.
Because the gateway 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) or computer visible and available to the Internet. The rule tells
the gateway to direct inbound traffic for a particular service to one local server or computer
based on the destination port number. This is known as port forwarding.
Port Triggering
Port triggering is an advanced feature that can be used to easily enable gaming and other
Internet applications that the firewall would otherwise block. Using this feature requires that
you know the port numbers that the application uses.
