Netgear CG814WB 사용자 설명서

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Reference Manual for the Model CG814W Wireless Cable Modem Gateway
4-8
Protecting Your Network
 
Using Port Triggering
Port Triggering is an advanced feature that allows you to dynamically open inbound ports based on 
outbound traffic on different ports. This is an advanced feature that can be used for gaming and 
other internet applications.
Port Forwarding can typically be used to enable similar functionality, but it is static and has some 
limitations. Ports will be open to traffic from the internet until the port forwarding rule is removed. 
Additionally, port forwarding does not work well for some applications when your WAN IP 
address is assigned by DHCP, and is changed frequently. Port Triggering opens in incoming port 
temporarily and can does not require the server on the internet to track your IP address if it is 
changed.
Port Triggering monitors outbound traffic. When the gateway detects traffic on the specified 
outbound port, it remembers the IP address of the computer that sent the data and “triggers” the 
incoming port. Incoming traffic on the triggered port is then forwarded to the triggering computer. 
An example of Port Triggering for Internet Relay Chat (IRC) is shown in 
. When you 
connect to an IRC server, the server tries to connect back on port 113 to do an Ident lookup. Unless 
you have configured Port Forwarding to open port 113, the traffic will be blocked. In this example, 
the initial login to the server in the range of ports 6660 to 6670 will be detected. This will trigger