User's Manual

SR804N Cable Modem User Manual
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If both external and Local/internal port numbers are present, the Local port number is
a mandatory field and the external port number is optional. If the external port
number is used, the RG will perform a translation from external port number to
internal port number.
5.3.6 Port Triggers
Choose Advanced > Port Triggers to display the following page.
Figure 23 Port Triggers
Port Triggers are similar to Port Forwarding except that they are not static ports held
open all the time. When the CMRG detects outgoing data on a specific IP port
number set in the “Trigger Range”, the resulting ports set in the “Target Range” are
opened for incoming (or sometimes referred to as bi-directional ports) data. If no
outgoing traffic is detected on the “Trigger Range” ports for 10 minutes, the “Target
Range” ports will close. This is a safer method for opening specific ports for special
applications (e.g. video conferencing programs, interactive gaming, file transfer in
chat programs, etc.) because they are dynamically triggered and not held open
constantly or erroneously left open via the router administrator and exposed for
potential hackers to discover.
5.3.7 DMZ Host
Choose Advanced > DMZ Host to display the following page.