When a specific type of traffic is sent through a specific outbound port, Port Triggering opens a specific inbound port for responses from the destination of the outbound traffic. Port Triggering opens ports when a network device connects to an outbound port, but only opens the inbound port to one device at a time. 600 seconds after the data exchange is complete, the open ports are closed for security and to make the ports available for other uses. For this reason, Port Triggering is more secure and flexible than Port Forwarding. Port Triggering is useful when a remote server requires that data to be sent from one port but then the remote server sends responses to another port.
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