Port triggering is a dynamic extension of port forwarding. Unlike port forwarding, which is always active after it is configured, port triggering works by creating a port forwarding rule (inbound firewall rule) that is only activated when it is triggered by detecting specified outbound packets. After the rule is triggered, specified inbound packets (from the Internet) are forwarded to the computer that triggered it.
Port triggering has some advantages over port forwarding:
- Port forwarding requires that you specify a device’s IP address during configuration, and the IP address can never change. Port triggering does not require that you know a device’s IP address in advance; the IP address is captured automatically.
- Port forwarding is configured for a single device on your network. Port triggering can be used by any device on your network, although only one computer can use it at a time.
- Port forwarding creates a static mapping of a port number or range of ports to a single local computer. Port triggering can dynamically open ports to any computer when needed and close the ports when they are no longer needed.
Port triggering is particularly useful for applications that must open incoming ports that are different from the outgoing port, or if you have an application that must use port forwarding to more than one local computer (but not simultaneously).
For port triggering setup instructions, see the following articles:
- How do I enable port triggering on my NETGEAR router?
- How do I add a custom port triggering service on my NETGEAR router?
For more information: