User's Manual

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6.4 Port Triggering
Port triggering can be used for dynamic port forwarding configuration. By setting port triggering rules,
inbound traffic is allowed to arrive at a specific network host using ports different than those used for the
outbound traffic. The outbound traffic triggers which ports inbound traffic is directed.
For example, a gaming server is accessed using UDP protocol on port 2222. The gaming server responds by
connecting the user using UDP on port 3333 when starting gaming sessions. In this case, port triggering must
be used, since it conflicts with the following default firewall settings:
The firewall blocks inbound traffic by default.
The server replies to the TG590’s IP, and the connection is not sent back to the host, since it is not
part of a session.
To resolve the conflict, a port triggering entry must be defined, which allows inbound traffic on UDP port
3333, only after a network host generated traffic
to UDP port 2222. This results in accepting the inbound traffic from the gaming server, and sending it back to
the network host which originated the outgoing traffic to UDP port 2222.
To use port triggering:
1. Select Port Triggering from the left side of any Security screen. The “Port Triggering” screen appears.
2. Select either “User Defined” or “Show All Services” from the drop-down list next to “Add.”
3. If Show All Services is selected in step 2, select a Service from the list. The service is added to the Port