User manual

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Actiontec Broadband Router User Manual
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Chapter 5 Configuring the Router’s Security
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 Router’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 serv-
er, 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 “Specify Protocol” or “Show All Services” from the drop-down list
next to “Add.”