TRENDnet TEW-633GR User Manual page 41

Advanced_Firewall
The router provides a tight firewall by virtue of the way NAT works. Unless you configure the router to
the contrary, the NAT does not respond to unsolicited incoming requests on any port, thereby making
your LAN invisible to Internet cyber attackers. However, some network applications cannot run with a
tight firewall. Those applications need to selectively open ports in the firewall to function correctly. The
options on this page control several ways of opening the firewall to address the needs of specific types
of applications. See also Virtual Server, Port Forwarding, Application Rules, and UPnP for related
options.
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