6. Firewall Features - Port Forwarding

The SMC2804WBRP-G provides the ability to specify up to 20 Virtual Servers for supporting servers or applications that need to allow access from the Internet. Figure 11 shows the configuration options available.

Figure 11: Virtual Servers provide automatic redirection to web or FTP servers

Some applications such as Internet gaming, videoconferencing and Internet telephony use dynamically assigned ports and therefore can't be handled by using a Virtual Server. Use of these applications is also typically desired by more than one user, which static port mapping also can't handle.

The Special Applications feature (Figure 12) solves these problems by monitoring outbound data for specific ports called "trigger ports". When the firewall sees a data packet using this port, it temporarily opens the Public Ports that are also specified in the rule and closes them when the data comes in. SMC provides a half-dozen pre-configured Special Application rules such as Battle.net, Dialpad, MSN Gaming Zone.

Figure 12: Trigger ports can be helpful when playing online first-person shooters