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Firewall 51
■Special Applications — Special Applications allows you to specify ports to be open for specific applications to work properly with the Network Address Translation (NAT) feature of the Router. See “Special Applications” on page 54.
■Virtual Servers — This function enables you to route external (Internet) calls for services such as a web server, FTP server, or other applications through your Router to your internal network. See “Virtual Servers” on page 56.
■Client IP Filters — You can configure the Router to restrict access to the Internet,
■MAC Address Filtering — This is a powerful security feature that allows you to specify which computers are allowed on the network. See “MAC Address Filtering” on page 62.
■DMZ
See “DMZ” on page 63.
CAUTION: DMZ reduces network security, and 3Com recommends you only use it on a temporary basis.
SPI Stateful Packet Inspection (SPI) inspects, and if required blocks packets at the application layer. SPI also maintains TCP and UDP session information, including timeouts and the number of active sessions, and provides the ability to detect and prevent certain types of network attacks such as DoS attacks.
Denial of Service (DoS) attacks are aimed at devices and networks with a connection to the Internet. The goal is not to steal information, but to disable a device or network so users no longer have access to network resources.