SMC Networks AR4505GW - Manual (Page 76)

C
ONFIGURING THE
ADSL R
OUTER
4-38
Firewall
The ADSL Router ’s firewall inspects packets at the application layer,
maintains TCP and UDP session information including time-outs and the
number of active sessions, and provides the ability to detect and prevent
certain types of network attacks.
Network attacks that deny access to a network device are called
Denial-of-Service (DoS) attacks. DoS attacks are aimed at devices and
networks with a connection to the Internet. Their goal is not to steal
information, but to disable a device or network so users no longer have
access to network resources.
The ADSL Router firewall function protects against the following DoS
attacks: IP Spoofing, Land Attack, Ping of Death, IP with zero length,
Smurf Attack, UDP port loopback, Snork Attack, TCP null scan, and TCP
SYN flooding. (See page 4-45 for details.)
The firewall does not significantly affect system performance, so we advise
leaving it enabled to protect your network. Select Enable and click the
“SAVE SETTINGS” button to open the Firewall submenus.