3Com WL-603 - Manual (Page 92)

90 C HAPTER 5: C ONFIGURING THE R OUTER
Firewall This section is for configuration settings of the Router’s firewall function.
Your Router is equipped with a firewall that will protect your network
from a wide array of common hacker attacks including Ping of Death
(PoD) and Denial of Service (DoS) attacks. You can turn the firewall
function off if needed. Turning off the firewall protection will not leave
your network completely vulnerable to hacker attacks, but 3Com
recommends that you leave the firewall enabled whenever possible.
SPI Stateful Packet Inspection (SPI) - The Intrusion Detection Feature of the
Router limits access for incoming traffic at the WAN port.
This feature is called a "stateful" packet inspection, because it examines
the contents of the packet to determine the state of the communications;
i.e., it ensures that the stated destination computer has previously
requested the current communication. This is a way of ensuring that all
communications are initiated by the recipient computer and are taking
place only with sources that are known and trusted from previous
interactions. In addition to being more rigorous in their inspection of
packets, stateful inspection firewalls also close off ports until connection
to the specific port is requested.
Figure 68 Firewall Screen