Firewall & Dmz - D-Link DSL-2542B User Manual

Section 3 – Configuration
Firewall & DMZ
To access the Firewall & DMZ window, click the Firewall & DMZ button in the Advanced directory.
Firewalls may conflict with certain interactive applications such as video
conferencing or playing Internet video games. For these applications, a
firewall bypass can be set up using a DMZ IP address. The DMZ IP
address is a "visible" address and does not benefit from the full protection
of the firewall function. Therefore it is advisable that other security
precautions be enabled to protect the other computers and devices on the
LAN. It may be wise to use isolate the device with the DMZ IP address
from the rest of the LAN.
If you want to use video conferencing, for example, and still use a firewall,
you can use the DMZ IP address function. In this case, you must have a
PC or server through which video conferencing will take place. The IP
address of this PC or server will then be the DMZ IP address. You can
designate the server's IP address as the DMZ by going to the DMZ
Settings section and typing in the IP address in the IP Address field
provided and then enabling its status by ticking the Enable DMZ
checkbox, clicking Apply Settings, and then clicking the Reboot button
on the left panel to let your changes take effect.
For the system that uses the DMZ IP address, you may want to manually
assign an IP address to it and adjust your DHCP server addresses so that
the DMZ IP address is not included in the DHCP server range. This way
you avoid possible IP address problems if you reboot the DMZ system.
The Firewall Settings section allows the Router to enforce specific
predefined policies intended to protect against certain common types of
attacks. Stateful Packet Inspection (SPI) is a packet inspection process
that blocks unwanted and unrequested packets trying to reach PCs on
your LAN. A DoS "denial-of-service" attack is characterized by an explicit
attempt by attackers to prevent legitimate users of a service from using
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