In
the scenario above, the DMZ is connected through Firewall-1 and the
access router to the Internet, and is connected to the LAN through Firewall-2.
The dual firewall design provides multi-tier network protection so that
if intruders penetrate the external Firewall-1, the LAN is still protected
by Firewall-2. This design provides the system administrator the time
to analyze his logs from the IDS hardware and update his security profile.