14
Chapter
Chapter 14 Firewall
151
C
HAPTER
14
Chapter 14
Firewall
14.1 Overview
This chapter shows you how to enable the Device firewall. Use the firewall to protect your Device
and network from attacks by hackers on the Internet and control access to it. The firewall:
• allows traffic that originates from your LAN computers to go to all other networks.
• blocks traffic that originates on other networks from going to the LAN.
• blocks SYN and port scanner attacks.
By default, the Device blocks DDOS, LAND and Ping of Death attacks whether the firewall is enabled
or disabled.
The following figure illustrates the firewall action. User
A
can initiate an IM (Instant Messaging)
session from the LAN to the WAN (1). Return traffic for this session is also allowed (2). However
other traffic initiated from the WAN is blocked (3 and 4).
Figure 98
Default Firewall Action
WAN
LAN
3
4
1
2
A
14.1.1 What You Can Do in the Firewall Screens
• Use the
General
screen (
) to select the firewall protection level on the
Device.
• Use the
Default Action
screen (
) to set the default action that the
firewall takes on packets that do not match any of the firewall rules.
