User's Manual

14
Chapter
Chapter 14 Firewall 151
CHAPTER 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 LA
N 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 fir
ewall 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 D
efault Firewall Action
WAN
LAN
3
4
1
2
A
14.1.1 What You Can Do in the Firewall Screens
•Use the General screen (Section 14.2 on page 153) to select the firewall protection level on the
Device.
•Use the De
fault Action screen (Section 14.3 on page 154) to set the default action that the
firewall takes on packets that do no
t match any of the firewall rules.