ZyXEL Communications PMG5318-B20A - Firewall; Overview; What You Can Do in the Firewall Screens

PMG5318-B20A User’s Guide 127
CHAPTER 15
Firewall
15.1 Overview
This chapter shows you how to enable the GPON Device firewall. Use the firewall to protect your
GPON 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 GPON 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 66 Default Firewall Action
15.1.1 What You Can Do in the Firewall Screens
•Use the General screen (Section 15.2 on page 130) to enable firewall and set the default action
that the firewall takes on packets depending on packet direction.
•Use the Rules screen (Section 15.3 on page 131) to view the configured firewall rules and add,
edit or remove a firewall rule.
WAN
LAN
3
4
1
2
A