ZyXEL Communications EX3510-B1, User Manual

Page: 199 / 313

EX3510-B1 User’s Guide
199
C
HAPTER
16
Firewall
16.1 Firewall Overview
This chapter shows you how to enable and configure the Zyxel Device’s security settings. Use the firewall
to protect your Zyxel Device and network from attacks by hackers on the Internet and control access to
it. By default 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.
The following figure illustrates the default 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 123 Default Firewall Action
16.1.1 What You Can Do in this Chapter
• Use the General screen to configure the security level of the firewall on the Zyxel Device ( Section 16.2
on page 200 ).
• Use the Protocol screen to add or remove predefined Internet services and configure firewall rules
( Section 16.3 on page 201 ).
• Use the Access Control screen to view and configure incoming/outgoing filtering rules ( Section 16.4
on page 203 ).
• Use the DoS screen to activate protection against Denial of Service (DoS) attacks (. Section 16.5 on
page 206 ).