Firewall; Chapter 17 Firewall; Firewall Overview; What You Can Do In This Chapter - ZyXEL Communications EX5501-B0 User Manual

17.1 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 127 Default Firewall Action

17.1.1 What You Can Do in this Chapter

• Use the General screen to configure the security level of the firewall on the Zyxel Device
on page
• Use the Protocol screen to add or remove predefined Internet services and configure firewall rules
(Section 17.3 on page
• Use the Access Control screen to view and configure incoming/outgoing filtering rules
on page
• Use the DoS screen to activate protection against Denial of Service (DoS) attacks
page 216).
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Firewall

(Section 17.2
(Section 17.4
(.Section 17.5 on