Firewall; Chapter 15 Firewall; Overview; What You Can Do In This Chapter - ZyXEL Communications SBG3500-N000 User Manual

15.1 Overview

This chapter shows you how to enable and configure the SBG3500-N's security settings. Use the
firewall to protect your SBG3500-N 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 97 Default Firewall Action
LAN
A

15.1.1 What You Can Do in this Chapter

• Use the General screen to configure the security level of the firewall on the SBG3500-N
15.2 on page
• Use the Service screen to add or remove predefined Internet services and configure firewall
rules (Section 15.3 on page
• Use the Access Control screen to view and configure incoming/outgoing filtering rules
15.4 on page
• Use the DoS screen to activate protection against Denial of Service (DoS) attacks
on page 241).
SBG3500-N000 User's Guide
1
2
236).
237).
239).
C
HAPTER
WAN
3
4
1 5

Firewall

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