Firewall; Chapter 17 Firewall; Overview; What You Can Do - ZyXEL Communications NBG6503 User Manual

17.1 Overview

This chapter shows you how to enable and configure the firewall that protects your NBG and your
LAN from unwanted or malicious traffic.
Enable the firewall to protect your LAN computers from attacks by hackers on the Internet and
control access between the LAN and WAN. By default the firewall:
• allows traffic that originates from your LAN computers to go to all of the networks.
• blocks traffic that originates on the 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 92 Default Firewall Action

17.2 What You Can Do

• Use the General
• Use the Services screen
delete/modify the services you want to block and the date/time you want to block them.
C
(Section 17.4 on page 126) screen to enable or disable the NBG's firewall.
(Section 17.5 on page
NBG6503 User's Guide
125
HAPTER
127) screen enable service blocking, enter/
1 7

Firewall