Firewall; Chapter 9 Firewall; Overview; What You Can Do - ZyXEL Communications NR2101 User Manual

9.1 Overview

Use these screens to enable and configure the firewall that protects your NR2101 and your LAN from
unwanted or malicious traffic.
Enable the firewall to protect your LAN devices 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 devices 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 68 Default Firewall Action

9.1.1 What You Can Do

• Use the Firewall Settings screen to configure predefined Internet services and firewall rules
on page

9.1.2 What You Need To Know

The following terms and concepts may help as you read through this chapter.
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Firewall

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