Firewall; Chapter 17 Firewall; Overview; What You Can Do - ZyXEL Communications NBG6616 User Manual

17.1 Overview

Use these screens to enable and configure the firewall that protects your NBG6616 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 87 Default Firewall Action
LAN
A

17.1.1 What You Can Do

• Use the General screen to enable or disable the NBG6616's firewall
• Use the Services screen enable service blocking, enter/delete/modify the services you want to
block and the date/time you want to block them

17.1.2 What You Need To Know

The following terms and concepts may help as you read through this chapter.
C
HAPTER
WAN
1
2
3
4
(Section 17.3 on page
NBG6616 User's Guide
131
1 7

Firewall

(Section 17.2 on page 133).
133).