Firewalls; Chapter 9 Firewalls; Overview; What You Can Do In The Firewall Screens - ZyXEL Communications P-660HN User Manual

C
H A P T E R

9.1 Overview

This chapter shows you how to enable and configure the ZyXEL Device firewall. Use these
screens to enable and configure the firewall that protects 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 79 Default Firewall Action

LAN
A

9.1.1 What You Can Do in the Firewall Screens

• Use the General screen
on the ZyXEL Device, and set the default action that the firewall takes on packets that do
not match any of the firewall rules.
• Use the Rules screen
add, edit or remove a firewall rule.
• Use the Threshold screen
Device uses to determine when to start dropping sessions that do not become fully
established (half-open sessions).
P-660HN-Fx User's Guide
WAN
1
2
(Section 9.2 on page 156) to enable firewall and/or triangle route
(Section 9.3 on page 157) to view the configured firewall rules and
(Section 9.4 on page 163) to set the thresholds that the ZyXEL
9

Firewalls

3
4
151