Firewalls; Chapter 10 Firewalls; Overview; What You Can Do In The Firewall Screens - ZyXEL Communications P-793H v3 User Manual

10.1 Overview

This chapter shows you how to enable and configure the P-79X firewall. Use these screens to
enable and configure the firewall that protects your P-79X 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 59 Default Firewall Action
LAN
A

10.1.1 What You Can Do in the Firewall Screens

• Use the General screen
default action that the firewall takes on packets that do not match any of the firewall rules.
• Use the Rules screen
edit or remove a firewall rule.
• Use the Threshold screen
to determine when to start dropping sessions that do not become fully established (half-open
sessions).
C
HAPTER
WAN
1
2
(Section 10.2 on page 103) to enable firewall on the P-79X, and set the
(Section 10.3 on page 104) to view the configured firewall rules and add,
(Section 10.4 on page
P-79X Series User's Guide
99

Firewalls

3
4
107) to set the thresholds that the P-79X uses
1 0