ZyXEL Communications P-661H Series User Manual

Chapter 9 Firewall Configuration

P-661H/HW Series User’s Guide

Click Security > Firewall to display the following screen. Activate the firewall by selecting 
the Active Firewall check box as seen in the following screen.
Refer to 

 for more information. 

Figure 86   Firewall: General

The following table describes the labels in this screen. 

Table 60   Firewall: General

Active Firewall

Select this check box to activate the firewall. The ZyXEL Device performs access 

control and protects against Denial of Service (DoS) attacks when the firewall is 

activated.

Bypass Triangle 

Route

Select this check box to have the ZyXEL Device firewall permit the use of triangle 

route topology on the network. See the appendix for more on triangle route 

topology.

Note: Allowing asymmetrical routes may let traffic from the WAN go 

directly to a LAN computer without passing through the 
router. See 

 for more on triangle 

route topology and how to deal with this problem.

Packet Direction

This is the direction of travel of packets (LAN to LAN / Router, LAN to WAN, 

WAN to WAN / Router, and WAN to LAN).
Firewall rules are grouped based on the direction of travel of packets to which they 

apply. For example, LAN to LAN / Router means packets traveling from a 

computer/subnet on the LAN to either another computer/subnet on the LAN 

interface of the ZyXEL Device or the ZyXEL Device itself.