Chapter 11 Firewall

1A computer on the LAN initiates a connection by sending a SYN packet to a receiving server on the WAN.

2The ZyXEL Device reroutes the packet to Gateway A, which is in Subnet 2.

3The reply from the WAN goes to the ZyXEL Device.

4The ZyXEL Device then sends it to the computer on the LAN in Subnet 1.

Figure 69 Using IP Alias to Solve the Triangle Route Problem

11.3 General Firewall Screen

Click Security > Firewall to open the General screen. Use this screen to enable or disable the ZyXEL Device’s firewall, and set up firewall logs.

Figure 70 General

The following table describes the labels in this screen.

Table 46 Firewall General

LABEL

DESCRIPTION

Enable 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.

 

 

Packet Direction

This is the direction of travel of packets.

 

Firewall rules are grouped based on the direction of travel of packets to which they

 

apply.

 

 

 

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ZyXEL NBG-334SH User’s Guide