ZyXEL Communications NBG334SH - Manual (Page 123)

Chapter 11 Firewall
ZyXEL NBG-334SH User’s Guide
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1 A computer on the LAN initiates a connection by sending a SYN packet to a receiving
server on the WAN.
2 The ZyXEL Device reroutes the packet to Gateway A, which is in Subnet 2.
3 The reply from the WAN goes to the ZyXEL Device.
4 The 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.