Operation Manual

Chapter 12 Firewall
NBG334S User’s Guide
129
1 A computer on the LAN initiates a connection by sending a SYN packet to a receiving
server on the WAN.
2 The NBG334S reroutes the packet to Gateway A, which is in Subnet 2.
3 The reply from the WAN goes to the NBG334S.
4 The NBG334S then sends it to the computer on the LAN in Subnet 1.
Figure 69 Using IP Alias to Solve the Triangle Route Problem
12.3 General Firewall Screen
Click Security > Firewall to open the General screen. Use this screen to enable or disable the
NBG334S’s firewall, and set up firewall logs.
Figure 70 Security > Firewall > General l
The following table describes the labels in this screen.
Table 50 Security > Firewall > General
LABEL DESCRIPTION
Enable Firewall Select this check box to activate the firewall. The NBG334S 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.