Configuring The Firewall Screen - ZyXEL Communications UAG4100 User Manual

The reply from the WAN goes to the UAG.
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The UAG then sends it to the computer on the LAN1 in Subnet 1.
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Figure 164 Using Virtual Interfaces to Avoid Asymmetrical Routes

25.2.1 Configuring the Firewall Screen

Click Configuration > Firewall to open the Firewall screen. Use this screen to enable or disable
the firewall and asymmetrical routes, set a maximum number of sessions per host, and display the
configured firewall rules. Specify from which zone packets come and to which zone packets travel to
display only the rules specific to the selected direction. Note the following.
• Besides configuring the firewall, you also need to configure NAT rules to allow computers on the
WAN to access LAN devices. See
• The UAG applies NAT (Destination NAT) settings before applying the firewall rules. So for
example, if you configure a NAT entry that sends WAN traffic to a LAN IP address, when you
configure a corresponding firewall rule to allow the traffic, you need to set the LAN IP address as
the destination.
• The ordering of your rules is very important as rules are applied in sequence.
Chapter 25 Firewall
Chapter 15 on page 179
UAG4100 User's Guide
241
for more information.