ZyXEL Communications ZYWALL USG 2000 Manual page 325

• The first row blocks LAN access to the IRC service on the WAN.
• The second row is the firewall's default policy that allows all traffic from the LAN
to go to the WAN.
The ZyWALL applies the firewall rules in order. So for this example, when the
ZyWALL receives traffic from LAN, it checks it against the first rule. If the traffic
matches (if it is IRC traffic) the firewall takes the action in the rule (drop) and
stops checking the firewall rules. Any traffic that does not match the first firewall
rule will match the default rule and the ZyWALL forwards it.
Now suppose that your company wants to let the CEO use IRC. You can configure
a LAN to WAN firewall rule that allows IRC traffic from the IP address of the CEO's
computer. You can also configure a LAN to WAN rule that allows IRC traffic from
any computer through which the CEO logs into the ZyWALL with his/her user
name. In order to make sure that the CEO's computer always uses the same IP
address, make sure it either:
• Has a static IP address,
or
• You configure a static DHCP entry for it so the ZyWALL always assigns it the
same IP address (see
Now you configure a LAN to WAN firewall rule that allows IRC traffic from the IP
address of the CEO's computer (192.168.1.7 for example) to go to any destination
address. You do not need to specify a schedule since you want the firewall rule to
always be in effect. The following figure shows the results of your two custom
rules.
Figure 205 Limited LAN to WAN IRC Traffic Example
ZyWALL USG 2000 User's Guide
DHCP Settings on page 236
Chapter 20 Firewall
for information on DHCP).
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