Firewall Rules Example; Figure 132 Blocking All Lan To Wan Irc Traffic Example; Table 46 Blocking All Lan To Wan Irc Traffic Example - ZyXEL Communications ZyWALL 2 Plus User Manual

Chapter 11 Firewall
Once these questions have been answered, adding rules is simply a matter of entering the
information into the correct fields in the web configurator screens.

11.5 Firewall Rules Example

Suppose that your company decides to block all of the LAN users from using IRC (Internet
Relay Chat) through the Internet. To do this, you would configure a LAN to WAN firewall
rule that blocks IRC traffic from any source IP address from going to any destination address.
You do not need to specify a schedule since you need the firewall rule to always be in effect.
The following figure shows the results of this rule.

Figure 132 Blocking All LAN to WAN IRC Traffic Example

Your firewall would have the following configuration.

Table 46 Blocking All LAN to WAN IRC Traffic Example

#
1
Default
• 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 the 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. 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
200
DESTINATIO
SOURCE
N
Any Any
Any Any
Section 6.8 on page 139
SCHEDULE SERVICE
Any IRC
Any Any
for information on static DHCP).
ACTION
Drop
Allow
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