Chapter 11 Firewall
Your firewall would have the following configuration.
Table 66 Blocking All LAN to WAN IRC Traffic Example
# | SOURCE | DESTINATIO | SCHEDULE | SERVICE | ACTION | |
N | ||||||
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1 | Any | Any | Any | IRC | Drop | |
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Default | Any | Any | Any | Any | Allow | |
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•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 Section 6.8 on page 153 for information on static DHCP).
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 154 Limited LAN to WAN IRC Traffic Example
Your firewall would have the following configuration.
Table 67 Limited LAN to WAN IRC Traffic Example
# | SOURCE | DESTINATIO | SCHEDULE | SERVICE | ACTION | |
N | ||||||
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1 | 192.168.1.7 | Any | Any | IRC | Allow | |
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2 | Any | Any | Any | IRC | Drop | |
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Default | Any | Any | Any | Any | Allow | |
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| 249 |
ZyWALL 2WG User’s Guide | |
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