ZyXEL Communications 100 Series User Manual

Chapter 19 Firewall

ZyWALL USG 100/200 Series User’s Guide

• The third row is (still) the firewall’s default policy of allowing all traffic from LAN1 to go 

to the WAN.

Alternatively, you configure a LAN to WAN rule with the CEO’s user name (say CEO) to 
allow IRC traffic from any source IP address to go to any destination address.

Your firewall would have the following configuration. 

• The first row allows any LAN1 computer to access the IRC service on the WAN by 

logging into the ZyWALL with the CEO’s user name. 

• The second row blocks LAN access to the IRC service on the WAN. 

• The third row is (still) the firewall’s default policy of allowing all traffic from LAN1 to go 

to the WAN.

The rule for the CEO must come before the rule that blocks all LAN1 to WAN IRC traffic. If 
the rule that blocks all LAN1 to WAN IRC traffic came first, the CEO’s IRC traffic would 
match that rule and the ZyWALL would drop it and not check any other firewall rules.

The following Internet firewall rule example allows a hypothetical MyService from the WAN 
to IP addresses 192.168.1.10 through 192.168.1.15 (Dest_1) on LAN1. 

1 Click Firewall. Click the Add icon (

) in the heading row to configure a new first 

entry (as in this example) or the Add icon (

) in an entry to add a rule below the 

selected entry. Remember the sequence (priority) of the rules is important since they are 
applied in order.

Table 112   Limited LAN to WAN IRC Traffic Example 2

1

CEO

Any

Any

Any

IRC

Allow

2

Any

Any

Any

Any

IRC

Deny

Default

Any

Any

Any

Any

Any

Allow