ZyXEL Communications Corporation NBG6503 Manuel D’Utilisation

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NBG6503 User’s Guide
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Firewall
17.1  Overview   
This chapter shows you how to enable and configure the firewall that protects your Router and your 
LAN from unwanted or malicious traffic.
Enable the firewall to protect your LAN computers from attacks by hackers on the Internet and 
control access between the LAN and WAN. By default the firewall:
• allows traffic that originates from your LAN computers to go to all of the networks. 
• blocks traffic that originates on the other networks from going to the LAN. 
The following figure illustrates the default firewall action. User A can initiate an IM (Instant 
Messaging) session from the LAN to the WAN (1). Return traffic for this session is also allowed (2). 
However other traffic initiated from the WAN is blocked (3 and 4).
Figure 91   
Default Firewall Action
17.2  What You Can Do
• Use  the  General (
) screen to enable or disable the Router’s firewall.
• Use  the  Services screen (
) screen enable service blocking, enter/
delete/modify the services you want to block and the date/time you want to block them.