ZyXEL Communications Corporation VMG1312T10C Manuel D’Utilisation

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VMG1312-T10C User’s Guide
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Firewall
14.1  Overview
This chapter shows you how to enable the Device firewall. Use the firewall to protect your Device 
and network from attacks by hackers on the Internet and control access to it. The firewall:
• allows traffic that originates from your LAN computers to go to all other networks. 
• blocks traffic that originates on other networks from going to the LAN.
• blocks SYN and port scanner attacks.
By default, the Device blocks DDOS, LAND and Ping of Death attacks whether the firewall is enabled 
or disabled.
The following figure illustrates the 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 103   
Default Firewall Action
14.1.1  What You Can Do in the Firewall Screens
• Use  the  General screen (
) to select the firewall protection level on the 
Device.
• Use  the  Default Action screen (
) to set the default action that the 
firewall takes on packets that do not match any of the firewall rules.
• Use  the  Rules screen (
) to view the configured firewall rules and add, 
edit or remove a firewall rule.
WAN
LAN
3
4
1
2
A