ZyXEL Communications Corporation EMG2881-T20A Manuel D’Utilisation

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EMG2881-T20A User’s Guide
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C
HAPTER
 10
Security
10.1  Overview   
Use these screens to enable and configure the firewall that protects your EMG2881-T20A 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 56   Default Firewall Action
10.1.1  What You Can Do
• Use the IPv4 Firewall screen to enable or disable the EMG2881-T20A’s IPv4 firewall (
).
• Use the IPv6 Firewall screen to enable or disable the EMG2881-T20A’s IPv6 firewall (
).
10.1.2  What You Need To Know
The following terms and concepts may help as you read through this chapter.