ZyXEL p-2802h-i1 Manual Do Utilizador

 Chapter 11 Firewalls

P-2802H(W)(L)-I Series User’s Guide

• LAN to WAN

These rules specify which computers on the LAN can access which computers or services 
on the WAN.

By default, the ZyXEL Device’s stateful packet inspection drops packets traveling in the 
following directions:

• WAN  to  LAN

These rules specify which computers on the WAN can access which computers or services 
on the LAN. 

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You also need to configure NAT port forwarding (or full featured NAT address 
mapping rules) to allow computers on the WAN to access devices on the LAN.

• WAN  to  WAN/  Router 

By default the ZyXEL Device stops computers on the WAN from managing the ZyXEL 
Device or using the ZyXEL Device as a gateway to communicate with other computers on 
the WAN. You could configure one of these rules to allow a WAN computer to manage the 
ZyXEL Device.

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You also need to configure the remote management settings to allow a WAN 
computer to manage the ZyXEL Device.

You may define additional rules and sets or modify existing ones but please exercise extreme 
caution in doing so.
For example, you may create rules to:

• Block certain types of traffic, such as IRC (Internet Relay Chat), from the LAN to the 

Internet.

• Allow certain types of traffic, such as Lotus Notes database synchronization, from specific 

hosts on the Internet to specific hosts on the LAN.

• Allow everyone except your competitors to access a web server.
• Restrict use of certain protocols, such as Telnet, to authorized users on the LAN.

These custom rules work by comparing the source IP address, destination IP address and IP 
protocol type of network traffic to rules set by the administrator. Your customized rules take 
precedence and override the ZyXEL Device’s default rules.