Firewall Rules Overview - ZyXEL Communications LTE Series User Manual

12.7.1 Firewall Rules Overview

Your customized rules take precedence and override the Zyxel Device's default settings. The Zyxel
Device checks the source IP address, destination IP address and IP protocol type of network traffic
against the firewall rules (in the order you list them). When the traffic matches a rule, the Zyxel Device
takes the action specified in the rule.
Firewall rules are grouped based on the direction of travel of packets to which they apply:
• LAN to Router
• LAN to WAN
By default, the Zyxel Device's stateful packet inspection allows packets traveling in the following
directions:
• LAN to Router
These rules specify which computers on the LAN can manage the Zyxel Device (remote
management).
Note: You can also configure the remote management settings to allow only a specific
computer to manage the Zyxel Device.
• 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.
Note: 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 Router
By default the Zyxel Device stops computers on the WAN from managing the Zyxel Device. You could
configure one of these rules to allow a WAN computer to manage the Zyxel Device.
Note: 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.
Chapter 12 Firewall
• WAN to LAN
• WAN to Router
LTE Series User's Guide
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