Chapter 15 Configuring Ip Filters; Overview Of Ip Filters; Viewing Your Ip Filter Configuration - ZyXEL Communications Prestige 623 series User Manual

Prestige 623 Series Dual-link ADSL Router
Chapter 15
Configuring IP Filters
The IP filter feature enables you to create rules that control the forwarding of incoming and
outgoing data between your LAN and the Internet. This chapter explains how to create IP filter
rules.

15.1 Overview of IP Filters

IP filters enable you to control the types of data that pass to and from your network. You can create IP filter
rules to block certain computers on your LAN from accessing certain types of data or Internet locations.
You can also block incoming access to computers on your LAN.
When you define an IP filter rule and enable the feature, you instruct the Prestige to examine each data
packet it receives to determine whether it meets criteria set forth in the rule. The criteria can include the size
of the packet, the network or internet protocol it is carrying, the direction in which it is traveling (for
example, from the LAN to the Internet or vice versa), the IP address of the sending computer, the
destination IP address, and other characteristics of the packet data.
If the packet matches the criteria established in a rule, the packet can be either accepted (forwarded towards
its destination), or denied (discarded), depending on the action specified in the rule.
No IP filter rules are predefined and the feature is disabled by default on the
Prestige. All valid data packets are accepted and forwarded to their destination.

15.2 Viewing Your IP Filter Configuration

To view your current IP filter configuration, click Services in the task bar and IP Filter. The IP Filter
Configuration screen displays.
Configuring IP Filters 15-1