Quick Reference Guide

Reference Guide for the Model RT338 ISDN Router

9-2 Configuring Filters

Router Filter Structure

You can configure up to 12 filter sets, each with up to six rules. For IP packets, these rules involve

comparing the protocol type of a data packet (for example, TCP, UDP), source or destination

address, or port number. Also, a generic filter may be defined to merely test for a byte or pattern of

bytes in a particular location in the packet. When a rule is met (or not met), a user-specified action

is taken. This action may be to forward the packet, drop the packet, or go to the next rule.

When implementing these filter sets, you can link up to four of the filter sets to screen the data

packet. Therefore, with each filter set having up to six rules, you can have a maximum of 24 rules

active for a single filtering application.

Configuring a Filter Set

To configure a filter set:

From the Manager Interface Main Menu, enter 21 to open Menu 21 - Filter Set Configuration

as shown in Figure 9-2.

From this menu, you can choose from 12 filter sets.

Figure 9-2. Menu 21 - Filter Set Configuration

Menu 21 - Filter Set Configuration

Filter Filter

Set # Comments Set # Comments

------ ----------------- ------ -----------------

1 $netbeui 7 _______________

2 NetBIOS LAN 8 _______________

3 _______________ 9 _______________

4 _______________ 10 _______________

5 _______________ 11 _______________

6 _______________ 12 _______________

Enter Filter Set Number to Configure= 0

Edit Comments=

Press ENTER to Confirm or ESC to Cancel:

Filter.fm Page 2 Friday, October 6, 2000 5:28 PM