Quick Reference Guide

Reference Guide for the Model RT338 ISDN Router
9-6 Configuring Filters
Destination:
IP Addr Enter the destination IP address of the packet you want to filter. The address is usually
written in dotted-decimal notation such as a.b.c.d where a, b, c, and d are numbers
between 0 and 255.
IP Mask Enter the IP subnet mask that is used to mask the bits of the IP address given in
Destination: IP Addr. Refer to Chapter 1, “Introduction,” for more information.
Port # Enter the destination port of the packets that you want to filter. The range of this field is
0 to 65535.
Port # Comp Select the comparison quantifier you want to enable to compare to the value given in
Destination: Port #. There are five options for this field:
• None (default)
• Less
• Greater
• Equal
• Not Equal
Source:
IP Addr Enter the source IP address of the packet you want to filter. The IP address is usually
written in dotted-decimal notation such as a.b.c.d where a, b, c, and d are numbers
between 0 and 255.
IP Mask Enter the IP subnet mask that is used to mask the bits of the IP Address given in
Source: IP Addr. See “Netmask” on page 1-9 for information about IP subnet masks.
Port # Enter the source port of the packets that you want to filter. The range of this field is
0 to 65535.
Port # Comp Select the comparison quantifier you want to use to compare to the value given in
Source: Port #. There are five options for this field:
• None (Default)
• Less
• Greater
• Equal
• Not Equal
TCP Estab Choose what type of TCP packets to filter. There are two options:
• Yes—Filter match only established TCP connections
• No—Filter match both initial and established TCP connections (Default)
This field is dependent upon the IP Protocol field. This field is inactive (N/A) unless the
value in that field is 6 (TCP protocol). In this field, you determine
More Choose whether or not you want to pass the packet through the next filter rule before
an action is taken. Two options are available for this field:
•Yes
• No (default)
If More is Yes, then Action Matched and Action Not Matched is N/A.
Table 9-4. TCP/IP Filter Rule Fields (continued)
Field Description
Filter.fm Page 6 Friday, October 6, 2000 5:28 PM