Packet Filters; Introduction; Filtering Overview; Filtering Capabilities - 3Com OfficeConnect 3C100XF Cli User's Manual

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Introduction

Filtering Overview

Filtering Capabilities

Filter Types

P F
ACKET ILTERS
This chapter describes procedures for setting up packet filters for the
OfficeConnect Gateway. The following topics are described:
Filtering Overview


Filter Types


Creating Filters


Configuring Filters


Managing Filters


Filter Examples


Keywords


Packet Filters are primarily used in networks that cross organizational or corporate
boundaries. They control inter-network data transmission by accepting or rejecting
passage of specific packets through network interfaces based on packet header
information.
When data packets are received by a network interface, the packet filter analyzes
the packet header information against its set of rules. Based on these rules that
you define, the filter permits the packet to pass through or discards it.
The OfficeConnect Gateway supports the following filtering capabilities:
Input and output filtering; packet filters can be created to control inbound or


outbound data packets
Source and destination address filtering; a packet filter can accept or deny


access to a host or user based on the address of the source and / or destination
Protocol Filtering; inbound or outbound network traffic can be evaluated based


on the protocol
Source and destination port filtering; a packet filter can control what services


local or remote users can access
Filtering can be used to control the content of IP Routing Information Packets


(RIP) sent / received on specific ports
Established session filtering; a packet filter can permit users to connect with a


remote network without letting remote users have access to the local network
(or vice versa)
Filters can be classified by the following types: