Wireless Gateway Series User's Guide

ZyAIR Wireless Gateway Series User’s Guide
x Table of Contents
Chapter 11 Introduction to Firewalls ....................................................................................................... 11-1
11.1 Firewall Overview ...................................................................................................................11-1
11.2 Types of Firewalls....................................................................................................................11-1
11.2.1 Packet Filtering Firewalls ................................................................................................11-1
11.2.2 Application-level Firewalls..............................................................................................11-1
11.2.3 Stateful Inspection Firewalls............................................................................................11-2
11.3 Introduction to ZyXEL’s Firewall ...........................................................................................11-2
11.4 Denial of Service .....................................................................................................................11-2
11.4.1 Basics ...............................................................................................................................11-3
11.4.2 Types of DoS Attacks ......................................................................................................11-4
11.5 Stateful Inspection ...................................................................................................................11-7
Chapter 12 Firewall Screens .....................................................................................................................12-1
12.1 Access Methods .......................................................................................................................12-1
12.2 Firewall Policies Overview......................................................................................................12-1
12.3 Rule Logic Overview...............................................................................................................12-2
12.3.1 Rule Checklist..................................................................................................................12-2
12.3.2 Security Ramifications.....................................................................................................12-2
12.3.3 Key Fields For Configuring Rules ...................................................................................12-3
12.4 Guidelines For Enhancing Security With Your Firewall .........................................................12-3
12.5 Connection Direction Examples ..............................................................................................12-4
12.5.1 LAN to WAN Rules.........................................................................................................12-4
12.5.2 WAN to LAN Rules.........................................................................................................12-5
12.6 Enabling Firewall.....................................................................................................................12-6
12.6.1 Configuring Content Filtering..........................................................................................12-8
12.6.2 Configuring Firewall Services .......................................................................................12-11
12.6.3 Predefined Services........................................................................................................12-13
Chapter 13 Remote Management.............................................................................................................13-1
13.1 Remote Management Overview............................................................................................... 13-1
13.1.1 Remote Management Limitations....................................................................................13-1
13.1.2 Remote Management and NAT .......................................................................................13-2
13.1.3 System Timeout ...............................................................................................................13-2
13.2 Telnet .......................................................................................................................................13-2
13.3 Configuring TELNET..............................................................................................................13-3
13.4 Configuring FTP......................................................................................................................13-4
13.5 Configuring WWW..................................................................................................................13-5
13.6 Configuring SNMP ..................................................................................................................13-6
13.6.1 Supported MIBs...............................................................................................................13-8
13.6.2 SNMP Traps ....................................................................................................................13-8
13.6.3 REMOTE MANAGEMENT: SNMP ..............................................................................13-9
13.7 Configuring DNS...................................................................................................................13-10
13.8 Configuring Security..............................................................................................................13-11