ZyXEL Communications Prestige 2602H Series - Manual (Page 16)

Prestige 2602H/HW Series User’s Guide
16 Table of Contents
Chapter 11
Dynamic DNS Setup............................................................................................. 161
11.1 Dynamic DNS .................................................................................................161
11.1.1 DYNDNS Wildcard ................................................................................161
11.2 Configuring Dynamic DNS .............................................................................161
Chapter 12
Time and Date....................................................................................................... 163
12.1 Pre-defined NTP Time Servers List ................................................................163
12.2 Configuring Time and Date ............................................................................163
Chapter 13
Firewalls................................................................................................................ 167
13.1 Firewall Overview ...........................................................................................167
13.2 Types of Firewalls ..........................................................................................167
13.2.1 Packet Filtering Firewalls ......................................................................167
13.2.2 Application-level Firewalls ....................................................................167
13.2.3 Stateful Inspection Firewalls ................................................................168
13.3 Introduction to ZyXEL’s Firewall .....................................................................168
13.3.1 Denial of Service Attacks ......................................................................169
13.4 Denial of Service ............................................................................................169
13.4.1 Basics ...................................................................................................169
13.4.2 Types of DoS Attacks ...........................................................................170
13.4.2.1 ICMP Vulnerability ......................................................................172
13.4.2.2 Illegal Commands (NetBIOS and SMTP) ....................................172
13.4.2.3 Traceroute ...................................................................................173
13.5 Stateful Inspection ..........................................................................................173
13.5.1 Stateful Inspection Process ..................................................................174
13.5.2 Stateful Inspection and the Prestige .....................................................175
13.5.3 TCP Security .........................................................................................175
13.5.4 UDP/ICMP Security ..............................................................................176
13.5.5 Upper Layer Protocols ..........................................................................176
13.6 Guidelines for Enhancing Security with Your Firewall ....................................176
13.6.1 Security In General ...............................................................................177
13.7 Packet Filtering Vs Firewall ............................................................................178
13.7.1 Packet Filtering: ....................................................................................178
13.7.1.1 When To Use Filtering .................................................................178
13.7.2 Firewall .................................................................................................178
13.7.2.1 When To Use The Firewall ..........................................................178
Chapter 14
Firewall Configuration ......................................................................................... 181
14.1 Access Methods .............................................................................................181