ZyWALL 50 Internet Security Gateway
6.2.1
6.2.2
Applying NAT ....................................................................................................................6-6
6.3
NAT Setup ..................................................................................................................................6-8
6.3.1
Address Mapping Sets ........................................................................................................6-8
6.4
6.4.1
6.5
General NAT Examples............................................................................................................6-16
6.5.1
Internet Access Only.........................................................................................................6-16
6.5.2
6.5.3
6.5.4
Chapter 7 Firewalls ..................................................................................................................................7-1
7.1
What Is a Firewall? .....................................................................................................................7-1
7.2
Types of Firewalls ......................................................................................................................7-1
7.2.1
7.2.2
7.2.3
7.3
7.4
Denial of Service ........................................................................................................................7-3
7.4.1
Basics..................................................................................................................................7-3
7.4.2
Types of DoS Attacks .........................................................................................................7-4
7.5
Stateful Inspection ......................................................................................................................7-7
7.5.1
7.5.2
7.5.3
TCP Security.....................................................................................................................7-10
7.5.4
UDP/ICMP Security .........................................................................................................7-10
7.5.5
Upper Layer Protocols ......................................................................................................7-11
Table Of Contents
xi