P312 Broadband Security Gateway
Table Of Contents xiii
12.2 Telnet Under NAT....................................................................................................................12-1
12.3 Telnet Capabilities....................................................................................................................12-1
12.3.1 Single Administrator........................................................................................................ 12-1
12.3.2 System Timeout................................................................................................................12-2
12.4 Telnet Under the Firewall.........................................................................................................12-2
Firewall and Content Filters............................................................................................................IV
Chapter 13 What is a Firewall......................................................................................................13-1
13.1 Types of Firewalls.................................................................................................................... 13-1
13.1.1 Packet Filtering Firewalls.................................................................................................13-1
13.1.2 Application-level Firewalls.............................................................................................. 13-1
13.1.3 Stateful Inspection firewalls............................................................................................. 13-2
13.2 Introduction to ZyXEL’s Firewall............................................................................................13-2
13.3 Denial of Service...................................................................................................................... 13-3
13.3.1 Basics................................................................................................................................13-3
13.3.2 Types of DoS attacks........................................................................................................13-4
13.4 Stateful Inspection.................................................................................................................... 13-6
13.4.1 Stateful Inspection Process...............................................................................................13-7
13.4.2 Stateful Inspection & the Prestige.................................................................................... 13-8
13.4.3 TCP Security.................................................................................................................... 13-8
13.4.4 UDP/ICMP Security......................................................................................................... 13-9
13.4.5 Upper Layer Protocols......................................................................................................13-9
13.5 Guidelines For Enhancing Security With Your Firewall..........................................................13-9
13.5.1 Security In General.........................................................................................................13-10
Chapter 14 Introducing the Prestige Firewall ..............................................................................14-1
14.1 SMT Menus.............................................................................................................................. 14-1
14.1.1 View Firewall Log............................................................................................................14-2
14.1.2 Attack Types.....................................................................................................................14-2
14.2 The Big Picture – Filtering, Firewall and NAT........................................................................ 14-5
14.3 Packet Filtering Vs Firewall..................................................................................................... 14-6
14.3.1 Packet Filtering:................................................................................................................14-6
14.3.2 Firewall:............................................................................................................................14-7
Chapter 15 Introducing the Prestige Web Configurator...............................................................15-1
15.1 Web Configurator Login and Welcome Screens...................................................................... 15-1
15.2 Enabling the Firewall............................................................................................................... 15-2