ZyXEL Communications Broadband Security Gateway P-312, User Manual, Page: 13 / 254

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