ZyXEL Communications ZYWALL10 - Manual (Page 13)

ZyWALL 10 Internet Security Gateway
Table of Contents xiii
11.2 Call Control Support ................................................................................................................ 11-2
11.2.1 Budget Management......................................................................................................... 11-2
11.2.2 Call History ...................................................................................................................... 11-3
11.3 Time and Date Setting .............................................................................................................. 11-4
How often does the ZyWALL update the time?............................................................................... 11-6
11.4 Remote Management Setup...................................................................................................... 11-7
11.5 Boot Commands ....................................................................................................................... 11-8
Chapter 12 Telnet Configuration and Capabilities ............................................................................. 12-1
12.1 About Telnet Configuration...................................................................................................... 12-1
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 Behind the Firewall ....................................................................................................... 12-2
Firewall and Content Filters ......................................................................................................................... 13-1
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 ZyWALL ................................................................................. 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 ZyWALL Firewall .................................................................................. 14-1