Table of Contents
ZyWALL P1 User’s Guide
14
Chapter 9
Firewall................................................................................................................................... 141
9.1 Firewall Overview ............................................................................................................. 141
9.2 Packet Direction Matrix ...................................................................................................... 142
9.3 Packet Direction Examples ................................................................................................ 143
9.3.1 To VPN Packet Direction .......................................................................................... 144
9.3.2 From VPN Packet Direction ..................................................................................... 145
9.3.3 From VPN To VPN Packet Direction ........................................................................ 146
9.4 Security Considerations ..................................................................................................... 148
9.5 Firewall Rules Example .....................................................................................................148
9.6 Asymmetrical Routes ......................................................................................................... 150
9.6.1 Asymmetrical Routes and IP Alias ........................................................................... 150
9.7 Firewall Default Rule (Router Mode) ................................................................................. 151
9.8 Firewall Default Rule (Bridge Mode) ................................................................................. 153
9.9 Firewall Rule Summary .................................................................................................... 155
9.9.1 Firewall Edit Rule ................................................................................................... 157
9.10 Anti-Probing ................................................................................................................... 160
9.11 Firewall Thresholds ....................................................................................................... 161
9.11.1 Threshold Values .................................................................................................... 162
9.12 Threshold Screen ............................................................................................................ 162
9.13 Service ............................................................................................................................ 164
9.13.1 Firewall Edit Custom Service ................................................................................ 165
9.14 My Service Firewall Rule Example .................................................................................. 165
Chapter 10
Intrusion Detection and Prevention (IDP)........................................................................... 171
10.1 Introduction to IDP ........................................................................................................ 171
10.2 Firewalls and Intrusions ................................................................................................... 171
10.3 IDS and IDP .................................................................................................................... 172
10.4 Host IDP ......................................................................................................................... 172
10.5 Network IDP ................................................................................................................... 172
10.6 Example Intrusions .......................................................................................................... 172
10.6.1 SQL Slammer Worm .............................................................................................. 173
10.6.2 Blaster W32.Worm ................................................................................................. 173
10.6.3 Nimda ..................................................................................................................... 173
10.6.4 MyDoom ................................................................................................................. 173
10.7 ZyWALL IDP .................................................................................................................... 174
Chapter 11
Configuring IDP..................................................................................................................... 175
11.1 Overview .......................................................................................................................... 175
11.2 General Setup .................................................................................................................. 175
11.3 IDP Signatures ................................................................................................................. 177
