ZyXEL Communications ZYWALL 35 User Manual page 16

Table of Contents
Part III: Security.................................................................................... 241
Chapter 11
Firewall................................................................................................................................... 243
11.1 Firewall Overview ............................................................................................................ 243
11.2 Packet Direction Matrix .................................................................................................... 244
11.3 Packet Direction Examples .............................................................................................. 246
11.3.1 To VPN Packet Direction ........................................................................................ 247
11.3.2 From VPN Packet Direction ................................................................................... 248
11.3.3 From VPN To VPN Packet Direction ...................................................................... 250
11.4 Security Considerations ................................................................................................... 252
11.5 Firewall Rules Example ................................................................................................... 253
11.6 Asymmetrical Routes ....................................................................................................... 254
11.6.1 Asymmetrical Routes and IP Alias ......................................................................... 255
11.7 Firewall Default Rule (Router Mode) ................................................................................ 255
11.8 Firewall Default Rule (Bridge Mode) .............................................................................. 258
11.9 Firewall Rule Summary ................................................................................................... 259
11.9.1 Firewall Edit Rule
11.10 Anti-Probing
11.11 Firewall Thresholds
11.11.1 Threshold Values .................................................................................................. 266
11.12 Threshold Screen ........................................................................................................... 266
11.13 Service .......................................................................................................................... 268
11.13.1 Firewall Edit Custom Service .............................................................................. 269
11.14 My Service Firewall Rule Example ................................................................................ 270
Chapter 12
Intrusion Detection and Prevention (IDP)........................................................................... 275
12.1 Introduction to IDP
12.1.1 Firewalls and Intrusions ......................................................................................... 275
12.1.2 IDS and IDP .......................................................................................................... 276
12.1.3 Host IDP ................................................................................................................ 276
12.1.4 Network IDP .......................................................................................................... 276
12.1.5 Example Intrusions ................................................................................................. 276
12.1.6 ZyWALL IDP .......................................................................................................... 278
Chapter 13
Configuring IDP..................................................................................................................... 279
13.1 Overview .......................................................................................................................... 279
13.1.1 Interfaces ............................................................................................................... 279
13.2 General Setup ................................................................................................................. 280
13.3 IDP Signatures ................................................................................................................ 282
13.3.1 Attack Types ........................................................................................................... 282
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ZyWALL 5/35/70 Series User's Guide