ZyXEL Communications 802.11g ADSL 2+ 4-Port Security Gateway HW-D Series - Manual (Page 16)

P-662H/HW-D Series User’s Guide
16 Table of Contents
11.3 Rule Logic Overview ......................................................................................182
11.3.1 Rule Checklist .......................................................................................182
11.3.2 Security Ramifications ..........................................................................182
11.3.3 Key Fields For Configuring Rules .........................................................183
11.3.3.1 Action ...........................................................................................183
11.3.3.2 Service .........................................................................................183
11.3.3.3 Source Address ...........................................................................183
11.3.3.4 Destination Address ....................................................................183
11.4 Connection Direction ......................................................................................183
11.4.1 LAN to WAN Rules ................................................................................184
11.4.2 Alerts .....................................................................................................184
11.5 General Firewall Policy ................................................................................184
11.6 Firewall Rules Summary ...............................................................................185
11.6.1 Configuring Firewall Rules ...................................................................187
11.6.2 Customized Services ............................................................................190
11.6.3 Configuring A Customized Service .......................................................191
11.7 Example Firewall Rule ....................................................................................191
11.8 Predefined Services .......................................................................................195
11.9 Anti-Probing ....................................................................................................197
11.10 DoS Thresholds ...........................................................................................198
11.10.1 Threshold Values ................................................................................198
11.10.2 Half-Open Sessions ............................................................................199
11.10.2.1 TCP Maximum Incomplete and Blocking Time ..........................199
11.10.3 Configuring Firewall Thresholds ..........................................................200
Chapter 12
Anti-Virus Packet Scan ........................................................................................ 203
12.1 Overview ........................................................................................................203
12.1.1 Types of Computer Viruses ..................................................................203
12.2 Signature-Based Virus Scan ..........................................................................203
12.2.1 Computer Virus Infection and Prevention .............................................204
12.3 Introduction to the ZyXEL Device Anti-virus Packet Scan .............................204
12.3.1 How the ZyXEL Device Virus Scan Works ..........................................205
12.3.2 Limitations of the ZyXEL Device Packet Scan ......................................205
12.4 Anti-Virus Packet Scan Configuration ...........................................................205
12.5 Registration and Online Update ....................................................................207
12.5.1 Updating the Anti-Virus Packet Scan ....................................................209
Chapter 13
Content Filtering .................................................................................................. 211
13.1 Content Filtering Overview ............................................................................211
13.2 Configuring Keyword Blocking ......................................................................211
13.3 Configuring the Schedule ..............................................................................212