ZyXEL P-660HW-D1 v2 User Guide - Page 15

Table of Contents 9.4.2 Types of DoS Attacks 146 9.5 Stateful Inspection ...148 9.5.1 Stateful Inspection Process 149 9.5.2 Stateful Inspection and the ZyXEL Device 150 9.5.3 TCP Security ...150 9.5.4 UDP/ICMP Security 151 9.5.5 Upper Layer Protocols 151 9.6 Guidelines for Enhancing Security with Your Firewall 152 9.6.1 Security In General 152 9.7 Packet Filtering Vs Firewall 153 9.7.1 Packet Filtering: ...153 9.7.2 Firewall ...153 Chapter 10 Firewall Configuration ...155 10.1 Access Methods ...155 10.2 Firewall Policies Overview 155 10.3 Rule Logic Overview ...156 10.3.1 Rule Checklist ...156 10.3.2 Security Ramifications 156 10.3.3 Key Fields For Configuring Rules 157 10.4 Connection Direction ...157 10.4.1 LAN to WAN Rules 158 10.4.2 Alerts ...158 10.5 General Firewall Policy 158 10.6 Firewall Rules Summary 159 10.6.1 Configuring Firewall Rules 161 10.6.2 Customized Services 164 10.6.3 Configuring a Customized Service 164 10.7 Example Firewall Rule ...165 10.8 Predefined Services ...169 10.9 Anti-Probing ...171 10.10 DoS Thresholds ...172 10.10.1 Threshold Values 172 10.10.2 Half-Open Sessions 173 10.10.3 Configuring Firewall Thresholds 173 Chapter 11 Content Filtering ...177 11.1 Content Filtering Overview 177 11.2 Configuring Keyword Blocking 177 11.3 Configuring the Schedule 178 11.4 Configuring Trusted Computers 179 P-660HW-Dx v2 User's Guide 15