ZyXEL Communications 802.11g HomePlug AV ADSL2+ Gateway P-660HWP-Dx User Manual page 15

Part IV: Security ................................................................................... 155
Chapter 10
Firewalls................................................................................................................................. 157
10.1 Firewall Overview ........................................................................................................... 157
10.2 Types of Firewalls ............................................................................................................ 157
10.2.1 Packet Filtering Firewalls ....................................................................................... 157
10.2.2 Application-level Firewalls ...................................................................................... 158
10.2.3 Stateful Inspection Firewalls ................................................................................... 158
10.3 Introduction to ZyXEL's Firewall ...................................................................................... 158
10.3.1 Denial of Service Attacks ....................................................................................... 159
10.4 Denial of Service ............................................................................................................. 159
10.4.1 Basics ..................................................................................................................... 159
10.4.2 Types of DoS Attacks ............................................................................................. 160
10.5 Stateful Inspection ........................................................................................................... 162
10.5.1 Stateful Inspection Process .................................................................................... 163
10.5.2 Stateful Inspection and the P-660HWP-Dx ............................................................ 164
10.5.3 TCP Security .......................................................................................................... 164
10.5.4 UDP/ICMP Security ................................................................................................ 165
10.5.5 Upper Layer Protocols ........................................................................................... 165
10.6 Guidelines for Enhancing Security with Your Firewall ..................................................... 166
10.6.1 Security In General ................................................................................................ 166
10.7 Packet Filtering Vs Firewall ............................................................................................. 167
10.7.1 Packet Filtering: ..................................................................................................... 167
10.7.2 Firewall ................................................................................................................... 167
Chapter 11
Firewall Configuration .......................................................................................................... 169
11.1 Access Methods ............................................................................................................... 169
11.2 Firewall Policies Overview ............................................................................................... 169
11.3 Rule Logic Overview ........................................................................................................ 170
11.3.1 Rule Checklist ........................................................................................................ 170
11.3.2 Security Ramifications ............................................................................................ 170
11.3.3 Key Fields For Configuring Rules .......................................................................... 171
11.4 Connection Direction ........................................................................................................ 171
11.4.1 LAN to WAN Rules ................................................................................................. 172
11.4.2 Alerts ...................................................................................................................... 172
11.5 General Firewall Policy
11.6 Firewall Rules Summary ................................................................................................. 173
11.6.1 Configuring Firewall Rules
11.6.2 Customized Services ............................................................................................. 178
11.6.3 Configuring a Customized Service ....................................................................... 178
11.7 Example Firewall Rule ..................................................................................................... 179
P-660HWP-Dx User's Guide
................................................................................................. 172
................................................................................... 175
Table of Contents
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