ZyXEL Communications ZyWall 70 User Manual page 13

9.6 Guidelines For Enhancing Security With Your Firewall ....................................177
9.7 Packet Filtering Vs Firewall ..............................................................................177
Chapter 10
Firewall Screens................................................................................................... 179
10.1 Access Methods .............................................................................................179
10.2 Firewall Policies Overview .............................................................................179
10.3 Rule Logic Overview ......................................................................................180
10.4 Connection Direction Examples .....................................................................181
10.5 Alerts ..............................................................................................................183
10.6 Configuring Firewall .......................................................................................183
10.7 Example Firewall Rule ...................................................................................190
10.8 Predefined Services .......................................................................................194
10.9 Anti-Probing ...................................................................................................196
10.10 DoS Thresholds ...........................................................................................197
Chapter 11
Content Filtering Screens ................................................................................... 201
11.1 Content Filtering Overview .............................................................................201
Table of Contents
9.5.3 TCP Security ...........................................................................................175
9.5.4 UDP/ICMP Security ................................................................................176
9.5.5 Upper Layer Protocols ............................................................................176
9.7.1 Packet Filtering: ......................................................................................177
9.7.1.1 When To Use Filtering ...................................................................177
9.7.2 Firewall ...................................................................................................178
9.7.2.1 When To Use The Firewall ............................................................178
10.3.1 Rule Checklist .......................................................................................180
10.3.2 Security Ramifications ..........................................................................181
10.3.3 Key Fields For Configuring Rules .........................................................181
10.3.3.1 Action ..........................................................................................181
10.3.3.2 Service ........................................................................................181
10.3.3.3 Source Address ...........................................................................181
10.3.3.4 Destination Address ....................................................................181
10.4.1 LAN To WAN Rules ..............................................................................182
10.4.2 WAN To LAN Rules ..............................................................................182
10.6.1 Rule Summary ......................................................................................186
10.6.2 Configuring Firewall Rules ....................................................................187
10.6.3 Configuring Custom Services ...............................................................190
10.10.1 Threshold Values ................................................................................198
10.10.2 Half-Open Sessions ............................................................................198
10.10.2.1 TCP Maximum Incomplete and Blocking Time .........................198
11.1.1 Restrict Web Features ..........................................................................201
11.1.2 Create a Filter List .................................................................................201
ZyWALL 70 User's Guide
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