ZyXEL Communications ZyXEL ZyWALL 35 - Manual (Page 13)

ZyWALL 35 User’s Guide
11
Chapter 10
Firewall Screens................................................................................................... 185
10.1 Access Methods .............................................................................................185
10.2 Firewall Policies Overview .............................................................................185
10.3 Rule Logic Overview ......................................................................................186
10.3.1 Rule Checklist .......................................................................................186
10.3.2 Security Ramifications ..........................................................................187
10.3.3 Key Fields For Configuring Rules .........................................................187
10.3.3.1 Action ..........................................................................................187
10.3.3.2 Service ........................................................................................187
10.3.3.3 Source Address ...........................................................................187
10.3.3.4 Destination Address ....................................................................188
10.4 Connection Direction Examples .....................................................................188
10.4.1 LAN To WAN Rules ..............................................................................188
10.4.2 WAN To LAN Rules ..............................................................................188
10.5 Alerts ..............................................................................................................189
10.6 Configuring Firewall .......................................................................................189
10.6.1 Rule Summary ......................................................................................192
10.6.2 Configuring Firewall Rules ....................................................................193
10.6.3 Configuring Custom Services ...............................................................196
10.7 Example Firewall Rule ...................................................................................196
10.8 Predefined Services .......................................................................................200
10.9 Anti-Probing ...................................................................................................202
10.10 Configuring Attack Alert ...............................................................................203
10.10.1 Threshold Values ................................................................................204
10.10.2 Half-Open Sessions ............................................................................204
10.10.2.1 TCP Maximum Incomplete and Blocking Time .........................204
Chapter 11
Content Filtering Screens ................................................................................... 207
11.1 Content Filtering Overview .............................................................................207
11.1.1 Restrict Web Features ..........................................................................207
11.1.2 Create a Filter List .................................................................................207
11.1.3 Customize Web Site Access ................................................................207
11.2 General Content Filter Configuration ..............................................................207
11.3 Content Filtering with an External Database ..................................................210
11.4 Categories and Registering ............................................................................210
11.5 Customization .................................................................................................217
11.6 Customizing Keyword Blocking URL Checking ..............................................220
11.6.1 Domain Name or IP Address URL Checking ........................................220
11.6.2 Full Path URL Checking ........................................................................220
11.6.3 File Name URL Checking .....................................................................220