Fortinet FortiGate 100 - Manual (Page 10)

Contents
10
Fortinet Inc.
Configuring L2TP ............................................................................................................ 213
Configuring the FortiGate unit as a L2TP gateway ..................................................... 214
Configuring a Windows 2000 client for L2TP.............................................................. 217
Configuring a Windows XP client for L2TP ................................................................. 218
Network Intrusion Detection System (NIDS) ................................................... 221
Detecting attacks ............................................................................................................ 221
Selecting the interfaces to monitor.............................................................................. 222
Disabling the NIDS...................................................................................................... 222
Configuring checksum verification .............................................................................. 222
Viewing the signature list ............................................................................................ 223
Viewing attack descriptions......................................................................................... 223
Enabling and disabling NIDS attack signatures .......................................................... 224
Adding user-defined signatures .................................................................................. 224
Preventing attacks .......................................................................................................... 225
Enabling NIDS attack prevention ................................................................................ 225
Enabling NIDS attack prevention signatures .............................................................. 226
Setting signature threshold values.............................................................................. 226
Configuring synflood signature values ........................................................................ 228
Logging attacks............................................................................................................... 228
Logging attack messages to the attack log................................................................. 228
Reducing the number of NIDS attack log and email messages.................................. 229
Antivirus protection........................................................................................... 231
General configuration steps ............................................................................................ 231
Antivirus scanning........................................................................................................... 232
File blocking .................................................................................................................... 233
Blocking files in firewall traffic ..................................................................................... 233
Adding file patterns to block........................................................................................ 233
Blocking oversized files and emails ................................................................................ 234
Configuring limits for oversized files and email........................................................... 234
Exempting fragmented email from blocking.................................................................... 234
Viewing the virus list ....................................................................................................... 234
Web filtering ....................................................................................................... 235
General configuration steps ............................................................................................ 235
Content blocking ............................................................................................................. 236
Adding words and phrases to the banned word list .................................................... 236
URL blocking................................................................................................................... 237
Using the FortiGate web filter ..................................................................................... 237
Using the Cerberian web filter..................................................................................... 240
Script filtering .................................................................................................................. 242
Enabling the script filter............................................................................................... 242
Selecting script filter options ....................................................................................... 242