5.4. DHCP Relaying ................................................................................... 187
5.5. IP Pools .............................................................................................. 190
6. Security Mechanisms ....................................................................................... 193
6.1. Access Rules ....................................................................................... 193
6.1.1. Introduction .............................................................................. 193
6.1.2. IP spoofing ............................................................................... 193
6.2. ALGs ................................................................................................. 196
6.2.1. Overview ................................................................................. 196
6.2.2. The HTTP ALG ........................................................................ 197
6.2.3. The FTP ALG ........................................................................... 200
6.2.4. The TFTP ALG ......................................................................... 206
6.2.5. The SMTP ALG ........................................................................ 207
6.2.6. The POP3 ALG ......................................................................... 216
6.2.7. The SIP ALG ............................................................................ 216
6.2.9. The TLS ALG ........................................................................... 239
6.3.1. Overview ................................................................................. 242
6.4.1. Overview ................................................................................. 259
6.5.1. Overview ................................................................................. 265
6.5.3. IDP Rules ................................................................................. 267
6.5.7. IDP Actions .............................................................................. 271
6.6.1. Overview ................................................................................. 276
7. Address Translation ........................................................................................ 283
7.1. NAT .................................................................................................. 283
7.2. NAT Pools .......................................................................................... 288
7.3. SAT ................................................................................................... 291
6
User Manual