7. Address Translation ........................................................................................ 369
7.1. Overview ............................................................................................ 369
7.2. NAT .................................................................................................. 370
7.3. NAT Pools .......................................................................................... 375
7.4. SAT ................................................................................................... 378
8. User Authentication ........................................................................................ 391
8.1. Overview ............................................................................................ 391
9. VPN ............................................................................................................. 415
9.1. Overview ............................................................................................ 415
9.1.1. VPN Usage ............................................................................... 415
9.1.3. VPN Planning ........................................................................... 417
9.2. VPN Quick Start .................................................................................. 419
9.3. IPsec Components ................................................................................ 429
9.3.1. Overview ................................................................................. 429
9.4. IPsec Tunnels ...................................................................................... 444
9.4.1. Overview ................................................................................. 444
9.5. PPTP/L2TP ......................................................................................... 463
9.5.1. PPTP Servers ............................................................................ 463
9.5.2. L2TP Servers ............................................................................ 464
7
User Manual