Chapter 9 High Availability for FortiOS 5.0 : Configuring FRUP : FRUP configuration example : Configuring FGT-B
  
Configuring FGT-B
Use the same firmware version as FGT-A and set the FortiGate unit to factory defaults. Change the host name to FGT-B.
From CLI enter the following command:
config system ha
set hbdev "ha1" 50 "ha2" 100
set override disable
set priority 128
set frup enable
config frup-settings
set active-interface "wan2"
set active-switch-port 14
set backup-interface "wan1"
end
end