Chapter 9 High Availability for FortiOS 5.0 : FortiGate Session Life Support Protocol (FGSP) : Synchronizing the configuration
  
Synchronizing the configuration
The FGSP also includes configuration synchronization, allowing you to make configuration changes once for both FortiGate units instead of requiring you to make duplicate configuration changes on each FortiGate unit. Settings that identify the FortiGate unit to the network, for example, interface IP addresses and BGP neighbor settings, are not synchronized so each FortiGate unit maintains its identity on the network.
By default configuration synchronization is disabled. You can use the following command to enable it.
config system ha
set standalone-config-sync enable
end