Chapter 10 Install and System Administration for FortiOS 5.0 : Advanced concepts : Modem : Modes : Configuring redundant mode
  
Configuring redundant mode
Redundant mode provides a backup to an interface, typically to the Internet. If that interface fails or disconnects, the modem automatically dials the configured phone number(s). Once connected, the FortiGate unit routes all traffic to the modem interface until the monitored interface is up again. The FortiGate unit pings the connection to determine when it is back online.
For the FortiGate to verify when the interface is back up, you need to configure a Ping server for that interface. You will also need to configure security policies between the modem interface and the other interfaces of the FortiGate unit to ensure traffic flow.
To configure redundant mode as needed - web-based manager
1. Go to System > Network > Modem.
2. Select the Mode of Redundant.
3. Select the interface the modem takes over from if it fails.
4. Select the Dial Mode of Dial on Demand.
5. Enter the Idle Timeout of 2 minutes.
6. Select the number of redials the modem attempts if connection fails to 5.
7. Select Apply.
To configure standalone mode as needed- CLI
config system modem
set mode redundant
set interface wan1
set auto-dial enable
set idle-timer 2
set redial 5
end
See Also
Configuring stand alone mode
Ping server
Modes
Modem