Chapter 9 High Availability for FortiOS 5.0 : HA and failover protection : Remote link failover : Detecting HA remote IP monitoring failovers
  
Detecting HA remote IP monitoring failovers
Just as with any HA failover, you can detect HA remote IP monitoring failovers by using SNMP to monitor for HA traps. You can also use alert email to receive notifications of HA status changes and monitor log messages for HA failover log messages. In addition, FortiGate units send the critical log message Ping Server is down when a ping server fails. The log message includes the name of the interface that the ping server has been added to.