Chapter 13 Logging and Reporting : Troubleshooting and logging : Connection issues between FortiGate unit and logging devices
  
Connection issues between FortiGate unit and logging devices
If external logging devices are not recording the log information properly or at all, the problem will likely be due to one of two situations: no data is being received because the log device cannot be reached, or no data is being sent because the FortiGate unit is no longer logging properly.