FortiGuard services use Anycast routing. Sometimes, your ISP or routing table directs the FortiGate to a non-responsive FortiGuard server.
Several FortiOS versions have known bugs causing the "unable to load fortiguard ddns servers list" symptom, particularly in: FortiGuard services use Anycast routing
In these versions, even with perfect connectivity, the GUI or CLI cannot parse the provider list due to a JSON schema mismatch or SSL certificate issues. In these versions, even with perfect connectivity, the
The inability to load the list is almost exclusively caused by connectivity issues between the FortiGate and Fortinet’s backend infrastructure (FortiGuard servers). The firewall requires a valid FortiGuard license and specific outbound network access to fetch this dynamic list. In these versions
Common root causes include: