Subject: Unable to Load FortiGuard DDNS Servers List on FortiGate Firewalls
GUI Fix: Navigate to Network > Interfaces, edit your WAN interface, and uncheck Override internal DNS. CLI Fix: Subject: Unable to Load FortiGuard DDNS Servers List
Ensure your FortiGate is configured to use reliable DNS servers (like FortiGuard's own or public ones like Google 8.8.8.8) to fetch the server list. If all else fails, try resetting the FortiGuard
A valid response returns a JSON array of providers. An error here indicates API-level blocking. GUI Fix : Navigate to Network > Interfaces
Then restart the FortiGuard service:
This error prevents the firewall from fetching the official list of supported DDNS providers (such as FortiGuard DDNS, No-IP, or DynDNS) from Fortinet’s servers. Without this list, you cannot select a provider, configure the service correctly, or update your dynamic IP.
If ping fails with ping: cannot resolve guard.fortinet.net: Unknown host, you have a DNS problem.