Unable To Load Fortiguard Ddns Servers List On Fortigate Firewalls -

Troubleshooting: Unable to Load FortiGuard DDNS Servers List

Note: If the firewall is behind a proxy, you must configure the FortiGate to use the proxy via CLI: Troubleshooting: Unable to Load FortiGuard DDNS Servers List

execute ping guard.fortinet.net

• DNS resolution failures (cannot resolve Fortinet’s domain names).
• Incorrect or missing default gateway.
• Firewall policies blocking the FortiGate’s own outbound traffic.
• FortiGuard web filtering or anycast issues.
• Firmware bugs in specific FortiOS versions.

1. DNS Resolution Failure – The FortiGate cannot resolve fortiguard.com or related DDNS service domains.
2. Connectivity Issues – Firewall policies or routing block outbound access to FortiGuard servers.
3. FortiGuard License Expiry – An expired or invalid FortiGuard contract may restrict DDNS services.
4. Firmware Bug – Specific FortiOS versions have known issues with the DDNS server list retrieval.
5. Custom DNS Settings – Using non-default DNS servers that fail to resolve FortiGuard domains.