This report details the diagnosis and resolution of an issue where a FortiGate firewall fails to populate the Dynamic DNS (DDNS) server list provided by FortiGuard. This issue typically manifests in the Graphical User Interface (GUI) under , where the "DDNS Server" dropdown menu is empty or displays a loading error. Without this list, administrators cannot configure automatic DDNS updates for domains hosted on FortiGuard servers.
: A handshake failure (common in older versions like v7.0) may require you to lower the minimum SSL version if there is a protocol mismatch. config system global ssl-min-proto-version TLS1.0 end Use code with caution. Copied to clipboard Hardware/Firmware Limitations This report details the diagnosis and resolution of
The “Unable to load FortiGuard DDNS servers list” error typically stems from connectivity or DNS problems, not the DDNS service itself. By following this guide—testing DNS, verifying policies, and using CLI workarounds—you can restore DDNS functionality. If issues persist, contact Fortinet Support with the debug output from diagnose debug application update -1 and diagnose debug enable . : A handshake failure (common in older versions like v7
If the list cannot be loaded but the administrator knows the DDNS IP or server name (for example, if using a 3rd party provider like No-IP, or a known FortiGuard server IP), it is possible to configure DDNS via CLI bypassing the GUI dropdown. 7.0.1–7.0.5) | See table below |
execute fortiguard refresh-now execute ddns refresh-list
SSH into the FortiGate or use the console. Run:
| Cause Category | Specific Issue | FortiOS Versions Affected | |----------------|----------------|----------------------------| | | Firewall policy blocking outbound HTTPS to FortiGuard | All | | DNS Resolution | Cannot resolve update.fortiguard.net or fortiguard.com | All | | SSL/TLS | Expired or untrusted FortiGate system certificate | 6.2+, 7.0+ | | FortiGuard Filtering | Web/DNS filter blocking FortiGuard itself | 6.4+ | | Service Availability | Regional FortiGuard outage or maintenance | Rare, but occurs | | Proxy Configuration | Explicit web proxy not configured or bypassed | All | | Licensing | Expired FortiGuard Unified or DDNS license | 7.2+ | | Bug/Firmware | Known bug in specific builds (e.g., 7.0.1–7.0.5) | See table below |