Ensure they are valid (e.g., 8.8.8.8 , 1.1.1.1 , or your internal resolvers). Also verify:
Check current error and system status
If using DHCP/PPPoE on your WAN, disable the setting that allows the ISP to override your DNS, as this often breaks FortiGuard resolution: Network > Interfaces > Edit WAN > Unselect Override internal DNS config system interface edit dns-server-override disable end Use code with caution. Copied to clipboard 3. Disable Anycast and Switch to UDP Ensure they are valid (e
If your FortiGate GUI displays the error you are likely unable to select a domain for your dynamic DNS configuration. This common issue typically stems from DNS resolution conflicts, Anycast protocol interference, or specific interface settings that block communication with FortiGuard. 1. Disable "Override Internal DNS" Disable Anycast and Switch to UDP If your
, it often receives DNS settings from your ISP. If the "Override internal DNS" option is enabled, these ISP-provided servers might fail to resolve FortiGuard’s specific DDNS domains. Navigate to Network > Interfaces , edit your WAN interface, and uncheck Override internal DNS config system interface edit dns-server-override disable end Use code with caution. Copied to clipboard 2. Solve Anycast Connectivity Issues Disable "Override Internal DNS" , it often receives
. It is also unavailable on high-end appliances, FortiGate-VMs, or when in transparent mode. For persistent issues, you can review detailed logs using diagnose debug application ddnscd -1 diagnose debug enable for your particular FortiOS version to ensure the syntax matches? Unable to load FortiGuard DDNS server list