System DNS Server Settings

[Don_Z_]

I have my primary and secondary DNS servers set to OpenDNS but my system and DHCP lan are still getting the Comcast DNS servers that are being picked up dynamically. See the attached image.

Why isn't my system and DHCP using the DNS servers that I have specified instead of the dynamic ones?

Thanks for any help.

[ahmadhusain]

check the DHCP option on the fortigate if you have the other dhcp server 

Go to interface and change the configuration 

Please find the attached 

if you have configured the dhcp on the FG then you can specify the dns as per your doamin

[ede_pfau]

From your snapshot, it isn't clear that the dynamically acquired DNS are in fact in use. It might well be that this is only an informational hint as your WAN port uses a dynamic assignment protocol (DHCP or PPPoE).

In System > Interfaces > WAN1, you specify whether you want to use the offered DNS or the one you specified in System > DNS ("override system DNS"). This pertains to the DNS the FGT itself is using, for FQDN objects, FortiGuard, WebFilter etc.

As already mentioned you specify which DNS to use for your DHCP clients, in the interface setup, DHCP server > Advanced... This is totally apart from the system DNS - I often assign 9.9.9.9 to DHCP clients.