WinServer 2016 ADDC DNS and PFSense DNS

[akuani]

Hi All, I've been looking for answers on this online and I can't find a definitive & satisfactory answer. I am basically making a network in which client computers will only have a AD DC DNS (192.168.2.4) & back-up Google DNS (8.8.8.8 ) on the PFSense LAN DHCP server. However, even when I set the AD DC DNS to forward, root hints disabled, to PFSense DNS (192.168.2.1) sometimes it will not look-up, even pfsense.mydomain.loc.

To put it simply:

AD DC DNS -> PFSense DNS -> Upstream DNS Server

I know that this may seem a dirty approach but I have no other idea (enlighten me!) and I don't want to have the AD DC serve as the DHCP server since not all devices are connected to the AD DC. I'm doing since there seems to be a requirement for WPAD to resolve wpad.mydomain.loc to the PFSense IP (192.168.2.1).

EDIT: domain for pfsense and DC are different.

Thanks in advance!