Recommendation for Router WAN DNS Settings, when LAN DNS points to Pi-Hole (by DHCP)

[deHakkelaar]

@titust11

Yes I can see it's an extended thread, but nobody gives a definitive answer there.

I'll highlite some:

@bennor3814

If one flashes the Asus-Merlin firmware (https://www.asuswrt-merlin.net/ ) to their Asus router, one can disable the router's IP address from being included as a LAN DNS. In the Asus-Merlin configuration; LAN > DHCP set "Advertise router's IP in addition to user-specified DNS" to "No".

@bennor3814

Using Conditional Forwarding (on the Pi-Hole) may cause a loop which could potential cause issues depending on how one configures their router (using Pi-Hole as router WAN DNS for example).

@bennor3814

The Pi-Hole documentation (Post-Install - Pi-hole documentation ) does not mention or suggest using the Pi-Hole(s) IP address in the router's WAN DNS fields

@titust11

Then I can put anything in the router's WAN DNS Upstream server, right?

Yes except when you use/enable Pi-hole's conditional forwarding against your router.
In that case entering the Pi-hole IP for WAN DNS on the router would create a partial DNS loop.