Pi-hole DNS setup with Opnsense

[meazz1]

I have 2 Pi-hole I want to implement on my home network.
here's my network layout. What would be the best way to setup everything?

LAN- 192.168.4.0 - home network
DNS 1 - 192.168.4.200 -Pi-hole#1
DNS 2 - 192.168.4.201 -Pi-hole#2
=========================
VLAN IOT - 10.0.20.0/24
DNS 1 - 8.8.8.8
DNS 2 - 8.8.4.4

[baqwas]

Hello @meazzi,

You need TWO Pi-hole servers? High-availability because even alert notifications would be too slow for your LAN?

You're going for a router-behind-router plan for your IoT? You would need to dedicate a 192.168.4.x static address for the second "router" and configure your IoT sub-net to use it as the external gateway.

Kind regards.

[meazz1]

My LAN and VLAN are already setup on Opnsense router. I'm using only one router.
Not sure what you mean by router behind router?

I want LAN to use Pihole(s) DNS. Why two? So if one fails other one will still provide DNS quiries.
IOT on a different different VLAN and that one should use only 8.8.8.8 & 8.8.4.4.

[FullyBorked]

I might be misunderstanding, any reason you can't just set your dhcp settings to present your piehole servers for dns as opposed to google's dns?