I am running a Brume3 @ OpenWrt 21.02-SNAPSHOT, 5.4.281, 4.9.0. I use it as a gateway driven by an ONT, to a switch that drives an EERO, and several cameras. The Brume3 also goes directly to a Raspberry Pi 4.5B as DNS that is running NUT as well as the Pi Hole (PiH) thus all of the ethernet connections are in use not that it matters much.
At one point, before my experiment, I wound up with the Pi (fixed ip) outside the DHCP range. I have booted since then many times, an the Pi was exactly where I expected. Exactly how I did this I don’t recall but it is not possible now at this firmware level. The Pi was set for automatic so it received what IP address the brume doled out.
Today I was looking at how the PiH reported the clients and all of the records were from the brume3 ip. Digging around a bit I found that this could be resolved by placing the PiH ip in the advanced section of DHCP. So I added the PiH ip as DNS 1 and rebooted.
At this point all of the local host names were not being resolved. I could access them via IP.
Things got out of hand pretty quickly as I tried removing the DNS entry from DHCP and wound up with no DNS until I threw in the towel and restored the config from one I had saved. At this point the existing reservation for the Pi outside the DHCP was not being honored.
So, did 4.9.0 clean up DHCP, and, was adding the DNS to DHCP all I needed to change in the Brume3 to force the DNS to the PiH to get the clients reported instead of the Brume3? Is there an option that will provide the local DNS to the Pi?
I realize that I will (or should) have set the ip of the Pi using nmtui, but will I still be stuck without the local hosts not being resolved?
Hopefully some of this makes sense.
Edit: I see that DNS records can be added to the PiH and that probably will solve everything, except properly setting up the DNS so the clients are reported to the PiH individually instead of being reported as the router.
So, if we understand correctly, you basically want to:
Configure the Raspberry Pi's IP address as the DNS server provided via DHCP, so that Pi-hole can directly see the client IP addresses.
Configure the Pi-hole on Raspberry Pi in some way so that local domain names can still be resolved properly.
If our understanding is correct, then:
You can still configure this under Admin Panel → Network → LAN → DHCP. The DNS server address only needs to be reachable within the same subnet and does not have to be within the DHCP lease range.
Please also configure an Address Reservation for the Raspberry Pi in the same section to prevent its IP address from changing and causing unexpected issues.
After that, you can configure Conditional Forwarding / Reverse Server in Pi-hole on the Raspberry Pi, so that local domain name queries can be forwarded to Brume 3 for resolution.
Will thank you for the suggestions. I have configured reservations for all of the clients and the Raspberry. The point was in spite of having a reservation outside the DHCP range, the Raspberry Pi was given an address within the DHCP range. It was as though the reservation was not being applied when I booted the brume.
At this point I am outside the home country and with a need to have a stable platform at home I will not be able to try any changes until our return.
Thank you. I will pursue the conditional forwarding when we return.
If possible, please check whether the Raspberry Pi's MAC address shown under Admin Panel → Clients matches the MAC address configured for the reserved IP.
If they do not match, it is possible that the Raspberry Pi has enabled a randomized MAC address, and the MAC address changed after the reservation was configured, causing the issue.
Also, please note that the Raspberry Pi should be configured to obtain an IP address via DHCP rather than using a static IP. A DHCP reservation will not take effect if the device is configured with a static IP address.