Conditional forwarding works without explicit configuration in v5

Help
1

Hi,

my network is 192.168.0.0/24, and my router is at 192.168.0.1 (fritz.box). The router is also the DHCP server for this network.

I have a Linux host (192.168.0.20) that uses 192.168.0.1 as its DNS resolver.

Details

cat /etc/resolv.conf

domain fritz.box
search fritz.box
nameserver 192.168.0.1

I noticed the following:

On that Linux host, when I spin up docker-pi-hole version 5 (e.g. 2024.07.0) and configure any device on the network to use Pi-hole as its DNS, I can see that the client IP is properly reverse-resolved. The device appears on the dashboard under 'Clients' e.g. as phone.fritz.box.
This works with Pi-hole's default settings out of the box.

With version 6, this stopped working. I can see only the IP address of the device, no hostname.

I am aware, that this can be easily fixed by configuring conditional forwarding: true,192.168.0.0/24,192.168.0.1,fritz.box

I’m just interested to know why and how reverse DNS worked in v5 without explicitly configuring conditional forwarding.

Thanks

2

Please upload a debug log and post just the token URL that is generated after the log is uploaded by running the following command from the Pi-hole host terminal:

pihole -d

or if you run your Pi-hole as a Docker container:

docker exec -it <pihole-container-name-or-id> pihole -d

where you substitute <pihole-container-name-or-id> as required.

3

This was already fixed.

Please follow the template including a debug Token.

EDIT:

Sorry I misunderstood your issue.

I thought you were trying to configure reverse servers without explicitly settings the hostname part ,fritz.box... using just true,192.168.5.0/24,192.168.5.2, that's why I said it was already fixed.

4

v5: https://tricorder.pi-hole.net/2EUB4rBx/
v6: https://tricorder.pi-hole.net/VDI27t8E/

A test DNS query was made from 192.168.5.10. In v5, this IP address resolves to workstation.fritz.box.

5

I'm not an expert in dnsmasq options, so I'm not sure what exactly it is causing the difference between the 2 servers and this is a guess.

Apparently there is one thing that could explain it:

Pi-hole v5 doesn't set domain and local options in /etc/pihole/dnsmasq.conf.

Pi-hole v6 sets them in /etc/pihole/dnsmasq.conf when no reverse servers are configured, using the dns.domain value (it defaults to "lan").

-rw-r--r-- 1 pihole pihole 5.1K Mar 18 00:26 /etc/pihole/dnsmasq.conf
   (...)
   domain=lan
   local=/lan/

This could explain why clients using .fritz.box hostnames are not returned in v6.

My suggestion is to set your router in conditional forwarding.

6

Sorry for the late reply. I've tried that, but it makes no difference. Also FTL doesn't know about my router, as long as I haven't configured conditional forwarding.

So my guess is, v5 uses the container DNS to do reverse lookups, while v6 doesn't use it.

Within the container dig -x 192.168.5.10 works fine and returns the correct hostname.

7

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