Pihole stopped logging queries even though there was a lot of DNS activity

[Anant]

Expected Behaviour:

I can see all DNS queries that have happened in the recent past (specifically, the last 12 hours). The network was in use quite heavily with at least two streaming services in use, about 8-10 devices connected and accessing the Internet - Mobile and Laptop devices as well as one smart Television.
Why are all the query (including stats) missing? How do I stop losing out on the queries? This happens quite frequently and most commonly at around the evening, night and early morning time (in my Timezone)

Actual Behaviour:

All DNS queries for the last 12-14 hours are missing from both the dashboard and the "Long Term Data -> Query Log" interfaces. ALL client queries. Please see the screenshots below:

Debug Token:

My debug token is: https://tricorder.pi-hole.net/mobz80w3sa

[Anant]

Just to add, queries are not being logged right this instant as well. The loading of pihole's discourse, the posting of my query etc, none of them resulted in a DNS lookup which is, weird. I am literally working on two laptops - a Macbook Pro and a Dell running Windows 10. They're both performing different tasks and are connected to my network and the Internet and both are resulting in no DNS queries at all? That's quite surprising

[DL6ER]

In your debug log, I see that your router is announcing the Pi-hole but also itself as DNS server. Is this expected?

      dns-server: 192.168.0.6
      dns-server: 192.168.0.1

This may be the reason why DNS resolution continues to work after FTL stopped serving queries. So far, it is unclear if your devices just stopped using the Pi-hole or if there really is a problem.

How did you configure your router? Which upstream DNS server die5s the router use? And does blocking still work at times where you don't see queries in the logs?

[Anant]

Hi @DL6ER , thank you for replying.
My router (under DHCP) has 192.168.0.6 as the DNS server. No other DNS server is configured in the DHCP section.
The Pihole has Quad9 as the upstream DNS provider.
Also, as you can see from the screenshot, queries were logged till abvout 16 hours or so ago. I did not notice this earlier as I wasn't on my laptop or even monitoring pihole. Correspondingly, I've not made any changes to the pihole (infact, I've not touched the pihole instance for almost 12-15 days now except looking at the query logs to monitor traffic)

[Anant]

My Router DHCP configuration:

[DL6ER]

@Anant

My Router DHCP configuration

Okay. Your router definitely announces itself as DNS server. You can check this by running

sudo pihole-FTL dhcp-discover

and seeing it returns two DNS server fields:

@DL6ER

      dns-server: 192.168.0.6
      dns-server: 192.168.0.1

Try filling in the IP of your Pi-hole also as Secondary DNS server and check again with the dhcp-discover feature.

[Anant]

Thank you. I've made the change as you recommended. The

sudo pihole-FTL dhcp-discover

command now gives the following output:
DHCP options:
Message type: DHCPOFFER (2)
server-identifier: 192.168.0.1
lease-time: Infinite
netmask: 255.255.255.0
broadcast: 192.168.0.255
dns-server: 192.168.0.6
dns-server: 192.168.0.6
router: 192.168.0.1

I'll monitor this change for a few days and update back here (and close the thread) accordingly.

Thank you for your help. Hope this solves the issue