Hi, I'm using pi-hole on my Raspberry Pi 4B for almost a year now and everything worked fine, until a few days ago. Without me changing anything suddenly almost no request seem to go through the pi-hole and after a few days of troubleshooting it still wont go back to its original functionality. I am a little lost now and need help please.
## Expected Behaviour:
Operatin system: Debian
Hardware: Raspberry Pi 4B
The pi-hole is configured to serve all clients in my local network. My router is configured and all worked fine until a few days ago. The pi-hole is exspected to block ads in browsers and apps.
## Actual Behaviour:
Since a few days ago it wont block any ads etc. and if you look in the query-log almost no queries are send by any device in my network, which cant be true. Even when testing on multiple devices with websites that definitly contain ads, no query was send or picked up. What's even weirder is that some (but only a handful) of queries are going over the pi-hole route and are beeing logged.
I tried a pi restart, updated and upgraded the pi, checked my router configurations (which were unchanged), updated pi-hole and the gravity-list, but nothing fixed my issue.
If no queries are seen on Pihole the problem most likely is in the network configuration:
Check the clients if their network settings include DNS pointing to pihole (or alternatively the router‘s upstream DNS points to Pihole if the clients use the router as DNS - what would be second to best).
From a client that you believe should be connected to the Pi-Hole for DNS, from the command prompt or terminal on that client (and not via ssh or Putty to the Pi), what is the output of
*C:\Users\Paul>nslookup pi.hole*
*Server: UnKnown*
*Address: 2a03:ed00:0:11::200*
**** pi.hole wurde von UnKnown nicht gefunden: Non-existent domain.*
I receive the same output with my setup in my router where I set the DNS-Server to my pi (Picture 1) and when I try to directly set the server in my network adapter settings (Picture 2).
I tried the command on multiple devices in my network (some are connected over wifi and some over lan) and got the same result.
Thanks for your reply. I checked and can't find an issue. More information about what I tried is in my reply to jfb. Maybe you read something out of it or spot a possible mistake
C:\Users\Paul>nslookup pi.hole
DNS request timed out.
timeout was 2 seconds.
Server: UnKnown
Address: 192.168.0.1
DNS request timed out.
timeout was 2 seconds.
DNS request timed out.
timeout was 2 seconds.
DNS request timed out.
timeout was 2 seconds.
DNS request timed out.
timeout was 2 seconds.
*** Zeitüberschreitung bei Anforderung an UnKnown.
That's the output I get after disabling the IPv6 protocol on my client
I am not familiar with nslookup: is the parameter the query or the DNS server to ask? But in both cases, pi.hole seems not to be a good test case.
But nevertheless if something is not working without IPv6 anymore this is a hint, that your system may use IPv6 (which is unmanaged in most home networks).
Just a hint for me, but since I have no idea of Windows I can‘t give you better ideas how to continue to understand and configure the path for DNS queries properly. (Either by forcing to use v4 for queries or directing v6 based queries also to Pihole (what I did)).
I just quickly want to state, that everything is working now.
I reinstalled pi-hole on my Raspberry Pi and added an DNS override for IPv6 protocol on my router with the IPv6 IP-Address of the Pi.
The second action probably fixed the issue.
