DNS Service failiure

[TheFrog]

Actual Behaviour:

I should be getting normal adblocking or atleast no error thrown at me
I have a :
PiOS 12
Rasberry Pi 5 2GB RAM

Actual Behaviour:

An error message shows up and no blocking occurs, with this showing up in the pihole page: ||2025-07-24 15:09:47|NTP|Error in NTP client:
Cannot resolve NTP server address: Try again|
| --- | --- | --- |
I configured the router DHCP to the pihole Ip adress, but the issue persists even after I put the original one back 8.8.8.8; The pihole IP address doesnt even show up in the routers list, but it is conected (via ethernet). It doesnt work with neither

Debug Token:

https://tricorder.pi-hole.net/D1R4H8FR/

[Bucking_Horn]

@TheFrog

Error in NTP client:
Cannot resolve NTP server address: Try again

To get rid of that warning, you could disable Pi-holes NTP client and server.
You'll find Pi-hole's NTP options under Settings | All settings » Network Time Sync.
All settings is only available in Expert mode.

However, that error is unrelated to your observation of nothing being blocked.
That is caused by your router advertising two public DNS server IPv6 addresses, as shown in your debug log:

   * Received 104 bytes from fe80::1 @ eth0
     (…)
     Recursive DNS server 1/2: 2001:4860:4860::8888
     Recursive DNS server 2/2: 2001:4860:4860::8844
     DNS server lifetime:infinite

This allows your clients to by-pass Pi-hole via Google's DNS servers.

You'd have to find a way to configure your router to stop advertising its public IPv6 as DNS server, or to advertise your Pi-hole host machine's IPv6.

You'd have to consult your router's documentation sources on further details for its IPv6 configuration options.

If your router doesn't support configuring IPv6 DNS, you could consider disabling IPv6 altogether, provided you'd not depend on IPv6 for reasons.

If your router doesn't support that either, your IPv6-capable clients will always be able to bypass Pi-hole via IPv6.
You could then try to mitigate this, by setting Pi-hole as the only upstream of your router, provided your router supports it.
But note that you won't be able to attribute DNS requests to original individual IPv6 clients in such a configuration.

In addition, your debug log shows you are running unbound on the same machine and port as Pi-hole:

*** [ DIAGNOSING ]: Ports in use
    (…)
[✓] udp:0.0.0.0:53 is in use by pihole-FTL
[✗] udp:127.0.0.1:53 is in use by unbound (https://docs.pi-hole.net/main/prerequisites/#ports)

This would cause conflicts and may even prevent either unbound's or Pi-hole's DNS service to start correctly.

You'd have to either disable unbound or move it to a different port, see also unbound - Pi-hole documentation.

[TheFrog]

Muchas gracias.
I did what you wrote here and it mostly works, some websites still load ads but I believe its just not present on the current list, because http://googleadservices.com/ is unreachable.
The configuration on my router (Huawei HG8245H) you go to IPv6 --> LAN address configuration --> Enable DHCPv6 server --> Uncheck. If you uncheck the above box Enable route advertisemen, the internet stops working (oops).

Again, thank you. I much apreaciate all the work and the help you and the whole community give to noobies like me and many others. The warning disapeared by itself.