Pi-Hole running but no evidence

[Satjanand]

Please follow the below template, it will help us to help you!

Expected Behaviour:

Pi-Hole is expected to block adds and serve the web interface upon visiting ip-address/admin

Actual Behaviour:

services are running, but no adds are blocked and web interface is not being served upon visiting ip-addresss/admin

Debug Token:

euf22aq478

[Bucking_Horn]

Your debug log shows Pi-hole to be operational with full IPv4 connectivity.

However, your router is distributing its own IP address as local DNS server alongside Pi-hole, allowing clients to bypass Pi-hole:

*** [ DIAGNOSING ]: Discovering active DHCP servers (takes 10 seconds)
      dns-server: 192.168.1.236
      dns-server: 192.168.1.1

Configure your router to distribute Pi-hole as your sole DNS server.

[Satjanand]

Thank you for pointing that out. I noticed that before, and I wondered if this could be the problem. It just doesn't explain to me why 192.168.1.236/admin is unreachable. (Or does it?)

Now, I should mention that untill yesterday I had Pi-Hole running on a different Pi (Zero W), but it burned when I connected it to a faulty power supply. So now I am trying to run Pi-Hole on my HomeAutomation RPI 3B.

So, router config has not been changed in the meanwhile. The same DNS config (showing in image below) was used in the previous situation, which worked.

So could it be that this secondary DNS entry is hardprogrammed somewhere in my HomeAutomation RPI?

And is it possible that this also causes 192.168.1.236/admin not to be found?

[Bucking_Horn]

Try and fill in Pi-hole's IP as Secondary DNS as well, or use 0.0.0.0 if your router insists on IPs being different.

@Satjanand

It just doesn't explain to me why 192.168.1.236/admin is unreachable. (Or does it?)

No.
Though it does explain why you cannot access http://pi.hole/admin at times (since only Pi-hole is providing resolution for that name), Pi-hole's web UI should always be available via its IP address.

You'd have to look for other causes, like a double IP definition in your router or your browser's auto-completion or maybe just a typo...

[Satjanand]

Thank you again for your input.

@Bucking_Horn

Try and fill in Pi-hole's IP as Secondary DNS as well

I tried that, but that broke my internet.

@Bucking_Horn

You'd have to look for other causes, like a double IP definition in your router or your browser's auto-completion or maybe just a typo...

I strongly believe that the IP-address is entered correctly.

[Bucking_Horn]

@Satjanand

I tried that, but that broke my internet.

You either have an IP address conflict in your network, or something is blocking access to your Pi-hole.
Check your router for address conflicts and your Pi-hole machine's firewall settings.

[Satjanand]

@Bucking_Horn

firewall settings

Bingo! Thank you.

UFW was holding back traffic. Upon disabling UFW, all worked as expected. I followed these instructions for UFW and all seems to be working well.

Thank you for now. Great community you got here.

[Bucking_Horn]

Glad it's working now, and thanks.

Since you do not seem to be aware of it: Please consider using Pi-hole's own documentation as your prime source for Pi-hole, e.g. on firewalls.

[Satjanand]

Yes, yes, I know. It just didn't occur to me I was running ufw on that RPI3.
Other than that: yes, yes.

(and thank you)