PiHole is a great DNS proxy and worked 100% of the time!
Actual Behaviour:
PiHole is inoperative. We had a power failure this morning and it was of sufficient duration that the UPS died. Now, after the LAN is totally powered up PiHole is not functional. The last entry in the Query Log was several hours ago -- before the power died. Tried to sudo apt-get update and pihole -up but it appears that PiHole is not resolving the targets.
The LAN is otherwise operating file -- but only after I was able to change the DNS from PiHole to 9.9.9.9 on each and every device on the network.
The RPi is accessible via remote desktop and I can also get to the PiHole web interface. Pings to the internet from the Pi work fine. However, the Pi is unable to resolve addresses.
I've rebooted the pi several times -- no effect. I've also run pihole -r -- no effect. DNS seems not to be installed but there is no DNS available to go get it. Also changed the RPi DNS from 127.0.0.1 to 9.9.9.9 - no effect.
Debug Token:
Unable: "There was an error up-loading your debug log."
It appears that the PiHole is unable to resolve the address which is to receive the log.
Okay, lets get this stuff up and running again. Bare with me, as I would like to get a couple of answers:
How many days were there in between this time Pi-hole went down, and the reboot before?
You confirmed you can reach the (virtual) machine from LAN. Can you also reach the internet from the (virtual) machine? (can you ping a site by IP or domain name from it?)
Not sure. Probably the last time I rebooted was when I installed 4.2.2, which was shortly after its release.
I can reach all LAN devices and WAN hosts if I specify the address. L2 connectivity is OK. DNS does not work. Period. Example: "pihole -r" can't find some of the needed files because it can't resolve the hosts. "sudo apt-get update" does not work for the same reason. So, no way to update the apparently-missing FTL (whatever that is) since the download location can't be resolved.
What I did after I sent the message to which you kindly responded:
Tried various attempts at "pihole -r" Unsuccessful.
Enabled wi-fi on the Pi to see if I could set the DNS. Did not work ( I think the DNS was likely set to 127.0.0.1 for that adapter also, even though PiHole was instructed to use only ETH0.)
Set the DNS for the Pi manually to 9.9.9.9 since 127.0.0.1 was not working. Those settings SEEMED not to "stick" -- perhaps because PiHole was running?
Tried to ping various hosts from the command line -- not resolved.
Something I learned not to do unless really needed: Uninstalled PiHole and reinstalled. Ahhhh -- worked!
So, I have no idea WHY PiHole went "out to lunch." But it appears to have returned to Planet Earth. The reinstsall seemed to ahve "done it." Not my preferred solutoin -- I'd have liked to understand what happened so I could do all in my power to avoid it. (Wondering if PiHole needs a back-up DNS setting -- so if 127.0.0.1 does not work it can try to "save itself" -- and the OS -- by using one of the upstream services.)
Agreed! Sometimes during the course of one's efforts to "get things working again" one loses information needed to troubleshoot the underlying problem. I suspect that's the case here.
While the actual workings of PiHole are purely "black art," what is clear is that FTL either stopped working and/or needed an upgrade. And, more severely, the key to resolution was stopping PinHole from using LOCALHOST as the DNS. And, the only way I knew to do that was to uninstall and reinstall -- sorta "brute force."
This is likely to cause of your problems. Pis don't always respond well to power loss - open files get corrupted, SD card gets corrupted, time gets lost, etc.
