Raspberry Pi loses network connection

[break]

Hi,

Expected Behaviour:

I'm running Pihole on a Raspberry Pi Zero 2 W, with Raspbian Bookworm. I've been using Pihole for years without issues. But for a couple of months now, presumable after updating to v6, the issue started to occur.

Actual Behaviour:

The Raspberry Pi on which Pihole runs completely looses network connection every couple of days, and I'm forced to reboot it. I'm assuming the Raspberry Pi is still running but I have no way to check as it is a headless server and I also cannot establish SSH connection anymore. I see these errors in the FTL.log file.

2025-05-07 17:00:00.905 CEST [550M] WARNING: Connection error (192.168.178.1#53): failed to send UDP request (Network unreachable)
2025-05-07 17:00:22.366 CEST [550M] WARNING: Connection error (208.67.222.222#53): failed to send UDP request (Network unreachable)
2025-05-07 17:34:30.613 CEST [550M] WARNING: Connection error (208.67.220.220#53): failed to send UDP request (Network unreachable)
2025-05-07 18:00:00.512 CEST [550M] WARNING: Connection error (192.168.178.1#53): failed to send UDP request (Network unreachable)
2025-05-07 18:08:38.862 CEST [550M] WARNING: Connection error (208.67.222.222#53): failed to send UDP request (Network unreachable)
2025-05-07 18:42:47.112 CEST [550M] WARNING: Connection error (208.67.220.220#53): failed to send UDP request (Network unreachable)
2025-05-07 19:16:55.362 CEST [550M] WARNING: Connection error (208.67.220.220#53): failed to send UDP request (Network unreachable)
2025-05-07 19:51:03.612 CEST [550M] WARNING: Connection error (208.67.220.220#53): failed to send UDP request (Network unreachable)
2025-05-07 20:25:11.862 CEST [550M] WARNING: Connection error (208.67.220.220#53): failed to send UDP request (Network unreachable)
2025-05-07 20:59:20.112 CEST [550M] WARNING: Connection error (208.67.220.220#53): failed to send UDP request (Network unreachable)
2025-05-07 21:33:28.362 CEST [550M] WARNING: Connection error (208.67.220.220#53): failed to send UDP request (Network unreachable)
2025-05-07 22:07:36.612 CEST [550M] WARNING: Connection error (208.67.220.220#53): failed to send UDP request (Network unreachable)

I've changed my configuration with suggestsion from a couple of help threads here without success.
This one UDP Error, among others.

I recently upgraded to Bookworm hoping it would somehow magically resolve the issue but that hasn't happened.

Debug Token:

https://tricorder.pi-hole.net/4qCCXQEs/

I would love some help with this issue.

[deHakkelaar]

Have you tried another power adapter and cable?
Raspi's can crash or even corrupt storage (SD card etc) if the power isnt sufficient.
See also below:

https://www.raspberrypi.com/documentation/computers/raspberry-pi.html#power-supply-warnings

You could also check the systemd journals for errors/warnings etc for the current --boot:

sudo journalctl --full --no-hostname --catalog --priority warning --boot

Or two boots back (-2):

sudo journalctl --full --no-hostname --catalog --priority warning --boot -2

List all boots:

sudo journalctl --list-boots

[break]

Thank you for your response.

I am using a power supply a bought from my raspberry pi supplier. I've also used a couple of different ones just to be sure. It didn't change the situation at all.

I've made some progress with diagnosis though. I now think the issue might be related to wifi problems of the raspberry pi itself as discussed here. It reconnects every 20 minutes. Maybe it fails to reconnect every once and a while and then stops retrying? I will try a few suggestions from that thread.

I am now convinced that this has nothing to do with Pi Hole though, so I guess this issue can be closed.