DNS server failure

Help
1

Expected Behaviour:

pihole functions normally, resolves sites, blocks when needed, no error messages, query log is current etc

Also, with v6 of pihole, the static DHCP UI is virtually incomprehensible (compared to v5). I don't know if that's a consequence of the issues i'm experiencing or a UI change. It's vastly less user friendly currently.

Raspbian GNU/Linux 11 (bullseye)

  • response after cat /etc/os-release

Core [v6.0.6]
FTL [v6.1]
Web interface [v6.1]

  • pulled this from web UI and pihole -r

Raspberry Pi 3 Model B Rev 1.2

  • response after cat /sys/firmware/devicetree/base/model

Haven't a clue about docker. I'm sorry.

Actual Behaviour:

pihole does not resolve domains (i had to change my DNS server to a public one, not pihole)

pihole reports top left of UI "DNS server failure"

running pihole -r seems to indicate that Systemd-resolved is not enabled, it attempts to restart, the -r message sound like this has been successful, yet i still get DNS server failure and no pihole resolution, even after a raspberry pi restart

"[i] Testing if systemd-resolved is enabled
[i] Systemd-resolved is not enabled
[i] Restarting services...
[✓] Enabling pihole-FTL service to start on reboot...
[✓] Restarting pihole-FTL service...
[✓] Deleting existing list cache
[✓] DNS resolution is available"

context:

  • was having issues with a website (portal.samsungfinance.co.uk). Was timing out
  • during troubleshooting i tried whitelisting domain (although i was getting a normal / green response from pihole when checking the domain etc)
  • i then discovered i couldn't delete or disable this whitelisted domain (maybe a permissions thing as previously reported "While executing domainlist_by_group statement: attempt to write a readonly database")
  • didn't really understand the thread though (i understand the principle of permissions but am limited to windows user & group stuff. Completely out of my depth on linux)
  • tried pihole -r
  • can't remember why but i then tried pihole -up
  • am certain i agreed to disabling lighttpd, as recommended by the installer (was moving from 5.x to 6.x pihole)
  • seemed to update ok
  • browser UI reported "DNS server failure"
  • nothing i do seems to be able to clear this error and pihole doesn't appear to work, though the UI seems to function.

NOTE: pihole -r 'seems' to run ok, though every time i've run it, i get the same Systemd-resolved is not enabled

NOTE1: i interact with my raspberry pi using its native VNC server and realVNC viewer client

Debug Token:

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

additional question

can i uninstall pihole 6 and install v5 again?

i made a full backup (teleporter) before upgrading to v6

At least v5 largely worked for me (aside from the the issues with deleting of whitelist entries)

2

The debug log shows FTL failed to start with this error:

May 11 00:44:30 raspberrypi pihole-FTL[2224]: dnsmasq: DHCP host has multiple names at line 135 of /etc/pihole/dnsmasq.conf
May 11 00:44:30 raspberrypi dnsmasq[2224]: DHCP host has multiple names at line 135 of /etc/pihole/dnsmasq.conf
May 11 00:44:30 raspberrypi dnsmasq[2224]: FAILED to start up

It means one or more hosts are appearing more than once in the hosts list.

You configure the same MAC Address (the one starting with "88:88:") twice for 2 different IPs: 192.168.1.12 and 192.168.1.16.

1 Like
3

thanks!

i used the /etc/pihole/pihole.toml file

tried to just comment out one of the MAC duplications (prefer to edit out than delete). Using # to create a comment didn't seem to preserve it line (it did change colour to reflect it was a comment).

It just disappeared in the UI and in .toml and .conf

Anyway, managed to get to only one instances of that MAC - saved preferences in the UI and no longer got a hex error (when i tried to edit out that MAC / IP line via the UI and save preferences)

however, repairing pihole still doesn't restart service

The tail.log for pihole reports:

"DHCP host has multiple names at line 134 of /etc/pihole/dnsmasq.conf"

"FAILED to start up"

line 134 just points to the other MAC instance

I've scrutinised all the static host entries and there really is only one instance of that MAC address, so i've no idea why it's reporting a problem with that line.

i just can't see any issue with the syntax etc, so am baffled.

regards,

Gary

4

Please post a new debug Token with your fixed configuration.

5

thanks sir

have cracked it (almost hesitate to describe my stupidity)

the MAC separators in the remaining instance were dashes, not colons :man_facepalming:

how on earth they'd got entered like that in the first place, i have no idea

correcting this resolved the problem

NOTE: deleting the entry also got the server running again

pihole seems to be running ok now

Even managed to edit the whitelist successfully (which prompted all this time wasting)

thank you for your prompt support