DNS nameserver problems (after LM 21 upgrade)

[oligneisti]

I upgraded to LM 21 yesterday (from 20.3). Suddenly I couldn't access certain sites with Firefox/Chromium (I could use Tor but that is a viable solution for me). After a bit of testing I found that I could access all sites that were *.is (Iceland, where I live) but had problem with "foreign" domains. This even extended to sites I run from the same machine, one is *.net but the other *.is. No problem accessing *.is while *.net could not be found. On the other hand major sites like Google and Twitter were easily accessible though images on Twitter did not show up.

I've had little experience with changing DNS settings in Linux Mint despite having used the distro for over a decade. It usually just works. I decided to change the nameserver from "127.0.0.53" to "208.67.222.222" (OpenDNS). Everything started working immediately.

I am fine for now but if anyone else has a problem this might help them and if this is a bigger problem, and not just some random weirdness for me, it might need to be looked at.

[karlchen]

Hello, oligneisti.

Your problem report reminds me of that recent report by Parm6: DNS connectivity problem, Mint 21.

Parm6, too, resorted to a workaround.

It might be helpful, if either of you two could share the requested details with us, while the problem is still there. Else diagnosing and resolving, not working around, will depend on guesses.

Regards,
Karl

[oligneisti]

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System:
  Kernel: 5.15.0-46-generic x86_64 bits: 64 compiler: gcc v: 11.2.0 Desktop: Cinnamon 5.4.9
    tk: GTK 3.24.33 wm: Mutter dm: LightDM Distro: Linux Mint 21 Vanessa base: Ubuntu 22.04 jammy
Machine:
  Type: Laptop System: Framework product: Laptop v: AB serial: <superuser required>
  Mobo: Framework model: FRANBMCP0B v: AB serial: <superuser required> UEFI: INSYDE v: 03.10
    date: 07/19/2022
Battery:
  ID-1: BAT1 charge: 50.9 Wh (100.0%) condition: 50.9/55.0 Wh (92.5%) volts: 17.5 min: 15.4
    model: NVT Framewo serial: <filter> status: Not charging
CPU:
  Info: quad core model: 11th Gen Intel Core i7-1165G7 bits: 64 type: MT MCP arch: Tiger Lake
    rev: 1 cache: L1: 320 KiB L2: 5 MiB L3: 12 MiB
  Speed (MHz): avg: 728 high: 993 min/max: 400/4700 cores: 1: 799 2: 482 3: 480 4: 890 5: 704
    6: 774 7: 703 8: 993 bogomips: 44851
  Flags: avx avx2 ht lm nx pae sse sse2 sse3 sse4_1 sse4_2 ssse3 vmx
Graphics:
  Device-1: Intel TigerLake-LP GT2 [Iris Xe Graphics] driver: i915 v: kernel ports: active: eDP-1
    empty: DP-1, DP-2, DP-3, DP-4 bus-ID: 00:02.0 chip-ID: 8086:9a49
  Display: x11 server: X.Org v: 1.21.1.3 driver: X: loaded: modesetting unloaded: fbdev,vesa
    gpu: i915 display-ID: :0 screens: 1
  Screen-1: 0 s-res: 2256x1504 s-dpi: 96
  Monitor-1: eDP-1 model: BOE Display res: 2256x1504 dpi: 201 diag: 343mm (13.5")
  OpenGL: renderer: Mesa Intel Xe Graphics (TGL GT2) v: 4.6 Mesa 22.0.5 direct render: Yes
Audio:
  Device-1: Intel Tiger Lake-LP Smart Sound Audio driver: snd_hda_intel v: kernel bus-ID: 00:1f.3
    chip-ID: 8086:a0c8
  Sound Server-1: ALSA v: k5.15.0-46-generic running: yes
  Sound Server-2: JACK v: 1.9.20 running: no
  Sound Server-3: PulseAudio v: 15.99.1 running: yes
  Sound Server-4: PipeWire v: 0.3.48 running: yes
Network:
  Device-1: Intel Wi-Fi 6 AX210/AX211/AX411 160MHz driver: iwlwifi v: kernel pcie: speed: 5 GT/s
    lanes: 1 bus-ID: aa:00.0 chip-ID: 8086:2725
  IF: wlp170s0 state: up mac: <filter>
Bluetooth:
  Device-1: Intel AX210 Bluetooth type: USB driver: btusb v: 0.8 bus-ID: 3-10:4 chip-ID: 8087:0032
  Report: hciconfig ID: hci0 rfk-id: 0 state: down bt-service: enabled,running rfk-block:
    hardware: no software: yes address: <filter>
Drives:
  Local Storage: total: 1.82 TiB used: 1.54 TiB (84.6%)
  ID-1: /dev/nvme0n1 vendor: Samsung model: SSD 970 EVO Plus 2TB size: 1.82 TiB speed: 31.6 Gb/s
    lanes: 4 serial: <filter> temp: 37.9 C
Partition:
  ID-1: / size: 1.79 TiB used: 1.54 TiB (86.1%) fs: ext4 dev: /dev/nvme0n1p2
  ID-2: /boot/efi size: 511 MiB used: 73.4 MiB (14.4%) fs: vfat dev: /dev/nvme0n1p1
Swap:
  ID-1: swap-1 type: file size: 2 GiB used: 0 KiB (0.0%) priority: -2 file: /swapfile
Sensors:
  System Temperatures: cpu: 43.8 C mobo: N/A
  Fan Speeds (RPM): N/A
Repos:
  Packages: 3960 apt: 3922 flatpak: 38
  No active apt repos in: /etc/apt/sources.list
  Active apt repos in: /etc/apt/sources.list.d/official-package-repositories.list
    1: deb https: //mirrors.dotsrc.org/linuxmint-packages vanessa main upstream import backport
    2: deb https: //mirrors.opensource.is/ubuntu jammy main restricted universe multiverse
    3: deb https: //mirrors.opensource.is/ubuntu jammy-updates main restricted universe multiverse
    4: deb https: //mirrors.opensource.is/ubuntu jammy-backports main restricted universe multiverse
    5: deb https: //mirrors.opensource.is/ubuntu jammy-security main restricted universe multiverse
  Active apt repos in: /etc/apt/sources.list.d/signal-xenial.list
    1: deb [arch=amd64 signed-by=/usr/share/keyrings/signal-desktop-keyring.gpg] https: //updates.signal.org/desktop/apt xenial main
  No active apt repos in: /etc/apt/sources.list.d/spotify.list
  Active apt repos in: /etc/apt/sources.list.d/vscode.list
    1: deb [arch=amd64,arm64,armhf] http: //packages.microsoft.com/repos/code stable main
Info:
  Processes: 310 Uptime: 4m Memory: 31.14 GiB used: 3.16 GiB (10.2%) Init: systemd v: 249
  runlevel: 5 Compilers: gcc: 11.2.0 alt: 11/9 Client: Cinnamon v: 5.4.9 inxi: 3.3.13

Code: Select all

nslookup dns.google.com

Non-authoritative answer:
Name:	dns.google.com
Address: 8.8.8.8
Name:	dns.google.com
Address: 8.8.4.4
Name:	dns.google.com
Address: 2001:4860:4860::8888
Name:	dns.google.com
Address: 2001:4860:4860::8844

Code: Select all

nslookup 8.8.8.8

8.8.8.8.in-addr.arpa	name = dns.google.

Authoritative answers can be found from:

[karlchen]

Hello, oligneisti.

I am a bit confused by the output, which you shared for the command nslookup dns.google.com

Code: Select all

Non-authoritative answer:
Name:	dns.google.com
Address: 8.8.8.8
Name:	dns.google.com
Address: 8.8.4.4
Name:	dns.google.com
Address: 2001:4860:4860::8888
Name:	dns.google.com
Address: 2001:4860:4860::8844

Seems as if the 2 first output lines are missing. They should read similar to this:

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Server:		xx.xx.xx.xx
Address:	xx.xx.xx.xx#53

I.e. the absent lines would have told the IP address of the DNS server in use and its port.
Regards,
Karl

[oligneisti]

Code: Select all

Server:		208.67.222.222
Address:	208.67.222.222#53

Non-authoritative answer:
Name:	dns.google.com
Address: 8.8.4.4
Name:	dns.google.com
Address: 8.8.8.8
Name:	dns.google.com
Address: 2001:4860:4860::8844
Name:	dns.google.com
Address: 2001:4860:4860::8888

[karlchen]

Hello, oligneisti.

The nslookup output tells that your workaround, which you had explained in your initial post, is still in place. As a consequence nslookup is unlikely to fail. Hm.

Do you perhaps connect to the internet tthrough a VPN?

Karl