DNS Probe Possible - DNS address could not be found

[Abraxus]

Hi. I'm new to Ubuntu Mate and I am not able to connect to internet anymore ( with any browser), probably caused by Proton VPN uninstall. My browsers can't connect ( DNS Probe Possible error) So I re-installed Proton, but it didn't solved the problem. I've succeeded to connect to the web by changing my name server address to 8.8.8.8 in the file: etc\resolv.conf - except that Ubuntu rewrote that modification, Now the etc/resolv.conf does not exist anymore and has been renamed: resolv.conf.d and there is no nameserver address inside that folder; Only 3 files: Base, Head and Tail - no place to input nameserver 8.8.8.8 I can't either find no other place to input that nameserver address on Ubuntu Mate, The only browser that can connect is Thor (VPN). I'm on wired internet.

Does someone has a permanent solution for that annoying problem?

[jaybo]

Not sure if this helps, but I had DNS issues after upgrading to 22.04. I fixed the issue with the following two commands:

$ sudo rm -f /etc/resolv.conf
$ sudo ln -s /run/systemd/resolve/resolv.conf /etc/resolv.conf

More explanation can be found [here.](https://ubuntu-mate.community/t/upgrade-to-22-04-broke-dns/26205)

[Abraxus]

Hi jaybo! Thank you for your answer. Unfortunately these two commands didn't do anything. I found that if I change my iPv4 address to 8.8.8.8 , that could solve the DNS problem. Does someone knows how to do that on Ubuntu Mate 22.04?

[ricmarques]

Hi, @Abraxus

You wrote:

@Abraxus

Hi jaybo! Thank you for your answer. Unfortunately these two commands didn't do anything. I found that if I change my iPv4 address to 8.8.8.8 , that could solve the DNS problem. Does someone knows how to do that on Ubuntu Mate 22.04?

I suggest that you check the following discussion here in the Ubuntu MATE Community discussion forums, started by @alpinejohn a few months ago (on 22 January 2023):

How can you change DNS servers on Ubuntu-Mate 22.04 (e.g. for a pi-hole)?

Hello I have looked on the internet and have come to the conclusion that Ubuntu-Mate 22.04 does not have a GUI element for easily setting the DNS server(s). However, some other desktop-environments do. Furthermore, my investigations suggest that on Ubuntu-Mate 22.04 systemd looks after DNS server settings, and that changing any systemd DNS server settings via the terminal is a daunting task with a serious risk of things going wrong. Have I overlooked something? Is there an easy way to change…

... and, specifically, read the following answer in that topic posted by @tkn (thom) that I think will solve your issue of setting up a network connection in Ubuntu MATE to use a specific DNS Server IP address:

How can you change DNS servers on Ubuntu-Mate 22.04 (e.g. for a pi-hole)?

I also use a custom DNS, it is actually quite ease to select another one: Click the network icon on the taskbar. select: Edit Connections -> (select the connection of your choice) -> cogwheel change Method to "Automatic (DHCP) addresses only" fill in your dns-address** on the line "DNS servers" ** if you want more dns-addresses, seperate them with a comma. [DNS] In this example you see 127.0.2.1 as DNS because I have a DNS-crypt-proxy locally but you can fill in any legitimate DNS addres…

I hope this helps

[DaveHighland]

The linux version of the Proton VPN app has an annoying habit of sometimes leaving a connection active even after you quit the app. I think it's plausible that you have a connection remaining even after uninstalling the app. It's worth looking into.

Try running this command and examine the output:

nmcli connection

Here's the sample output from my system (some connections redacted):

NAME UUID TYPE DEVICE
Proton VPN CH-US#2 ba9a6cf9-0675-4cca-82a9-7b863b33036f vpn wlp2s0
pvpn-ipv6leak-protection d156d1bf-a38c-4cc1-b78d-bf7df5795a8f dummy ipv6leakintrf0
XXXXX d729b3fb-b5de-4b0e-a4b9-59658fc1cf74 wifi wlp2s0
proton0 843bcbb4-8786-4d31-b21a-95e70a7ef82d tun proton0
XXXXX d557bb26-90a1-4dbd-9387-a73c6d398d13 wifi --
XXXXX 1b49067f-e4e3-4766-8dc5-83ceb43ddbc0 wifi --
Wired connection 1 5a5ee6e0-61fd-38f1-a551-44ea03870b9a ethernet --

Note that Proton VPN installs three connections when it's active. The "pvpn-ipv6leak-protection" seems to be the most tenacious, often remaining when the app has been exited.

If you see any of these connections persisting after quitting or uninstalling the app, use nmcli to delete it. For example:

nmcli connection delete pvpn-ipv6leak-protection

[LRDP1]

Hello Community,I don't know if Abraxus resolved his problem, but I've got protonVPN since it began and the same problem appears when VPN is still running when the session is disconnecting. thus the only connection runs with DNS 127.0.0.54. I had to correct by rewriting the /etc/resolv.conf with box DNS (ex : 192.168.1.1).
Finally, after research, the only solution is to install resolvconf and to write some good DNS in /etc/resolvconf/resolv.conf.d/base :

<` Dynamic resolv.conf(5) file for glibc resolver(3) generated by resolvconf(8)
# DO NOT EDIT THIS FILE BY HAND -- YOUR CHANGES WILL BE OVERWRITTEN
# 127.0.0.53 is the systemd-resolved stub resolver.
# run "systemd-resolve --status" to see details about the actual nameservers.
nameserver 127.0.0.1
nameserver 192.168.1.1
nameserver 127.0.0.53 '<

But, for security, disconnect the VPN before closing the session.

hoping to have helped. Sorry for my English, I'm french and learned English 55 years ago.

[Bombilla]

Welcome @LRDP1 to the community!