Bug with ProtonVPN on PureOS causes DNS and other network services to not work

While I was investigating another issue related to Wi-Fi, I had been given instructions by the support staff as to how to replicate the issue I was discussing with them. In the process, I “discovered” a bug within ProtonVPNs software. There is a post that does not explicitly give the information on which VPN provider and if you do not use the software, you might not know.

In addition to that, I tried a plethora of troubleshooting techniques before coming to this conclusion and resolving the issue.

So I decided to post them here, hoping to help make it more easily understood and easier to find by future users.

The post I am referring to is here: https://forums.puri.sm/t/laptop-resets-dns-lookup-server-to-nothing-preventing-access-to-the-internet/15794

Before following the above steps, which I personally did in a much more random and not as eloquent manner (I sort of stumbled on the commands to run elsewhere). The only thing that really helped was toggling the kill switch on/off.

Troubleshooting steps I took that lead nowhere, but symptoms of the issue:

  • I tried connecting over various mechanisms. Using different wifis, bluetooth, ethernet, and a teter all failed and produced the same results.
  • I could ping the default gateway.
  • Even though my adapter automatically gleaned the ISPs DNS server IP, I could not ping, traceroute, nor query the DNS server.
  • Aside from pinging the DG, no other network communication worked.

I ran through most of the steps identified in the above link. Bear in mind the VPN client was showing as disconnected the entire time. Toggling the kill switch to off, immediately resolved the issue.

If there are any other questions, let me know. But, hopefully this helps a couple people out.

So far after initially being grumpy about PureOS, I am loving it.

1 Like

I’ve seen this before, its been happening for a while now. A solution that worked for me (if someone is having this problem but not having killswitches) is to connect protonvpn and then have it disconnect versus some other means like shutting the computer down.