Internet stopped working after regular software update [Fedora 42 KDE]

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Hi. I’m on Fedora 42 and I performed a regular software update via Discover yesterday. Today my Internet of my PC stopped working.

My network consists of router + Raspberry Pi with pi-hole running, PC is connected to the router via Ethernet cable.

What I’ve tried so far:

  • unplugging and replugging Ethernet cable: no change
  • restarting router and Raspi: no change
  • pinging router, raspberry, or Google from my PC does not work: it says something like sendmsg: operation not permitted
  • Other types of connections like USB-tethering also does not work

What works:

  • Notebook and smartphone can connect to router via Wi-Fi and browse Internet just fine
  • I downloaded the Fedora 42 LiveUSB via notebook and used it to boot my PC: Ethernet connection works!

Based on the facts that other clients work fine and the PC works fine with LiveUSB I figure the update broke something.

How can I figure out the root cause? And especially, how can I fix the broken packages without an Internet connection?

1 Like

Hi Dave,

had a similar issue with the upgrade to 42, see this thread.
In my case Mullvad VPN and its lockdown mode was the cause. Logging in Mullvad VPN and deactivating the lockdown mode solved my issue.
Tried so many things (SELinux, Iptables etc.) and it was so easy.

4 Likes

Holy shit! You are my savior! I have Mullvad VPN installed but I haven’t configured lockdown mode. Why was it enabled all of a sudden? And why does lockdown mode work when Mullvad is not even launched (on start-up)?!

Yeah, I spent a lot of hours troubleshooting today, only to find out that it was that easy.
Was activated with an update of Mullvad (mistake by the Mullvad maintainers in my opinion). That is how lockdown mode is supposed to work = as long as you are not connected to a Mullvad server, even if application is not running, you are not supposed to have internet access.

This was exactly my problem, thank you Sven!

Yea, it looks like an issue with the Mullvad package. I assume this problem will affect many other users as well. I hope they find this post. Thx again for the help!

I had the same issue and as the OP I was troubleshooting nftables and iptables until I went mad.

Out of curiosity, how did you find the problem? I am not even running MullvadVPN, I had the app installed though and that was apprently enough to ruin my day.

yes, I had exactly this problem too. this is insane. I never used mullvad and never had issues until I restarted with system updates …really a poor design app who does not even warn me about it. I am also curious how you figure that out. please teach us. I have spent 2 hours in troubleshooting the network and was going mad too.