Updated: February 20, 2026
In addition to a couple of physical systems, I run roughly two dozen Linux virtual machines, most of them Ubuntu-based. Because of this unlikely high count of systems, I often encounter problems most other people don't see. Case in point: random networking connectivity issues in Ubuntu (or flavors) running with the latest available kernel at the time of writing.
The issue manifests in various ways. You try to connect to a Web page, it says: no connectivity, but then immediately thereafter, it does connect. You try to update your system, and you get errors. You try to ping a system, which you know is pingable, routable and will give you the expected result, and you get still more errors. If you repeatedly try these actions, they will succeed, but about 50% of cases will initially fail. Let's debug and fix this.
Problem in more detail
I noticed the problem at first only in Chrome in one VM. Then, in Firefox, in another. Chrome tries to automatically refresh the pages, but in Firefox, it looks as though the connection reset while loading the page, and you need to "hard" refresh. On the command line, apt throws all sorts of errors:
E: The repository 'https://dl.google.com/linux/chrome/deb stable Release' no
longer has a Release file.
W: Updating from such a repository can't be done securely, and is therefore disabled by default.
W: See apt-secure(8) manpage for repository creation and user configuration details.
E: https://dl.google.com/linux/chrome/deb stable Release is not (yet) available (Cannot initiate
the connection to dl.google.com:443. - connect (101: Network is unreachable))
But if you try the apt update command multiple times, you will succeed eventually. The ping command will complain about the broadcast address and firewall rules, regardless of the destination. After you run it again, it will work normally.
ping [whatever]
ping: Do you want to ping broadcast? Then -b. If not, check your local firewall rules
And the issue only manifests in Ubuntu kernel 6.8.0-100. The older kernels work fine, and this problem does not happen there. Indeed, let me now show you how you can easily and quickly load an older kernel, wait for this silly bug to be fixed in the next release, and then move on with your Linux life.
Solution, workaround
The simplest fix is to test an older kernel, which, spoiler, solves the issue. Open your GRUB default configuration file in a text editor:
sudo nano /etc/default/grub
Here, change the following two directives:
GRUB_TIMEOUT_STYLE=hidden
GRUB_TIMEOUT=0
Change to:
GRUB_TIMEOUT_STYLE=menu
GRUB_TIMEOUT=[Some number]
By some number, I mean a value that will allow you to see the GRUB menu, and then click the down arrow key button and select an older kernel, in this case 6.8.0-94-generic, the previous one. Let's say 10 seconds.
GRUB_TIMEOUT=10
Save the file, exit. Now, update the GRUB bootloader:
sudo update-grub
Reboot, and you will see your problems are gone.
Conclusion
I am really annoyed by this bug. In an LTS no less. I mean, seriously. Worst of all, it has potentially serious implications, as you may end up with packet loss and important connections suddenly being cut, which is not what you want. Effectively, the systems become unreliable with this kernel. Luckily, the workaround is quite simple and quick and fully reversible.
Thus, if your network suddenly behaves erratically in Ubuntu and flavors, it's most likely not you, not your gear, not your DNS or anything. It's most likely kernel 6.8.0-100. Check it, and if that's the case, boot into an older instance, and see what gives. There's a pretty good chance you won't have any trouble any more. Well, that completes this short guide. On to the next escapade in the slowly deteriorating Linux desktop world.
Cheers.