So after having this issue when trying to upgrade from 5 to 6 last week I did a fresh install of 6 but I think it was after installing OMV-Extras that it all started again. OMV-Extras I don't think has installed fully & again I can ping 8.8.8.8 but not google.com.
Following through post "DNS not resolving on OMV 6.0.42-2 after setting interface DNS" I have similar results!
ZitatPlease do us a favor and install the system from scratch. Installing systemd from the backports has made your system unmaintainable and put the package management in a state where it seems impossible to fix the package conflicts.
And again from Votdev further down the post:
ZitatInstall debian and then install OMV over debian. Note that running the OMV install script will also install omv-extras and, if memory serves, will enable backports by default.
Like "nila" in the above post I didn't knowingly install through 'backports'.
So my question is what should I do if I have to do another fresh install?