What is the easiest way to update/upgrade an offline Ubuntu machine with the help of a Windows machine that has internet access?
This question also applies to installing new packages offline and not only updates/upgrades.
The Linux system shall remain completely cut off from the Windows machine, meaning there should be no ethernet connection or the likes between the two computers.
Please have patience, since I haven't updated this since two weeks.
There are some complications getting apt-offline to work properly on Lubuntu and all other methods seem to be too old and deprecated:
AptOff - last update 2006
AptMedium - last update 2007
Keryx - last update 2011, looks like this project was discontinued
I hope I will be able to somehow update the offline machine, finally.
While I was still not able to update/upgrade the offline system due to authentication errors, I accepted an answer, because it's taking too long.