Due to internet problems where I am living, I need to maintain a mechanism to update my linux installations without ever depending on the internet.
In case I need to download the packages to a small microserver that I mounted on a 1TB HD NanoPI, so when I'm in my lab I can upgrade the other machines.
I tried with Kyrix, but it's very old, then I discovered apt-offline, but this one needs the internet to install it.
How do I proceed to do such maintenance?