Here in the home we have 3 laptops running Ubuntu Linux and limited internet bandwidth. So with all three machines grabbing their own updates from online sources I was beginning to wonder how I could make it that one computer updates and the others update from that one already updated computer.
Apt-cacher was my salvation!
Basically here is how it works…
You have two computers both running Ubuntu Hardy (or the same release of any Linux distro) and you want Computer#1 to update directly from the internet and Computer#2 to update as much as possible from the updates already downloaded by Computer#1.
So you configure Computer#2 to work through Computer#1 and look through the packages available there and take as much as it needs from Computer#1. Anything it needs that cannot be found on Computer#1 can be downloaded from the internet by Computer#2.
Here is the how-to I followed to get this working in Ubuntu Hardy. LINK HERE