I've added almost nothing new to this post: http://ubuntuforums.org/showthread.php?t=564301
Ergo, all glory to 'coolen'. My only contribution, and a very small one at that, is showing a solution for a system, with a switch rather than a router.
Anyway, here's my reproduction of the prescribed method. I've changed almost nothing. The main purposes for reproducing the approach here are 1) so that I can remember it myself and 2) so that other people get independent verification that the method does indeed work.
The server ip address in the example is set to 192.168.1.2.
sudo apt-get install apt-cacher-ng
sudo vim /etc/services (or sudo nano, gksu gedit etc.)
(I had a whole lot of stuff in my /etc/services)
apt-cacher 3142/tcp #apt-cacher-ng service
apt-cacher 3142/udp #apt-cacher-ng service
'coolen' adds AUTOSTART=1 to /etc/default/apt-cacher-ng
As far as I understand that's not necessary.
sudo /etc/init.d/apt-cacher-ng start
Make sure that your firewall is not blocking connections to port 3142 (e.g. configure gufw).
To turn on:
sudo vim /etc/apt/apt.conf.d/01proxy
Do sudo apt-get update and you're done
(If you want to go back to the default repos, turn off by changing to
(I basically looked at https://help.ubuntu.com/community/Apt-Cacher-Server)
sudo vim /etc/apt/sources.list
If your sources.list file currently looks like this:
deb ftp://ftp.au.debian.org/debian/ testing main contrib non-free
deb ftp://ftp.au.debian.org/debian/ stable main contrib non-free
deb ftp://ftp.au.debian.org/debian/ unstable main contrib non-free
change it so that it looks like this:
deb http://192.168.1.2:3142/ftp.au.debian.org/debian/ testing main contrib non-free
deb http://192.168.1.2:3142/ftp.au.debian.org/debian/ stable main contrib non-free
deb http://192.168.1.2:3142/ftp.au.debian.org/debian/ unstable main contrib non-free
Do sudo apt-get update and you're done.