Debian archive proxy and partial mirror builder apt-proxy
automatically builds a Debian HTTP mirror based on requests
which pass through the proxy. It's great for multiple Debian
machines on the same network with a slower internet link. The
archive is automatically kept up to date using http, ftp or
rsync. Cache cleaning of unused and old versions is
configurable. You can also import the contents of your apt cache
into the archive using apt-proxy-import.
This will install all the needed packages. You might want to
install rsync and dpkg-dev. You need dpkg-dev only if you want
to merge a local apt cache to apt-proxy. rsync package is only
needed, if you want to use rsync to download packages.
After the installation of apt-proxy is complete you have to edit
the /etc/apt-proxy/apt-proxy.conf file. Mainly you add all your
local apt sources you have.