How to use an apt caching proxy

[Diederik de Haas <didi.debian@cknow.org>]

Hello,

I want to start experimenting with live-helper and to avoid downloading the same package over and 
over again, I've set up apt-cacher-ng to cache downloaded packages and created a 
/etc/apt/apt.conf.d/02proxy file with the following contents:
Acquire::http { Proxy "http://192.168.1.5:3142";; };

The source.list file could there stay the same and I've verified it's working correctly with aptitude 
update/safe-upgrade for machines in my local LAN (all machines have that 02proxy file).

But I'm having troubles getting live-helper to use that proxy, so it's downloading each package over 
and over again. I concluded that since I didn't see a change in apt-cacher-ng's cache folder, nor 
saw I any speed increase in the following attempts.

I've tried the following commands:
from lh_config man page:
lh_config --apt-http-proxy http://192.168.1.5:3142
lh_build

lh_config --apt-http-proxy "http://192.168.1.5:3142";
lh_build

from http://wiki.debian.org/DebianLive/Howto/Cache_Packages:
lh_config --mirror-binary "http://192.168.1.5:3142/ftp.nl.debian.org/debian/";
lh_config --mirror-binary-security "http://192.168.1.5:3142/security.debian.org/";
lh_build

And each time I saw the following msg: 
Checking component main on http://ftp.us.debian.org/debian...

Main question:
What am I doing wrong here and what to do so it will use apt-cacher-ng's proxy?

Related question:
What's the difference between --apt-http-proxy and --mirror-binary (with the proxy IP:port prepended 
to it)


Thanks in advance,
  Diederik