All existing answers I found are for the pre-multiarch era (chroot)
https://help.ubuntu.com/community/MultiArch says it is OK to install i386 package on amd64 under the multiarch environment, but doesn't say how.
Officilal image is multiarch netinstall - see what up-right corner of Debian main web page suggests . So this image: http://cdimage.debian.org/debian-cd/6.0 … etinst.iso Other images exists just like solution for something, another architecture, etc. But in majority these solutions are for those people with no network.