When having more than one Gentoo installation at the same location, you should seriously consider sharing the Portage tree to avoid a lot of unnecessary downloads. This can be done by having the tree on only one machine and share it with NFS, the Network File System.

Server (Gentoo Linux)
First, we're going to configure the server, having the Portage tree installed in /usr/portage. I suggest following the first half of my previous article on setting up a NFS connection between Gentoo and FreeBSD.

I think it won't ever happen to me that NFS will 'just work'. During the process of getting server and client work together, you'll almost always encounter at least one permission denied, go to hell.

To me, NFS is like black magic. Getting it to work consists of trial and error and feel lucky afterwards.

The big plan was to use a /usr/ports directory from another machine on the same network. Shouldn't be too hard, right?