Gnutella on LAN

[rabin]

How do I restrict any of the Linux Gnutella clients (Limewire, Phex, Gtk-Gnutella, Qtella...) to only search for hosts on a LAN?

I am looking for this functionality similar to the Gnucleus (http://www.gnucleus.net) LAN edition on Windows.

I'm on Debian unstable with a permanent lan connection and IP addresses given out by DHCP.

Thanks,
Rabin.