read this: http://wiki.openwrt.org/MiniHowtos/QoSHowto

if you can make heads or tails of it, you've got my admiration..


try googling "blocking Limewire"....

I have no experience with blocking, or tunneling, gnutella, as I've never had to do it before...

also, since yur running a linux machine, perhaps you can use it as a gateway, and firewall it and run a 'rope': http://www.lowth.com/p2pwall/ (though that article is a tad out of date, and I suspect the algorithm is also out of date)