-If you know the IP addresses, you can use an ACL.
- Configure Netflow monitoring and use a free tool like NetFlow Analyzer to see who is hogging your bandwidth and block access to those site using the resolved IP addresses.
My solution was to setup Untangle web appliance in bridge mode between the firewall and switch. (see below).
I used the "free" version
Then you can use the Web Filter "block file types" to block "popular" torrent files extensions like.
.zip,.tgz,mp3,mpg,zip...etc.
Its not perfect. But it works to keep up a good fight :-)
http://wiki.untangle.com/index.php/File:Bridge_mode.png
http://wiki.untangle.com/index.php/Introduction#Untangle_Server_as_a_Bridge
