block Torrent through firewall
Deep packet inspection is the way to go here. The traffic has to be examined in order to block it effectively. If encryption is used, though, all bets are off.
You might try looking at Untangle. It sounds like it could do what you want.
Most commercial firewalls only block incoming, they allow all outgoing and that is sometimes enough to get torrents working with minimal speed.
If you need to block it, the best thing you can do is block all outgoing on the router, excluding items that are needed such as smtp, pop3, http, https.
Also, block UPnP as this dynamically allows clients to assign / make outgoing/incoming connection rules.
You could use a Squid proxy server or a Smoothwall firewall appliance. These would work because traffic shaping needs to use "deep packet inspection" to detect the protocol type.
If you cant figure out how to block the traffic then you have 2 more options:
- Limit bandwidth by IP
- Limit number of inbound connections by IP (that would slow Torrent to a crawl).