I've got a bit of an issue where I have a few people using my internet connection simultaneously, however there is a single person on the network who insists on seeding their torrents 24/7 at my max upload - 1024kbps
My downlink is 10mbps, obviously while the upload is being raped my DL speeds are around 2mbps. So this is having a pretty severe effect on my network.
I'm running Ubuntu 12.04 on a homeserver set up as a router. What I'd like to do is set this person's maximum upload at 400kbps. I'm not too fussed about the other users, so I don't want a tool which will apply the same rules to everyone - just specific user's IP addresses (preferably MAC address, though that's not too important).
I know a little bit about linux but would you please explain as if you would a person who knew absolutely nothing about ^^. Thanks!