[Gizby]

Okay, after looking over µTorrent's FAQ, I'd like to link/quote some items concerning DHT.

Does µTorrent support DHT or Peer Exchange?
As of version 1.2, µTorrent supports DHT, but not Peer Exchange. It respects only the private flag included in the .torrent

µTorrent will NEVER support private flags given by the tracker in the announce response! It is a dirty fix, and is EXTREMELY unreliable. Only the private flag embedded into the torrent will be supported because it is reliable and relatively secure by design.

Does DHT mean my torrents from private trackers are getting leaked?

So long as the torrents are created with the private flag (µTorrent and Azureus support this functionality in their torrent creators), DHT will be disabled automatically for that torrent. You can verify this by double clicking on the torrent: if "Enable DHT" is greyed out, it's disabled for that torrent.

µTorrent will NEVER support getting the private flag from the tracker announce, because this method is considered to be very insecure and unreliable. If you are a tracker admin and want the private flag to work reliably, please enforce using the private flag in the .torrent on the tracker level. BitComet's torrent maker does not make private torrents properly, nor does the client respect the private flag (see this article on Slyck).

I don't want DHT on anyway, how do I turn it off?

Open the options, go to Torrent Options, and uncheck "Enable DHT." This will turn off DHT for ALL torrents. Alternatively, you can disable it on a per-torrent basis: double click the torrent or right click and select properties, then uncheck "Enable DHT."

There is also an option to have DHT disabled for new torrents by default, allowing you to have DHT enabled globally without having to worry about your private torrents using DHT when they lack a private flag.

What is DHT?

DHT (Distributed Hash Table, technical explanation) is an addition to certain BitTorrent clients that allows them to work without a tracker. What this means is that your client will be able to find peers even when the tracker is down, or doesn't even exist anymore. It allows the swarm to continue as normal without a tracker. You can also host torrents without a tracker. (see Does µTorrent support trackerless torrents?).

µTorrent's DHT implementation is the same as Mainline and BitComet's, but unfortunately this is incompatible with Azureus's implementation.

So it seems to me that µTorrent should be in the clear even with versions after 1.2.x.x. The screenshot below is the properties window for a DIME torrent runnig in µTorrent 1.3.


I've circled the 'Enable DHT' tick box. For this torrent, it is greyed out. For other torrents I have running on other trackers, the option is open.

So, since µTorrent respects the rights of a tracker to turn off this option, and since DIME turns it off when you have to redownload your own torrent, it seems like any version of µTorrent should be kosher over there as long as you don't download torrents from before May. At least that's how I see it.