simonc Posted February 1, 2006 Report Share Posted February 1, 2006 I am wondering whether utorrent's PEX supports other client like Bitcomet?I asked this because... I am downloading a "private torrent" off a "private tracker".When I checked the property, DHT and PEX is greyed out.DHT is disabled from preferences.PEX is enabled from preferences.From the peer list, I can see a lot of X flag clients (obtained from PEX according to FAQ).Not sure whether its a bug or something.. just want to inform about this issue. Link to comment Share on other sites More sharing options...
boo Posted February 1, 2006 Report Share Posted February 1, 2006 µTorrent respect the private flag (which are in private torrents),therefore DHT and PEX gets disabled for that torrent. Link to comment Share on other sites More sharing options...
Firon Posted February 1, 2006 Report Share Posted February 1, 2006 Maybe it doesn't turn off PEX... And it only does PEX with other µT clients. Link to comment Share on other sites More sharing options...
simonc Posted February 1, 2006 Author Report Share Posted February 1, 2006 If what boo said is right, how did the X flag client shows up in the peer list?At the time of the issue, there was 1 utorrent client connected, version 1410.The rest are BitComet and a few Azureus. Link to comment Share on other sites More sharing options...
simonc Posted February 1, 2006 Author Report Share Posted February 1, 2006 I suspect it was the BitComet who leaked the peer list to the outsiders.When the outsiders connect to me directly, they appear as X flagged.All the X flagged are BitComet clients. Link to comment Share on other sites More sharing options...
Martin Levac Posted February 2, 2006 Report Share Posted February 2, 2006 I've seen all kinds of X peers, not just BC clients. BitTornado, BitComet, uTorrent, ABC, Azureus perhaps more and both incoming and local connections.The way I see it, uTorrent must have a mechanism to know where the peer comes from before it flags it X. It must have recieved at least one peer list through PEX to compare to before it can flag one peer as obtained through PEX. At least one other peer must have the ability to PEX and must have it enabled (or must have the same problem) for that to happen.If uTorrent truly disables PEX if the torrent is private, it must be a peer using a different client than uTorrent or a problem with correctly flagging peers. If other clients are supposed to be incompatible with uTorrent's PEX method, then uTorrent truly does not disable PEX on private torrents or it has the same flagging problem.I imagine that PEX is negotiated between uTorrent b412 peers at the handshake level. If that is the case, it negotiates it even if one peer has it disabled. If that is not the case, uTorrent still accepts PEX lists from other peers even if PEX is disabled on this peer. If neither of the above is the case, there's a problem with uTorrent reporting correctly where this peer came from.Does uTorrent negotiate PEX on the handshake even if PEX is disabled on this peer? Does uTorrent accept PEX peer lists even if PEX is disabled on this peer? Does uTorrent send PEX peer lists on requests even if PEX is disabled on this peer?uTorrent must not do all of the above if PEX is disabled on this peer either globally by the user and per torrent with the privatei1 infodict.ML Link to comment Share on other sites More sharing options...
nightshifted Posted February 2, 2006 Report Share Posted February 2, 2006 [All this is in the context of a torrent on a private tracker with the private=1 infodict key.]Just a thought; suppose a peer has joined the swarm via the tracker since your last announce and got your IP:port pair from the tracker and connected to you; how can your client tell where that peer learned about you?Or suppose it's a large swarm and there are too many peers for the tracker to give you a complete list when you announce, and someone not in any list the tracker gave you but legitimately in the private-tracker swarm connects to you; how can you know where the peer learned your IP:port pair?If you initiate the connection, then your client knows, but if you accept the connection, you can't. Not having been in a list you got from the tracker doesn't prove that the peer is an interloper. Link to comment Share on other sites More sharing options...
Martin Levac Posted February 2, 2006 Report Share Posted February 2, 2006 I think it compares tracker list to PEX list. If the peer is in both, he's not flagged, if he's in the PEX list only, he's flagged once he connects. Regardless of whether he's local or incoming. If on a subsequent scrape the same peer comes from the tracker, the flag disappears.The point is, since uTorrent is supposed to disable PEX if the torrent is private, there's no reason for PEX peers to appear in my list unless there's a bug.For the private flag to have any value, it must be respected, otherwise what's the use of putting it in the torrent in the first place?ML Link to comment Share on other sites More sharing options...
simonc Posted February 2, 2006 Author Report Share Posted February 2, 2006 I am interested in how a client is flagged as X too.From my posts above, I think X is flagged when a peer is not found in the tracker's list of peers, just like Martin Levac said.Tracker List Received---1.1.1.12.2.2.23.3.3.38.8.8.8Complete Tracker List---1.1.1.12.2.2.23.3.3.34.4.4.45.5.5.56.6.6.67.7.7.78.8.8.8A client with the IP: 5.5.5.5 connects to me.Question arises: How did he get my IP? How should I flag him?If it is a private torrent, then I shouldn't flag him X technically since he probably gotten my IP off the tracker too.I should flag him X, if its not a private torrent, since it is possible he got my IP from PEX or from the tracker.Any admin care to explain how the process of flagging a client X ?( Like ML said above, for a private torrent, there shouldn't be any X flagged client in the peer list )---Just so people don't jump saying uTorrent leak the peer list, I have double confirmed that those X flagged clients are indeed in the tracker's peer list. I just don't know why they are flagged X since PEX didn't happen. It's probably just a flagging bug. Link to comment Share on other sites More sharing options...
Xu Posted February 2, 2006 Report Share Posted February 2, 2006 The point is, since uTorrent is supposed to disable PEX if the torrent is private, there's no reason for PEX peers to appear in my list unless there's a bug.For the private flag to have any value, it must be respected, otherwise what's the use of putting it in the torrent in the first place?MLRespecting the privacy flag means not giving out peers. Accepting incoming connections and marking them as suspected PeX (since you didn't see them on the last peerlist you got from the tracker) is the right thing to do. The trackers don't want you hammering them every time you get a new connection from a peer to see if they are on the peerlist.My question is for each case of an X flag on your private torrent, are they also marked I? And also watch if some of those X's disappear when the client updates with the tracker.I'm guessing the X is a guessed flag, as there's no way to find out how an incoming connection got your ip/port. Link to comment Share on other sites More sharing options...
Martin Levac Posted February 3, 2006 Report Share Posted February 3, 2006 I've seen both local and incoming connections flagged X. I've seen more than half of my peer list (over 70/120) flagged X. I've seen exclusively seeds flagged X, not all but the great majority. I've seen the reverse as well. I've seen a great majority of incoming peers flagged X but I haven't seen the reverse yet or just haven't noticed if it happened. All cases in a private tracker environment with private torrents.PEX was enabled at first, I disabled it at some point and I was still getting peers flagged X on new torrents started after I had disabled it.I think the X flag on incoming conns is deduced, not guessed. On local connections initiated with peers obtained by PEX, it's obviously explicit.ML Link to comment Share on other sites More sharing options...
nightshifted Posted February 3, 2006 Report Share Posted February 3, 2006 Then maybe the thing to do is to elaborate a little in the FAQ, when it is updated after there's a production release with PEX: that X means a peer may have been found via PEX rather than via the tracker. Link to comment Share on other sites More sharing options...
ludde Posted February 3, 2006 Report Share Posted February 3, 2006 X is shown for all peers that I learned about from PEX. Even if you got them from the tracker too. Link to comment Share on other sites More sharing options...
Martin Levac Posted February 4, 2006 Report Share Posted February 4, 2006 1.4.1b417PEX disabled from the start and I still see X for many peers on a private torrent. Link to comment Share on other sites More sharing options...
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