Dravonic Posted February 19, 2012 Report Share Posted February 19, 2012 Recently came across a torrent that is causing me a lot of trouble with hashfails. 110 pieces downloaded, 143 hashfails, about 40 banned peers.I've never seen anything of the sort even though I'm using utorrent for years. I find it hard to believe that so many bad peers are concentrated in this single torrent, when more than 200 others rarely get more than 3 hashfails, most getting none. It isn't even such a popular torrent (less than 2000 peers in the swarm). I believe I've encountered a/some malicious peer(s) that utorrent is having trouble to detect.I've had a look around and thanks to the manual I found out it has 2 settings I can toy around with for banning peers, bt.ban_ratio and bt.ban_threshold. The threshold is easy to grasp, but the ratio is rather complicated when I have no idea what kind of calculations are involved. What are sane values I can use here? Or better yet, where can I find a detailed explanation of this ratio? Does anyone have any suggestions?It is very likely that this guy is exploiting default values, meaning a bit of tweaking should help me out here.Using utorrent 3.1.2 build 26753. Link to comment Share on other sites More sharing options...
DreadWingKnight Posted February 19, 2012 Report Share Posted February 19, 2012 DLink router with either DMZ or gaming mode enabled? Link to comment Share on other sites More sharing options...
Dravonic Posted February 19, 2012 Author Report Share Posted February 19, 2012 Nope. Old Cisco Linksys and I'm not crazy enough to DMZ my computer.As mentioned it is a problem with this particular torrent. Downloading others simultaneously with no problem. Link to comment Share on other sites More sharing options...
DreadWingKnight Posted February 19, 2012 Report Share Posted February 19, 2012 The hashfail banning code handles banning of bad peers properly with the default settings. Making them more or less strict than default will likely cause more problems and wasted bandwidth down the road.Is there any pattern to the IP addresses getting banned for causing the hashfails? Link to comment Share on other sites More sharing options...
Dravonic Posted February 20, 2012 Author Report Share Posted February 20, 2012 No pattern at all. See for yourself:[2012-02-19 15:03:03] Banned 12.9.73.202:34917 until forever[2012-02-19 15:03:03] Banned 186.29.38.77:34583 until forever[2012-02-19 15:03:03] Banned 85.64.92.104:41276 until forever[2012-02-19 15:03:03] Banned 41.224.215.84:56410 until forever[2012-02-19 15:03:09] Banned 201.223.247.116:32150 until forever[2012-02-19 15:03:09] Banned 24.63.61.89:44853 until forever[2012-02-19 15:03:53] Banned 94.215.33.184:54740 until forever[2012-02-19 15:04:02] Banned [2001:0:4137:9e76:10bd:2de9:9c11:8342]:34776 until foreverJust an excerpt, but it should be enough. Many simultaneous bans going on also, meaning utorrent really has no idea which one is the problematic one. Like here for example:[2012-02-19 15:01:18] Banned 84.215.150.196:46218 until forever[2012-02-19 15:01:18] Banned 189.61.43.11:58625 until forever[2012-02-19 15:01:18] Banned 190.45.58.14:20103 until forever[2012-02-19 15:01:18] Banned [2001:0:5ef5:79fb:28df:3ff0:ae59:2183]:10105 until forever[2012-02-19 15:01:18] Banned [2001:0:4137:9e76:1453:7d7:e7c0:c2a6]:44853 until foreverIt just looks like these guys are being mistaken as bad peers due to a malicious one.The hashfail banning code may handle bad peers properly, but a malicious one with knowledge of this ratio system can stay just above the ratio to avoid being banned, provided it's not so hard to do so. I actually have no idea if it is since I don't know the ratio formula being used.Obviously, I considered a problem with my internet connection, which is why I made sure I had another torrent downloading. This was the only one getting hashfails. Of course this may not be a malicious peer problem at all, but I really have no idea what else would cause this. Link to comment Share on other sites More sharing options...
DreadWingKnight Posted February 20, 2012 Report Share Posted February 20, 2012 The hashfail banning code may handle bad peers properly, but a malicious one with knowledge of this ratio system can stay just above the ratio to avoid being banned, provided it's not so hard to do so. I actually have no idea if it is since I don't know the ratio formula being used.It's actually quite difficult to do because the ban system is quite a bit more sophisticated than it first appears. The less peers involved in an individual piece the more accurate the ban.The big causes are:1> malicious peers2> an effect that has been nicknamed "DLink DMZ Download Destroyer". Some routers have a bug that causes remapped packets with a 4-byte sequence that would match an IP address that would remap to become corrupt by the remap.3> Corruption in the remote files caused by media indexer applications. Link to comment Share on other sites More sharing options...
Dravonic Posted February 20, 2012 Author Report Share Posted February 20, 2012 Crap, could this be caused by dimwits using itunes or whatever and the program eventually modifies the mp3 metadata causing them to seed an altered file? Don't clients first check a piece's integrity before seeding it or part of it? Or they just assume a completed torrent is correct? Link to comment Share on other sites More sharing options...
DreadWingKnight Posted February 20, 2012 Report Share Posted February 20, 2012 The protocol only requires the check on download and re-load. Link to comment Share on other sites More sharing options...
Dravonic Posted February 20, 2012 Author Report Share Posted February 20, 2012 What do you mean by re-load? Reloading the client?Either way, that doesn't seem to be the problem, I'm getting hashfails everywhere, not just at the first piece of a file. Link to comment Share on other sites More sharing options...
DreadWingKnight Posted February 20, 2012 Report Share Posted February 20, 2012 Removing and re-adding the torrent.If a file's data is changed sufficiently, the entire file will hashfail from a given peer. Link to comment Share on other sites More sharing options...
Dravonic Posted February 20, 2012 Author Report Share Posted February 20, 2012 Oh true, I completely forgot that. It will shift everything and cause a hashfail for the whole file, obviously This being an MP3 torrent that certainly sounds more plausible than some guy corrupting the whole swarm this efficiently. But if so, this problem alone is causing me hashfails more than half of the time a piece is downloaded. Doesn't this happen often enough with these kinds of torrents it's reason enough to warrant a protocol change? Link to comment Share on other sites More sharing options...
4uvak91 Posted March 6, 2012 Report Share Posted March 6, 2012 HiI'm running µTorrent 3.1.2 (build 26773) on Win 7 Enterprise x64 SP1. I have router model Telewell TW-EA510 v3©. I'm downloading torrent of size 13GB that includes multi .rar-files. The problems is that i get A LOT of hash fails.[2012-03-06 15:33:04] *** xxx: PIECE 647 FAILED HASH CHECK[2012-03-06 15:33:29] *** xxx: PIECE 774 FAILED HASH CHECK[2012-03-06 15:33:58] *** xxx: PIECE 647 FAILED HASH CHECK[2012-03-06 15:34:40] *** xxx: PIECE 29 FAILED HASH CHECK[2012-03-06 15:34:47] *** xxx: PIECE 647 FAILED HASH CHECK[2012-03-06 15:35:15] *** xxx: PIECE 24 FAILED HASH CHECK[2012-03-06 15:35:45] *** xxx: PIECE 29 FAILED HASH CHECK[2012-03-06 15:36:15] *** xxx: PIECE 647 FAILED HASH CHECKI'm downloading from private tracker. It seems that µtorrent doesn't even ban bad peers, only a few.Do you know where m8 be a problem?I also run pingtest http://www.pingtest.net/result/58365835.png Link to comment Share on other sites More sharing options...
DreadWingKnight Posted March 6, 2012 Report Share Posted March 6, 2012 If peers are getting banned on the logger tab, then you're dealing with either something in your setup being the cause or something going on in the swarm that is preventing the bans. Link to comment Share on other sites More sharing options...
4uvak91 Posted March 6, 2012 Report Share Posted March 6, 2012 If peers are getting banned on the logger tab, then you're dealing with either something in your setup being the cause or something going on in the swarm that is preventing the bans.I got protocol encryption ON so I disabled it, but i still gettings this:[2012-03-06 16:04:52] *** xxx: PIECE 723 FAILED HASH CHECK[2012-03-06 16:04:52] Banned 92.244.7.9:61657 until forever[2012-03-06 16:06:09] *** xxx: PIECE 756 FAILED HASH CHECK[2012-03-06 16:06:32] *** xxx: PIECE 527 FAILED HASH CHECK[2012-03-06 16:06:56] *** xxx: PIECE 756 FAILED HASH CHECK[2012-03-06 16:07:16] *** xxx: PIECE 527 FAILED HASH CHECKhere is my settings: http://dl.dropbox.com/u/56276014/settings.dat Link to comment Share on other sites More sharing options...
4uvak91 Posted March 6, 2012 Report Share Posted March 6, 2012 so any help please? Link to comment Share on other sites More sharing options...
4uvak91 Posted March 8, 2012 Report Share Posted March 8, 2012 so any help please? Link to comment Share on other sites More sharing options...
DreadWingKnight Posted March 8, 2012 Report Share Posted March 8, 2012 There may be a bug in your router's code causing the issue or the seeds have modified files that they're seeding that break. Link to comment Share on other sites More sharing options...
4uvak91 Posted March 9, 2012 Report Share Posted March 9, 2012 There may be a bug in your router's code causing the issue or the seeds have modified files that they're seeding that break.Ok I try to reinstall/update the router's frimware. Can it be problem in HDD or what you mean by that "the seeds have modified files that they're seeding that break." ? Thanks anyway Link to comment Share on other sites More sharing options...
4uvak91 Posted April 22, 2012 Report Share Posted April 22, 2012 still having this!!!! can the problem be in network card (inbuilt in motherboard)? Link to comment Share on other sites More sharing options...
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