Joel,

I am curious what you are using that triggers a throttle/tarpit when Bittorent 
is detected.

Thanks,
Bob Williamson
Network Administrator
Annie Wright Schools | 827 N Tacoma Ave, Tacoma, WA 98403 | 
www.aw.org<http://www.aw.org/>
D: 253.272.2216 | F: 253.572.3616 | 
[email protected]<mailto:[email protected]>

From: The EDUCAUSE Wireless Issues Constituent Group Listserv 
[mailto:[email protected]] On Behalf Of Coehoorn, Joel
Sent: Wednesday, October 8, 2014 8:22 AM
To: [email protected]
Subject: Re: [WIRELESS-LAN] Cisco WLC AVC- Blocking most, but not all, 
Bittorrent- Anyone else seeing this?

I've found that some Bittorrent clients just do. not. give. up.

You block a torrent, the clients will try, try again, often changing something 
in how they send the messages: route over https, exclude certain peers, etc, 
and eventually they sometimes find a way around the block.

What I've seen that's most effective in really defeating bittorrent is 
throttling/tarpitting the user's traffic: not just bittorrent itself, but 
*everything* originating from that internal IP. Send them back to the dial up 
era. When the bittorrent traffic stops, their connection returns to normal 
within a few minutes.

Students in this situation have figured out pretty quickly that bittorrent was 
causing their slowness issues. From the student's perspective, bittorrent 
breaks their computer. The great thing here is that it really does tend to 
follow that thought process, and the blames tends to be assigned to the 
protocol or something wrong with their bittorrent configuration, rather than 
with your network. At this point, the behavior is self-correcting.  If a 
student does complain, you point them to bittorrent as a possible factor, and 
they'll get it soon it enough.

There's some good news/bad news for this approach, though. The good news is 
that you don't have to detect every packet from every torrent stream for a 
student to have an effective block. The bad news is that some unwanted traffic 
still does get through (though usually not enough to offend the copyright 
gods), and that there is a risk for small false positives creating slow 
connections for innocent users... especially when there are some legitimate 
bittorrent uses such as research data, linux distributions, game updates, etc. 
I tend to not apply this policy to the population at large, but only to those 
who have already tripped a flag somewhere: log first, find where your 
torrenters are, and apply the tarpit policy rule to that group.





[http://www.york.edu/Portals/0/Images/Logo/YorkCollegeLogoSmall.jpg]


Joel Coehoorn
Director of Information Technology
402.363.5603
[email protected]<mailto:[email protected]>



The mission of York College is to transform lives through Christ-centered 
education and to equip students for lifelong service to God, family, and society

On Wed, Oct 8, 2014 at 8:54 AM, Lee H Badman 
<[email protected]<mailto:[email protected]>> wrote:
We recently started relying on the 5508 AVC capability to block Bittorrent, 
which it seems to do fairly well. But… we are getting an increasing number of 
take-down notices where Bittorrent was used to do something, but drilling into 
the data in PI shows that nothing was detected by the WLC  for the activity 
that led to the take-down. In other words, the system doesn’t see the 
Bittorrent activity.

We have all three Bittorrent protocols in use (Bittorrent/encrypted/network), 
and can tell that most Bittorrent is indeed being blocked. But what is getting 
by is probably sufficient enough that we may have to abandon the WLC P2P 
strategy and go back to an appliance. Has anyone been through this, and found 
anything else to add to the profile to help stem the Bittorrent? (We also have 
the obvious ones like eDonky, etc)

Thanks-

Lee

Lee Badman
Wireless/Network Architect
ITS, Syracuse University
315.443.3003<tel:315.443.3003>
(Blog: http://wirednot.wordpress.com)



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