[afnog] Use of BitTorrents in Academic Environments

Phil Regnauld regnauld at nsrc.org
Tue Feb 26 15:59:33 UTC 2013

amon.kasonda at unza.zm (amon.kasonda) writes:
> Dear All,
> I am seeking advice from IT experts in academic environments on
> how they have handled the issue of BitTorrents on their network.
> As a university we have blocked this service because of the effect
> it has on internet bandwidth and issues pertaining to security. This
> is an inherent default configuration policy I have found in the 
> university. However, our users strongly feel the service must be 
> restored to enhance their learning and internet experience. Your 
> independent views in this regard are welcome.

    Hello Amon,

    A few observations and questions from an outsider:

    While I understand that bittorrent is frighteningly efficient
    at downloading lots of content in a short time (which is,
    after all, that which it was designed to do), but I'm a bit
    curious about the security aspect. Would you care to elaborate
    on that particular point ? It would actually be useful for
    us as the question of dealing with bittorrent is quite a
    popular one when we talk to universities around the world.

    Is it insecure clients ? Or something else ?

    The next question is: how do you block bittorrent ? In doing
    so, are you certain that you are not blocking other services
    ?  Filtering ports 6881-6999 may not be enough as motivated
    users will find ways around it, such as changing the ports,
    or using encryption/ Tor. Third party solutions such as DPI
    or similar (NBAR) will have an impact on performance -
    something that may not be an issue today, but as networks
    get faster, this will almost certainly be a bottleneck (or
    get really expensive to license).

    The third question is: while a major part of bittorrent
    content may not be of educational interest, can you be
    certain that limiting access to it is not going to hurt
    someone's research ?

    For instance: http://en.wikipedia.org/wiki/BitTorrent#Education


* Florida State University uses BitTorrent to distribute large scientific
  data sets to its researchers.[37]
* Many universities that have BOINC distributed computing projects have used
  the BitTorrent functionality of the client-server system to reduce the
  bandwidth costs of distributing the client side applications used to process
  the scientific data.

    Finally, a suggestion: what some universities have done is:

    1. Create an Acceptable Use Policy that all students and
    faculty must sign upon enrolling. This AUP will amont other
    things state that users and faculty are not allowed to use
    university facilities including Internet access to access
    or download material obtain illegally, and that university
    staff can terminate internet access for these users should
    they do so repeatedly.

    2. Setup a passive monitor (span port, mirroring) to monitor
    traffic with something like Snort or NfSen, and upon detecting
    traffic on these ports, redirect the client's port 80 traffic
    to a webpage, where something similar is displayed:

"You are currently, or have recently, been using bittorrent. If you
are running bittorrent, please take the following measures: limit
your upload and download rates as a courtesy to other users and
make sure you are not downloading material you do not have permission
to copy, as stated in the AUP. Do note that your IP, MAC address
and the time of this connection has been logged.

If this is not the case, please disregard this message and click
Continue, but know that you may unknowingly be running software
that was installed without your knowledge."

    What we've seen is that this (and it may be different in some
    parts of the world), is usually enough to make users think twice
    about using bittorrent for downloading content.

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