[tor-talk] Network diversity [was: Should I warn against Tor?]

[Jens Lechtenboerger]

On Mo, Jul 08 2013, grarpamp wrote:

>> From the paper by Murdoch and Zieliński [3]:
>> [3]  http://www.freehaven.net/anonbib/#murdoch-pet2007
>> “We suggest that existing models, based on Autonomous System (AS)
>> diversity, do not properly take account of the fact that while, at
>> the AS level abstraction, a path may have good administrative domain
>> diversity, physically it could repeatedly pass through the same
>> Internet eXchange (IX).”
>
> It would be interesting to include a traceroute service in each node
> such that path building might take into consideration such IX/AS
> repetitions over the proposed full path. Note however that MPLS
> routing used to engineer traffic schemes can hide the actual path
> from traceroute (though mitigated by its usual use only within one AS).
> And other than of geolocation, it's quite hard to align IX nodes with
> traceroute data.

Thanks a lot for bringing up this topic.  Actually, there is a 2009
paper exploring the IX structure [1].  Their data set is published
at [2].

Being German I restricted EntryNodes to DE and ran traceroutes to
the 3 German guards selected by my Tor client.  Two of those
traceroutes showed IP addresses of DE-CIX (so I don’t want them),
while the third one does not contain any IP address of [2].
I guess I’ll check that out systematically to find “my” EntryNodes.

When restricting Tor nodes by country, I recommend to update
src/config/geoip first.  E.g., zeller is listed as German node with
Tor v0.2.3.25 (where geoip dates back to May 2012), but lies in
Seattle [3], which can be corrected with a new MaxMind download.

> [Somewhere in all of this there is something to be said for peer
> owned p2p meshnets and co-op's...]

Definitely.

Best wishes
Jens


Footnotes:
[1]  http://www2.research.att.com/~bala/papers/imc09-ixp.pdf
[2]  http://www-rp.lip6.fr/~augustin/ixp/
[3]  http://zeller.torservers.net/