
How to Catch When Proxies Lie [pdf] - jsnell
https://www.andrew.cmu.edu/user/nicolasc/publications/Weinberg-IMC18.pdf
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gcommer
A very thorough and relevant piece of network measurement work! Awesome.

An interesting result not related to the title is some scary disagreements
between popular geoip databases and the active probes the authors used(§6.2):

> All five of the IP-to-location databases are more likely to agree with the
> providers’ claims than either active-geolocation approach is. As discussed
> earlier, we are inclined to suspect that this is because the proxy providers
> have influenced the information in these databases. We have no hard evidence
> backing this suspicion, but we observe that there is no pattern to the
> countries for which the IP-to-location databases disagree with provider
> claims. This is what we would expect to see if the databases were being
> influenced, but with some lag-time.

The paper does call out the geoip databases in question (DB-IP, Eureka,
IP2Location, IPInfo, MaxMind) -- but not the VPN providers, which is
unfortunate.

Also, the code looks quite good: [https://github.com/zackw/active-
geolocator](https://github.com/zackw/active-geolocator)

~~~
choot
They missed one which is used by lots of ad networks including Google and
Facebook: digital element's ip location DB.

~~~
citrin_ru
Why Google and Facebook will need external vendor for geo IP DB? They have GPS
data (or location based on WiFi / Cellular triangulation if GPS is switched
off) and can name own geo IP DB. Given number of users this DB will be more
accurate than most other vendors can provide.

