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This is a testbed implementation of various “active geolocation” algorithms. Please see the website for an overview of the project and the paper ("How to Catch when Proxies Lie: Verifying the Physical Locations of Network Proxies with Active Geolocation", 2018 Internet Measurement Conference) for findings so far.

Running the measurement client

If you came here from the website, you’re probably interested in running the measurement client, which is in the measurement-client subdirectory of this repository.

You should only run the client if you are willing to tell us the latitude and longitude of the computer you’re running it on, to at least 1/100 of a degree (roughly half an arcminute, or 1km of position uncertainty, depending on the latitude). The best way to determine the position with this accuracy is using GPS. Most smartphones can take a GPS reading. The iPhone ships with a “Compass” utility that, among other things, shows you your latitude and longitude (in degrees, minutes, and seconds; you will have to convert). For Android, you need a third-party app: we suggest “My GPS Coordinates.”

If you don’t have a GPS-capable phone or dedicated receiver, or you can’t go to where the computer is and take a GPS reading, the next best option is to look up the postal address of the building, using one of the several conversion services available online (e.g. 1, 2, 3). In this case, please make sure to feed the latitude and longitude back into a mapping service and verify that it’s accurate.

Don’t look your IP address up in a geolocation service, because one of the goals of this project is to independently audit the accuracy of those services.

The measurement software has two components, one written in Python and the other in C. The Python component has no dependencies outside the standard library, and is known to work with versions 2.7, 3.4, and 3.5 of the interpreter. The C component is self-contained (not a Python module), depends only on standard ISO C and POSIX interfaces, and is known to work on recent versions of Linux, FreeBSD, and OSX. It should work on any modern Unix. (If you know how to time TCP handshakes with high accuracy on Windows, we’d be glad to take your patches.)

Because of the C component, running the client from the command line is a three-step procedure. Starting from a Git checkout of this repository:

$ cd measurement-client
$ ./configure
$ make
$ ./probe --latitude=<LATITUDE> --longitude=<LONGITUDE>

where <LATITUDE> and <LONGITUDE> are the latitude and longitude you looked up earlier, as decimal degrees. Use negative numbers for south of the equator / west of Greenwich, and remember to round off the numbers to the precision you are comfortable with. If you don’t want the data you submit to be included in any future publication of a redacted version of our database, append --no-publication to the probe command.

The final probe command can take as much as an hour to run, but 5 to 20 minutes is more typical. It reports its progress once a minute. The results are automatically uploaded to the project website, and are also written to a file probe-result-YYYY-MM-DD-N.json.

By running probe, you assert that you are age 18 or older, and you consent to the collection of your computer’s IP address, its latitude and longitude as reported by you, and the time it takes network messages to reach roughly 200 other computers and return. You understand and agree that Carnegie Mellon is legally required to preserve all research data for at least three years, and could be required to disclose your location and IP address by a future law, regulation, subpoena or court order.

If any of the above steps fail, please file an issue. We will need to see the unedited, complete output of the above commands up to the point where they failed, and we will also need to know which operating system and compiler you are using. It’s helpful if you attach the file config.log to the issue (you may have to rename it config.txt first, because Github). Note: to maintain the confidentiality of your IP address and location, do not attach any probe-result-YYYY-MM-DD-N.json files to Github issues.

If you have access to computers in several cities, please do run the software on all of them. It’s not as helpful to run it on more than one computer in the same city, unless their routes to the Internet backbone are very different (for instance, if one gets its connectivity from a residential ISP, and another from a cellphone system).

If you have access to VPN or SOCKSv5 proxies, and you can find out the accurate location of the proxy as well as the client host, please do run the measurement through the proxy. For VPNs, activate the VPN as the default route, then do:

$ ./probe --latitude=<CLIENT LAT> --longitude=<CLIENT LONG> \
          --proxy-latitude=<PROXY LAT> --proxy-longitude=<PROXY LONG>

For SOCKS you must explicitly state the proxy’s address. Authentication is not supported.

$ ./probe --latitude=<CLIENT LAT> --longitude=<CLIENT LONG> \
          --proxy-latitude=<PROXY LAT> --proxy-longitude=<PROXY LONG> \
          --socks5 <HOST>:<PORT>

What does the measurement client do?

It downloads a list of IP addresses from this website, and then it makes several TCP connections to each address, and measures the time for the connection to resolve. (If a connection succeeds, it is immediately closed; no data is sent or received.) It randomizes the list and spaces out the connections in time, to minimize impact on the remote peers.

Once all the measurements are made, the results are transmitted back to this website along with your computer’s IP address and reported location. If you took measurements via a proxy, we don’t learn your computer’s IP address but we do learn the proxy’s, and we learn both computers’ physical locations.

All of the submitted data is stored either encrypted or on computers under our physical control. We may publish the data set in the future; if we do, it will include your computer’s location and AS number but not its IP address. If you don’t want the data you submit to be included in such a publication, append --no-publication to the probe command.


Testbed implementation of various "active geolocation" algorithms.







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