1. Why does TopHat send probes to my network?
    TopHat is a research project which aims at measuring the underlying topology of PlanetLab and the Internet. TopHat agents are currently deployed on PlanetLab nodes, and send active measurement probes (mainly ping- and traceroute-link traffic) to a subset of selected hosts (currently only other PlanetLab nodes). The results can be used for research or operational purposes.

  2. How do you select the IP addresses you probe?
    A list of prefixes is obtained from the RouteViews project, and we have a method to extract a list of edge routers pertaining to each BGP prefix. For more details, see this document.

  3. The probe traffic does not look like regular traceroute. Why?

  4. Why is TopHat scanning the same ports on several machines in the same subnet?

  5. Can TopHat stop probing my network?
    Of course, just send us an email telling which subset we should stop probing and we will add you to our blacklist.

  6. How can I cite TopHat?
    You can cite the following paper.

  7. How can I create a link to TopHat website?
    You can just make a link to the current website ( http://www.top-hat.info ). We provide a short description of the TopHat infrastructure ( description ) and our TDMI measurement platform ( description ).

  8. Credits :
    The banner image comes from the Opte project, and is licensed under Creative Commons.