Fast IPv4 scanning has enabled researchers to answer a wealth of security and networking questions. Yet, despite widespread use, there has been little validation of the methodology’s accuracy, including whether a single scan provides sufficient coverage. In this paper, we analyze how scan origin affects the results of Internet-wide scans by completing three HTTP, HTTPS, and SSH scans from seven geographically and topologically diverse networks. We find that individual origins miss an average 1.6–8.4% of HTTP, 1.5–4.6% of HTTPS, and 8.3–18.2% of SSH hosts. We analyze why origins see different hosts, and show how permanent and temporary blocking, packet loss, geographic biases, and transient outages affect scan results. We discuss the implications for scanning and provide recommendations for future studies.

Study Details

Study

On the Origin of Scanning: The Impact of Location on Internet-Wide Scans
ACM Internet Measurement Conference (IMC), October 2020

Authors

Gerry Wan, Liz Izhikevich, David Adrian, Katsunari Yoshioka, Ralph Holz, Christian Rossow, Zakir Durumeric

Contact

Gerry Wan

Dataset Details

We provide access to the raw ZMap and ZGrab scans that are run from each network perspectives across three trials.

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