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Center for Applied Internet Data Analysis
First released in 1998, skitter is a tool for actively probing the Internet in order to analyze topology and performance.

Skitter was also used in reference to the Macroscopic Topology Measurements Project and the Skitter infrastructure, which has since been replaced with the Archipelago (Ark) infrastructure.

On Feb 8, 2008, after 10 years of data collection and 4TB of data, we deactivated skitter data collection and transitioned to our next generation topology measurement infrastructure named Archipelago (Ark). We already perform large-scale topology measurements on Ark, and we recommend researchers use this new dataset, which employs an improved measurement methodology. The new IPv4 Routed /24 Topology Dataset collected on Ark extends back to Sep 13, 2007 and overlaps with the last five months of skitter data.

Skitter Goals

Sample Visualization from skitter Data

The research goals of this project are described on our Macroscopic Topology Measurements page. Specific data collection goals include:

  • Measure Forward IP Paths
    skitter records each hop from a source to many destinations. by incrementing the "time to live" (TTL) of each IP packet header and recording replies from each router (or hop) leading to the destination host.
  • Measure Round Trip Time
    skitter collects round trip time (RTT) along with path (hop) data. skitter uses ICMP echo requests as probes to a list of IP destinations.
  • Track Persistent Routing Changes
    skitter data can provide indications of low-frequency persistent routing changes. Correlations between RTT and time of day may reveal a change in either forward or reverse path routing.
  • Visualize Network Connectivity
    By probing the paths to many destination IP addresses spread throughout the IPv4 address space, skitter data can be used to visualize the directed graph from a source to much of the Internet.

Acceptable Use Agreement

All skitter data are publicly available since February 2014.

Access to these data is subject to the terms of the following CAIDA Acceptable Use Agreement (printable version in PDF format)

When referencing this data (as required by the AUA), please use:

The CAIDA UCSD Macroscopic Skitter Topology Dataset - < dates used >,
Also, please, report your publication to CAIDA.

Data Access

  • Access the publicly available CAIDA Macroscopic Skitter Topology Dataset

Research and Publications Based on Skitter Data

Please send any questions regarding skitter to

  Last Modified: Tue Oct-13-2020 22:22:00 UTC
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