The contents of this legacy page are no longer maintained nor supported, and are made available only for historical purposes.


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.

Please read the terms of the CAIDA Acceptable Use Agreement (AUA) for Publicy Accessible Datasets below:

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

The CAIDA UCSD Macroscopic Skitter Topology Dataset - <dates used>,
You are required to report your publications using this dataset 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

Related Objects

See to explore related objects to this document in the CAIDA Resource Catalog.
Last Modified