This dataset contains information useful for studying the topology of the Internet. Data is collected by a globally distributed set of Ark monitors. The monitors use team-probing to distribute the work of probing the destinations among the available monitors.

We collect data by sending scamper probes continuously to destination IP addresses. Destinations are selected randomly from each routed IPv4 /24 prefix on the Internet such that a random address in each prefix is probed approximately every 24 hours (one probing cycle). Because team-probing distributes the probing work across all monitors, a single destination /24 will be probed by only one monitor in each probing cycle.

Scamper records addresses seen at each hop from a source to a destination by incrementing the "time to live" (TTL) of each IP packet header. In the current configuration, scamper probes with ICMP packets, using the Paris traceroute technique (ICMP-paris) to improve measurement integrity across load-balanced links. Data prior to November 2007 used an alternate UDP traceroute method. Data collected for each path probed includes:

• IP length, TTL, size, and transmit time of probe packets
• RTT, IPID, TOS, and TTL, and size fields of response packets
• IP length, TTL, and TOS fields of the probe packet that reached each hop (extracted from the response packet)
• The ICMP type and code of responses
• Any RFC 4950 ICMP extensions included in response packets

Data has been collected continuously since September 13, 2007.

Caveats that apply to this dataset:

• The IPv4 Routed /24 Topology Dataset uses a dynamic destination list. Measurements to consistent IPv4 addresses are not available in this dataset.
• Because team-probing distributes measurements across many monitors, the randomly selected IP addresses in a given routed prefix are not probed by the same set of monitors consistently over time.

Reading Topology Data

You can write analysis scripts that process this data (available in the warts format) using the output from the sc_warts2json, sc_analysis_dump, or sc_warts2csv utilities included in the scamper distribution package, which generate easy-to-parse textual formats. You can also write Python scripts using the scamper python module included in the scamper distribution package.

Other tools that you may want to consider are the sc_wartsdump and sc_warts2text tools. Neither tool produces output that is designed to be parsed by a script. sc_wartsdump prints out practically all information contained in a warts file, while sc_warts2text prints out text in a similar format to regular traceroute.

Data availability

• Data older than one year is available as a public dataset. You can obtain access using this form.
• The most recent one year of data is available for use by academic researchers and US government agencies. This data is also available for corporate entities (including corporate researchers) who participate in CAIDA's membership program. Please, complete and submit the online form to request access to the most recent data. It usually takes about two to three business days to process your request. Upon approval you will receive an email with instructions on how to download the data you requested. If you have any questions or problems using this form, please contact data-info@caida.org.

Acceptable Use Agreement for the public data

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 IPv4 Routed /24 Topology Dataset - <dates used>,
https://www.caida.org/catalog/datasets/ipv4_routed_24_topology_dataset/

You are required to report your publications using this dataset to CAIDA.

Request Data Access

• Access the publicly available CAIDA IPv4 Routed /24 Topology Dataset (and other topology data)
• Request Access to the restricted CAIDA IPv4 Routed /24 Topology Dataset

Topology Datasets

• Freely Available Datasets
  • The Ark IPv4 Routed /24 Topology Dataset (data older than one year only)
  • The Ark IPv4 Routed /24 DNS Names Dataset (data older than one year only)
  • IPv4 TNT MPLS Topology Dataset (data older than one year only)
  • Ark Internet Topology Data Kits (ITDK) (data older than one year only)
  • The Ark IPv6 Topology Dataset
  • The Ark IPv6 DNS Names Dataset
  • The IPv6 Routed /48 Topology Dataset
  • IPv4 Routed /24 AS Links (September 2007 - ongoing)
  • IPv6 AS Links (December 2008 - ongoing)
  • AS Rank
  • AS Relationships
  • Skitter Macroscopic Topology Data
  • Skitter Internet Topology Data Kits (ITDK) - April 2002 and April/May 2003
  • Skitter AS Links (January 2000 - February 2008)
  • Skitter Router Adjacencies
  • AS Taxonomy
  • PAM 2010 "Improving AS Annotations" Supplement
• Restricted Access Datasets
  • The Ark IPv4 Routed /24 Topology Dataset (incl. most recent one year)
  • The Ark IPv4 Routed /24 DNS Names Dataset (incl. most recent one year)
  • IPv4 TNT MPLS Topology Dataset (incl. most recent one year)
  • The Ark IPv4 Prefix-Probing Dataset (incl. most recent one year)
  • Ark Internet Topology Data Kits (ITDK) (incl. most recent one year)
  • Complete Routed-Space DNS Lookups

References

For more information on CAIDA topology measurements, see:

• Internet Topology Data Comparison
• The Archipelago Project (Ark)
• Macroscopic Topology Measurements

For more information on topology measurements in general see:

• University of Oregon Route Views Project
• Paris traceroute