skitter

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.

| Macroscopic Topology Project Skitter AS Links Dataset Request Data Access |

| skitter goals architecture ITDK results sample analysis code visualizations router adjacencies |

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.

Research and Publications Based on Skitter Data

CAIDA publications based on skitter data
Non-CAIDA publications based on skitter data (list compiled based on Internet search)
Non-CAIDA publications using skitter data (list compiled based on feedback from skitter data users)
Non-CAIDA publications referencing skitter tool or data
Skitter data application procedure and official CAIDA Topology Data Request form for academic researchers and corporate entities (including corporate researchers) who participate in CAIDA's membership program who wish to download/use skitter data

Acceptable Use Agreement

Please read the terms of the CAIDA Acceptable Use Agreement below: (printable version in PDF format)
CAIDA ACCEPTABLE USE AGREEMENT The following terms comprise the Acceptable Use Policy (AUP) and Data License Agreement (collectively, the "AGREEMENT", or, "Acceptable Use Agreement (AUA)") for all for all datasets made available to You by the Cooperative Association for Internet Data Analysis (CAIDA), a research unit at the University of California San Diego (UCSD) and governed by The Regents of the University of California. Certain datasets may have additional Supplemental provisions. References to this AGREEMENT shall include any and all relevant Supplemental provisions. CAIDA has the authority and reserves the right, in its sole discretion, to refuse requests for dataset(s) or discontinue further access and use to anyone. If You feel Your request is inappropriately denied please contact CAIDA by sending a message to data-info@caida.org. In consideration for requesting and receiving access to CAIDA dataset(s), You acknowledge that You understand and agree to be bound by the terms and conditions of this AGREEMENT. Any violation of this AGREEMENT may result in the immediate suspension or termination of this AGREEMENT and/or other action entitled by law such as injunctive or equitable relief. You are individually liable and responsible for compliance with this AGREEMENT. This AGREEMENT is legally binding under the laws of the State of California, United States. You may terminate this Agreement by contacting CAIDA in writing and receiving acknowledgement of such request. 1. LICENSE CAIDA's authorization to access the data grants You a limited, non-exclusive, non-transferable, non-assignable, and terminable license to copy, modify, and use the data in accordance with this AGREEMENT solely for the purpose of non-profit research, non-profit education, commercial internal testing and evaluation of the data, or for government purposes by or on behalf of the U.S. Government. No license is granted for any other purpose and there are no implied licenses in this Agreement. This Agreement shall become effective as of the date of approval by CAIDA and shall remain in force for a period of one year, unless terminated earlier or amended in writing. CAIDA shall have the right without obligation or recourse of any kind to You, to use any of Your feedback from the license period, solely for its non-profit educational and/or research purposes. If You desire to use or otherwise incorporate any copyrightable part of this data for commercial purposes, You should contact the UC San Diego Technology Transfer Office, (858) 534-5815, fax: (858) 534-7345. 2. GENERAL CONDITIONS (i) You will not impersonate any individual or entity, misrepresent any affiliation with another person, entity or association, use false information, or otherwise conceal Your identity from CAIDA at any time for any purpose. (ii) You consent that CAIDA can make public or otherwise disclose Your name as the registrant requestor, the name of Your Affiliated Institution, the name of the dataset(s) that CAIDA has made available to You under this AUA, and the brief description of the type of research being undertaken that You provided to CAIDA. (iii) You will abide by any and all modifications. If a modification(s) occurs, it is effective when adopted by CAIDA, and will be explicitly communicated to You via Your registered email address. Your continued access of the data indicates Your assent to any and all modification(s). If You do not agree to comply with the modification(s), You acknowledge that You will: (a) inform CAIDA immediately, at which point Your access to the data will be terminated and no longer authorized; (b) no longer access or use this data. 3. USE RESTRICTIONS If You have any concerns or questions about these restrictions, You are encouraged to contact CAIDA management via email to data-info@caida.org. To obtain an exemption from any of these restrictions, You will need a written authorization from CAIDA management. (i) While using non-anonymized data set(s), You will respect the privacy of end users and organizations that may be identified in the data. For any publication or other disclosure, You will anonymize or de-identify IP addresses, network names, and domain names or other data identified in Supplemental provisions (if any) by using commonly accepted techniques such as one of the methods recommended by CAIDA (http://www.caida.org/projects/predict/anonymization). (ii) While using anonymized data set(s), You will not attempt to reverse engineer, decrypt, de-anonymize, derive or otherwise re-identify anonymized information. (iii) You will not distribute, disclose, transfer or otherwise make available the dataset(s) to any person other than those employed by your institute who are assisting or collaborating with You using the dataset(s). Other entities with whom You are collaborating in research using the dataset(s) must request access to the dataset(s) separately and directly from CAIDA. (iv) All conditions, restrictions and obligations attached to this data shall accompany any and all subsequent uses and disclosures of this dataset by You. Therefore, You are personally and fully responsible for communicating this AUA and ensuring its compliance as to any and all users described above to whom You make the data available. 4. USE OBLIGATIONS (i) If You create a publication (including web pages, papers published by a third party, and publicly available presentations) using data from this dataset, You must provide CAIDA with a copy of (or a link to) the publication and You must cite the data as follows: The CAIDA UCSD [DataSet Name] - [dates used], http://www.caida.org/data/[dataset-URL] (ii) At the end of the research, or semi-annually (whichever is sooner), You will report a summary of the research and any findings/conclusions to CAIDA. This information is used in reports to our funding agencies. (iii) You agree to expunge any and all copies of the received Dataset(s) upon completion or termination of stated research and/or termination of data access or use. Completion of stated research shall allow for a reasonable period of time that You may need to retain the dataset(s) in order to satisfy scientific reproducibility obligations. 5. ACCOUNTABILITY AND ENFORCEMENT (i) CAIDA's authorization to access the data grants You a limited, non-exclusive, non-transferable, non-assignable, and terminable license to copy, modify, and use the data in accordance with this AGREEMENT solely for the purpose of non-profit research, non-profit education, commercial internal testing and evaluation of the data, or for government purposes by or on behalf of the U.S. Government. No license is granted for any other purpose and there are no implied licenses in this Agreement. This Agreement shall become effective as of the date of approval by CAIDA and shall remain in force for a period of one year, unless terminated earlier or amended in writing. CAIDA shall have the right without obligation or recourse of any kind to You, to use any of Your feedback from the license period, solely for its non-profit educational and/or research purposes. (ii) You will notify CAIDA immediately of all relevant details if: (a) confidentiality or privacy is compromised; or (b) You receive any legal, investigatory, or other government demand to reverse engineer, decrypt, de-anonymize or otherwise disclose anonymized or confidential data. (iii) If requested, You will provide CAIDA evidence of compliance with this AGREEMENT, such as a written description of Your data protection plan or a written affirmation that You have disposed of any and all copies of the received dataset from all systems reasonably known to you. (iv) DISCLAIMER OF WARRANTIES. CAIDA USES ITS BEST EFFORTS TO PROVIDE DATA IN ACCORDANCE WITH ETHICAL PRINCIPLES AND SCIENTIFIC INTEGRITY. HOWEVER, THE DATA PROVIDED HEREIN IS ON AN "AS IS" BASIS. NEITHER CAIDA, ITS RESEARCHERS, RESEARCH PARTNERS, LICENSORS, AND DATA PROVIDERS, NOR THE UNIVERSITY OF CALIFORNIA AND ITS TRUSTEES, OFFICERS, EMPLOYEES, AND AGENTS MAKE ANY WARRANTY, EITHER IMPLIED OR EXPRESS, OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, INCLUDING, BUT NOT LIMITED TO, THE ACCURACY, TIMELINESS, COMPLETENESS, RELIABILITY, OR AVAILABILITY OF CAIDA DATA, APPLICATIONS, OR SERVICES ACCESSIBLE THROUGH OR MADE AVAILABLE BY CAIDA. TO THE EXTENT ALLOWED BY LAW, YOU WILL INDEMNIFY, DEFEND AND HOLD HARMLESS CAIDA AND THE UNIVERSITY OF CALIFORNIA FROM ALL LIABILITIES, CLAIMS, DEMANDS, COSTS, JUDGMENTS, DAMAGES, LOSSES AND EXPENSES ARISING OUT OF OR IN CONNECTION WITH ANY USE OF THE DATA BY YOU. IN NO EVENT SHALL CAIDA AND THE UNIVERSITY OF CALIFORNIA BE LIABLE TO YOU OR ANY THIRD PARTY FOR ANY INDIRECT, CONSEQUENTIAL, INCIDENTAL, SPECIAL OR PUNITIVE DAMAGES, ARISING FROM YOUR USE OF THE DATA. 6. INTELLECTUAL PROPERTY This section applies only if You are licensing the data for the purpose of commercial internal testing and evaluating the data. (i) Except as specifically provided in paragraphs (ii), (iii) or (iv) of this Section, all right, title and interest in and to any "Intellectual Property" -- any invention, discovery, improvement, computer or other program, related documentation and work of authorship . that is developed for commercial use by You or Your employer, employees or agents, either individually or jointly with CAIDA, using any information provided by CAIDA under this Agreement, shall be the joint property of UCSD/CAIDA and You, and that shared portion is hereby assigned to UCSD/CAIDA, solely for its non-profit educational and/or research purposes. As between CAIDA and You, You retain exclusive and all right, title and interest in and to "Your Intellectual Property" -- the information originating with or provided by You. (ii) You obtain an exemption from the default Intellectual Property provisions in Section (i) for specific developments via a written authorization from CAIDA management; (iii) You obtain a full Commercial License from the UC San Diego Technology Transfer Office that grants alternative rights in the Intellectual Property; or (iv) You make the Intellectual Property freely available and without restrictions to the public, provided such disclosure complies with obligations regarding sensitive information described in Section 5(i).

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

The CAIDA UCSD Macroscopic Topology Dataset - < dates used >,
http://www.caida.org/tools/measurements/skitter

Please send any questions regarding skitter to skitter-info@caida.org.