We also provide the DNS query and response traffic resulting from the DNS lookups required to construct the DNS Names dataset.
DNS names are useful for obtaining additional information about routers and hosts making up the Internet topology. For example, DNS names of routers often encode the link type (backbone vs. access), link capacity, Point of Presence (PoP), and geographic location. We have DNS Names data starting March 2008.
We perform these DNS lookups centrally at CAIDA using a custom-built bulk DNS lookup service. This service performs millions of DNS lookups per day. In general, we perform DNS lookups soon after we collect the topology traces so that the results better match the state of the Internet at trace collection time. However, to avoid undue load on remote DNS nameservers and to keep the daily lookup volume at a manageable level, we never perform a lookup for an address if we have successfully obtained a result in the preceding 7 days. Apart from this 7-day rule, we always perform a lookup whenever we encounter an IP address in traces. This means that we do repeat lookups at 7-day granularity for addresses that repeatedly occur in the traces. If the first attempt to look up a given IP address fails, then we retry up to two more times, waiting about one day between retries.
In addition to the DNS names we have in the past provided the daily trace files containing DNS query and response traffic resulting from these DNS lookups. This was discontinued in April 2014, because of a change in the data collection procedure. These traces capture the DNS traffic between our local recursive name server and global DNS servers (rather than the less useful final DNS results seen by DNS clients). These data are available in two forms: the most recent 30 days of DNS traffic files (i.e. from 30 days upto the current day); and a historic collection of DNS traces about three weeks long at quarterly intervals going back to July 2008. Traces are available in two formats: a standard pcap file, and a textual dump of each pcap file containing the most useful values from the DNS responses.
- 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 firstname.lastname@example.org.
Acceptable Use Agreement for the public data
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 IPv4 Routed /24 DNS Names Dataset - <dates used>,
Please, report your publications using this dataset to CAIDA.
Request Data Access
- 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
For more information on CAIDA topology measurements, see:
For more information on topology measurements in general see: