“This public dataset contains all IPv4 measurements from Archipelago (Ark) that are older than approximately one year, and all IPv6 measurements (upto the present).”

…

“The IPv4 Routed /24 DNS Names Dataset provides fully-qualified domain names for IP addresses seen in the traces of the IPv4 Routed /24 Topology 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.”

• Source
• The CAIDA UCSD IPv4 Routed /24 DNS Names Dataset
• The CAIDA UCSD IPv6 DNS Names Dataset
• Data URL, IPv4
• Data URL, IPv6
• Acceptable Use Agreement

“This dataset consists of a daily snapshot of the reverse zones (in-addr.arpa and ip6.arpa) as published by the RIRs on their public FTP servers in the /pub/zones/ directory. The RIRs use this data operationally. The zones under in-addr.arpa and ip6.arpa are assembled from these files.”

• Source
• Data URL
• Terms of Service