About
About ActiveDNS
ActiveDNS is a free DNS intelligence search for security researchers: find the subdomains of a domain, every name that resolved to an IP address or network, or all names behind an ASN — continuously updated, newest observations first. Beside a domain it shows the zone the name is in, as the resolver saw it; Zone View draws the zone as a graph, where every value shared with other zones is a way to them.
Search reference
Domains
An exact name such as www.example.com, or every name under a domain with *.example.com or *.example.co.uk.
Wildcards must sit under a registrable domain: *.com, *.co.uk and www.*.com are not accepted.
A name that is a CNAME alias is listed under the name you searched for, marked CNAME, with the addresses of the name it points to. Tick Show CNAME chains to see the path.
Select a name, address or ASN in the results to pivot to it. A name opens every name under its registrable domain (*.example.com), or the name alone when you are there already.
Networks
A single IPv4 or IPv6 address, or a network in CIDR notation down to /24 (IPv4) or /48 (IPv6).
Autonomous systems
Every resolution observed inside an AS, for example AS13335.
Zones
A domain search also shows the zone the name is in, as the resolver saw it: its parent and nameservers, and what stands out about it. An address search shows the nameservers at the address. Select it to open it in Zone View.
Zone View draws the zone as a graph: nameservers and their addresses, SOA, DNSSEC, and servers that refused the zone. Select a zone or an address to move there, or a shared value to list the other zones with the same nameserver, NS set, SOA contact or key. A few is a lead; thousands is a provider. A shared value is a lead, not proof.
Results are ordered by last observation, newest first, 100 per page. A pair that keeps resolving is re-observed at least every 45 days and stays in the database; one that stops is kept 90 days after its last observation. Zone facts are kept 90 days after they were last seen.