# RFC 9511 probe description for research.dnscensus.org
Canonical: https://research.dnscensus.org/.well-known/probing.txt
Contact: mailto:abuse@dnscensus.org
Expires: 2027-07-31T23:59:59Z
Preferred-Languages: en
Description: DNS research queries for registered-domain apex records. The authoritative rail asks one A question per domain under per-IP, per-prefix, and per-operator limits. A separate recursive baseline asks A, AAAA, and MX questions through Google Public DNS and Cloudflare 1.1.1.1, capped at 500 queries per second to each service from one disclosed source address. We send no EDNS Client Subnet, spoofed traffic, vulnerability probes, or amplification queries.