Methodology

NSdig is a live diagnostic utility. For domains, it queries multiple independent public DNS resolvers in parallel—including providers such as Google, Cloudflare, OpenDNS, Quad9, and others—so you see how answers differ across the global DNS ecosystem. Results are fetched on demand; we do not rely on long-lived caches for propagation views, so you get a snapshot that reflects what those resolvers return at query time.

DNS health uses standard DNS lookups (NS, SOA, MX, and glue checks) against the same live infrastructure to flag common configuration issues.

For IP addresses, geolocation and ASN context are read from on-server MaxMind GeoLite2 MMDB files (no outbound HTTP geo call); port checks open short-lived TCP connections to a small set of well-known ports with a tight timeout so the UI stays responsive. DNSBL / RBL checks issue DNS queries against major public blocklist zones to see whether the address appears listed, again in near real time.

WHOIS and registry data depend on registrar and TLD policies; availability and field names may vary by domain.