DNS Guides

Use DNS lookup to inspect records, verify routing, troubleshoot mail, and compare public DNS visibility.

Find domains observed on the same IPv4 address and understand shared hosting or infrastructure relationships.

Use public subdomain data to build a cleaner domain inventory and find exposed hosts.

Discover domains that share authoritative name-server infrastructure with a target.

Find domains that share mail exchanger hosts and understand email routing relationships.

Search reverse DNS names to map IP addresses back to hostnames and infrastructure patterns.

Understand DS, DNSKEY, RRSIG, and NSEC records when reviewing domain DNSSEC posture.

Check TLS certificates for any domain or IP and read issuer, validity, chain trust, and negotiated TLS security.

Verify the DNS policies that protect a domain from spoofing and improve mail delivery.

Understand DNS-based blocklists, why an IP gets listed, and how to read listing reasons.

Why DNS changes take time to appear, how caches and TTLs work, and how to verify propagation across regions.

What a domain DNS audit covers: delegation, nameservers, SOA, mail records, DNSSEC, and security policies.

How ECS lets resolvers share client location hints, why GeoDNS depends on it, and how to test it.

What dangling CNAME records are, why they enable subdomain takeover, and how to find and fix them.