library · 12 record types
DNS lookup library
12 DNS record types — what they do, how to query them, and why each matters for security.
MX — Look up MX records for a domainMX records tell senders where to deliver mail for a domain. Each MX has a prefer…
TXT (SPF) — Look up SPF records for a domainSPF (Sender Policy Framework) is a TXT record listing servers authorized to send…
TXT (DKIM) — Look up DKIM records for a domainDKIM (DomainKeys Identified Mail) signs outgoing mail with a private key; receiv…
TXT (DMARC) — Look up DMARC records for a domainDMARC tells receivers what to do with mail that fails SPF or DKIM (`none`, `quar…
TXT — Look up TXT records for a domainTXT records hold arbitrary text — historically for human notes, now mostly for m…
CAA — Look up CAA records for a domainCAA (Certification Authority Authorization) tells which CAs are allowed to issue…
SRV — Look up SRV records for a serviceSRV records advertise which host serves a given service on a given port — used b…
CNAME — Look up CNAME records (canonical name)CNAME maps an alias to a canonical name. Resolvers chase the chain transparently…
NS — Look up NS records (name servers)NS records list the authoritative name servers for a domain — the servers that h…
SOA — Look up SOA records (Start of Authority)SOA holds zone administrative metadata: primary NS, contact email, serial number…
DNSKEY / DS / RRSIG — Look up DNSSEC records (DNSKEY, DS, RRSIG)DNSSEC adds cryptographic signatures to DNS responses — receivers verify that re…
PTR — Reverse DNS lookup (PTR records)Reverse DNS turns an IP back into a hostname — useful for log analysis, mail ser…