What a DNS lookup does
The Domain Name System (DNS) is the internet's address book. People remember names like example.com, but machines route traffic using IP addresses. A DNS lookup asks a resolver, "what records exist for this name?" — and the answer tells your device where (and how) to connect. This page sends those queries over DNS-over-HTTPS, so the lookup itself is encrypted in transit.
The record types, explained
- A
- Maps a name to an IPv4 address. The most common record.
- AAAA
- Maps a name to an IPv6 address (the "quad-A" record).
- CNAME
- An alias pointing one name to another name, which is then resolved further.
- MX
- Mail exchanger — which mail servers accept email for the domain, each with a priority.
- TXT
- Free-form text. Widely used for SPF, DKIM, DMARC and domain-ownership verification.
- NS
- The authoritative name servers responsible for the domain's zone.
- SOA
- Start of authority — the zone's primary name server, contact, and timing values.
- SRV
- Locates the host and port for a specific service (used by SIP, XMPP, and others).
- CAA
- Declares which certificate authorities are allowed to issue TLS certificates for the domain.
- PTR
- Reverse lookup — maps an IP address back to a name. Enter an IPv4 address for this type.
Understanding TTL
Every record carries a TTL (time to live) in seconds — how long resolvers may cache it before checking again. A low TTL (say 300) lets changes propagate quickly, which is handy before a migration; a high TTL (like 86400) reduces query load but means edits take longer to reach everyone. After you change a record, the old value can linger anywhere in the world until its TTL expires.
Why answers can differ
DNS is distributed and cached, so the result you see depends on which resolver answered and what it had cached. A freshly changed record may appear updated through one resolver and stale through another until caches expire. If you're troubleshooting propagation, compare several resolvers and remember the TTL is the upper bound on how long the old value can survive.