Understand resolvers and TTL

Checked against v1.241.1 on 2026-11-02 · Source reviewed

Resolver and authoritative server

A recursive resolver obtains and caches answers on behalf of clients. An authoritative server publishes a zone. A result from one recursive resolver is one observation, not a worldwide census.

TTL and cached answers

TTL is expressed in seconds. An answer already cached under an older TTL can persist until that cache expires. Lowering the TTL later does not rewrite that cached entry. Negative answers can also be cached, so a newly added record may remain absent temporarily.

Preference versus actual resolver

A preferred resolver can fail or fall back. Report the resolver actually shown with the result, rather than assuming the preference was used. Include the observation time and requested record type.

What to check next

Compare intended values across sampled resolvers. Separate a returned nonmatching value from an unavailable check. Do not promise a fixed global propagation deadline.

Verification scope: Current form labels, registry and source reviewed; live provider, mailbox, saved-work lifecycle and host acceptance remain separate.