Guide
What DNS records tell you
DNS is not only “the IP for a name.” Different record types describe mail servers, aliases, text policies, and which nameservers are in charge.
Why you should care
After you change DNS, visitors may still see the old answer until caches expire. Comparing public resolvers is how you watch that catch-up.
Mail (MX), website (A/AAAA), and verification (TXT) are independent questions about the same domain.
Common record types
A and AAAA map a name to IPv4 and IPv6. CNAME is an alias. NS lists authoritative nameservers. MX points to mail hosts. TXT holds policy and proofs (SPF, domain verification).
Asking the wrong type looks like “DNS is broken” when the A record is fine.
Resolvers agree
Public DNS returns the same answer
- Your query
- Several public resolvers
- One consistent answer
Resolvers differ
Propagation, geo-DNS, or mixed records
- Your query
- Several public resolvers
- Mixed answers
Not a leak test
A DNS checker asks famous public resolvers what they think a name is. A DNS leak test asks which resolver handled *your* lookup while you browse.
Use the checker for propagation and records. Use the leak test for VPN privacy.
How to check
Query the name and type you just changed. Consistent answers mean public resolvers have caught up; mixed often means wait for TTL.
Remember
- Public resolver compare is not a map of every ISP cache.
- Geo-aware DNS can look “mixed” on purpose.
- This does not show which DNS your laptop used.
- Wait at least one TTL before assuming a change failed.
