DNS & EMAIL
DNS Propagation Checker
Check whether Google, Cloudflare, Quad9, OpenDNS and the local resolver return matching DNS records.
39DMultiple locationsChoose the test server below
RUN TEST
DNS Propagation Checker
HOW IT WORKS
About the DNS Propagation Checker
The checker sends the same query to a fixed selection of recursive resolvers. Differences commonly occur while old cached records expire or when authoritative nameservers disagree.
How to use this result
- Run the test from this server.Use a public hostname, address, prefix or ASN in the format requested above.
- Compare test locations.Choose another available 39D node or run a local command to identify location-specific behaviour.
- Correlate related evidence.Use the related tools below to compare DNS, routes, ports, TLS and application responses.
- Keep the time and context.Routing, DNS caches and reputation data change, so record when the result was collected.
Common interpretation issues
- Resolver agreement does not prove that every resolver worldwide has updated.
- Negative answers can also be cached.
- A low TTL only helps after previously cached high-TTL data has expired.
NEED HELP INTERPRETING THE RESULT?
39D supports business networks, cyber security and managed IT.
For ongoing support or a larger infrastructure project, speak to the 39D team.
Frequently asked questions
How long does propagation take?
It depends mainly on the previous record’s TTL and resolver caching behaviour.
Why do authoritative servers matter?
Recursive resolvers ultimately obtain answers from them, so inconsistent authoritative data creates inconsistent results.