A DNS lookup on your computer can return a different answer from WebCheck because they may use different DNS resolvers and network paths. A difference during a recent DNS change is not, by itself, proof that either result is wrong.
Why answers differ
Recursive resolvers cache records for the time allowed by DNS. After a provider change, one resolver may still return a cached answer while another has refreshed. Some DNS providers also return different public addresses by location or for IPv4 and IPv6 traffic.
WebCheck resolves the hostname from its monitoring environment. Its DNS check records normalized A, AAAA, CNAME, MX and NS records. TTL values are not included in the recorded evidence, and one result cannot show what every resolver or visitor sees.
Compare the same lookup
- Check that both lookups use the same hostname, including any subdomain.
- Compare the same record type and note whether the answers are IPv4 or IPv6.
- Compare the time of each lookup with the DNS provider’s change history.
- For a recent migration, check the authoritative DNS configuration as well as the resolver used by your computer.
Review a WebCheck DNS change
Open the DNS run and compare its recorded answers with the previous result. A successful first run establishes the reference; a later difference is reported for review. WebCheck does not currently provide a dashboard control to accept a new DNS baseline, so investigate an expected change before treating it as an outage.
DNS answers can vary legitimately. Review the intended provider configuration and the observed records before changing the monitor.