API failures often get blamed on code first. DNS checks can quickly show whether clients can find the API hostname at all.

Useful dig commands

dig api.example.com A
dig api.example.com CNAME
dig @1.1.1.1 api.example.com A

Troubleshooting checklist

  1. Check A and AAAA records.
  2. Check CNAME chains for platform endpoints.
  3. Compare internal and public resolvers if the API is private.
  4. Only debug TLS and application routes after DNS resolves correctly.

How to interpret the result

If the answer matches the expected value, DNS is probably not the layer causing the current symptom. Continue with HTTP, TLS, mail server, firewall, or application checks. If the answer is missing, stale, or different between resolvers, keep the investigation in DNS until the public answer is correct.

Support note

When opening a ticket with a DNS provider, include the exact name, record type, resolver tested, returned value, and time of the lookup. That is much more useful than saying “DNS is not working.”