DNS checks before a migration reduce downtime. Dig helps confirm old values, new values, TTLs, and delegation before traffic is moved.

Commands to use

dig example.com A
dig www.example.com CNAME
dig example.com MX
dig example.com TXT

Checklist

  1. Record current A, AAAA, CNAME, MX, and TXT values.
  2. Lower TTL in advance if the provider recommends it.
  3. Create new records before switching where possible.
  4. Check authoritative DNS after the change.
  5. Compare public resolvers during the cutover.

How to use the result

The DNS answer should be compared with the intended source of truth: registrar delegation, DNS provider zone, hosting target, email provider instructions, certificate authority challenge, or internal network documentation. If they do not match, fix the source record before troubleshooting higher layers.