Different DNS answers can occur when authoritative nameservers do not contain matching zone data or while caches still hold an older record.
- Identify the domain’s authoritative nameservers.
- Query each authoritative nameserver and compare the relevant records.
- Check for stale or missing A, AAAA, CNAME, MX, or TXT records.
- If a nameserver change was recent, allow recursive resolvers to replace cached delegation and record data.
- Avoid repeatedly changing values during propagation because that creates multiple generations of cached answers.
TTL controls caching of DNS records; delegation changes involve registrar/registry nameserver information and can take additional time to become consistent.
