DNS Propagation Guide
What is DNS propagation?
DNS propagation is the period while recursive resolvers refresh cached DNS records after a zone change. Different resolvers may show old or new answers until TTL expires.
Which DNS records should I check after a migration?
Check A, AAAA, MX, TXT, NS, CNAME and CAA records after server moves, mail changes, CDN onboarding or certificate authority changes.
Why do resolvers return different answers?
Resolvers cache answers independently. TTL, DNSSEC issues, authoritative nameserver lag and split-horizon DNS can create temporary differences.