DNS propagation means DNS changes are being refreshed across resolvers, networks, and caches. Confirm authoritative DNS first, then test from multiple resolvers or networks. If authoritative DNS is correct but some users still see old results, cache, TTL, ISP resolvers, browser cache, CDN cache, or nameserver propagation may still be in progress.
Who This Guide Is For This guide is for: · Users who changed DNS records · Users who changed nameservers · Businesses checking website or email after changes · Agencies troubleshooting client DNS · Users checking DNSSEC or CDN behavior
Before You Start Before you start, prepare: · Domain name · Record type changed · Old and new values · Current nameservers · DNS provider access · Time of change · TTL if known · DNSSEC status · CDN status · Affected website or email service
Step-by-Step Instructions Step 1: Confirm What Changed Identify the exact record or nameserver update. · A, AAAA, CNAME, MX, TXT, DS, NS, CAA, SRV Step 2: Confirm Expected Nameservers If the domain still uses old nameservers, records at the new provider are not live. · Check registrar nameserver settings Step 3: Check Authoritative DNS Authoritative result shows what the current nameservers publish. · If authoritative is wrong, fix DNS provider settings Step 4: Test Multiple Resolvers Compare local network, mobile data, public resolvers, and DNS lookup tools. · Different caches refresh at different times Step 5: Check TTL High TTL can keep old results visible longer. · Do not change records repeatedly Step 6: Check Browser, Device, Router, and Office Cache Local cache can make one user see old results. · Try another device or network Step 7: Check CDN Cache Old content may be CDN-related even when DNS is correct. · Clear CDN cache if needed Step 8: Check Website Hosting Records Confirm DNS points to correct hosting, app, or CDN target. · Wrong value is not a propagation issue Step 9: Check Email Records Review MX, SPF, DKIM, DMARC and provider verification records. · Email systems may cache records Step 10: Check DNSSEC and Domain Status DNSSEC mismatch or hold status can look like propagation failure. · Review DS/DNSKEY and clientHold/serverHold Step 11: Avoid Repeated Changes Document one change, wait, and test. · Repeated edits create mixed cached states
Troubleshooting Lookup Shows Old Record Possible reasons: · Resolver cache · High TTL · Nameserver propagation · Authoritative still old What to do: · Check authoritative · Wait for TTL · Avoid edits Lookup Shows No Record Possible reasons: · Record missing · Wrong host field · Wrong DNS provider · DNSSEC failure What to do: · Fix DNS zone · Check nameservers · Restore backup Works for Some Users Only Possible reasons: · Cache differences · ISP resolver · CDN cache What to do: · Test multiple networks · Check CDN and authoritative DNS Email Works for Some Senders Only Possible reasons: · MX cache · SPF/DKIM issue · mail server cache What to do: · Check authoritative MX and TXT · Review bounce messages
Common Mistakes Mistake 1: Assuming propagation is always the problem Review this item before making changes or opening a support ticket. Mistake 2: Checking only one network Review this item before making changes or opening a support ticket. Mistake 3: Changing records again too soon Review this item before making changes or opening a support ticket. Mistake 4: Forgetting TTL Review this item before making changes or opening a support ticket. Mistake 5: Ignoring nameservers Review this item before making changes or opening a support ticket. Mistake 6: Forgetting email records Review this item before making changes or opening a support ticket. Mistake 7: Ignoring CDN cache Review this item before making changes or opening a support ticket. Mistake 8: Ignoring DNSSEC Review this item before making changes or opening a support ticket. Mistake 9: Not documenting change time Review this item before making changes or opening a support ticket. Mistake 10: Not keeping DNS backup Review this item before making changes or opening a support ticket.
FAQ 1. What is DNS propagation? The refresh of DNS changes across resolvers and caches. 2. Why do some users see old site? Their resolver or network may still cache old records. 3. How do I know propagation is complete? Authoritative and most resolvers show expected values and live services work. 4. What is TTL? Time To Live, or how long records may be cached. 5. Should I keep changing records? No. First confirm authoritative DNS. 6. Can propagation affect email? Yes, especially MX and TXT changes. 7. Can DNSSEC look like propagation? Yes, validation failure can cause resolution issues. 8. Can NiceNIC help check propagation? NiceNIC can review domain-side and NiceNIC-managed DNS settings.