How DNS Caching and TTL Affect Delegation and Record Changes

DNS changes are not always visible everywhere at the same time. DNS answers are cached. After you change name server delegation at your registrar or edit records in your DNS zone, authoritative servers can serve the new data immediately, while many resolvers still return older answers until their cache entries expire. That gap is normal, and how long it lasts depends mainly on the time-to-live (TTL) values and resolver behavior.

Table of Contents

• Record changes and TTL
• Delegation changes and caching
• Negative caching
• What to do next
• Have more questions?

Record changes and TTL

When you change an A, AAAA, CNAME, MX, or other record at your DNS host, authoritative name servers publish the new value quickly. Recursive resolvers that already cached the old answer keep serving it until the TTL on that cached answer reaches zero, then they fetch fresh data. See How Long Does a New DNS Record Take to Resolve? and DNSimple TTL Settings Reference for product defaults and how to lower TTL ahead of planned changes.

Delegation changes and caching

Changing which servers are authoritative (for example after pointing your domain to DNSimple) updates delegation at the registry. Resolvers cache delegation responses too. Parents publish NS records for your zone with their own TTLs; until those caches expire, some clients may still query your previous name servers. That is why support often cites up to roughly 24 hours for broad propagation even though WHOIS may already list new name servers.

Delegation caching and record caching are different layers. WHOIS can show updated NS data while an individual resolver still follows older delegation until its cache entry expires.

Negative caching

If a resolver recently learned that a name did not exist or got an error, it may cache that negative result (NXDOMAIN or NODATA) for the negative TTL derived from the SOA record. After you add a new record or fix delegation, negative caching can briefly hide the fix from some resolvers even when authoritative data is already correct.

What to do next

• For browser or laptop tests, flush local DNS cache so your device does not reuse stale answers.
• For delegation problems, follow Troubleshoot DNSimple Name Servers and Troubleshoot Domain Resolution Issues.
• For record-specific problems, see Troubleshoot Record Resolution Issues.

Have more questions?

If you have questions about propagation or caching, contact support, and we will be happy to help.