In short: DNS changes are published quickly by the authoritative server, but recursive resolvers may keep the earlier answer until its TTL expires. Different users can therefore see different answers temporarily.
What TTL means
The Time To Live is the number of seconds a resolver may cache a DNS answer. Lowering it before a planned change can shorten the caching period, but it does not remove copies that were already cached using the previous TTL.
Plan a change
- Document the current zone and service endpoints.
- At least one old TTL period beforehand, reduce the TTL on records that will change.
- Build and test the destination before changing public DNS.
- Change the required records and verify the authoritative answer.
- Monitor both old and new services during the transition.
- Restore a sensible TTL after the migration is stable.
Nameservers take special care
Changing nameservers delegates the whole zone and can affect websites, email and verification records together. Copy the complete zone to the new provider first and retain the old DNS service during the transition.
How to test
- Query the authoritative nameserver and at least two independent public resolvers.
- Check A and AAAA records separately.
- For email changes, check MX, SPF, DKIM and DMARC as well.
- Test from more than one network and avoid relying only on a browser cache.
If the old answer remains too long
Confirm the domain is delegated to the nameservers you edited and that all authoritative nameservers return the same value. Apparent propagation problems are often changes made in a DNS zone that is not authoritative.
Further guidance
See the InterWorx guide to managing DNS records in SiteWorx.
Transfer, nameserver and WHOIS changes are different
A registrar transfer changes who manages the domain. Nameservers decide which DNS provider is authoritative, while individual DNS records decide where the website and email go. WHOIS or RDAP shows registration data and may be cached by third-party lookup services.
Because these are separate systems, a transferred domain can still point to the previous host, and WHOIS may appear old while DNS is already correct. Check the authoritative nameservers and records before assuming that propagation is the cause. See InterWorx DNS-record guidance.
