Plan changes around existing caches
Lowering TTL before a migration can shorten future caching after resolvers refresh, but it does not erase answers already cached under the old value. Make the adjustment early enough for the previous TTL window to pass before changing the record.
After a change, check the authoritative answer and several resolvers, while expecting temporary differences. Some clients or applications may cache longer or use an independent local cache.
Choose TTLs for operational needs
Short TTLs help during active changes but increase queries and do not guarantee immediate propagation. Longer TTLs may reduce lookups for stable records; choose based on provider guidance and required response time.
During troubleshooting, compare authoritative value, TTL, and resolver cache state. Avoid repeated edits during propagation because they make observations harder to interpret.