DNS Propagation

DNS propagation is the informal name for the period during which updated domain name records become visible through different DNS resolvers and caches. DNS is a distributed system, so previously cached answers can remain in use until their time-to-live, or TTL, expires. Changing a website's hosting destination may therefore appear to work for one person before another sees the new address. Updates can also be affected by resolver behavior and configuration errors; there is no universal completion time for every change. Domain changes should be planned with attention to website access and email records. DNS propagation describes the spread of record updates, not the entire website migration process.