What is DNS Propagation?
DNS propagation is the time it takes for updated DNS records to spread across all DNS servers worldwide after a change is made. During propagation, some users may see the old records while others see the new ones, depending on which DNS server their query reaches.
How Does DNS Propagation Work?
When you update a DNS record, the change is made on your authoritative nameserver, but DNS resolvers around the world have cached the old record. The cached records remain in use until their TTL (Time to Live) expires, at which point the resolver fetches the updated record. This is why DNS propagation can take anywhere from a few minutes to 48 hours, depending on the TTL values set on the previous records.
To minimize propagation time, you can lower the TTL value well in advance of planned DNS changes, giving cached records time to expire before the actual change. During propagation, you can check the status using tools like dig, nslookup, or online DNS propagation checkers. Understanding DNS propagation is important when migrating websites, changing hosting providers, or updating any DNS records to avoid unexpected downtime or routing issues.