About a record lookup
An A record maps a domain name to an IPv4 address, such as 203.0.113.10. It is how a browser finds the server for a website.
Reading the result
- Several A records mean the site is spread over multiple servers (round-robin).
- A short TTL means changes spread quickly; a long TTL means they take longer.
- Sites behind a CDN return the CDN's addresses, not your own server's.
A worked example
Looking up example.in returns two addresses, 203.0.113.10 and 203.0.113.11, each with a TTL of 300 seconds. Two records mean visitors are spread between two servers. After you move to a new host, change the A record and wait up to the old TTL for caches to expire.
Checking before a migration
- Note the current records so you can roll back.
- Lower the TTL a day before the change.
- Confirm the new address with the lookup once changed.
