Address records

An A record associates a name with an IPv4 address; an AAAA record associates it with IPv6. Both may exist for the same name. Adding AAAA is not merely a formatting change: the server and network must actually serve the site at that IPv6 address.

Why CNAME is different

A CNAME makes one name an alias of another name. Its target is a domain name rather than a directly entered IP address. Follow the target supplied by your hosting service. Do not confuse a DNS provider’s special apex-alias features with standard CNAME behavior.

Checks after a change

Test the site over both IPv4 and IPv6. An old AAAA record can send some visitors to the wrong server even when IPv4 works. Verify the DNS answer, HTTPS certificate, and expected page content together; seeing a record in a dashboard does not prove that every visitor reaches the right deployment.

An outdated AAAA record

Suppose a migration updates the A record but leaves AAAA pointing at the old server. Some visitors may see the new site while others see the old page. Query both record types and compare them with the hosting service’s expected targets. Verify how IPv6 is provided before removing records; correcting an obsolete destination differs from removing IPv6 support.

Further reading

DNS records — RFC 1035 ↗

Put it into practice

Inspect one public IP, or compare a list of addresses with the bulk lookup tool. Location results are approximate.

Single lookup ↗ Bulk lookup ↗