What is an AAAA Record?
An AAAA record (pronounced "quad-A") is the IPv6 equivalent of an A record. It maps a domain or subdomain to a 128-bit IPv6 address. As the world runs out of traditional IPv4 addresses, AAAA records are becoming essential for modern internet connectivity.
Structure of an AAAA Record
example.com. 3600 IN AAAA 2606:2800:220:1:248:1893:25c8:1946
- Host: The domain name (e.g.,
example.comorwww). - TTL (Time to Live): How long (in seconds) the record should be cached by DNS resolvers.
- Class: Usually
IN(Internet). - Type:
AAAA. - Value: The 128-bit IPv6 address.
Why "AAAA"?
The name comes from the fact that IPv6 addresses (128 bits) are four times larger than IPv4 addresses (32 bits). Therefore, a "Quad-A" record is needed to store the larger address.
Dual-Stack Connectivity
Most modern websites use both A and AAAA records for the same hostname. This is called "Dual-Stacking." Modern browsers will typically prefer IPv6 (AAAA) if it's available and working correctly.
Transition to IPv6
The internet is currently in a long-term transition from IPv4 to IPv6. While IPv4 only allows for about 4.3 billion addresses, IPv6 provides 340 undecillion (3.4 × 10³⁸) addresses-enough for every grain of sand on Earth to have its own IP address.
Best Practice: Consistency
Ensure that your A and AAAA records point to the same logical resource. If your A record points to a load balancer, your AAAA record should point to the IPv6 address of that same load balancer or a compatible IPv6 gateway.