What is AAAA Record?
Also known as: Quad-A Record
A DNS resource record that maps a hostname to a 128-bit IPv6 address, analogous to the A record for IPv4.
The AAAA record (also called Quad-A record) is a DNS resource record type defined in RFC 3596. It stores a IPv6 address associated with a fully qualified domain name. The name AAAA comes from the four A characters in the record type code 28. It serves the same purpose for IPv6 that the A record serves for IPv4.
When a client needs to resolve a hostname to an IPv6 address, it sends a DNS query for type AAAA. The DNS server responds with one or more AAAA records containing 128-bit IPv6 addresses. Common IPv6 address formats include the full notation (2001:db8:85a3::8a2e:370:7334) and shortened forms. Modern operating systems and applications may try AAAA queries before or in parallel with A queries, following RFC 6724 or Happy Eyeballs (RFC 8305) for dual-stack connectivity.
AAAA records are authoritative records stored on DNS nameservers. They share the same TTL, CNAME, and delegation mechanisms as other DNS record types. Zone files and DNS management interfaces treat them at the same level as A records. With the exhaustion of IPv4 addresses and gradual IPv6 adoption, AAAA records have become essential for direct IPv6 reachability on the public internet. They are used alongside A records for dual-stack deployments, and are required for native IPv6-only networks.
Key facts
- Record type 28, defined in RFC 3596.
- Maps a hostname to one 128-bit IPv6 address.
- Analogous to the A record for IPv4.
- Can coexist with A records for dual-stack hosts.
- Supported by all modern DNS resolvers and servers.
How it works in practice
Related terms
References
More in DNS
A Record
A DNS resource record that maps a hostname to a 32-bit IPv4 address. It is the most fundamental record type for translating domain names to numeric addresses on the Internet.
Authoritative DNS
An authoritative DNS server holds the definitive resource records for a specific domain and responds to queries with the final answer for that zone, not a cached copy.
CAA Record
A CAA (Certification Authority Authorization) DNS record lets domain owners specify which certificate authorities are permitted to issue SSL/TLS certificates for their domain.
CNAME Record
A DNS record that maps an alias hostname to the true or canonical hostname, allowing multiple names to resolve to the same IP address without duplicating A or AAAA records.
DNS
The Domain Name System (DNS) is a hierarchical, distributed naming system that translates human-readable domain names (like example.com) into IP addresses and other resource records used by internet protocols.
DNS Anycast
DNS Anycast uses one IP address served from multiple geographically distributed nameservers; queries are routed to the nearest or healthiest node, improving resilience and reducing latency.
DNS Caching
DNS caching stores resolved domain name query results for the specified TTL duration to avoid repeated queries to upstream authoritative servers.
DNS Hijacking
DNS hijacking is an attack or misconfiguration that returns forged DNS responses, causing users to connect to attacker-controlled hosts instead of the intended server.
DNSSEC
DNSSEC (DNS Security Extensions) add cryptographic digital signatures to DNS records, enabling resolvers to verify that responses have not been tampered with or spoofed.
DoH
DNS over HTTPS (DoH) encrypts DNS queries and responses inside HTTPS traffic, preventing on-path observers from seeing or tampering with DNS lookups.