AAAA Record

Stands For: AAAA (Quad-A) Record

Definition: An AAAA record (pronounced “quad-A record”) is a type of resource record in the Domain Name System (DNS). Its function is to map a domain name (or hostname) to its corresponding 128-bit IPv6 address. It is the IPv6 equivalent of the A record.

Key Characteristics:

• Mapping: Directly associates a hostname (e.g., www.example.com) with an IPv6 address (e.g., 2001:0db8:85a3:0000:0000:8a2e:0370:7334).
• Purpose: Enables clients to find and connect to servers over the IPv6 internet. As IPv6 adoption grows, AAAA records are becoming increasingly critical for web connectivity.
• Dual-Stack Support: A single hostname can have both an A record (for IPv4) and an AAAA record (for IPv6). This allows the host to be accessible over both protocols, a configuration known as “dual-stack”. A client’s operating system will typically prefer the IPv6 connection if available.
• Structure: A typical AAAA record includes:
  • Name: The hostname the record applies to.
  • TTL (Time to Live): The caching duration in seconds.
  • Class: IN (for Internet).
  • Type: AAAA.
  • Address: The destination 128-bit IPv6 address.

Related Records:

• A Record: The counterpart for IPv4, mapping a hostname to a 32-bit IPv4 address.
• PTR Record: Used for reverse DNS, mapping an IP address back to a hostname. For IPv6, these records exist in the .ip6.arpa domain.

Usage Note: As of June 2025, AAAA records are an essential part of the internet’s transition to IPv6. They are necessary for any service that needs to be natively accessible to the growing number of IPv6-only or IPv6-first users and networks.