As we are in the midst of IPv4 address exhaustion, AAAA records have become the bridge to the future – connecting domains to the vast IPv6 address space that will power the next billion devices online.
What is an AAAA record
An AAAA record is a DNS record that maps domain names to IPv6 addresses, serving as the IPv6 equivalent of traditional A records. While A records handle 32-bit IPv4 addresses, AAAA records manage 128-bit IPv6 addresses – providing an astronomical increase in available address space essential for modern internet scalability.
Here's what an actual AAAA record looks like:
Compare this side-by-side with an A record:
- A record:
example.com → 192.0.2.1(IPv4) - AAAA record:
example.com → 2606:2800:220:1:248:1893:25c8:1946(IPv6)
The name "AAAA" represents four times the address space of "A" records – a nod to IPv6's vastly expanded capacity. In practice, AAAA records coexist with A records in dual-stack configurations, allowing domains to serve both IPv4 and IPv6 clients simultaneously, ensuring compatibility during the ongoing transition period.
How AAAA records work
The IPv6-capable DNS resolution process mirrors IPv4 but with added intelligence. Modern systems perform dual-stack DNS queries, requesting both A and AAAA records simultaneously. The Happy Eyeballs algorithm, implemented in most browsers, optimizes connection attempts by racing IPv4 and IPv6 connections, using whichever responds faster.
A typical DNS query returns both record types:
example.com. IN A 192.0.2.1
example.com. IN AAAA 2001:db8::1
Clients choose between IPv4 and IPv6 based on network configuration, operating system preferences, and connection quality. Most modern systems prefer IPv6 when available but maintain IPv4 as a fallback. TTL values control caching behavior just like A records, though administrators often set shorter TTLs during IPv6 deployment for flexibility. When IPv6 connectivity fails, clients automatically fall back to IPv4, ensuring service continuity.
Common AAAA record configurations
Dual-stack hosting remains the standard approach, maintaining both A and AAAA records for maximum compatibility. IPv6-only services are emerging, particularly for CDN integration where providers like Cloudflare excel at IPv6 delivery. Load balancing works identically to IPv4 – multiple AAAA records distribute traffic across servers.
Regional routing via anycast works seamlessly with IPv6, often providing better performance than IPv4 due to simplified routing tables.
Warning: Always test IPv6 connectivity thoroughly before removing A records. Many enterprise networks still lack full IPv6 support.
Mobile networks increasingly adopt IPv6-first strategies, with major carriers routing primarily through IPv6 to conserve scarce IPv4 addresses.
IPv6 adoption and best practices
Global IPv6 adoption now exceeds 40%, with some countries surpassing 70% penetration. Testing dual-stack connectivity requires checking both protocols independently. Monitor IPv6 performance metrics separately from IPv4 – latency and routing often differ significantly. Security considerations for AAAA records mirror A records, but IPv6's larger address space changes scanning and discovery dynamics.
IPv6 readiness checklist:
- AAAA records configured correctly;
- IPv6 connectivity verified from multiple devices / locations;
- Firewall rules updated for IPv6 traffic;
- Monitoring systems tracking both protocols.
Future-proofing your infrastructure means implementing IPv6 today, even if most traffic remains IPv4.
Manage your DNS transition
Managing AAAA records alongside traditional A records doubles the complexity of DNS management. With domains spread across multiple registrars and varying IPv6 support levels, maintaining consistent dual-stack configurations becomes challenging.
Whether you're transitioning to IPv6 or managing hybrid infrastructure across dozens of domains, centralized DNS control ensures smooth operations and future readiness.
Questions about AAAA records or IPv6 migration? Contact our team – we aim to help businesses navigate the transition to modern DNS infrastructure every day