What Is an AAAA Record? DNS AAAA Record Explained

An AAAA record maps a hostname to an IPv6 address. It does for IPv6 what an A record does for IPv4: it tells resolvers which address should be returned when a client asks for that hostname.

If your service supports IPv6, publishing an AAAA record allows IPv6-capable clients and networks to connect directly without relying on IPv4 translation or fallback behaviour.

As IPv6 adoption continues to grow, AAAA records matter more for performance, compatibility, and long-term network readiness.

example.com. 300 IN AAAA 2001:db8::10

This record tells resolvers that example.com can be reached at the IPv6 address 2001:db8::10. As with other DNS records, the TTL controls how long recursive resolvers may cache the response.

• A record returns an IPv4 address such as 203.0.113.10
• AAAA record returns an IPv6 address such as 2001:db8::10
• A hostname can publish both A and AAAA records at the same time
• Clients usually prefer IPv6 when it is available and working

Dual-stack deployments commonly publish both record types so the same hostname can serve both IPv4-only and IPv6-capable clients.

You should publish an AAAA record only when the service is genuinely reachable over IPv6. That means the server, firewall rules, reverse proxy, and any upstream protection or load-balancing layer must all support IPv6 end to end.

Adding an AAAA record before the service is actually reachable can create intermittent failures because some clients will try IPv6 first and hit a broken path.

• An IPv6 address is published but the server is not listening on IPv6
• Firewall or security group rules allow IPv4 traffic but block IPv6 traffic
• The published IPv6 address belongs to the wrong interface or host
• A stale AAAA record remains after a migration
• Resolvers show inconsistent answers because the change is still propagating

AAAA issues are often harder to notice than A record issues because the service may still appear to work from IPv4-only networks while failing for users who prefer IPv6.

dig example.com AAAA

dig @1.1.1.1 example.com AAAA

dig @8.8.8.8 example.com AAAA

DNS lookup is only the first check. After confirming the AAAA answer, also test real network reachability to make sure the service is responding over IPv6 and not just publishing an address.

• What Is DNS?
• Why Does One Hostname Resolve to Multiple IPs?
• How to Check DNS Propagation

If you want to validate this topic in practice, these DNS Pro tools are the fastest next step.

• Record Lookup
• DNS Propagation Checker
• Domain DNS Summary