AAAA Record IPv6

The AAAA record (also called "quad-A record") maps a domain name to an IPv6 address. It's the IPv6 equivalent of the A record and is essential for modern internet connectivity as the world transitions from IPv4 to IPv6.

What Is an AAAA Record?

An AAAA record creates a direct mapping between a domain name (like example.com) and an IPv6 address (like 2001:0db8:85a3:0000:0000:8a2e:0370:7334). The name "AAAA" reflects that IPv6 addresses are four times longer than IPv4 addresses (128 bits vs 32 bits).

While A records handle IPv4 addresses, AAAA records handle the newer IPv6 protocol. Most modern websites should have both A and AAAA records to support all users.

Why IPv6 and AAAA Records Matter

IPv4 addresses (like 192.168.1.1) are running out. The 4.3 billion available IPv4 addresses aren't enough for the billions of devices now connected to the internet. IPv6 provides approximately 340 undecillion addresses (3.4×10³⁸), ensuring we won't run out anytime soon.

Benefits of IPv6 include:

• Larger address space — Virtually unlimited unique addresses
• Better routing — More efficient routing tables
• No NAT required — Direct end-to-end connectivity
• Built-in security — IPsec support is mandatory
• Improved performance — No NAT translation overhead

AAAA Record Format

An AAAA record consists of these components:

example.com.    3600    IN    AAAA    2001:db8:85a3::8a2e:370:7334

IPv6 Address Format

IPv6 addresses are 128 bits long, written as eight groups of four hexadecimal digits separated by colons:

2001:0db8:85a3:0000:0000:8a2e:0370:7334

IPv6 addresses can be shortened by:

• Removing leading zeros — 0db8 becomes db8
• Using :: for consecutive zeros — :0000:0000: becomes :: (only once per address)

So the address above becomes:

2001:db8:85a3::8a2e:370:7334

Common AAAA Record Use Cases

1. Dual-Stack Configuration

Most domains should have both A (IPv4) and AAAA (IPv6) records. This "dual-stack" approach ensures compatibility with all clients:

example.com.    300    IN    A       93.184.216.34
example.com.    300    IN    AAAA    2606:2800:220:1:248:1893:25c8:1946

2. Subdomains with IPv6

Create AAAA records for subdomains that need IPv6 support:

www.example.com.     300    IN    AAAA    2606:2800:220:1:248:1893:25c8:1946
api.example.com.     300    IN    AAAA    2606:2800:220:1:248:1893:25c8:1947

3. IPv6-Only Services

Some services may only be accessible via IPv6:

ipv6only.example.com.    300    IN    AAAA    2001:db8::1

AAAA Record Best Practices

• Always use dual-stack — Provide both A and AAAA records for maximum compatibility.
• Match TTL values — Use the same TTL for A and AAAA records pointing to the same service.
• Test IPv6 connectivity — Verify your server actually accepts IPv6 connections before adding AAAA records.
• Don't use IPv4-mapped IPv6 — Addresses like ::ffff:192.168.1.1 defeat the purpose of IPv6.
• Use compressed notation — While both formats work, the shortened form is more readable.

A Record vs. AAAA Record

How to Add an AAAA Record

The process is similar to adding an A record:

1. Log in to your DNS provider or domain registrar
2. Navigate to DNS settings or Zone Editor
3. Add a new record with type "AAAA"
4. Enter the hostname (@ for root, or subdomain name)
5. Enter the IPv6 address
6. Set the TTL (or use default)
7. Save the record

Troubleshooting AAAA Records

Common issues and solutions:

• Site loads over IPv4 but not IPv6 — Your AAAA record exists but the server isn't listening on IPv6. Check server configuration.
• Invalid IPv6 address error — Check the format. IPv6 addresses use colons, not dots.
• Slow connections — May indicate "happy eyeballs" fallback from IPv6 to IPv4. Test both protocols.
• Works on some networks only — Some ISPs don't support IPv6. This isn't a DNS issue.