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AAAA Records Explained: Adding IPv6 Support

Learn what an AAAA record is, how it connects a domain to an IPv6 address, when to use it, and how to avoid common IPv6 DNS problems.

By CheckDomainHealth Editorial Team Reviewed by Dionis Ceban Updated Jun 28, 2026 7 min read Beginner

Introduction

An AAAA record is a DNS record that points a domain or subdomain to an IPv6 address. It works similarly to an A record, but instead of returning an IPv4 address, it returns an IPv6 address.

AAAA records are used when a website, application, server or CDN supports IPv6. Adding an AAAA record can improve IPv6 compatibility, but it should only be done when the destination server is actually reachable over IPv6. If the AAAA record points to an incorrect or unreachable IPv6 address, some visitors may experience connection problems.

Quick answer

Quick answer

An AAAA record maps a domain or subdomain to an IPv6 address. It is the IPv6 version of an A record. Use AAAA records only when your hosting server, VPS, CDN or website platform provides a working IPv6 address for the hostname.

What is an AAAA record?

An AAAA record, also called a quad-A record, connects a hostname to an IPv6 address.

Example 
example.com → 2001:db8::10

In this example, example.com resolves to an IPv6 address. A browser or service using IPv6 can then try to connect to that address.

2001:db8::10 is a documentation example. Replace it with the real IPv6 address from your hosting, VPS, CDN or server provider.

A record vs AAAA record

A and AAAA records both connect hostnames to IP addresses, but they use different IP versions.

A record

  • Points to an IPv4 address
  • Used for traditional IPv4 connectivity

example.com → 192.0.2.10

AAAA record

  • Points to an IPv6 address
  • Used for IPv6 connectivity

example.com → 2001:db8::10

A domain can have both A and AAAA records. In that case, visitors may connect over IPv4 or IPv6 depending on their network, device and resolver behavior.

When should you use an AAAA record?

Your server has IPv6 enabled

Use an AAAA record when your hosting server or VPS has a working IPv6 address.

Your CDN supports IPv6

Use AAAA records if your CDN or proxy provider gives IPv6 endpoints or manages them automatically.

You want IPv6 compatibility

AAAA records help IPv6-capable visitors reach your website over IPv6.

Service hostnames with IPv6

AAAA records can be used for mail, API, app or panel subdomains if those services support IPv6.

Do not add an AAAA record just because IPv6 sounds better. The IPv6 address must be reachable and configured on the server or service.

When should you avoid an AAAA record?

Avoid or remove an AAAA record when:

  • your server does not have IPv6 configured
  • the IPv6 address is old or no longer assigned
  • the web server is not listening on IPv6
  • the firewall blocks IPv6 traffic
  • SSL is not configured correctly for IPv6 traffic
  • your CDN or hosting provider tells you not to add manual AAAA records

A broken AAAA record can cause problems for IPv6 users even if IPv4 still works correctly.

Why this matters

Why this matters

AAAA records matter because modern networks increasingly support IPv6. If your domain has a correct AAAA record, IPv6-capable users can reach your website or service over IPv6. If the AAAA record is wrong, some users may experience slow loading, timeouts or failed connections even when the IPv4 A record works.

How to check an AAAA record

Use the DNS Lookup tool to check whether a domain or subdomain publishes an AAAA record.

What to compare

When checking an AAAA record, compare these five values.

Hostname

The domain or subdomain you are checking, such as example.com or app.example.com.

Current IPv6 address

The IPv6 address currently returned by public DNS.

Expected IPv6 address

The IPv6 address provided by your hosting, VPS, CDN or website platform.

IPv6 reachability

Whether the server or service actually responds over IPv6.

Active nameserver

The DNS provider currently controlling the live DNS zone.

If DNS returns the correct IPv6 address but the website still fails over IPv6, check server binding, firewall rules, CDN configuration and SSL.

Check AAAA record now

Use DNS Lookup to confirm whether your domain has an IPv6 address configured.

Run DNS Lookup →

Common AAAA record problems

AAAA record points to the wrong IPv6 address

High

The hostname points to an IPv6 address that does not belong to the current server, hosting provider or CDN.

Next step: Confirm the correct IPv6 address and update the AAAA record at the active DNS provider.

IPv6 address exists but server does not respond

High

DNS returns an IPv6 address, but the web server or service is not reachable over IPv6.

Next step: Check server network configuration, web server listening addresses and firewall rules.

IPv4 works but IPv6 fails

High

The A record may be correct while the AAAA record is broken, causing problems only for IPv6-capable users.

Next step: Test both A and AAAA records and remove or fix the AAAA record if IPv6 is not ready.

Old AAAA record after migration

Medium

The domain was moved to a new server, but the old IPv6 address remained in DNS.

Next step: Remove outdated AAAA records or replace them with the new provider’s IPv6 address.

www and root domain behave differently

Medium

The root domain and www hostname may have different A/AAAA/CNAME configurations.

Next step: Check both example.com and www.example.com.

SSL works on IPv4 but fails on IPv6

Medium

Traffic over IPv6 may reach a different server or SSL configuration.

Next step: Confirm that the IPv6 destination serves the correct website and certificate.

No AAAA record found

Low

The domain does not publish an IPv6 address.

Next step: This is not always a problem. Add AAAA only if your provider supports IPv6 and the service is ready.

How to configure or fix an AAAA record

  1. Confirm IPv6 support

    Check whether your hosting provider, VPS, CDN or server actually supports IPv6 for the hostname.

  2. Get the correct IPv6 address

    Use the IPv6 address provided by your hosting, VPS or CDN provider. Do not invent or reuse an old IPv6 address.

  3. Confirm where DNS is hosted

    Check the active nameservers for the domain. Make changes at the provider controlling the live DNS zone.

  4. Add or update the AAAA record

    Set the hostname and IPv6 address.

    Type: AAAA
Host: @
Value: 2001:db8::10
TTL: 300 or 3600

    The @ symbol usually represents the root domain, but some DNS providers use the full domain name instead.

  5. Check www and important subdomains

    If www, app, mail or other subdomains should support IPv6, check whether they also need AAAA records or provider-managed IPv6 support.

  6. Verify DNS and connectivity

    After saving the record, check DNS resolution and confirm that the website or service responds over IPv6.

  7. Remove broken AAAA records if IPv6 is not ready

    If IPv6 is not configured properly, it is usually better to remove the AAAA record than leave a broken IPv6 destination.

AAAA record examples

AAAA record example 
example.com.       300   IN   AAAA   2001:db8::10
app.example.com.   300   IN   AAAA   2001:db8::20
Check commands 
dig example.com AAAA
dig www.example.com AAAA
IPv6 connectivity test 
curl -6 https://example.com

These are examples only. Replace hostnames and IPv6 addresses with values from your provider. The 2001:db8::/32 range is reserved for documentation examples.

AAAA records and website migrations

During a hosting migration, it is common to update the A record but forget the AAAA record. This can cause IPv4 users to reach the new server while IPv6 users still reach the old server.

Before or after a migration, check:

  • A record for the root domain
  • AAAA record for the root domain
  • www record
  • CDN/proxy settings
  • SSL certificate on the destination server
  • firewall rules for IPv6

If you are not ready to serve the website over IPv6, remove the old AAAA record until IPv6 is properly configured.

AAAA records and SSL certificates

SSL certificates are tied to hostnames, but the server reached over IPv6 still needs to serve the correct website and certificate. If the AAAA record points to a different or unconfigured server, users may see SSL errors.

Check SSL after changing AAAA records, especially for root domain, www hostname, important subdomains and CDN/proxy configurations.

Frequently asked questions

Is an AAAA record required?

No. An AAAA record is only needed if your domain or service should be reachable over IPv6. Many websites work with only A records, although IPv6 support is increasingly common.

Can a domain have both A and AAAA records?

Yes. A domain can publish both A and AAAA records. IPv4 users may use the A record, while IPv6-capable users may use the AAAA record.

Why does my website work on IPv4 but fail on IPv6?

The A record may be correct while the AAAA record points to an unreachable or misconfigured IPv6 address. Check the AAAA record, server IPv6 configuration, firewall and SSL.

Should www have an AAAA record too?

Only if www should be reachable over IPv6 and your provider supports it. Check both the root domain and www hostname.

Can an AAAA record affect email?

Not usually for normal website traffic. However, if mail-related hostnames use AAAA records, the mail server must be reachable and configured correctly over IPv6.

How long does an AAAA record change take?

Many changes appear within minutes, but cached DNS values can remain until TTL expires.

Should I remove a broken AAAA record?

Yes, if IPv6 is not ready. A broken AAAA record can cause issues for IPv6-capable users even when IPv4 works.

Use these free tools to verify your configuration after applying changes.

DNS Lookup Domain Health Checker SSL Checker Website Status Checker HTTP Header Checker CAA Record Checker
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