DNS record types

Understanding AAAA records

An AAAA (“quad-A”) record does the same job as an A record, but for IPv6 addresses.

Updated · Published by HostFaddy · 3 min read

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What an AAAA record looks like

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

IPv6 addresses are 128-bit values written in hexadecimal groups separated by colons. A double colon (::) replaces one run of zero groups.

Do you need an AAAA record?

Only if your server has a working, publicly reachable IPv6 address. Many networks — especially mobile networks — prefer IPv6 when it's available, so a correct AAAA record can give those visitors a direct path to your site. If your host doesn't provide IPv6, simply don't publish one: visitors fall back to IPv4.

Why a wrong AAAA record is worse than none

Modern browsers try IPv6 and IPv4 almost in parallel (the “Happy Eyeballs” approach), but a stale AAAA record still causes trouble: some clients wait for IPv6 to time out first, and email servers may deliver to the IPv6 address and fail. After a move, the most common hidden problem is an AAAA record still pointing at the old server. Visitors on IPv6 networks see the old site while everyone else sees the new one.

Checklist after a hosting move

  1. Look up the AAAA record for both the root domain and www.
  2. If the new host gave you an IPv6 address, update the AAAA record to it.
  3. If the new host has no IPv6, delete the old AAAA record.

IPv6 and email

If your mail server has an AAAA record, other mail servers may connect and send to you over IPv6 — and, if it sends over IPv6, receivers will check the IPv6 address too. That means:

  • Your SPF record needs an ip6: entry (or an a/mx mechanism that covers it).
  • The IPv6 address needs a matching reverse DNS (PTR) record, set by whoever owns the address block.
  • Major providers such as Gmail apply stricter checks to mail arriving over IPv6, so missing PTR or SPF entries are more likely to send messages to spam.

Testing whether IPv6 actually works

Publishing an AAAA record only makes sense if the server answers on that address. From a machine with IPv6 connectivity:

curl -6 -I https://example.co.za
ping -6 example.co.za

If these fail while the IPv4 equivalents (curl -4) succeed, remove the AAAA record or ask your host to fix the server's IPv6 configuration.

Looking up AAAA records

dig example.co.za AAAA +short
nslookup -type=AAAA example.co.za

Frequently asked questions

Can a domain have both A and AAAA records?

Yes, and that's the normal setup for dual-stack servers. Clients choose based on their own connectivity.

Will removing the AAAA record break my site?

Not if a correct A record exists. IPv6-only clients are very rare and most networks provide IPv4 access through translation.

Does my mail server need an AAAA record?

Only if it actually accepts mail over IPv6. If it does, make sure IPv6 reverse DNS is set up too.