An AAAA record (“quad-A”) does the same job as an A record, but for IPv6 addresses.
yourdomain.co.uk. 3600 IN AAAA 2001:db8:85a3::8a2e:370:7334IPv4 and IPv6
- IPv4 addresses look like
203.0.113.10. There are too few for every device, so they’re in short supply. - IPv6 addresses look like
2001:db8::10. There are effectively unlimited numbers of them.
Many networks, especially mobile ones, prefer IPv6 when a domain offers it.
Why an AAAA record can cause trouble
Devices that support IPv6 try the AAAA address first. If a domain has an AAAA record pointing at an old server — often left behind after moving hosts — IPv6 users reach the old server while IPv4 users reach the new one. The symptom: the site works on your laptop but shows the old site, or nothing, on your phone.
If you move a domain to Traxio while keeping DNS elsewhere, delete any AAAA record that pointed at your previous host, unless you’ve been given an IPv6 address for your Traxio server.
Do I need one?
No. A site with only an A record is reachable by everyone, because IPv6 networks can still reach IPv4 addresses. An AAAA record is only useful when it points at the right server.