DNS over IPv6 — AAAA Records and IPv6 DNS Servers

IPv6 is the replacement for IPv4, the internet's original addressing system. IPv4 provides about 4.3 billion addresses, which seemed like a lot in 1983 but is nowhere near enough today. IPv6 provides 340 undecillion addresses — enough for every device on earth to have its own globally unique IP address.

DNS plays a crucial role in the IPv6 transition. The AAAA record maps domain names to IPv6 addresses, just as the A record maps them to IPv4. DNS resolvers themselves are accessible over IPv6, and major public DNS providers all support IPv6 natively.

This guide covers everything you need to know about DNS and IPv6: AAAA records, IPv6 DNS server addresses, configuration, and common issues.

AAAA Records — IPv6 Address Records

AAAA records are the IPv6 equivalent of A records. They map a domain name to a 128-bit IPv6 address. The name comes from the quadruple A format, reflecting that IPv6 addresses are four times the length of IPv4 addresses.

An AAAA record looks like this in a zone file: www.example.com. IN AAAA 2001:db8::1. The resolution process works exactly like A record resolution. The DNS resolver receives the AAAA record and returns the IPv6 address to the client. The client then connects to that address.

Every modern website should have both A and AAAA records. This is called dual-stack configuration. Devices that support IPv6 use the AAAA record. Devices limited to IPv4 use the A record. Having both ensures everyone can reach your site regardless of their network configuration.

IPv6 DNS Server Addresses

Major public DNS providers all support IPv6. Here are their IPv6 addresses:

Cloudflare: 2606:4700:4700::1111 and 2606:4700:4700::1001. These are the IPv6 versions of 1.1.1.1. Cloudflare also offers malware-blocking IPv6 DNS at 2606:4700:4700::1112 and family-safe at 2606:4700:4700::1113.

Google: 2001:4860:4860::8888 and 2001:4860:4860::8844. These correspond to the IPv4 addresses 8.8.8.8 and 8.8.4.4. Google's IPv6 DNS servers are just as fast and reliable as their IPv4 counterparts.

Quad9: 2620:fe::fe and 2620:fe::9. Quad9's IPv6 DNS servers include the same threat blocking and DNSSEC validation as their IPv4 service.

OpenDNS: 2620:119:35::35 and 2620:119:53::53. These correspond to 208.67.222.222 and 208.67.220.220.

When configuring DNS on an IPv6-capable network, you can enter these addresses alongside or instead of the IPv4 addresses. Most operating systems support both IPv4 and IPv6 DNS servers simultaneously.

DNS Resolution Over IPv6

DNS queries themselves can travel over IPv6. Your device sends the DNS query to the resolver using IPv6, and the resolver responds over IPv6. This is transparent to the user but provides the same benefits as other IPv6 traffic: potentially lower latency if the IPv6 path is more direct than IPv4.

IPv6 DNS resolution requires a few things to work. Your network must support IPv6. Your ISP must provide IPv6 connectivity. Your device must have a global IPv6 address. And you must configure IPv6 DNS servers, either through DHCPv6 or manually.

On dual-stack networks, the operating system typically tries both IPv4 and IPv6 for DNS queries. It uses the fastest responding protocol. On most modern networks, IPv6 is slightly faster because the NAT traversal overhead is absent.

How to Configure IPv6 DNS

On Windows, go to Network and Sharing Center, click your connection, open Properties, select Internet Protocol Version 6 (TCP/IPv6), and enter the IPv6 DNS addresses. You can enter both an IPv6 and IPv4 DNS server for redundancy.

On Mac, go to System Settings, Network, select your connection, click Details, and find the DNS section. Add the IPv6 DNS addresses alongside or instead of IPv4 addresses.

On Android, Private DNS supports DNS over TLS and accepts either IPv4 or IPv6 addresses. Go to Settings, Network & Internet, Private DNS, and enter the hostname or address.

On routers, the DNS configuration page typically accepts both IPv4 and IPv6 addresses. Some routers have separate fields for IPv6 DNS servers. Check the Advanced or IPv6 section of your router's admin panel.

Common IPv6 DNS Issues

DNS over IPv6 can fail if your ISP's IPv6 connectivity is unreliable. Some ISPs advertise IPv6 support but have poor routing or frequent outages. If you experience intermittent DNS failures with IPv6 DNS servers, try using only IPv4 DNS servers and see if the problem persists.

Some networks have broken IPv6 where the connection appears to work for initial setup but fails for actual traffic. This is often caused by firewall rules that allow ICMPv6 but block UDP on port 53 over IPv6. Test your IPv6 DNS using nslookup or dig with an IPv6 resolver.

If you host services, make sure your DNS provider supports AAAA records. Some legacy DNS providers do not. You may need to migrate to a modern provider that supports full IPv6 record management.

For testing your overall IPv6 connectivity, including DNS resolution, use our IPv6 test tool.