- Published on
What are A and AAAA Records?
- Authors
- Name
- Skip2 Networks
- Title
- Content Manager
A and AAAA DNS Records
In the Domain Name System (DNS), A records and AAAA records are fundamental types of resource records that map human-readable domain names to numerical IP addresses. An A record (short for "Address record") is used to store the IPv4 address of a hostname. When you type a domain name like example.com into your browser, the DNS resolver queries for its A record to find the corresponding IPv4 address (e.g., 192.0.2.1), which then allows your browser to connect to the correct server. These records are essential for directing traffic on the internet, as they provide the bridge between easy-to-remember domain names and the actual network locations of web servers and other internet resources.
Similarly, an AAAA record (pronounced "quad-A record") serves the same purpose but for IPv6 addresses. As the internet transitions from IPv4 to IPv6, AAAA records are becoming increasingly important. An IPv6 address is significantly longer than an IPv4 address (e.g., 2001:0db8:85a3:0000:0000:8a2e:0370:7334), and AAAA records enable domains to be resolved to these next-generation IP addresses. Many modern websites and services are configured with both A and AAAA records to ensure accessibility across both IPv4 and IPv6 networks, providing redundancy and future-proofing as IPv6 adoption continues to grow.
Example
Let's say a CDN company hosts a customer's website, cdnexample.com. The DNS records for this domain might look like this:
cdnexample.com. IN A 198.51.100.10 ; Maps to an IPv4 address
cdnexample.com. IN AAAA 2001:0db8::1 ; Maps to an IPv6 address
In this example, if a user's device supports IPv6, it might prefer to use the AAAA record to connect to the server at 2001:0db8::1. If it only supports IPv4, or if IPv6 connectivity is problematic, it would use the A record to connect to 199.51.100.10.