DNS A record
(also DNS address record)
DNS A record definition
The DNS “A” record is the most fundamental DNS record that exists in the DNS records system. The letter A stands for address, and the DNS “A” record shows the IP address of a specific domain. For instance, the DNS “A” record for the domain google.com will show Google’s IP address. DNS “A” records only show and hold IPv4 addresses, so if you want to see the IPv6 address of a domain, you won’t be able to through the domain’s DNS “A” record.
The DNS “A” record allows people to access URLs because it holds their root domains. So without a DNS “A” record, when people access a URL, they’ll get an error message back instead of the website that they want to open. Because the DNS “A” record does this, it is deemed the most important DNS record type. Also, without a DNS “A” record, people would have to memorize a web site’s whole IP address to find it on the internet. A DNS “A” record can also point to subdomains.
See also: DNS record, IPv4
DNS A record use cases
- Looking up IP addresses. The most common reason why people use DNS “A” records is to find the IP address of a specific domain. The DNS “A” record is also used to match a domain name to an IP address, allowing a device to access websites without the user having to memorize entire IP addresses.
- Operating a DNSBL. A DNSBL is a Domain Name System-based Blackhole list, and most organizations use a DNS “A” record to create and operate such a list. With a DNSBL, mail servers can recognize and block emails from spam accounts.