An A record is a DNS record that maps a domain name to an IPv4 IP address. For example, the www.dnscheck.co A record maps to the 18.104.22.168 IP address. The IPv6 equivalent of an A record is a AAAA (quad A) record.
A records are also be referred to as "address records" and "host records", and are defined in RFC 1035.
DNS Check can monitor your A records, and notify you if they become unresolvable, or start resolving to the wrong IP address.
Here are the fields that make up an A record:
|Name||A fully qualified domain name (FQDN).||www.dnscheck.co.|
|Type||The DNS record type. Always set to "A".||A|
|Address||An IPv4 IP address.||22.214.171.124|
DNS Zone File Examples
Here's an example of how an A record looks in a DNS zone file:
; Name Type Address www.dnscheck.co. A 126.96.36.199
The Name ends in a period in the above example, so it's a fully qualified domain name.
Alternatively, you can create an A record that's relative to the zone file's $ORIGIN. Here's an example of how to use this technique to define the same record as in the previous example:
$ORIGIN dnscheck.co. ; Name Type Address www A 188.8.131.52
- RFC 1035 - section 3.4.1 (A RDATA format) defines the format that A records follow.