Table of Contents
What is an A record?
An A record maps a domain name to the IP address (IPv4) of the computer hosting the domain. Simply put, an A record is used to find the IP address of a computer connected to the internet from a name.
The A in A record stands for Address. Whenever you visit a web site, send an email, connect to Twitter or Facebook or do almost anything on the Internet, the address you enter is a series of words connected with dots.
For example, to access the DNSimple website you enter
www.dnsimple.com. At our name server there is an A record that points to the IP address
220.127.116.11. This means that a request from your browser to
www.dnsimple.com is directed to the server with IP address
A Records are the simplest type of DNS records, yet one of the primary records used in DNS servers.
You can actually do quite a bit more with A records, including using multiple A records for the same domain in order to provide redundancy. Additionally, multiple names could point to the same address, in which case each would have its own A record pointing to the that same IP address.
Querying A records
You can use
dig to determine the A record associated to a domain name. The result is contained in the
ANSWER section and it contains the fully-qualified domain name (FQDN), the remaining time-to-live (TTL) and the IP address.
$ dig A api.dnsimple.com ; <<>> DiG 9.8.3-P1 <<>> A api.dnsimple.com ;; global options: +cmd ;; Got answer: ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 5792 ;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 0 ;; QUESTION SECTION: ;api.dnsimple.com. IN A ;; ANSWER SECTION: api.dnsimple.com. 59 IN A 18.104.22.168 ;; Query time: 80 msec ;; SERVER: 22.214.171.124#53(126.96.36.199) ;; WHEN: Sun Jul 31 22:21:31 2016 ;; MSG SIZE rcvd: 50
A record format
In DNSimple we represent A record with the following information:
|Name||The host name for the record, without the domain name. This is generally referred as “subdomain”. We automatically append the domain name.|
|TTL||The time-to-leave in seconds. This is the amount of time the record is allowed to be cached by a resolver.|
|Address||The IPv4 address the A record points to.|
Add an A record
You can create, update and delete A records for your domain using the DNSimple record editor.