What is a DNS A record?
An A record maps a domain or subdomain (hostname) to a 32-bit IPv4 address.
It is the most common and fundamental DNS record in the DNS system.
It resolves a domain name to an IP address, redirecting it to the server hosting the services associated with that domain name (website, email services, parking page, etc.).
Example:
domain.com. 86400 IN A 195.64.164.87
www.domain.com. 86400 IN A 195.64.164.87| domain.com | record type | value or IP address | TTL |
|---|---|---|---|
| @ | A | 195.64.164.87 | 86400 |
| www.domain.com | record type | value or IP address | TTL |
|---|---|---|---|
| @ | A | 195.64.164.87 | 86400 |
A DNS A record also allows the use of DNS blacklists, or DNSBLs (Domain Name System Blacklists). DNSBLs are spam-blocking blacklists that allow a server/website administrator to block messages suspected of being spam and originating from specific systems with a history of sending spam. They can, in particular, help mail servers identify and block emails suspected or known to be spam.
For more information on DNS A records, or on other types of DNS records that are also described, you can consult RFC 1035.