An A record (Address record) is a fundamental DNS record used to point a domain or subdomain to a specific 32-bit IPv4 address. It serves as the primary mechanism for translating human-readable hostnames into the numerical addresses required for internet communication.
How it works
When a client initiates a request for a domain, the DNS resolver retrieves the A record from the authoritative name server. This record provides the IPv4 address, such as 192.0.2.1, enabling the client to establish a direct connection to the web server or host associated with that domain.
- Redundancy: Multiple A records can be configured for a single hostname to provide basic load balancing and failover capabilities.
- Protocol: A records are strictly for IPv4 addresses; IPv6 addresses require the use of AAAA records.
- Caching: The Time to Live (TTL) value specifies how long recursive DNS servers should store the record before requesting an update.
A typical configuration in a zone file looks like this: example.com. 3600 IN A 93.184.216.34. In this instance, 3600 represents the TTL in seconds, and 93.184.216.34 is the destination IPv4 address of the host.