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DNS

A record

An A record is a DNS resource record that maps a domain name to an IPv4 address (32-bit number), enabling browsers and applications to find your server on the internet.

An A record maps a hostname or domain to its IPv4 address. It's the most common DNS record type and the one that makes your domain reachable.

How it works

When someone visits your domain, a DNS resolver queries your nameserver for the A record. The nameserver returns the IPv4 address (e.g. 93.184.216.34), and the client connects to that IP.

A records are stored in zone files like this:

example.com. 300 IN A 93.184.216.34

The 300 is the TTL (time-to-live) in seconds—how long resolvers cache the answer. You can have multiple A records for the same domain to enable simple round-robin load balancing across servers.

Important constraints

  • One record type per name: A domain can't have both an A record and a CNAME record at the same name. Choose one.
  • TTL and propagation: When you change an A record's IP, old cached values persist at resolvers until the previous TTL expires. Lower the TTL before a planned IP migration to speed the cutover.
  • IPv4 only: A records only map to IPv4. If you need IPv6 support, publish AAAA records alongside your A records.

Use the DNS lookup tool to check what A records are currently published for any domain.

TipLower the record's TTL a day before you change an A record — the new IP then propagates in minutes instead of hours.

Related terms

See it in context

InfraNest shows you your own records, zones and certificates, so the terms stop being abstract.

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