Address Record (A)
Maps a domain name to an IPv4 address — the most fundamental DNS record type.
Standards: RFC 1035
What is a DNS A record?
An A record (Address record) maps a hostname to a 32-bit IPv4 address. When you type "example.com" into a browser, a DNS resolver queries for the A record to find the server IP address to connect to. A records are the most common DNS record type and are essential for all IPv4-based services. A records support load balancing via round-robin DNS (multiple A records for one hostname). They have a TTL (Time To Live) that controls how long resolvers cache the value before re-querying. Shorter TTLs allow faster propagation of changes at the cost of more queries. Most domains need at least one A record for the apex domain (@) and one for the www subdomain. Wildcard A records (*.example.com) map any undefined subdomain to a single IP.
Record Structure
| Field | Description |
|---|---|
| Name | The hostname, e.g. example.com or subdomain.example.com |
| TTL | Time to live in seconds. Common values: 300 (5 min), 3600 (1 hr), 86400 (24 hr) |
| Class | Always IN (Internet) for standard DNS |
| Type | A |
| Address | IPv4 address in dotted-decimal notation, e.g. 93.184.216.34 |
Examples
example.com. 3600 IN A 93.184.216.34
www.example.com. 3600 IN A 93.184.216.34
example.com. 300 IN A 1.2.3.4 example.com. 300 IN A 5.6.7.8
*.example.com. 3600 IN A 93.184.216.34
Common Issues & Fixes
DNS_PROBE_FINISHED_NXDOMAIN — domain not resolving
The browser cannot find an IP for the domain. This usually means the A record is missing or pointing to the wrong IP.
✓ Fix: Check your DNS settings. Ensure an A record exists for the hostname with a valid IP. Use the DNS Lookup tool to verify.
Old IP cached — changes not propagating
After changing an A record, visitors still reach the old server because resolvers cached the previous value.
✓ Fix: Reduce TTL to 300 before making the change. After propagation (check with DNS Propagation Checker), restore TTL to 3600.
A record pointing to wrong server
Traffic is reaching the wrong server — common when migrating hosts.
✓ Fix: Update the A record to the new server IP. Wait for TTL expiry (or lower TTL first).