A Record (Address Record) (A Record)

Security Glossary - DNS

Definition: An A record maps a domain name to an IPv4 address. It is the most fundamental DNS record type, directly answering the question 'what IP address should traffic for this domain go to?' Multiple A records can exist for the same domain to provide load balancing or redundancy.

Why A Record Is Important

A records are the core mechanism by which domains point to servers. Without a correct A record, your domain does not resolve to any server and your website is unreachable. Misconfigured A records can point traffic to the wrong server, potentially exposing visitors to a different site or causing complete downtime.

When migrating servers, A records must be updated to point to the new IP address. Due to DNS caching, both the old and new servers should be running during the transition. If you remove the old server before DNS caches expire, visitors with cached DNS entries will see connection errors.

Multiple A records for the same domain create round-robin DNS, where different visitors are directed to different servers. This provides basic load distribution but is not true load balancing - it does not account for server health or load. For production load balancing, a dedicated load balancer behind a single A record is preferred.

How to Check

A DNS health check shows your domain's A records and the IP addresses they resolve to. Verify that the IP address matches your actual server. If you recently changed hosting, check that the A record points to the new server and that DNS propagation is complete.

Configuration Reference

ParameterValue
Record TypeA
Points toIPv4 address (e.g., 93.184.216.34)
Common TTL300-3600 seconds
Multiple valuesSupported (round-robin load balancing)
Proxied (Cloudflare)Supported
Check DNS Health

Common Questions About A Record

Can I have multiple A records for one domain?
Yes. Multiple A records create round-robin DNS, distributing traffic across several IP addresses. DNS resolvers typically return all records, and the client tries them in order. This provides basic redundancy but not health-aware load balancing.
What is the difference between an A record and a CNAME?
An A record maps a domain directly to an IP address. A CNAME maps a domain to another domain name, which then resolves to an IP via its own A record. CNAMEs add an extra DNS lookup but are useful for pointing to services like CDNs that may change IP addresses.
Disclaimer: DomainOptic provides automated informational scans only. Results do not constitute professional security advice, compliance certification, or a guarantee of security. Always verify findings independently.