DNS ALIAS records are a special type of DNS record that provides similar functionality to CNAME records but with additional flexibility and performance benefits. Unlike traditional CNAME records, ALIAS records can be used at the root domain level and provide better load balancing capabilities.
An ALIAS record is a special DNS record type that acts like a CNAME record but can be used at the root level of a domain. While CNAME records cannot be used for the root domain (also known as the apex domain), ALIAS records can be used to point the root domain to another hostname while still allowing other record types to exist for the same domain.
ALIAS records are not part of the official DNS specification but are implemented by various DNS providers as a solution to the limitations of CNAME records. They provide a way to alias the root domain to another hostname while maintaining DNS compatibility.
When a DNS query is made for a domain with an ALIAS record, the DNS server follows the alias target and returns the IP address(es) of the target hostname. This process is done transparently, so the client receives an A or AAAA record response containing the actual IP addresses, not the ALIAS record itself.
This behavior makes ALIAS records particularly useful for scenarios where you need to point your root domain to a load balancer, CDN, or cloud service that provides a hostname rather than a static IP address. The DNS provider automatically resolves the target hostname and returns the current IP addresses to clients.
ALIAS records are commonly used with cloud services like AWS Application Load Balancers, CloudFront distributions, or other services that provide hostnames instead of static IP addresses for improved reliability and performance.
Here's what an ALIAS record looks like for the domain example.com:
