CNAME Record
DNS record that points one domain name to another as its canonical name.
A CNAME (Canonical Name) record in DNS points one domain name to another, which is then treated as the canonical name. When a resolver encounters a CNAME, it follows the chain and looks up the A-record or AAAA-record of the target before returning a final answer to the client.
A typical use is aliasing service names onto provider-managed hosts: www.example.com is set as a CNAME to a platform-specific host (example.cloudprovider.net), letting the provider change the underlying IP addresses without the domain owner having to touch their own records.
A CNAME cannot coexist with other records on the same name. For that reason CNAME is not allowed at the zone apex (example.com), since the apex must hold NS records and usually MX records. A CNAME should also not be used in place of an MX record — mail routing requires real MX records, not an alias.
Key Points
- Points a name to another canonical name
- Resolvers follow the chain to an
AorAAAArecord - Common for aliasing onto external platforms
- Cannot coexist with other records on the same name
- Not allowed at the zone apex (
example.com) - Should not be used as a substitute for
MXrecords