CNAME record
A CNAME record points a DNS alias to another name. It is not an HTTP redirect and does not configure the destination server.
What is a CNAME record?
A CNAME record identifies a DNS name as an alias of another name. RFC1035 describes this reference to the canonical name. Its target is a domain name, not an IP address or a full web link containing a page path.
Example: connecting a portal name to a service
In a fictional design, the public portal name points through a CNAME to the name specified by the service provider. Name resolution can use this to find the required address data. The web service must still accept the public portal name and provide a matching certificate.
The CNAME alone does not change the address used in the browser. Redirecting to another website would require a separate HTTP response. Individual page paths cannot be redirected with it either.
Before switching, the team therefore checks the DNS reference, destination resolution and actual portal access. The mere presence of the alias confirms neither successful operation nor that the application has been made available for access.
Sources
Related terms
- Domain Name SystemDNS supplies data about names, such as a web server’s address. Name resolution, the server connection and application behaviour are separate steps.
- DomainA domain is a named part of the DNS namespace. The name does not create a website; hosting, email and the application still need to be connected.
- A recordAn A record maps a DNS name to an IPv4 address. It does not configure the website or define HTTPS, paths or an HTTP redirect.
- Return-PathReturn-Path records the SMTP reverse path in a header. It explains the technical route for error reports, not a person’s identity.
- Envelope-FromEnvelope-From identifies the SMTP sender for transport and error feedback. It must be distinguished from the visible sender address.
- DMARC aggregate reportA DMARC aggregate report summarises a reporting mail system’s domain checks over a period. It helps examine sending sources and misconfigurations.
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