Subdomain
A subdomain sits within a parent DNS namespace. It can name a service; its administration and security still need to be planned.
What is a subdomain?
A subdomain is a domain contained within another domain. The IETF defines this relationship using complete name components. A merely similar character string is insufficient; the hierarchy of dot-separated parts is what matters.
Example: a portal under the company domain
In the fictional example, portal.studio.example sits below studio.example. Another name such as hilfe.portal.studio.example sits below that in turn. The names illustrate the relationship; they are not configured public services.
The team can operate a separate portal service or deliver it alongside other services on the same infrastructure. The additional name does not dictate that choice. A separate name also does not automatically make data, permissions and operations independent.
Clarify the DNS mapping, suitable certificate coverage and access rules for the actual service. A subdomain does not have to be a separate DNS zone. An appropriate delegation creates a separate zone whose administration must be assigned.
Sources
Related terms
- 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.
- DNS zoneA DNS zone is an administrative unit for DNS data. Its boundaries follow delegation; not every subdomain automatically becomes a separate zone.
- Transport Layer SecurityTLS protects data in transit between its endpoints. Application permissions, stored data and further connections need their own measures.
- 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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