The full DNS name of a host, zone included, for example www.contoso.com.
Also called fully qualified domain name.
Read more: Microsoft Learn
In the Ultra Transcenders books
AZ-104AZ-700SC-5002V0-17.25AI-200SC-900SC-200SC-300AZ-400AZ-802SC-401MD-102ALZ
Each book explains FQDN in context, with comparison tables and the common traps.
Terms in this definition
- DNS
The system that turns names into addresses. In Azure, private endpoints depend on private DNS zones, which are queried through 168.63.129.16.
Related terms
- Application rule
Azure Firewall rule type that controls outbound HTTP, HTTPS and MSSQL traffic according to the destination FQDN, with full URL filtering requiring Premium. DNAT and network rules are evaluated before it.
- Application segment
Destination defined on an enterprise application for Microsoft Entra Private Access, made up of an FQDN, wildcard FQDN, IP or range together with ports and protocol. Matching traffic is reachable solely by users assigned to that app.
- Connection troubleshoot
One-time Network Watcher check from a VM to another VM, an FQDN, a URI or an IP and port, reporting whether it is reachable, the latency and which hop (route or NSG) breaks it.
- External endpoint
Traffic Manager endpoint type pointing to an IPv4/IPv6 address or FQDN, which can be outside Azure. MultiValue routing accepts only External endpoints defined by IP address.
- Microsoft Entra Internet Access
A secure web gateway within Global Secure Access that knows who the user is. Security profiles tied to Conditional Access decide which websites and SaaS services are allowed, judged by FQDN or category, and ports beyond the default 80 and 443 can be captured with custom rules.
- Network rule
In Azure Firewall, these rules filter on protocol, port, IP address or service tag, plus FQDN once DNS proxy is on. Evaluation order puts them after DNAT and ahead of application rules.
- Origin
Host behind Front Door that serves the content, such as an App Service app, storage, a load balancer or any custom host given by FQDN. An App Service app counts as one origin regardless of its worker count.
- Subject alternative name
The part of a certificate (SAN) that names each host it is good for. Microsoft Tunnel Gateway needs its FQDN or IP address there, and SCEP or PKCS profiles can supply extra values.