Tutorial / Cram Notes
A Fully Qualified Domain Name (FQDN) is a complete and specific domain name that identifies an addressable host on the Internet or an intranet. It consists of two parts: the hostname and the domain name. This includes a top-level domain (TLD), and possibly a subdomain, providing a complete path to a specific host.
An FQDN always reads from the most specific to the general part, arranged in a hierarchy from the left to right. A typical format of an FQDN is: hostname.subdomain.domain.top-level domain. It can be broken down as follows:
- Hostname: The unique name of the device within the domain.
- Subdomain (optional): A subdivision of the primary domain that can specify different services or areas of the organization.
- Domain: The central part of the FQDN that denotes the organization or entity that controls the namespace.
- Top-Level Domain (TLD): The most generalized part of the FQDN, such as .com, .org, .net, or a country code like .uk, .us.
For example, in the FQDN server1.department.company.com:
- server1 is the hostname.
- department is a subdomain of the company.
- company is the domain.
- com is the top-level domain.
Every FQDN is unique, and it directs to a specific IP address through the Domain Name System (DNS), which acts as the internet’s phonebook.
In the context of the AZ-600 Configuring and Operating a Hybrid Cloud with Microsoft Azure Stack Hub, an FQDN is important for accessing the services, naming resources, and ensuring that communication between the different components and the outside world is consistent and secure. For instance, an Azure Stack Hub deployment may use FQDNs to manage its internal and public endpoints for users and services.
Understanding Region Name in Azure Stack Hub
In Azure Stack Hub, a region is a set of cloud services and datacenter infrastructure located in a specific physical location operated by an organization or service provider. Region names are user-defined and play a crucial role in organizing, managing, and deploying resources.
When configuring your Azure Stack Hub, you define a region name which becomes part of the FQDN for the services deployed on your Azure Stack Hub. This enables you to manage and differentiate between data residency, compliance requirements, and network latency considerations.
For instance, an Azure Stack Hub might be deployed in two different locations, with the given region names East and West. The FQDNs could be structured as follows:
| Service | Region Name | FQDN Example |
|---|---|---|
| Azure Stack Portal | East | portal.east.azurestack.local |
| API Endpoint | East | api.east.azurestack.local |
| App Service | West | appservice.west.azurestack.local |
| SQL Resource Provider | West | sqlrp.west.azurestack.local |
By establishing separate region names, it is easier to designate and control the governance, data sovereignty, and network topology of resources in Azure Stack Hub. This ensures that users can deploy services in their corresponding regions while maintaining clear and structured access through domain naming.
In summary, the FQDN provides a complete address to access a service or host machine, crucial for identifying and connecting to resources on a network. In contrast, a region name in Azure Stack Hub helps organize services by their physical or logical location, for management and operational efficiencies.
Practice Test with Explanation
True/False: A fully qualified domain name (FQDN) includes the top-level domain of the Internet.
- True
A fully qualified domain name (FQDN) is a complete domain name including all higher-level domains, which includes the top-level domain (TLD) such as .com, .net, .org, etc.
True/False: An FQDN is case sensitive.
- False
Domain names, including FQDNs, are not case sensitive, which means uppercase and lowercase letters are treated as the same.
True/False: In an FQDN, the hostname is optional.
- False
An FQDN always includes a hostname along with the domain and the top-level domain.
What does a fully qualified domain name (FQDN) end with?
- A) A forward slash (“/”)
- B) A specific IP address
- C) A period (“.”)
- D) A colon (“:”)
C) A period (“.”)
An FQDN technically ends with a period that represents the root level of the DNS hierarchy, though this is often omitted in practice.
True/False: “Region” in Azure Stack Hub refers to the physical location of datacenters.
- True
In Azure Stack Hub, the term “region” refers to the physical location across the globe where a set of datacenters are located.
True/False: The region name in Azure Stack Hub must be unique across Azure and Azure Stack Hub deployments.
- True
The region name in Azure Stack Hub must be unique, as it helps to identify the specific location of services and to manage data residency and compliance requirements.
Which of the following is a component of an FQDN?
- A) Subnet mask
- B) Port number
- C) Subdomain
- D) Protocol type
C) Subdomain
An FQDN is composed of labels including subdomains, domain, and the top-level domain.
True/False: In an FQDN like “www.example.com.”, “example” is considered the top-level domain.
- False
In “www.example.com.”, “com” is the top-level domain, and “example” is the second-level domain.
Single Select: What is the difference between a domain name and an FQDN?
- A) An FQDN is always an IP address
- B) An FQDN is more specific and includes the hostname
- C) A domain name can never include a hostname
- D) A domain name is longer than an FQDN
B) An FQDN is more specific and includes the hostname
An FQDN is more specific because it includes the entire hierarchy including the hostname, domain, and top-level domain.
True/False: Azure Stack Hub regions are interconnected and provide automatic failover.
- False
Azure Stack Hub regions are not necessarily interconnected to provide automatic failover. The configuration and setup for such capabilities depend on the implementation by the service operator.
True/False: The “www” prefix in an FQDN is referred to as the top-level domain.
- False
The “www” prefix in an FQDN is considered a hostname or a subdomain, not the top-level domain.
Multiple Select: Which of the following can be part of an FQDN?
- A) Mail server hostname
- B) FTP server hostname
- C) SSL certificate
- D) Domain name
- E) Top-level domain name
A) Mail server hostname, B) FTP server hostname, D) Domain name, E) Top-level domain name
An FQDN can include different types of hostnames (such as mail servers, FTP servers), as well as the domain and the top-level domain name. An SSL certificate is not part of the FQDN; it utilizes FQDNs for validation and encryption purposes.
Can someone explain what exactly a Fully Qualified Domain Name (FQDN) is?
Sure! An FQDN is a complete domain name that specifies its exact location in the hierarchy of the Domain Name System (DNS). It includes the host name and all domain levels, including the top-level domain.
How does a region name differ from an FQDN in the context of Azure Stack Hub?
Great question! The region name in Azure Stack Hub defines the geographical location of the services, whereas the FQDN is used to uniquely identify a resource’s network address.
Can FQDNs be used for virtual machines in Azure Stack Hub?
Yes, FQDNs can be assigned to virtual machines to make them easily accessible over the network.
Thank you for this post!
I still don’t get the difference between DNS name and FQDN…
A DNS name can be part of an FQDN, but an FQDN is always complete and specifies its exact position within the DNS hierarchy.
So, is the region name used anywhere in the DNS hierarchy?
No, the region name is typically used to denote the physical location of resources rather than being part of the DNS hierarchy.
Adding an FQDN to our server improved our network organization!
Exactly, using FQDNs helps in segregating and managing network resources more efficiently.
I appreciate the in-depth explanations on FQDN and region names!