Basics of DNS

DNS 

Domain Name System

The Domain Name System (DNS) is a hierarchical naming system for computers, services, or other resources connected to the Internet or a network. It links with various information with domain names allotted to each of the participating systems.

It is maintained by distributed database system and uses the client server model.

DNS is as a part of Windows Network recognized as Domain Name System. DNS is a hierarchical system based on a tree structure named DNS namespace. 

Each DNS namespace has to have a root that can have infinite number of subdomains. The root is an empty string. Every node in the DNS namespace has a specific address by which it can be identified, called a FQDN. The dot is the standard separator between domain labels. The dot also separates the root from the subdomains, but is usually omitted by end-user and automatically added by DNS client service during a query. There are three types of internet top-level domains, organizational, geographical and reverse . 

Network administrator creates two types of zones in DNS, forward or reverse lookup. 

• In forward lookup zone the FQDN is mapped to an IP address, this is a conventional zone. 
• In reverse lookup zone the IP address is mapped to FQDN.

FQDN

Fully Qualified Domain Name is a complete domain name for any system. It can be comprised of several elements such as a hostname and a domain name.

A FQDN designates the specific location of an object within the DNS hierarchy as well it communicates the host’s position relative to the root of the DNS namespace. An FQDN enables each entity connected to the internet (computer, server, etc.) to be uniquely identified and located within the internet framework.

Generally, an FQDN is required to make a computer, device, resource, etc. accessible on the internet. However, defining an FQDN in local system isn’t sufficient to bring it online. You need to update the DNS record in the DNS settings so the DNS knows the specific location of that specific device.

-DR