por DNS (Domain Name System) or Domain Name System is one of the most important services for the operation of the Internet, and its function is make the equivalence between IP addresses and domain names so that browsers can load Internet resources. In addition, it contains other types of information stored for each domain, such as the services available on a certain network.
It is also defined as the hierarchical naming system used to obtain information about network and other services.
DNS history
The history of the Domain Name System can be traced back to the 1970s, a decade in which computers were assigned a numerical address that were connected to a network. Access to these devices used to be quite complex due to limitations in the nomenclature system, which required you to type the address of a device from memory in order to access it.
Later in history, an increase in the number of computers connected to the network occurred, so it was necessary find an easier way to remember IP address Of the device. This need gave rise to Domain Name Systemthat originally contained the mapping between hosts and IP addresses.
Paul Mockapetrisone of the so-called «fathers of the modern Internet», devised a file distribution system that could be accessible and more easily extensible to different computers, was in charge of develop the idea of DNS as a hierarchy system with levelswhere each tag assigned to a device contained the domain name as well as the TDL or extension.
This system became popular years later and In 1988 the IANA was created (Internet Assigned Numbers Authority), which would be in charge of supervising the global IP address assignment process. The work of the IANA would play a fundamental role in the unification and stability of the DNS internet protocol.
Likewise, a decade later, in 1998, the I CAN o Internet Corporation for Assigned Names and Numbers, to which some of the work carried out by the IANA would be delegated, and which currently works towards the objective of have a secure, interoperable and stable internet.
How does DNS work?
This system works through its resolution process or DNS Lookup. This process consists of a series of steps, in which first, the user enters a domain name in a web browser, i.e. a DNS request is sent.
After this, the device you are connected to will perform a check to see if a DNS record has already been stored for the domain you entered. DNS records are those IP addresses that correspond to domain names.
Your team will perform this check on their host files, that is, the plain file text that is responsible for mapping host names to IP addresses within an operating system. And then, it will look to see if you cache a DNS recordwhich is where it is usually found.
In the event that no IP address match is found in the host file or cache, the resolution process for this service will be extended.
DNS servers
To load a website, the intervention of 4 of the Domain Name System servers is required, these being:
DNS resource
Its function is receiving queries from client computers through applications such as web browsers. The DNS resource is also responsible for making additional requests for the user’s DNS query.
root name server
It acts as a reference to other more specific functions and is the first stage in translating hostnames into readable servers. This server, after querying a domain, will provide the name and address of the authorized server of the top-level domain zone. And then, it will give a list of the second level authorized servers, until a satisfactory response is obtained.
TLD Name Server
It is the highest level domain server, and is responsible for host the last part of the server name. It works by sending a response to recursive resolution addressed to an authoritative name server.
Authoritative name server
This server contains an answer within your local database for a domain you are asked about. In addition, it will be in charge of creating DNS records.
What is the next step?
Now that you know what the DNS Domain Name System is, what its history is, how it works and its different servers, Feel free to continue learning about this and other tools through our DevOps & Cloud Computing Full Stack Bootcampwhere in just 6 months you can become an expert in these topics and you will be able improve your technological development processes.