Domain Name System: In the world of networks, computers are not named as human beings. They use numbers because that’s how computers and similar devices communicate with each other. And identify each other in a network, which involves using numbers like IP addresses. Humans, on the other hand, are used to using names instead of numbers, either to speak directly with another person or to identify a country, a place or a thing. Humans identify themselves with names instead of figures.
Therefore, to bridge the communication gap between computers and humans and make communication much easier, network technicians have developed the Domain Name System. And DNS is synonymous with the domain name system. And the DNS resolves the names in numbers, to be more precise. It resolves the domain names in the IP addresses. For example, if you enter a web address in the web browser, DNS will resolve the name to a number because computers no longer know the numbers. For example, if you want to log in to a particular website, open your web browser and enter the domain name for that website.
Domain name system
Take the example of yahoo.com. Technically, it is not necessary to write yahoo.com to retrieve the Yahoo web page. You can simply type in the IP address if you already know what the IP address was. But since we are not used to storing and processing numbers, especially when there are millions of websites on the Internet. We can simply write the domain name and let the DNS convert it into an IP address for us.
So, back to our example, when you type yahoo.com in your web browser, the DNS server with the search in your database to find the corresponding IP address for this domain name. And when you find it will resolve that domain name to the IP address of the Yahoo website. Once this is done, the computer can communicate with a Yahoo web server and retrieve the web page. Therefore the DNS works as a phone directory when it searches for a number. It does not look for it first place, first look for the name, and it will give you the number. So to clarify this detail, let’s take a look at the steps that DNS takes.
So when you type yahoo.com in your web browser and your web browser or operating system can’t find the IP address in their cache memory, then this request is sent to the next level which is known as the resolution server. This resolution server is actually your internet service provider. Therefore, when the solver server receives the request, it checks its cache memory to find an IP address for yahoo.com. If it does not find it there then it will send it to the next level, which is called the Root server. Root servers are the root of a DNS hierarchy. There are 13 sets of these root servers strategically distributed around the world. They are managed by 12 different organizations. Each set of these root servers has its own IP address.
Therefore, when the root server receives the query from the IP address of yahoo.com, the root server will not know what the IP address is, but knows where to send the resolution to find the IP address. So the root server will direct the resolver to the top-level TLD or domain server for the dot com domain. Therefore, the solver will ask the TLD server for the IP address of yahoo.com.
The top-level domain server stores address information for top-level domains, such as .com and dot.com, and so on. This TLD server manages the dot com domain that includes yahoo.com. Therefore, when a TLD server receives a request for the yahoo.com IP address, it will not know what the yahoo.com IP addresses is. Therefore, the TLD will direct the resolver to the next and the last level, which are the authorized name servers. Then again, the resolver will ask the authorized name server for the IP address of yahoo.com.
The authorized name server (s) is responsible for knowing everything concerning the domain, including the IP address. They are the final authority. Therefore, when the authoritative name server receives the resolution request, the name server responds with the IP address of yahoo.com. And finally, the solver will tell your computer the IP address of yahoo.com. Your computer can retrieve the Yahoo web page. It is important to note that once the resolver receives the IP address, it will store it in its cache in case it receives another request for yahoo.com so that it does not have to repeat everything again.
Advantages of DNS
The DNS Domain Name Service acts as a lookup table that allows you to contact the correct servers when a user enters a URL in a web browser. This somewhat transparent service also provides other features that webmasters commonly use to organize their data infrastructure.
Domain Name System runs on DNS servers. When a user enters a URL, such as www.google.com, in a web browser, the request is not sent directly to Google’s servers. Instead, the request goes to a Domain Name System server, which uses a lookup table to determine various data, the most important thing is the IP address of the requested website. It then forwards this request to the appropriate servers and returns the requested information to the user’s web browser.
The DNS server parses three primary data, starting with the top-level domain. The top-level domain is designated by suffixes such as .com, .org, and .gov. Once the top-level domain is established, the second-level domain is scanned. For example, the www.google.com URL has a .com top-level domain and the second-level Google domain name. The second-level domain is usually defined simply as a domain name. Finally, the DNS server resolves the third-level domain, or subdomain, which constitutes the “www” part of the URL.
Domain Name System servers allow standard Internet users to use Internet resources without having to memorize port numbers and IP addresses. Similar services, such as different areas of the website, can also be hosted at different IP addresses for security reasons. This allows users to store simple URLs instead of complex and non-intuitive lists of IP addresses and port numbers. It also allows private servers created by home users to be available for free, but somehow they are protected from not knowing their IP address publicly.