DNS which stands for Domain Name System or the Domain Name Server, is a naming system for the resources like websites, computers or the services connected to the Internet or a private network. Owing to its importance for every online business, let us present to you how DNS works step by step methods.
How DNS Works Step by Step Process Explained
Domain Name System acts like a log book of the Internet by keeping a record of the various websites and services online on the Internet. Whenever we see and visit a website with the name like http://www.abc.com in our browser, the system uses this address to re-direct to the websites IP’s address. As it is difficult to remember the unique IP address for each website, the DNS naming system helps us to visit the websites easily.
Whenever we type the domain name of the website like http://www.abc.com; the computer system performs a series of methods which converts the human-readable easy website name into a machine-understandable IP address which is unique for every website and system. We presume to be typing the website name and the Internet directing us to the particular website directly. However, to understand how DNS works step by step; it is essential to understand the back-end functioning of the overall system.
An Overview of How DNS Works Step by Step:
Let us present to you the proper functioning of the entire Domain Name System in a detailed manner:
The request for fetching the relevant information starts as soon as the user types the name of the website into the system. The computer system of the user acts as a local Domain Name Server cache. It stores the information about several websites which were opened recently on the system. The computer system stores the information in its internal cache and thus as soon as the user inputs the name of any particular website, the information is retrieved at an instant. However, if the website has not been earlier opened in the particular computer system, there occurs a series of steps which includes sending a DNS query to search for the information and the respective website.
Inquire From the Recurrent DNS Servers
In the case when the information that the user has requested is not available locally on the computer system, the queries that were made would make a request to the ISP’s recurrent (recursive) DNS servers. These servers are the specialized computers or systems which perform the fundamental role of obtaining the relevant information from the wide network of the Internet services. The recursive DNS servers are specialized in the sense that they have their own set of caches. When the request is made to them, the process is ended here as the information the user is seeking is retrieved and returned to the user’s system.
Enquire from the Root Nameservers
There might be cases when the recursive servers might not be able to retrieve and return the relevant information enquired by the users. In such cases, the recursive servers fetch information from the root nameservers. A nameserver is the meta-cache of information which provides answers relating to the domain names with particular reference to the IP addresses. There are as many as thirteen nameservers which perform the role of a phone switchboard. They do not know the answer, but they can re-direct the query of the users to some other place where the relevant information could be found.
Take Information from the TLD Nameservers
The role performed by the root name servers is that it looks at the first part of the user’s request which it reads from right to left. For instance, www.abc.com, it reads it from the “.com” part. The root nameserver then redirects the user’s query to the TLD (Top Level Domain) nameservers for the “.com” part. There are various TLDs like .com, .gov, .org and many more. These TLDs have their own set of nameservers which in turn acts as a receptionist for each TLD. These servers might not have the exact information requested by the users, but they directly refer to the servers which have the exact information.
Refer to the Authoritative DNS Servers
After the “.com” part has been reviewed by the root nameserver, the next part of the address is reviewed by the TLD nameserver. For instance, “abc.com” will be referred now by the TLD nameserver. By this, the user’s request is directed to the possible nameservers where the relevant information could be found with the specific domain. It is the duty of the authoritative nameservers to keep all the information about a specific domain which is stored in its DNS records. There can be several types of records which are used to store the information related to the user’s request.
Retrieval of Information
Now that the authoritative nameservers have reached the exact place for retrieving the information with relation to a particular user request. The recursive servers retrieve this information from the authoritative nameservers and store it in the local cache of the computer system of the user. The recursive server stores the information in its personal cache as well so that the next time some other user would make the same request, it will redirect the user directly to its server. This saves time to repeat the process of searching for the entire information all over again. In addition to this, all the records usually have a time-to-live value which acts like an expiration date. After a certain period of time, the recursive servers will have to ask for the information, again and again, to ensure that it doesn’t become obsolete.
Get the Answer to the Query
Now that the recursive server has the information, it returns the answer to the local computer of the user. The computer would now store the information in its cache and then would pass it down to the web browser to enable the user to view the information.