DNS…WHAT IS THAT?
DNS is an abbreviation of Domain Name System. DNS resolves names to numbers. It works as an Internet phone book that translates domain names to IP addresses so that browsers can load Internet resources. Access to information can be through domain names like kenic.or.ke whereby browsers interact through Internet protocol (IP) address. The DNS servers remove the need for users to memorize the IP address.
When a user types in kenic.or.ke on the web browser, the DNS will search through the database to find a matching IP address for that domain name, and when it finds it, will resolve that domain name to the IP address of the KeNIC website. Once that is done, then the computer is able to communicate with the KeNIC web server and retrieve the web page. DNS basically works like a phone book. When you want to find a number you don’t look up the number first but the name, then you get the number.
How does the DNS work?
When you type in kenic.or.ke in your web browser and if the operating system can’t find the IP address in its own cache memory it will send a query to the next level; what is called the resolved server. It is basically your Internet servers provider (ISP), so when the resolver receives the query it will check its own cache memory to find an IP address for kenic.or.ke . If it can’t find it, it will send the query to the next level which is the root server
The root servers are at the top of the DNS hierarchy. There are 13 sets of these root servers and they are strategically placed around the world and operated by 12 different organizations. Each set of these root servers has its own unique IP address. When the root server receives the query for the IP address for kenic.or.ke is not going to know what the IP address says but the root server knows where to send the resolver to help find the IP address. The root server will direct the resolver to the Top Level Domain (TLD) server for the .ke domain. So the resolver will now ask the TLD server for the IP address for kenic.or.ke.
The TLD servers store the address information for TLD such as .ke. This particular TLD Server manages the .ke domain which kenic.or.ke is a part of. When the TLD server receives the query for the IP address of kenic.or.ke, the TLD server is not going to know what the IP address is for kenic.or.ke. The TLD will work through the resolver to the next and final level which is the authoritative name servers (ANS). Once again the resolver will now ask the authoritative name server for the IP address for kenic.or.ke. The ANS servers are responsible for knowing everything about the domain including the IP address. The name server will respond with the IP address for kenic.or.ke which will tell your browsing device the IP address for kenic.or.ke and it will retrieve the KeNIC web page. Once the resolver gets the IP address it will store it in its cache memory in case it receives another query for kenic.or.ke so that it doesn’t have to go through those steps again.