DNS is the protocol which is used to communicate over internet for the computers. Its acts like a translator were it converts domain names into IP address so the browser can read and load the websites efficiently. Browser don’t know how to reach the specific website here comes the DNS as we have already given a name as traslator to DNS it can be also a postman. Making it more simple in another words when we type a simple domain name our browser or application will use DNS to search for its IP address and connect us. Behind the scene DNS working is so complicate but undestanding it is easy one.

Why name resolution exists

Name Resolution is the process of translating a human-readable domain name into a machine-readable IP address. Deep diving into DNS it tells only whom to talk next there are root server which tells where the TLD information will get so this targets the TLD(top level domain) eg: .com again TLD goes to TLD server, so TLD are own by the TLD server, next TLD server again goes to A node where it says whom to talk next again it goes to authoratative DNS server which are like vercel, netfly, goDaddy,etc. This servers actually gives the IP to browser. Fun fact browser don’t talk to these all servers there is main server which is called Recursive DNS server which Gives IP to browser. And IP coonects to browser and loads the site this full process happens in miliseconds.

What is `dig` command and when it is used

`dig` command stands for Digital information gropper command.

`dig` command is a network tool with a basic command line interface that serves for making different DNS quries. Lets see the history dig commands was introduced by the Steve Hotz in the 1990. In early days it was only UNIX based later on it gained the popularity due to its flexibility and detalied output.

`dig` command is used to diagnose DNS issues, verify the DNS records, tarce the IP address, trace the full DNS resolution path.

When it is used

• Checking domain IP

• Verifying DNS records : checking if specific records are correctly set over different DNS server

• Tracing DNS paths : Use dig +trace to see the entire resolution chain from root server to the authoratative server for domain

• Checking record times : See the time to live (TTL) value to understand how often DNS records refresh.

Understanding `dig. NS` and Root name server

Root servers are top of the DNS hirerchy. It is the first process in DNS. Root server do not store IP address of the websites. Instead they guide the DNS resolvers to guide the top level domain(TLD) servers like .com, .in, .net, etc. in another words its task is to find the appropriate TLD server.

`dig .NS`

Name server tells which DNS servers are authoratative to domain. An name server records tells the internet where to go to find the official IP address of websites. So its like a backbone of the DNS.