Then if the result is still not found then, the query will be directed to root nameserver from where it will be redirected to the Top level domain(TLD) name servers.
These recursive servers contain their own local cache in which they will look for results. In the first attempt to browse a website by domain name, DNS resolver will query the ISP DNS server to look out for records, and if it is not found there, then a recursive DNS query starts which means querying DNS servers till the records are found. Now this story seems simple, but how does the cache actually get filled? Yes, you guess it right it filled when I browse the website, but the 2 nd part of the question is still not answered how it actually fetches the website in the first attempt. The local DNS cache can be checked using command:Īs you can see since in my cache there is already a request logged for now for future requests, all the queries to this domain can be fulfilled from local cache until the cache is refreshed and the respective IP is mapped under A record. DNS settings can be managed in the following ways in end user system.īut how does the request actually change it to ? Well, the DNS resolver first checks the local cache to see if it contains any records for the requested IP. Well, it is the job of the DNS resolver in the end user system to fetch the IP address for the requested domain.
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