Domain Name System( DNS)- Recursive DNS
What is DNS? When someone type in a domain name (Ex. google.com), it triggers a DNS lookup . During that process, the domain name will match a corresponding IP address that will be returned back to the client. There are 2 types of DNS lookups; iterative and recursive. A recursive DNS lookup implies that one DNS server interacts with other DNS servers and returns a matching IP address to the client. On a side note, a DNS server is when a user types a domain name. This enable a DNS lookup where several remote computers return a corresponding IP address to the user's computer and allow them to access the correct website. A DNS query on the other hand implies that the client can communicate directly to each DNS server involved in the lookup. In a DNS lookup, there are several DNS servers involved; DNS resolver, DNS root server, DNS TLD (Top-Level Domain) server, and DNS authoritative nameserver. In iterative DNS lookup, DNS resolver asks each DNS one by one until it finds t...